{"$schema":"nativecad-dfm-pack/1","id":"race-engines","title":"Race engines: how high-performance engines are made and what it asks of the CAD","sector":"race-engines","version":"2026-11-04","summary":"How race engine pistons, rods, cranks, blocks, heads, valvetrain, turbos and exhausts are made, tested and regulated (F1 2026 Section C, dated). Numbers tagged SRC or EST in basis.","aliases":["race engine","racing engine","performance engine","forged piston","billet crank","titanium rod","valve spring","engine block","cylinder head","cylinder liner","nikasil","dry sump","turbocharger","power unit","torque plate honing"],"crossSector":false,"size":"full","sources":[{"id":"fia-sc-i21","title":"FIA 2026 F1 Regulations Section C, Issue 21, 2026-10-19","accessed":"2026-11-04","url":"https://www.fia.com/system/files/documents/fia_2026_f1_regulations_-_section_c_technical_-_iss_21_-_2026-10-19.pdf","note":"Changes by issue. Entries cite the article, as PDF extraction scrambles clause numbers."},{"id":"honda-51","title":"Gotou, Yanagisawa: Reciprocating parts and crankshaft, Honda R&D TR 2009","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_51e.pdf"},{"id":"honda-42","title":"Honda R&D TR 2009: Formula One engine structural design","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_42e.pdf"},{"id":"honda-60","title":"Honda R&D TR 2009: Valvetrain for Formula One engine","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_60e.pdf"},{"id":"honda-233","title":"Mizoue et al: Hollow crankshaft, Honda R&D TR 2009","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_233e.pdf"},{"id":"honda-236","title":"Ishizuka et al: Metal matrix composite piston, Honda R&D TR 2009","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_236e.pdf"},{"id":"honda-241","title":"Minato, Mizogawa: Hollow titanium connecting rod, Honda R&D TR 2009","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_241e.pdf"},{"id":"honda-247","title":"Sanada: Titanium hollow valve and NaK valve, Honda R&D TR 2009","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_247e.pdf"},{"id":"honda-250","title":"Ito et al: DLC on camshaft and rocker arm, Honda R&D TR 2009","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_250e.pdf"},{"id":"honda-253","title":"Imai, Nishida: Laser clad welded valve seat, Honda R&D TR 2009","accessed":"2026-11-04","url":"https://global.honda/en/technical-review/PDF/F1-SP2/F1-SP_253e.pdf"},{"id":"epi-cup-f1","title":"EPI / Kane: NASCAR Cup and F1 engines compared (end-2006, 2014 update)","accessed":"2026-11-04","url":"https://wahiduddin.net/calc/refs/NASCAR_vs_Formula_One_engines_EPI.pdf","note":"Rod and piston package figures are the author's stated estimates."},{"id":"f1-dict","title":"Formula 1 Dictionary: F1 engine","accessed":"2026-11-04","url":"https://www.formula1-dictionary.net/f1-engine/","note":"Secondary reference, internally inconsistent in places."},{"id":"rtr-indycar","title":"RTR Sports: the engine used in IndyCar","accessed":"2026-11-04","url":"https://rtrsports.com/en/blog/the-engine-used-in-competitions-indycar/","note":"Secondary source, not the IndyCar rulebook."},{"id":"autosport-gr010","title":"Autosport: Toyota unveils twin-turbo V6 GR010 Hybrid, 2021","accessed":"2026-11-04","url":"https://www.autosport.com/wec/news/toyota-unveils-twin-turbo-v6-gr010-hybrid-le-mans-hypercar-for-2021-wec-5115264/5115264/"},{"id":"je-2618","title":"JE Pistons: 2618 vs 4032 material differences","accessed":"2026-11-04","url":"https://info.jepistons.com/2618-vs.-4032-material-differences"},{"id":"cp-rings","title":"CP-Carrillo piston and ring instruction sheet 2019 (ring gap chart, honing)","accessed":"2026-11-04","url":"https://www.cp-carrillo.com/files/cp_instructionsheet_2019final-web.pdf"},{"id":"el-ring-gap","title":"EngineLabs: setting piston ring end gap","accessed":"2026-11-04","url":"https://www.enginelabs.com/?p=6755"},{"id":"el-p2h","title":"EngineLabs: verifying piston-to-head clearance","accessed":"2026-11-04","url":"https://www.enginelabs.com/?p=6688"},{"id":"el-rod-bolt","title":"EngineLabs: measuring rod bolt stretch vs torque with ARP","accessed":"2026-11-04","url":"https://www.enginelabs.com/engine-tech/blueprint-series-measuring-rod-bolt-stretch-vs-torque-with-arp/"},{"id":"el-bearing","title":"EngineLabs: measuring and setting bearing clearances","accessed":"2026-11-04","url":"https://www.enginelabs.com/?p=6807"},{"id":"el-honing","title":"EngineLabs: cylinder honing (Total Seal Rpk, Rk, Rvk targets)","accessed":"2026-11-04","url":"https://www.enginelabs.com/?p=6481"},{"id":"el-nikasil","title":"EngineLabs: what Nikasil is and how it is applied","accessed":"2026-11-04","url":"https://www.enginelabs.com/?p=11602"},{"id":"el-leakdown","title":"EngineLabs: leak down testing","accessed":"2026-11-04","url":"https://www.enginelabs.com/?p=5833"},{"id":"el-drysump","title":"EngineLabs: pros and cons of a dry sump (Aviaid comments)","accessed":"2026-11-04","url":"https://www.enginelabs.com/?p=6647"},{"id":"wiki-drysump","title":"Wikipedia: Dry sump","accessed":"2026-11-04","url":"https://en.wikipedia.org/wiki/Dry_sump"},{"id":"gp-note29","title":"Grand Prix Engines Note 29: the Nikasil process","accessed":"2026-11-04","url":"https://www.grandprixengines.co.uk/Note_29.pdf"},{"id":"hpm-honing","title":"High Power Media: cylinder bore honing","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/cylinder-bore-honing"},{"id":"hpm-nitriding","title":"High Power Media: nitriding","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/nitriding-2"},{"id":"hpm-fillets","title":"High Power Media: fillets","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/fillets"},{"id":"hpm-oil-holes","title":"High Power Media: crankshaft oil drillings","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/crankshaft-oil-drillings"},{"id":"hpm-smooth","title":"High Power Media: smooth surface treatments","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/smooth-surface-treatments"},{"id":"hpm-crank-steel","title":"High Power Media: crankshaft steels","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/crankshaft-steels"},{"id":"hpm-surface","title":"High Power Media: which surface treatment is best","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/which-surface-treatment-is-best"},{"id":"hpm-rod-mat","title":"High Power Media: connecting rods, material choices (4)","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/connecting-rods-material-choices-4"},{"id":"hpm-albe","title":"High Power Media: aluminium-beryllium","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/aluminium-beryllium"},{"id":"hpm-seat-mat","title":"High Power Media: valve seat materials","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/valve-seat-materials"},{"id":"hpm-seat-cool","title":"High Power Media: valve seats, cool","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/valve-seats-cool"},{"id":"hpm-dlc","title":"High Power Media: DLC coatings","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/dlc-coatings-1"},{"id":"hpm-ring-mat","title":"High Power Media: piston ring materials","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/piston-ring-materials"},{"id":"hpm-ring-seal","title":"High Power Media: the piston and ring in harmony","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/the-piston-and-ring-in-harmony"},{"id":"hpm-skirt","title":"High Power Media: avoiding piston skirt wear","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/avoiding-piston-skirt-wear"},{"id":"hpm-inconel","title":"High Power Media: welding Inconel","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/welding-inconel"},{"id":"hpm-profiles","title":"High Power Media: profiles critical to performance, part 2","accessed":"2026-11-04","url":"https://www.highpowermedia.com/Archive/profiles-critical-to-performance-part-2"},{"id":"smiths-en40b","title":"Smiths High Performance: EN40B (722M24) datasheet, 2025","accessed":"2026-11-04","url":"https://www.smithshp.com/assets/pdf/steel/engineering-steel/en40b-engineering-steel-english.pdf"},{"id":"wys-en40b","title":"West Yorkshire Steel: EN40B nitriding steel","accessed":"2026-11-04","url":"https://westyorkssteel.com/alloy-steel/nitriding-steel/en40b"},{"id":"am-300m","title":"Aircraft Materials: 300M (AMS 6417, AMS 6419)","accessed":"2026-11-04","url":"https://aircraftmaterials.com/data/alstst/300m.html"},{"id":"tm-cgi","title":"Total Materia: compacted graphite iron, part one","accessed":"2026-11-04","url":"https://www.totalmateria.com/articles/compacted-graphite-iron-1/"},{"id":"materion-am162","title":"Materion: AlBeMet property datasheet","accessed":"2026-11-04","url":"https://hkvxni.files.cmp.optimizely.com/download/d896d6d2a04211ee94aa3aa4a5458726"},{"id":"sae-crank","title":"SAE 2001-01-3374: Fatigue life analysis of crankshaft at various surface treatments (abstract)","accessed":"2026-11-04","url":"https://saemobilus.sae.org/content/2001-01-3374"},{"id":"sinko-balance","title":"Sinko: balance quality grades table (ISO 1940-1 layout)","accessed":"2026-11-04","url":"https://www.sinko.co.jp/global_products/technical-documentation/technical/balance.html"},{"id":"fabrico-balance","title":"Fabrico: ISO 21940 balance quality grades","accessed":"2026-11-04","url":"https://www.fabrico.io/blog/iso-21940-balance-quality-grades/","note":"ISO 21940-11 is paywalled; grade rows here are from public summaries."},{"id":"aa1car-gasket","title":"AA1Car: head gaskets (flatness, MLS finish)","accessed":"2026-11-04","url":"https://www.aa1car.com/library/ar396.htm"},{"id":"motor-valves","title":"MOTOR: Performance Perspectives, high-performance valves","accessed":"2026-11-04","url":"https://www.motor.com/magazine-summary/performance-perspectives-high-performance-valves/"},{"id":"pat-4592313","title":"US4592313A: Pneumatic valve return","accessed":"2026-11-04","url":"https://patents.google.com/patent/US4592313"},{"id":"pat-11214852","title":"US11214852: Alloys for turbocharger components","accessed":"2026-11-04","url":"https://patents.google.com/patent/US11214852"},{"id":"pbs-turbine","title":"PBS: investment-cast turbine wheels","accessed":"2026-11-04","url":"https://www.pbsindia.com/investment-casting/turbine-wheels"},{"id":"mahle-3d","title":"MAHLE: 3D printed aluminium pistons for Porsche 911 GT2 RS","accessed":"2026-11-04","url":"https://newsroom.mahle.com/press/es/press-releases/mahle-produces-high-performance-aluminum-pistons-using-3d-printing-for-the-first-time-76416"},{"id":"manley-rods","title":"Manley: connecting rods product information","accessed":"2026-11-04","url":"https://images.truckid.com/manley/items/pdf/rods-product-information.pdf"},{"id":"foundry-isf","title":"Foundry Management & Technology: superfinish and fatigue life (2008)","accessed":"2026-11-04","url":"https://www.foundrymag.com/issues-and-ideas/article/21926235/superfinish-increases-fatigue-life-reduces-fuel-consumption-for-critical-parts"},{"id":"thornton-cryo","title":"Thornton, Slatter, Ghadbeigi: deep cryogenic treatment and dry sliding wear, Wear 305 (2013)","accessed":"2026-11-04","url":"https://wrap.warwick.ac.uk/id/eprint/182049"},{"id":"ms-dlc-pin","title":"MS Motorservice: piston pin with DLC coating","accessed":"2026-11-04","url":"https://www.ms-motorservice.com/tr/en/technipedia/piston-pin-with-dlc-coating-197"},{"id":"fastime-spring","title":"Fastime: seat vs open pressure explained","accessed":"2026-11-04","url":"https://fastimeperformance.com/blog/seat-pressure-vs-open-pressure-explained"},{"id":"astm-e1444","title":"ASTM E1444/E1444M Magnetic particle testing (scope page)","accessed":"2026-11-04","url":"https://store.astm.org/e1444_e1444m-16.html"},{"id":"astm-e1417","title":"ASTM E1417/E1417M Liquid penetrant testing (scope page)","accessed":"2026-11-04","url":"https://store.astm.org/e1417_e1417m-13.html"}],"entries":[{"id":"f1-2026-pu-geometry","kind":"dimension","tier":1,"title":"F1 2026 ICE fixed geometry (Section C Issue 21)","summary":"2026 F1 ICE: 1600 cc +0/-10, 90 deg V6, bore 80 +/-0.1, bore spacing 101.0 +/-2, crank at Y 0 Z 90 +/-0.5, deck height >= 168, rod 119.5-120.5, CR <= 16.0, turbo <= 150000 rpm. Issue 21 dated 2026-10-19; re-check each issue.","applies":["f1 power unit","v6"],"basis":"SRC: FIA Section C Issue 21, C5.1/5.3/5.4. Rules for 2026, they change by issue.","sources":["fia-sc-i21"],"tags":["f1","2026"],"value":{"table":[{"item":"pin dia","mm":"18.0-19.0"},{"item":"stem min","mm":4.95},{"item":"intake head","mm":"32.5-34.5"},{"item":"exhaust head","mm":"27.0-29.0"}]},"see":["power-transmission/crankshaft-stroke-throw"]},{"id":"f1-2026-pu-materials","kind":"rule","tier":1,"title":"F1 2026 PU materials: steel pistons, one-piece rods","summary":"2026 F1: pistons only AMS 6487, 15CDV6, 42CrMo4 or X38CrMoV5-3 steel; rods iron or Ti, one piece, no joints but cap and bush; crank and cams iron-based, no welds between journals; crankcase and heads Al or iron. Issue 21.","applies":["f1 power unit","piston","connecting rod","crankshaft"],"basis":"SRC: FIA Section C Issue 21, C15.6 and C15.7. Rules for 2026, they change by issue.","sources":["fia-sc-i21"],"tags":["f1","2026"],"value":{"table":[{"banned":"Mg alloys; MMC > 2 % v/v; W-base alloys (except counterweights, damper, ballast); ceramics; density > 18400 kg/m3; Al > 1 % Li or Ag; Be > 0.25 % (Cu alloys 2.2 %); Pt, Ru, Ir, Re > 5 %"}]}},{"id":"piston-2618-vs-4032","kind":"material","tier":1,"title":"Forged piston alloys 2618 and 4032","summary":"2618: 0.18 % Si, 64 ksi tensile, 54 ksi yield. 4032: 12.2 % Si, 55 ksi tensile, 46 ksi yield. 2618 grows 15 % more, so needs more cold clearance; use it for boost and high cylinder pressure, 4032 for tight street clearance.","applies":["forged piston"],"basis":"SRC: JE Pistons table, a piston maker. JE gives no clearance numbers.","sources":["je-2618"],"tags":["piston","2618"],"value":{"table":[{"alloy":"2618","Si_pct":0.18,"UTS_ksi":64,"YS_ksi":54,"fatigue_ksi":18},{"alloy":"4032","Si_pct":12.2,"UTS_ksi":55,"YS_ksi":46,"fatigue_ksi":16}]},"see":["race-engines/piston-thermal-clearance-calc"]},{"id":"ring-end-gap-chart","kind":"tolerance","tier":1,"title":"Piston ring end gap as bore (in) times a factor","summary":"Top ring gap = bore in inches x factor: 0.0045 street NA, 0.0050 high-perf or drag NA, 0.006 circle track or low boost, 0.0065 mid-high boost, 0.007+ high boost. Second ring 0.004-0.010 in larger than top. Oil rails min 0.015 in. Minimums.","applies":["piston ring"],"basis":"SRC: CP-Carrillo 2019 chart, stated as general minimums; ring supplier rules. Not a CAD dimension: it sets ring OD and groove back clearance.","sources":["cp-rings","el-ring-gap"],"tags":["ring","gap"],"value":{"min":0.0045,"max":0.007,"unit":"in","note":"per inch of bore; each 0.001 in over bore adds 0.00314 in gap"}},{"id":"piston-to-head-clearance","kind":"dimension","tier":1,"title":"Piston-to-head clearance by rod material","summary":"Piston-to-head minimum: steel rods 0.038-0.045 in (0.040 common, some 0.036); aluminium rods 0.050-0.065 in; domes check near 0.050 in with clay. Total = piston below deck + compressed gasket; read at pin centreline, rock 90 deg to pin.","applies":["piston","cylinder head","gasket"],"basis":"SRC: EngineLabs street-engine table. High-rpm engines need their own rod stretch check.","sources":["el-p2h"],"tags":["clearance","quench"],"value":{"min":0.038,"max":0.065,"typical":0.04,"unit":"in","note":"steel 0.038-0.045, aluminium rod 0.050-0.065"},"see":["automotive/rotating-assembly-clash-audit"]},{"id":"rod-material-choice","kind":"material","tier":1,"title":"Connecting rod materials: 4340, 300M, titanium","summary":"Forged 4340 then 300M (AMS 6417 270 ksi, AMS 6419 280 ksi) for steel; steel at 7.85 g/cm3 is almost 80 % denser than Ti rod alloy but much stiffer, which eases bolt fatigue. Cup rules: steel (EPI 2006); 2026 F1 allows iron or Ti.","applies":["connecting rod","titanium rod"],"basis":"SRC: Aircraft Materials typical values; HPM density comparison; EPI Cup rule; FIA C15.7.","sources":["am-300m","hpm-rod-mat","epi-cup-f1","fia-sc-i21"],"tags":["rod","300M"],"see":["materials/ti-6al-4v"]},{"id":"rod-bolt-stretch","kind":"rule","tier":1,"title":"Rod bolts: set preload by stretch, not torque","summary":"About 75-80 % of torque goes to friction; ARP specs load to 75 % of yield. ARP 3/8 in SBC bolt: 55 lb-ft with Ultra-Torque gives 0.0055-0.0060 in stretch. 30wt oil varied preload 17 %, Ultra-Torque 3 %. Leave both bolt ends reachable by a gauge.","applies":["connecting rod","fastener"],"basis":"SRC: EngineLabs with ARP figures; the bolt or rod maker spec governs. EST: gauge access as a CAD need follows from how the gauge seats on both bolt ends.","sources":["el-rod-bolt"],"tags":["bolt","arp"],"value":{"min":0.0055,"max":0.0065,"unit":"in","note":"examples: 3/8 in 0.0055-0.0060; Manley 7/16 in ARP 8740 0.0060-0.0065"},"see":["hardware/bolt-torque-and-preload-classes"]},{"id":"crank-steels-nitride","kind":"material","tier":1,"title":"Billet and forged crank steels, nitrided","summary":"EN40B (722M24, 3.0-3.5 Cr, 0.45-0.65 Mo): 850-1000 MPa T condition, 61-65 HRC nitrided case. Honda GKHYW (AFNOR 32CDV13) crank steel. EN40 forging or billet: bored, stress-relieved, nitrided. Nitriding runs 450-600 C and suits only steels tempered above that.","applies":["crankshaft","billet crank"],"basis":"SRC: Smiths and West Yorkshire Steel datasheets, HPM nitriding, Honda paper. Stockist typical values; case depth not on those sheets.","sources":["smiths-en40b","wys-en40b","hpm-nitriding","honda-51"],"tags":["crank","en40b"]},{"id":"crank-fillet-oilhole-rule","kind":"rule","tier":1,"title":"Crank fatigue starts at fillets and oil holes","summary":"Model fillets and oil-hole exits as finished, and carry a pre-nitride offset: radius oil exits before nitriding at 450-600 C, polish after, never grind through the case. In one FEA, ellipses gave no benefit over a plain 3 mm radius: no need for conics.","applies":["crankshaft"],"basis":"SRC: HPM oil drillings, nitriding and fillets articles. The FEA was one low-overlap bending case, stated as limited by its author.","sources":["hpm-oil-holes","hpm-nitriding","hpm-fillets"],"tags":["fillet","oil-hole"]},{"id":"bearing-clearance-rule","kind":"tolerance","tier":1,"title":"Plain bearing oil clearance per inch of journal","summary":"Start at 0.001 in per inch of journal: a 2.200 in main gets 0.0022 in, a 2.500 in main 0.0025 in. Never mix shells over 0.001 in apart or across makers. Measure in torqued housings to 0.0001 in.","applies":["crankshaft","connecting rod","bearing"],"basis":"SRC: EngineLabs builder rule, a starting point for street V8 journals.","sources":["el-bearing"],"tags":["bearing","clearance"],"value":{"typical":0.001,"unit":"ratio","note":"clearance / journal diameter"}},{"id":"bore-finish-rpk-rk-rvk","kind":"tolerance","tier":1,"title":"Plateau bore finish targets Rpk, Rk, Rvk","summary":"Total Seal, micro-inch: NA competition Rpk 7-10, Rk 18-22, Rvk 28-32; street 8-12, 30-35, 40-45; boost 10-15, 35-40, 50+. Moly or PVD rings: Ra 10-12 with 20-22 deg crosshatch (CP). Hold bore out-of-round to 0.0002 in. Ring maker governs.","applies":["cylinder liner","engine block"],"basis":"SRC: Total Seal via EngineLabs, CP sheet. Printed in micro-inch; 1 micro-inch = 0.0254 um. Call it out on the bore face, do not model it.","sources":["el-honing","cp-rings"],"tags":["honing","bore"],"value":{"table":[{"use":"street","Rpk":"8-12","Rk":"30-35","Rvk":"40-45"},{"use":"NA race","Rpk":"7-10","Rk":"18-22","Rvk":"28-32"},{"use":"boost","Rpk":"10-15","Rk":"35-40","Rvk":"50+"}],"note":"micro-inch"},"see":["standards-testing/surface-finish-by-process"]},{"id":"torque-plate-honing","kind":"process","tier":2,"title":"Honing under a torque plate","summary":"CP: a torque plate is required unless head-bolt holes are not part of the cylinder; final bore within +/-0.0002 in out of round, checked 360 deg top to bottom. Hot plates add realism. CAD: head-bolt bosses near the bore distort it; a liner decouples them.","applies":["engine block","cylinder liner","torque plate honing"],"basis":"SRC: CP sheet; EngineLabs says the bore goes significantly out of round when clamped (no number). EST: liner decoupling is inferred from CP's exemption.","sources":["cp-rings","el-honing","hpm-honing"],"tags":["torque-plate","honing","distortion"],"value":{"table":[{"limit":"out of round","in":0.0002},{"iron_chrome_ring_uin":"Ra 12-24, Rpk 2-24, Rk 28-48, Rvk 20-80"}]}},{"id":"deck-flatness-mls","kind":"tolerance","tier":2,"title":"Head and deck flatness and finish for MLS gaskets","summary":"MLS: about 0.002 in (0.05 mm) total distortion across block plus head. Finish: late-model 27-47 micro-inch Ra, Ford 4.6 8-12 Ra, 180 Rz max OEM; coated aftermarket 30-70 Ra, up to 480 Rz. Other gaskets 0.003-0.006 in. Gasket maker governs.","applies":["engine block","cylinder head","gasket"],"basis":"SRC: AA1Car service reference, a trade source; the ranges reflect different gaskets and years.","sources":["aa1car-gasket"],"tags":["deck","mls","flatness"],"value":{"max":0.002,"unit":"in","note":"combined distortion, MLS"}},{"id":"nikasil-bore","kind":"process","tier":2,"title":"Nikasil (Ni-SiC) plated aluminium bores","summary":"Nickel with SiC under 1 um electroplated on aluminium, about 0.004 in thick (0.2 mm on early Wankel). Diamond hone only; no chrome rings. Repair: nitric strip, weld, hone, replate. Cut the bore 0.004 in big and leave electrolyte access; steel inserts come out first.","applies":["nikasil","cylinder liner"],"basis":"SRC: EngineLabs plating shop, Grand Prix Engines note, CP ring note. EST: the undersize-for-plating CAD step, electrolyte access and insert removal follow from the stated thickness.","sources":["el-nikasil","gp-note29","cp-rings"],"tags":["nikasil","plating","bore"],"value":{"typical":0.004,"unit":"in","note":"plating thickness, one source"}},{"id":"valve-materials","kind":"material","tier":2,"title":"Race valve materials: Ti, TiAl, Inconel, sodium-filled","summary":"Ti valves 4.65 g/cm3, E 114 GPa; TiAl 4.05, 155 GPa (banned 2006, allowed in 2026 F1). Inconel or Nimonic for hot boosted exhausts. Sodium fills about 60 % of a gun-drilled stem, melts near 206 F. Ti needs a hard tip; stem to 0.0002 in.","applies":["valve"],"basis":"SRC: Honda paper for Ti and TiAl; MOTOR trade article for the rest; FIA C15.7 for 2026.","sources":["honda-247","motor-valves","fia-sc-i21"],"tags":["valve","titanium","inconel","sodium"]},{"id":"exhaust-inconel-fabrication","kind":"rule","tier":1,"title":"Thin-wall Inconel exhausts: limits and welding","summary":"F1 2026: Inconel 625, 625 LCF or 718 only, wall >= 1.0 mm to the turbine, mass >= 97 % of CAD. AM only at stub (150 mm max), 3-into-1 (230) and turbine joint (150). Practice: pre-annealed 625, TIG, pure argon back purge, no post-weld heat treat.","applies":["exhaust","manifold"],"basis":"SRC: FIA Issue 21 C5.8, C15.8; HPM welding article, no dimensions there. Rules for 2026, they change by issue.","sources":["fia-sc-i21","hpm-inconel"],"tags":["exhaust","inconel"],"value":{"min":1,"unit":"mm","note":"F1 2026 exhaust pipe wall"},"see":["automotive/exhaust-clamp-joint"]},{"id":"turbo-wheel-materials","kind":"material","tier":1,"title":"Turbocharger wheels: alloys and F1 2026 limits","summary":"Turbine: cast IN713C/LC, B1914, MAR-M247; inlet gas up to about 1050 C, wheel to 280000 rpm. F1 2026: compressor 100-110 mm Al-Li (<= 2.5 % Li) or Ti; turbine 90-100 mm iron or Ni; 150000 rpm; 4.8 barA; single stage; TC >= 12 kg.","applies":["turbocharger"],"basis":"SRC: PBS foundry, US11214852, FIA C5.3, C15.8. Billet 2618 compressor wheels appeared only in retail search results, so unsourced here.","sources":["pbs-turbine","pat-11214852","fia-sc-i21"],"tags":["turbo","mar-m247"],"value":{"table":[{"item":"compressor axial","mm":"30-35"},{"item":"turbine axial","mm":"35-40"},{"item":"wheel to wheel max","mm":175}]},"see":["turbomachinery/lost-wax-process-stages"]},{"id":"measured-engine-figures","kind":"dimension","tier":1,"title":"Published BMEP and piston speed by series and year","summary":"Published: F1 2006 15.17 bar at 17000 rpm, 26.5 m/s mean at 20000, peak accel 10622 g. Cup 2006 15.12 bar, 27.5 m/s at 10000, 5821 g. DFV-era NA about 14 bar. Boosted IndyCar about 24 bar is EST. Size rods and pistons from rpm and stroke, not by analogy.","applies":["race engine"],"basis":"SRC: EPI, F1 Dictionary. EST rows: mean piston speed 2 x stroke x rpm/60; BMEP 2P/(V n) at the rev limit from a secondary 700 hp, 2.2 L figure, so a floor.","sources":["epi-cup-f1","f1-dict","rtr-indycar","fia-sc-i21"],"tags":["bmep","piston-speed"],"value":{"table":[{"y":1967,"e":"DFV 3.0 V8","bmep_bar":14},{"y":2006,"e":"F1 2.4 V8","rpm":20000,"bmep_bar":"15.17/14.6","mps":26.5,"g":10622},{"y":2006,"e":"Toyota RVX-06","rpm":19000,"bmep_bar":14.3},{"y":2006,"e":"Cup 358","rpm":10000,"bmep_bar":"15.12/14.0","mps":27.5,"g":5821},{"y":2014,"e":"Cup 358, 890 hp","rpm":9000,"bmep_bar":"EST 15.7"},{"y":"2012-on","e":"IndyCar 2.2 V6TT","rpm":12000,"bmep_bar":"EST 23.7+","mps":"EST 20.7"},{"y":2026,"e":"F1 1.6 V6","stroke_mm":"EST 53.05","mps_at_15000":"EST 26.5"}],"note":"bmep at peak torque/peak power; mps mean m/s; g peak"}},{"id":"balance-grade-crank","kind":"tolerance","tier":2,"title":"Rotor balance grades for crankshafts","summary":"e_per (g mm/kg) = G x 1000 / omega, omega = rpm / 9.55. Crank table: G40 auto or truck, G16 six-plus cylinders with special requirements, G6.3 and G2.5 engine parts with special requirements. 10 kg at 9000 rpm G2.5: 26.5 g mm (EST).","applies":["crankshaft","balancing"],"basis":"SRC: Sinko table in ISO 1940-1 layout and Fabrico formula; ISO 21940-11 itself is paywalled and no race grade is published. EST: the worked example.","sources":["sinko-balance","fabrico-balance"],"tags":["balance","iso-21940"],"value":{"table":[{"G":40,"use":"auto, truck, rail cranks"},{"G":16,"use":"cranks, 6+ cyl special requirements"},{"G":6.3,"use":"engine parts, special requirements"},{"G":2.5,"use":"engine parts, special requirements"}]}},{"id":"dry-sump-layout","kind":"rule","tier":2,"title":"Dry sump pump sections and pickups","summary":"At least 1 pressure plus 1 scavenge; 4-5 scavenge sometimes; common practice is one per crankcase section. Aviaid: 2 scavenge sections sized like the pressure section suit most engines, a third for big pans or heads that trap oil. Sections run 0.60-2.00 in wide.","applies":["dry sump"],"basis":"SRC: EngineLabs quoting Aviaid (a pump maker), Wikipedia. Scavenge sections mostly move air. No sourced gallery size.","sources":["el-drysump","wiki-drysump"],"tags":["oil","dry-sump","scavenge"],"value":{"typical":2,"unit":"count","note":"scavenge sections, typical"},"see":["automotive/crankcase-ventilation-routing","automotive/external-head-oil-feed"]},{"id":"crankcase-windage-gap","kind":"rule","tier":1,"title":"Keep 3 mm between rotating parts and crankcase wall","summary":"Honda 2005 test: friction rises rapidly once the gap between rotating parts and crankcase wall is 3 mm or less, both radially to the rod and counterweight locus and axially to the counterweights. The rod bolt head usually sets the lowest locus.","applies":["engine block","crankcase","dry sump"],"basis":"SRC: Honda 2005 F1 test; engine and rpm not stated. Applying it to a slower engine is EST.","sources":["honda-42"],"tags":["windage","clearance"],"value":{"min":3,"unit":"mm"},"see":["automotive/rotating-assembly-clash-audit"]},{"id":"piston-thermal-clearance-calc","kind":"rule","tier":2,"title":"Piston thermal growth estimate","summary":"Growth = alpha x D x dT. 2618 alpha 22.6 ppm/K, MMC 15.5, AM162 13.9. An 80 mm 2618 piston 200 K over cold grows about 0.36 mm (EST), so the cold skirt is not the hot skirt. Take running clearance from the piston maker, then CAD cold size.","applies":["forged piston"],"basis":"EST: linear expansion arithmetic with SRC alpha from Honda and Materion. The bore grows too, so net clearance change is smaller. No numeric cold clearance was sourced.","sources":["honda-236","materion-am162","je-2618"],"tags":["clearance","cte"],"value":{"typical":0.36,"unit":"mm","note":"80 mm 2618 at dT 200 K, EST"}},{"id":"piston-f1-ribs-weight","kind":"dimension","tier":2,"title":"F1 aluminium piston sections and mass","summary":"Honda F1 pistons (95-97 mm bore): 255 g in 2000 to 210 g in 2004, thin areas 2 mm or less. Ribs went radial, then # ribs (-15 g), then # bridge ribs. Thermal stress of 50-75 MPa on top of gas and inertia loads cracked rib centres.","applies":["forged piston"],"basis":"SRC: Honda paper, 2000-2008 V10 and V8. Team data of its era; 2026 pistons must be steel.","sources":["honda-51"],"tags":["piston","ribs","mass"],"value":{"min":210,"max":255,"unit":"g"},"detail":"Combustion load about 7 t and inertia above 2 t per the paper. Cracks in the rib thin area and the bridge rib centre were not explained by pressure and inertia analysis alone; thermal analysis found them. Run a thermal case, not only a mechanical one, before thinning a crown rib. Skirt form moved from burner tests to CAE of thermal distortion and skirt stiffness."},{"id":"piston-oil-jet","kind":"feature","tier":2,"title":"Piston cooling oil jet","summary":"Honda went from 4-6 hole jets at just over 10 L/min per cylinder to 19 holes, then 24. Same oil, spread wider, cut peak piston temperature 25 C and ignition retard from 6.5 to 1.5 deg. A raised jet nearly touches the crown at TDC, so check its clash.","applies":["forged piston","engine block"],"basis":"SRC: Honda paper. A taller jet cracked under vibration on the exhaust side; it needs its own stiffness check.","sources":["honda-51"],"tags":["oil-jet","cooling"],"value":{"min":4,"max":24,"unit":"count","note":"holes per cylinder"},"see":["automotive/rotating-assembly-clash-audit"]},{"id":"piston-pin-clip-groove","kind":"rule","tier":3,"title":"Pin clip groove failures at high rpm","summary":"One-third of Honda 2008 bench engines stopped from pin clip loss, past 1000 km. Groove wear from micro-deformation, not buckling, was the theory. Bigger clip wire, peened and nitrided clips and an oil jet each helped until pressure rose. Pin diameters ran 17-18.7 mm.","applies":["forged piston","piston pin"],"basis":"SRC: Honda paper; the authors say the last countermeasures were unverified.","sources":["honda-51"],"tags":["pin","clip"],"value":{"min":17,"max":18.7,"unit":"mm","note":"Honda pin dia 2000-2008"}},{"id":"piston-valve-pockets","kind":"rule","tier":2,"title":"Valve pockets must allow rod twist","summary":"Honda measured rod shank torsional resonance up to 5 deg; pockets that were not elliptical let the valve strike. So the piston does not stay square to the crank axis: widen pockets around the circumference and verify with clay. No numeric piston-to-valve figure sourced.","applies":["forged piston","valve"],"basis":"SRC: Honda paper. Whether 5 deg applies off F1 rpm is unknown. Forum clearance numbers were left out.","sources":["honda-51"],"tags":["pocket","valve","resonance"],"value":{"value":5,"unit":"deg","note":"rod torsional amplitude, F1 V10/V8 era"},"see":["automotive/rotating-assembly-clash-audit"]},{"id":"piston-skirt-coatings","kind":"feature","tier":3,"title":"Piston skirt surface and coatings","summary":"Halving skirt streak depth cut friction but risked scuffing; Honda answered with steel plating, a metallic-pigment resin coat and skirt form changes. One 850 hp, 8500 rpm V8 ran phosphated 2618 with Mahle Grafal, 475 g, 10-12 races.","applies":["forged piston"],"basis":"SRC: Honda paper; HPM article on one 408-410 cu in V8. Skirt coating thickness was not published.","sources":["honda-51","hpm-skirt"],"tags":["skirt","coating","grafal"],"value":{"typical":475,"unit":"g","note":"piston mass in the HPM example"}},{"id":"ring-pack-race","kind":"dimension","tier":2,"title":"Race ring pack dimensions and materials","summary":"Honda expanded ring: 0.9 mm axial, 1.4 mm radial, taper within 6 arcmin, Ti from 2006 with tungsten-carbide coat and DLC expander, two rings per piston. Steel is the race default, nitrided; old TiN flash 2-3 um gives way to DLC. F1 2026 requires 3 rings.","applies":["piston ring","forged piston"],"basis":"SRC: Honda paper, HPM ring articles, FIA C5.4. The 2-ring pack was legal in its era; check the rulebook. HPM gives ring speed near 26 m/s and 300 C piston.","sources":["honda-51","hpm-ring-mat","hpm-ring-seal","fia-sc-i21"],"tags":["ring","dlc","nitride"],"value":{"table":[{"item":"axial width","mm":0.9},{"item":"radial","mm":1.4}]}},{"id":"albemet-piston-history","kind":"material","tier":3,"title":"Aluminium-beryllium pistons, 1998 to 2000","summary":"Ilmor made Al-Be pistons from 1998, cutting mass by a third; banned after 2000 on cost and health. AlBeMet AM162 today: 62 wt% Be, about 2.1 g/cm3, 193-202 GPa, 13.9 ppm/K, 210 W/mK. 2026 F1 caps non-copper alloys at 0.25 % Be.","applies":["forged piston"],"basis":"SRC: HPM on the history, Materion datasheet, FIA C15.6. HPM does not name the Ilmor alloy as AlBeMet; do not assume they match. Beryllium machining needs controls.","sources":["hpm-albe","materion-am162","fia-sc-i21"],"tags":["albemet","beryllium","history"],"value":{"table":[{"form":"HIP","YS_MPa":193,"E_GPa":197},{"form":"extruded","YS_MPa":276,"E_GPa":202},{"form":"sheet","YS_MPa":276,"E_GPa":193}]}},{"id":"mmc-piston-history","kind":"material","tier":3,"title":"SiC metal matrix pistons, 2004 to 2005","summary":"Honda AMC225XE: AA2124 plus 25 % v/v 3 um SiC, 113 GPa, 2.89 g/cm3, 15.5 ppm/K, 129 W/mK against AA2618 74.6, 2.76, 22.6, 165. 16 % lighter, +400 rpm. Forged from HIP stock near-net. Banned from 2006; F1 2026 caps MMC at 2 % v/v.","applies":["forged piston"],"basis":"SRC: Honda paper, FIA C15.6. Low CTE opened skirt clearance, needing hard plating and resin coat on skirt and top land.","sources":["honda-236","honda-51","fia-sc-i21"],"tags":["mmc","piston","history"],"value":{"table":[{"alloy":"AA2618","E_GPa":74.6,"rho":2.76,"cte":22.6,"k":165},{"alloy":"MMC","E_GPa":113,"rho":2.89,"cte":15.5,"k":129}]}},{"id":"printed-piston","kind":"process","tier":3,"title":"Laser powder bed printed pistons","summary":"MAHLE, Porsche and Trumpf: about 1200 layers, 12 h per blank, up to 20 % lighter, closed cooling gallery by the rings only printing allows; 6 pistons ran 200 h in a 700 HP 911 GT2 RS engine. Finish machine crown, grooves, pin bore and skirt.","applies":["forged piston","additive"],"basis":"SRC: MAHLE press release (a maker's claim); \"up to\". EST: machining list from normal piston finishing.","sources":["mahle-3d"],"tags":["am","piston","lmf"],"value":{"max":20,"unit":"%","note":"mass saving, maker claim"}},{"id":"piston-pin-offset","kind":"note","tier":3,"title":"Piston pin offset: no sourced figure","summary":"Pin offset moves the slap at TDC and gives each piston a required orientation. Published magnitudes found were forum posts only, so none is stated. Model the pin axis as a named parameter, mark the front of the crown, and take the value from the piston maker.","applies":["forged piston"],"basis":"EST: general engine practice. Left numberless on purpose; only forums gave values.","sources":[],"tags":["pin","offset","gap"]},{"id":"steel-piston-2026-mass","kind":"dimension","tier":2,"title":"F1 2026 reciprocating and crank mass floors","summary":"F1 2026 minimums: piston with pin, retainers, rings 350 g; rod with fasteners and bearings 320 g; crank assembly between journals 5800 g; turbo 12 kg; ICE 130-134 kg; PU 185 kg, CoG above Z 200. Design to the floor, then add ballast only where allowed.","applies":["f1 power unit","piston","connecting rod"],"basis":"SRC: FIA Issue 21 C5.5. Rules for 2026, they change by issue.","sources":["fia-sc-i21"],"tags":["f1","mass","2026"],"value":{"table":[{"part":"piston group","g":350},{"part":"rod group","g":320},{"part":"crank assy","g":5800}]}},{"id":"f1-2026-mounting-studs","kind":"dimension","tier":2,"title":"F1 2026 ICE mounting stud positions","summary":"Six M12 studs to the survival cell at [0, +/-270, 25], [0, +/-360, 270], [0, +/-190, 440]; four to gearbox at [480, +/-125, 25], [480, +/-265, 360], optional two at [480, +/-150, 140]. Tolerance +/-0.2. Each stud over 100 kN tensile. No other load path.","applies":["f1 power unit","engine block"],"basis":"SRC: FIA Issue 21 C5.4, coordinates [XPU, Y, Z] in mm at the stud centres. Rules for 2026, they change by issue.","sources":["fia-sc-i21"],"tags":["f1","mount","stud"],"value":{"table":[{"to":"survival cell","xpu":0,"y":"270/360/190","z":"25/270/440"},{"to":"gearbox","xpu":480,"y":"125/265","z":"25/360"},{"to":"gearbox optional","xpu":480,"y":150,"z":140}]}},{"id":"wec-hypercar-gr010","kind":"dimension","tier":2,"title":"WEC Hypercar data point: Toyota GR010, 2021","summary":"Toyota GR010 Hybrid, 2021 WEC: 3.5 L direct-injection twin-turbo V6, up to 500 kW maximum system output including hybrid boost, 200 kW front-axle motor. Bore, stroke, rpm and BMEP were not published, so no BMEP is derived.","applies":["race engine"],"basis":"SRC: Autosport launch report. Other sources give 500 kW differently; a regulated figure, not engine potential.","sources":["autosport-gr010"],"tags":["wec","lmh"],"value":{"max":500,"unit":"text","note":"kW system"}},{"id":"rod-loads","kind":"dimension","tier":2,"title":"Rod loads: F1 and Cup 2006 published estimates","summary":"F1 2006, 20000 rpm: 10622 g on a 295 g piston package gives 3133 kg at the pin bore, 4036 kg at the beam. Cup, 10000 rpm: 5821 g, 500 g, 2911 kg, 3725 kg. Rods: 102 mm Ti, 34 mm pin, 285 g; 157.5 mm steel H, 47 mm pin, 525 g min.","applies":["connecting rod"],"basis":"SRC: EPI, computed and estimated by its author for end-2006 engines. Honda independently gives inertia over 5 t on its big ends.","sources":["epi-cup-f1","honda-51"],"tags":["rod","load","acceleration"],"value":{"table":[{"e":"F1 2006","pin_kg":3133,"beam_kg":4036,"rod_g":285,"L_mm":102},{"e":"Cup 2006","pin_kg":2911,"beam_kg":3725,"rod_g":525,"L_mm":157.5}]},"see":["power-transmission/connecting-rod-length-ratio"]},{"id":"rod-big-end-compacting","kind":"dimension","tier":2,"title":"Compact F1 rod big end progression","summary":"Honda 2000 to 2008: bolt M10x1.25 to M9x1.0, head 9.4 to 5.4 mm, bearing shell 2 to 1.5 mm, cap clamp 19.5 to 15 mm, pin 35 to 34 mm. That let the counterweight radius and crank height drop. EPI assumed 8 mm bolts near 8000 lb preload.","applies":["connecting rod","fastener"],"basis":"SRC: Honda Fig. 10, read from extracted figure text, so treat row mapping as read not confirmed; EPI FEA assumption.","sources":["honda-42","epi-cup-f1"],"tags":["big-end","bolt"],"value":{"table":[{"item":"bolt","y2000":"M10x1.25","y2008":"M9x1.0"},{"item":"head mm","y2000":9.4,"y2008":5.4},{"item":"shell mm","y2000":2,"y2008":1.5},{"item":"clamp mm","y2000":19.5,"y2008":15}]}},{"id":"rod-hollow-diffusion-bond","kind":"process","tier":3,"title":"Hollow Ti rod by diffusion bonding (history)","summary":"Honda 2003-2004: two machined half blanks of rolled Ti, 830 C, 4.0 MPa, 5 h, surface Rt 1.6, gave 8 % less mass, 2.5 x shank rigidity, 18 % big-end rigidity, +250 rpm. Banned from 2005; 2026 F1 requires one piece. I and H sections are weak in torsion.","applies":["connecting rod","titanium rod"],"basis":"SRC: Honda papers, FIA C15.7. Lesson that survives the ban: limit shank thinning by torsional stiffness, not just tension and compression.","sources":["honda-241","honda-51","fia-sc-i21"],"tags":["hollow","diffusion-bonding","titanium"],"value":{"value":2.5,"unit":"ratio","note":"shank rigidity vs I section"}},{"id":"ti-rod-galling","kind":"rule","tier":2,"title":"Titanium rods gall: threads and small-end bushes","summary":"Ti galls at threads and on bush insertion, which raises a fatigue stress at the bore; steel does not. SP-700 had 25 % higher fatigue than 6Al-4V at Honda. EPI used Ti-6-2-2-2-2 at 17.7 Msi modulus for its model. Add a coating or bush spec in the CAD note.","applies":["titanium rod"],"basis":"SRC: HPM rod materials and DLC articles, Honda, EPI. HPM reports DLC on Ti small-end bores to stop bush pickup.","sources":["hpm-rod-mat","hpm-dlc","honda-241","epi-cup-f1"],"tags":["titanium","galling","bush"],"value":{"typical":25,"unit":"%","note":"SP-700 fatigue over 6Al-4V"},"see":["materials/ti-6al-4v"]},{"id":"rod-weight-peen-inspect","kind":"tolerance","tier":3,"title":"Production race rod finishing and weight match","summary":"Manley 4340 H-beam: forged, heat treated, stress relieved, shot peened, 100 % magnafluxed, weight matched to 1.5 g, 7/16 in ARP 8740 or ARP 2000. The maker says its power ratings are subjective: rpm, stroke, piston mass and power adders drive rod fatigue.","applies":["connecting rod"],"basis":"SRC: Manley catalogue, a maker listing; the +/- glyph did not extract, so 1.5 g is read as the band. No Almen intensity published.","sources":["manley-rods"],"tags":["rod","peen","weight"],"value":{"value":1.5,"unit":"g"}},{"id":"big-end-bore-check","kind":"test","tier":2,"title":"Big-end bore check under bolt load","summary":"Measure the big end with bolts at final preload: one rod showed 0.0015 in taper. Honda saw that big-end deformation and bearing crush interact: a softer Si-Cu shell at 148 GPa followed the bore. CAD: datum the bore on the bolted assembly; finish cap and rod together.","applies":["connecting rod","bearing"],"basis":"SRC: EngineLabs measurement, Honda bearing work. EST: finishing the bolted pair is general practice. No numeric ovality limit found.","sources":["el-bearing","honda-51"],"tags":["big-end","ovality","test"],"value":{"typical":0.0015,"unit":"in","note":"taper seen on one rod"}},{"id":"rod-bearing-si-bronze","kind":"material","tier":2,"title":"F1 rod bearing back metal: silicon bronze","summary":"Si-Cu back: 159 W/mK, 570 MPa 0.2 % proof, 148 GPa against steel back 50, 420, 210. Life reached 1500 km when contact pressure doubled. F1 rod bearing runs 2.6 x production speed and up to about 15 x the heat. Later Corson alloy.","applies":["bearing","connecting rod"],"basis":"SRC: Honda paper Table 2 and text. Higher crush needs rod bolt preload margin. In 2005 roller mains gained 4 kW but pumping losses cancelled it.","sources":["honda-51"],"tags":["bearing","bronze"],"value":{"table":[{"back":"Si-Cu","k":159,"YS_MPa":570,"E_GPa":148},{"back":"steel","k":50,"YS_MPa":420,"E_GPa":210}]}},{"id":"crank-surface-treatment-gains","kind":"process","tier":2,"title":"Crank fatigue gains: nitriding, fillet rolling, remelt","summary":"Small specimens: nitriding gave over 60 % longer life, fillet rolling at 500-900 kgf 40-80 %. Double-remelted nitriding steel over 30 % fatigue strength (one maker). Gas nitriding can take 90 h then straightening; 1 mm case is very slow; leave stock.","applies":["crankshaft","billet crank"],"basis":"SRC: SAE abstract, HPM. Conditions differ, so do not add them. Combining rolling with nitriding was not sourced. Nitride depth for race cranks not published.","sources":["sae-crank","hpm-crank-steel","hpm-surface","hpm-nitriding"],"tags":["nitriding","fillet-rolling","fatigue"],"value":{"min":40,"max":80,"unit":"%","note":"fatigue life from rolling, SAE specimens"}},{"id":"crank-journal-sizes","kind":"dimension","tier":2,"title":"F1 crank journals: history and 2026 floors","summary":"Honda pin/main: 35/52 in 2000, then 36/48, 34/46, 33/45, and 34/45 on the V8. F1 2026 floors: main >= 44.95 dia, >= 18.95 wide, >= 2500 mm2; pin >= 41.95, >= 17.95, >= 2200 mm2. Cup pin about 47 mm. The 2026 pin is far bigger than V8 pins.","applies":["crankshaft","bearing"],"basis":"SRC: Honda Table 1, FIA C5.4, EPI estimate. Bearing area counts surfaces within 0.06 mm of maximum radial thickness, verified by design.","sources":["honda-51","fia-sc-i21","epi-cup-f1"],"tags":["journal","f1","bearing"],"value":{"table":[{"y":2000,"pin":35,"main":52},{"y":2008,"pin":34,"main":45},{"y":2026,"pin":">=41.95","main":">=44.95"}]}},{"id":"crank-journal-finish","kind":"tolerance","tier":3,"title":"Journal polish, crown and direction","summary":"Customers may specify 3-4 um radial crown over a 40 mm journal; shoe polishers oscillate axially 1 mm. Polish in rotation direction after grinding against it; a poor grind cannot be polished out; do not polish seal diameters. No Ra target published here.","applies":["crankshaft"],"basis":"SRC: HPM article on one polishing process. Crown helps with crank bend; it is a drawing note, not B-rep.","sources":["hpm-smooth"],"tags":["journal","finish","crown"],"value":{"min":3,"max":4,"unit":"um","note":"crown over 40 mm"}},{"id":"crank-heavy-metal-counterweight","kind":"feature","tier":2,"title":"Heavy metal crank counterweights","summary":"Honda W alloy, 17.5-18 g/cm3: press-fit, plugged and welded to 2004, then bolted with M9 and dowel; counterweight radius 58.55, then 50 mm, crank 4.5 mm lower. Lead time 3 months to 3 weeks. 2026 F1 allows W counterweights; density limit 18400 kg/m3.","applies":["crankshaft"],"basis":"SRC: Honda papers, FIA C15.7. Welding between journals is banned since 2006, so bolt and dowel it. Bolted weights can be swapped to change balance rate quickly.","sources":["honda-42","honda-51","fia-sc-i21"],"tags":["counterweight","tungsten"],"value":{"min":50,"max":58.55,"unit":"mm","note":"radius"}},{"id":"crank-oil-feed-and-holes","kind":"feature","tier":2,"title":"Crank oil feed: from the nose, not the mains","summary":"Honda fed oil from the crank nose so centrifugal force pressurises it; keep channels near the axis, as main-fed oil fights it. A 2005 hollow main raised mean pressure 500 kPa. GKHYW steel and removing the oil-hole brittle layer ended torsion breaks from 2003.","applies":["crankshaft","dry sump"],"basis":"SRC: Honda papers, for 19000 rpm class engines. Hollow crank was friction welded, never raced, and now illegal in F1. Gun-drilling method and diameters not published.","sources":["honda-51","honda-233","hpm-oil-holes"],"tags":["oil","crank","gallery"],"value":{"value":500,"unit":"text","note":"kPa mean pressure gain, hollow main"}},{"id":"crank-hollow-friction-weld","kind":"process","tier":3,"title":"Hollow crank by friction welding (history)","summary":"Honda V10, 2005: hollow 34 mm pin, 6 +/-0.3 mm wall, friction welded at 1900 rpm, 30 t upset, 9 mm upset length; 5.75 kg vs 6.55 kg solid (9.5 and 10.3 with counterweights). Banned 2006, still barred in 2026 by no welds between journals.","applies":["crankshaft"],"basis":"SRC: Honda paper, FIA C15.7. Target offset 0.5 mm, achieved 0.35 mm; cranks over 1.0 mm offset were trued after nitriding.","sources":["honda-233","fia-sc-i21"],"tags":["hollow","friction-weld","history"],"value":{"typical":6,"unit":"mm","note":"wall"}},{"id":"crank-stress-relief-groove","kind":"feature","tier":2,"title":"Pin fillet stress relief groove and resonance map","summary":"Honda ended rare pin-fillet bending cracks with a CAE-shaped relief groove under the fillet. It kept torsional resonance outside 15000-19000 rpm by changing clutch attachment. Model a groove where the bearing side space allows; check it clears the shell.","applies":["crankshaft"],"basis":"SRC: Honda paper. Groove dimensions are not published. EST: shell clearance check.","sources":["honda-51"],"tags":["fillet","groove","resonance"],"value":{"min":15000,"max":19000,"unit":"text","note":"rpm band kept clear"}},{"id":"block-cgi","kind":"material","tier":2,"title":"Compacted graphite iron for blocks","summary":"CGI: GJV 400 400-475 MPa, 140-150 GPa, 39 W/mK; GJV 450 450-525 MPa, 145-155 GPa, 38 W/mK at 25 C. About 70-75 % stronger and 35 % stiffer than grey iron, near double the fatigue, and far harder to machine. Allow thinner walls only after FEA.","applies":["engine block"],"basis":"SRC: Total Materia, an aggregator; its abstract says 75 % and body 70 %. No block wall figure was found. EST: last sentence.","sources":["tm-cgi"],"tags":["cgi","iron","block"],"value":{"table":[{"grade":"GJV 400","UTS_MPa":"400-475","E_GPa":"140-150"},{"grade":"GJV 450","UTS_MPa":"450-525","E_GPa":"145-155"}]},"see":["load-driven-detailing/ldd-cast-wall-iron"]},{"id":"block-al-casting-pointer","kind":"process","tier":2,"title":"Aluminium blocks and heads: A356 class castings","summary":"A356.0-T6 about 230 MPa tensile, 165 MPa yield lives in load-driven-detailing with wall, draft, rib and hot-spot rules. Race addition: 3 mm shell water-jacket cores in Honda 2003 needed high strength shell cores. Billet only at very low volume (EST).","applies":["engine block","cylinder head"],"basis":"SRC: Honda on cores. EST: billet remark; the A356 strengths are not in Honda, they are typical handbook values from the ldd entry. A357-T6 was seen only as an unlabelled Scribd sheet, so is not stated; expect it above A356.","sources":["honda-42"],"tags":["a356","casting","block"],"value":{"value":3,"unit":"mm","note":"water jacket core"},"see":["load-driven-detailing/ldd-mat-al-castings","load-driven-detailing/ldd-cast-wall-pm-al","load-driven-detailing/ldd-cast-hotspot-junction"]},{"id":"block-closed-deck-bore-bridge","kind":"dimension","tier":2,"title":"Bore bridge and closed deck progress in F1","summary":"Honda bore-to-bore: 11 mm with separate thin sleeves (2000), 9 mm closed deck with 3 mm jacket core (2003), 6 mm with 3 drilled 3 mm coolant holes (2004). F1 2026: 101 +/-2 spacing and 80 bore leave about 21 mm (EST), so size is not the problem.","applies":["engine block","cylinder liner"],"basis":"SRC: Honda paper. EST: subtraction. Bridge cooling was changed to longitudinal flow in 2004.","sources":["honda-42","fia-sc-i21"],"tags":["bore-bridge","closed-deck"],"value":{"min":6,"max":11,"unit":"mm"}},{"id":"v-angle-and-crank-height","kind":"note","tier":3,"title":"Vee angle and crank height history at Honda","summary":"Honda ran 72, 80, 94 then 90 deg for balance and CoG. Crank height fell from 70.5 mm (2000) to 63 mm or lower. Engine weight fell from 122 kg (2000) to 88.6 kg (2005). Regulated 90 deg and 95 kg min from 2006; F1 2026 crank height is 90 mm.","applies":["engine block"],"basis":"SRC: Honda Table 1 and text, FIA C5.4. Table values read from extracted text.","sources":["honda-42","fia-sc-i21"],"tags":["vee","crank-height","history"]},{"id":"main-line-bore-check","kind":"test","tier":2,"title":"Main line and housing bore measurement","summary":"Measure housings torqued: bolting an oil pump adapter moved one clearance 0.0008 in. Journals on one crank varied 2.7383-2.7393 in, so shells may mix. Tools need 0.0001 in resolution. CAD: keep a clear path for a bore gauge; do not hide bores with webs.","applies":["engine block","crankshaft"],"basis":"SRC: EngineLabs example on a 454. EST: gauge access note. Cross-bolting and main line tolerance figures were not found.","sources":["el-bearing"],"tags":["main-bore","align-hone"],"value":{"typical":0.0008,"unit":"in","note":"shift from one adapter"}},{"id":"liner-types","kind":"note","tier":2,"title":"Liners: sleeve, closed deck, plated","summary":"Honda used separate thin sleeves to 2002, then closed deck with sleeves; plating removes sleeves altogether. A wet liner needs a top collar, deck seal and lower O-rings; a dry liner needs press-fit stock and a machined seat. Liner wall and fit were not published.","applies":["cylinder liner","engine block"],"basis":"SRC: Honda and EngineLabs for what was used. EST: wet and dry liner geometry is general practice. See recipe for a worked EST section.","sources":["honda-42","el-nikasil"],"tags":["liner","wet","dry"],"see":["race-engines/recipe-wet-cylinder-liner","piping/oring-groove-radial-piston"]},{"id":"f1-2026-head-rule","kind":"rule","tier":2,"title":"F1 2026 cylinder head construction","summary":"One head per bank, one piece, including ports and water passages above the deck. Seat inserts max 4 mm over valve head; seats plus guides max 3 % of head volume, others 1 %; 15 mm plug-axis insert. Exhaust outlets outboard only. 2 intake, 2 exhaust valves.","applies":["cylinder head","f1 power unit"],"basis":"SRC: FIA Issue 21 C5.1, C5.4, C15.7. Rules for 2026, they change by issue. Injector axis 70 +/-5 deg to the cylinder centreline.","sources":["fia-sc-i21"],"tags":["f1","head","insert"],"value":{"max":3,"unit":"%","note":"seat and guide inserts by head volume"}},{"id":"valve-seat-materials","kind":"material","tier":2,"title":"Valve seat insert materials","summary":"Copper alloys lead for bespoke race heads; CuBe (A3, A25) is common, Be-free Moldstar 90 and 22 are gaining. 2026 F1 caps Cu alloys at 2.2 % Be and allows infiltrated pre-forms for seats and guides. Titanium valves want soft seats, RC32 or less, with new seats each rebuild.","applies":["valve","cylinder head"],"basis":"SRC: HPM seat materials, FIA C15.6 and C15.7, MOTOR for Ti seats. Press-fit interference is not published.","sources":["hpm-seat-mat","fia-sc-i21","motor-valves"],"tags":["seat","cube","moldstar"],"value":{"options":["CuBe A3","CuBe A25","Moldstar 90","Moldstar 22","infiltrated pre-form"]}},{"id":"valve-seat-layout","kind":"rule","tier":2,"title":"Seat ring wall, bridge and coolant space","summary":"In a 4-valve race head, intake seats nearly touch and the walls merge; keep enough head around each for press stress, and lower ring height to bring coolant closer. Coolant between exhaust seats is possible; intakes have no room. Ti valve seat width at least 1 mm.","applies":["cylinder head","valve"],"basis":"SRC: HPM seat cooling, MOTOR. Valve bridge sees thermo-mechanical fatigue. Seat angles were not sourced; use the head maker's valve job.","sources":["hpm-seat-cool","motor-valves"],"tags":["seat","bridge","coolant"],"value":{"min":1,"unit":"mm","note":"Ti valve seat contact width"}},{"id":"laser-clad-seat","kind":"process","tier":3,"title":"Laser clad valve seats (history)","summary":"Honda from 2004: copper alloy spherical powder 80 +/-5 um in a 4 mm high arc-bottom slot, overlap start ramped. Valve up 1 mm dia (intake 40.6 to 41.6), 6 kW at high water temp, 0.4 kg saved. Non-fusion and embrittlement were the defect limits.","applies":["cylinder head","valve"],"basis":"SRC: Honda papers. 2026 F1 wording lets the sealing surface be the head, a permitted coating or a conventional insert; check before assuming cladding is legal.","sources":["honda-253","honda-42","fia-sc-i21"],"tags":["laser-clad","seat","history"],"value":{"typical":4,"unit":"mm","note":"slot height"}},{"id":"o-ring-fire-ring-note","kind":"note","tier":3,"title":"O-ring and fire-ring head sealing: not sourced","summary":"Receiver grooves and fire rings are normal for high cylinder pressure, but no page opened gave groove depth or protrusion. Do not invent one: take them from the gasket or ring maker. Note that grooves conflict with MLS gaskets, so a deck picks one sealing route.","applies":["cylinder head","engine block","gasket"],"basis":"EST: general practice with numbers left out on purpose.","sources":[],"tags":["o-ring","fire-ring","gap"],"see":["race-engines/deck-flatness-mls"]},{"id":"valve-spring-surge-limit","kind":"rule","tier":2,"title":"Valve spring surge and the pneumatic switch","summary":"Surge cannot be fully removed by dampers or variable pitch; steel springs limit around 12000 rpm in 1980s sources; pneumatic return took F1 near 20000. Low open pressure causes float; lowering installed height raises seat and open pressure. Leave room for coil bind margin.","applies":["valve spring"],"basis":"SRC: US4592313, F1 Dictionary, Fastime. Spring pressure charts I found were forums; beehive design data was not sourced. Coil bind margin number not given.","sources":["pat-4592313","f1-dict","fastime-spring"],"tags":["spring","surge","pneumatic"],"value":{"typical":12000,"unit":"text","note":"rpm, steel spring era"}},{"id":"pneumatic-valve-return","kind":"feature","tier":2,"title":"Pneumatic valve return in the head","summary":"F1 2008: 570 cm3 carbon air bottle, regulator, small thin-wall piston with seal over the valve. Honda cast the air passages into the head from 2003 with complex shell cores. 2026 F1 allows only passive regulator or standard ECU control, and valve motion must be cam driven.","applies":["valve spring","cylinder head"],"basis":"SRC: Honda valvetrain and structural papers, HPM profiles, FIA C8 and C5.1. US4592313 prefers a piston to restriction area ratio above 500:1.","sources":["honda-60","honda-42","hpm-profiles","pat-4592313","fia-sc-i21"],"tags":["pneumatic","air-spring","head"],"value":{"typical":570,"unit":"text","note":"cm3 air bottle"}},{"id":"valvetrain-loads-honda","kind":"dimension","tier":2,"title":"F1 valvetrain figures, Honda 2008","summary":"RA808E: Ti6246 intake valves (exhaust KS64411Ta), lift about 13.0-13.5 mm, stem 5.8 (bore 3.5), intake 41.6 and exhaust 32.4 dia, acceleration over 6000 G, gas 700 C or more, lift acceleration 50 mm/rad2 or more, cam SCM435 nitrided DLC. 2026 F1 stem >= 4.95.","applies":["valve","camshaft"],"basis":"SRC: Honda Table 1, read from extracted text with some column loss; check the PDF before reuse. Valve speed limit target 20000 rpm or more.","sources":["honda-60","fia-sc-i21"],"tags":["valve","lift","acceleration"],"value":{"typical":6000,"unit":"text","note":"G valve acceleration"},"see":["power-transmission/camshaft-lobe-basics"]},{"id":"valve-head-shape","kind":"rule","tier":3,"title":"Valve head mass: nail head and dished tulip","summary":"A thin stem needs a lighter head or valve control is lost. A flat nail head cuts mass but also flow; a dished tulip recovers flow but adds TDC volume, which may need piston pocket fill. Honda valvetrain reciprocating mass fell 30 % over 2000-2008.","applies":["valve"],"basis":"SRC: HPM profiles; the 30 % is Honda total valvetrain reciprocating mass, from followers, piston and valves together.","sources":["hpm-profiles","honda-60"],"tags":["valve","head","mass"],"value":{"typical":30,"unit":"%","note":"reciprocating mass cut"}},{"id":"ti-hollow-valve-nak","kind":"process","tier":2,"title":"Hollow Ti valve, EBW plug and NaK fill","summary":"Honda: head bored, plug EB welded, weld fatigue fell to 30 % so leave 1.27 mm unwelded; -4.4 g. NaK 78 wt% K, 50 % fill, under 10 ppm O2: intake -174 C, exhaust -103 C, but intake lost 5 kW. 2026 F1: hollow exhaust only, plain cylinder cavity.","applies":["valve"],"basis":"SRC: Honda paper, FIA C15.7. Cavity features may not exceed a plain cylinder 1.0 mm over the main cavity. Weld hairline cracks stayed unresolved in that test.","sources":["honda-247","fia-sc-i21"],"tags":["valve","hollow","sodium","ebw"],"value":{"min":1.27,"unit":"mm","note":"residual thickness"}},{"id":"dlc-cam-follower","kind":"process","tier":2,"title":"DLC on cam lobes and followers","summary":"Contacts reach 1 GPa or more and PV 20000 MPa m/s or more. Honda: DLC since 2002, cam IDV38S against softer DF1 follower at about 1.3 x hardness, soft run-in top layer, graded bond layer; about 5 kW saved, cams lasted 4 race events. Same hardness pairs attack each other.","applies":["camshaft","finger follower"],"basis":"SRC: Honda paper. Film hardness profile runs to under 1 um depth. PVD pin coatings up to 2 um, about 450 C limit, coefficient 0.1 per Motorservice.","sources":["honda-250","ms-dlc-pin","hpm-dlc"],"tags":["dlc","cam","follower"],"value":{"value":1.3,"unit":"ratio","note":"hardness ratio between pair"},"see":["power-transmission/cam-follower-pressure-angle"]},{"id":"finger-follower-layout","kind":"rule","tier":3,"title":"Finger follower geometry","summary":"Honda from 2002: finger followers saved 13.5 g over bucket tappets and added 1.0 mm or more lift. Cam almost over the valve stem brings lever ratio near 1, lowering surface pressure and raising stiffness. Shape by CAE for local stiffness and Hertz stress.","applies":["finger follower","camshaft"],"basis":"SRC: Honda valvetrain paper.","sources":["honda-60"],"tags":["follower","tappet"],"value":{"typical":1,"unit":"ratio","note":"lever ratio target"}},{"id":"cam-gear-drive","kind":"feature","tier":3,"title":"Gear camshaft drive and cam torsion","summary":"Gears stop timing drift from drive torque; Honda inertia weights and backlash tuning (AVRS) added 1500 rpm valve speed, rear-gear AVRS-G saved 2 kg, cam dampers added 1100 rpm. 2026 F1: timing gears iron-based, camshaft and lobes from one piece, no welds.","applies":["camshaft"],"basis":"SRC: Honda paper, FIA C15.7. Rev figures are valve-motion limits, not engine limits.","sources":["honda-60","fia-sc-i21"],"tags":["gear-drive","cam","billet"],"value":{"typical":1500,"unit":"text","note":"rpm gain"},"see":["power-transmission/camshaft-lobe-basics"]},{"id":"f1-2026-energy-rules","kind":"rule","tier":2,"title":"F1 2026 energy: no MGU-H, fuel flow, fuel","summary":"Only the engine and ERS-K may propel the car; turbo rotating energy may not transfer elsewhere, so no MGU-H. Fuel flow max 3000 MJ/h, 550 per cylinder, EF = 0.27 N + 165 below 10500 rpm. Injector fuel <= 350 barG. Advanced Sustainable fuel only.","applies":["f1 power unit","turbocharger"],"basis":"SRC: FIA Issue 21 C5.2, C5.3, C5.9, C16. No MGU-H is read from those clauses, Section C defines no such part. C5.14 has a 750 rpm band but no fixed rev limit that I found.","sources":["fia-sc-i21"],"tags":["f1","mgu-h","fuel"],"value":{"value":3000,"unit":"text","note":"MJ/h"}},{"id":"turbo-containment-wastegate","kind":"rule","tier":2,"title":"Turbo containment and wastegate limits in F1 2026","summary":"Max 2 wastegates and 2 pop-off valves, circular poppet only; turbo axis inboard of Y 25, 0 +/-1 deg to X; turbine debris must stay inside its housing. Compressor housing Al-Li up to 2.5 %; turbine parts in the gas iron or nickel, centre housing iron, Al or Ti.","applies":["turbocharger","wastegate"],"basis":"SRC: FIA Issue 21 C5.1, C5.3, C15.8. Rules for 2026, they change by issue. Road turbo housing material figures found were retail listings, left out.","sources":["fia-sc-i21"],"tags":["turbo","wastegate","containment"],"value":{"max":2,"unit":"count","note":"wastegates"},"see":["turbomachinery/spin-pit-overspeed-test","load-driven-detailing/ldd-test-rotor-overspeed"]},{"id":"intercooler-rule","kind":"rule","tier":3,"title":"F1 2026 heat exchanger core limits","summary":"Primary heat exchangers: core and tanks aluminium alloy, no additive core, tube wall >= 0.18 mm, tube internal section >= 10 mm2. Header tank relief max 3.75 barG. No latent heat cooling except fuel. A single oil tank. Check which exchangers count as primary in the article.","applies":["intercooler","f1 power unit"],"basis":"SRC: FIA Issue 21 C7.4, C5.22. Rules for 2026, they change by issue. Tube fin details continue in the article.","sources":["fia-sc-i21"],"tags":["intercooler","radiator","f1"],"value":{"min":0.18,"unit":"mm","note":"tube wall"}},{"id":"f1-2026-exhaust-am-envelope","kind":"dimension","tier":3,"title":"F1 2026 additive zones in the exhaust","summary":"AM allowed only at one stub or flange per primary (150 mm max in any direction), one 3-into-1 per bank (230 mm), one secondary-to-turbo joint per bank (150 mm). The rest must be fabricated tube at >= 1.0 mm wall, Inconel 625, 625 LCF or 718.","applies":["exhaust","additive"],"basis":"SRC: FIA Issue 21 C15.8, C5.8. Rules for 2026, they change by issue. A CAD agent can check these with a bounding box per printed part.","sources":["fia-sc-i21"],"tags":["am","exhaust","f1"],"value":{"table":[{"zone":"stub/flange","max_mm":150},{"zone":"3-into-1","max_mm":230},{"zone":"to turbo","max_mm":150}]}},{"id":"coolant-oil-integration","kind":"feature","tier":3,"title":"Integrating pumps and passages into castings","summary":"Honda cast scavenge pumps and water pumps into block and sump from 2002, adding stiffness; air separators at the front centrifuge blow-by. Aviaid sections match flow needed; too much makes pressure hard to control. Oil cooler bypass near 185 F.","applies":["engine block","dry sump"],"basis":"SRC: Honda paper, EngineLabs on a road-race Coyote. Oil gallery diameters are not published.","sources":["honda-42","el-drysump"],"tags":["oil","coolant","integration"],"value":{"typical":185,"unit":"text","note":"F, cooler thermostat"}},{"id":"isotropic-superfinish","kind":"process","tier":2,"title":"REM isotropic superfinish: what is proven","summary":"Stated Ra 0.02 um and Rz 0.2 um. The 4 to 5 x gear life figure is the process side's claim, no test cited. No independent crank or rod fatigue number was found. Verdict: credible for contact fatigue on gears; unproven on cranks. Removes little, keep edges.","applies":["crankshaft","gear","superfinish"],"basis":"SRC: FMT trade article from the developers' technology. Verdict is this pack's reading of what was available. EST: edge remark.","sources":["foundry-isf"],"tags":["rem","isf","superfinish"],"value":{"value":0.02,"unit":"um","note":"Ra claim"}},{"id":"cryogenic-verdict","kind":"note","tier":2,"title":"Cryogenic treatment: an honest verdict","summary":"Thornton 2013 (Wear 305): significant dry sliding wear gains in tool steels and a pearlitic brake steel, hardness mostly unchanged. No open source gave crank or rod fatigue data. Verdict: plausible for wear parts, no evidence to credit in a rod or crank design.","applies":["crankshaft","connecting rod"],"basis":"SRC: abstract only. EST: verdict. Fatigue reviews were found in search but could not be opened (403).","sources":["thornton-cryo"],"tags":["cryogenic","wear"]},{"id":"coating-limits-f1","kind":"rule","tier":2,"title":"Coating limits and thermal barriers in F1 2026","summary":"Coatings escape material bans if <= 25 % of base section and <= 0.8 mm (0.035 mm for Au, Pt, Ru, Ir, Re), no graphene. Ceramic allowed for insulation and exhaust-outside TBC. No energy-beam or photo-etched surface texture. CAD: cannot rely on laser-textured bores.","applies":["f1 power unit","coating"],"basis":"SRC: FIA Issue 21 C15.6. Rules for 2026, they change by issue. Piston crown TBC practice and numbers were not found.","sources":["fia-sc-i21"],"tags":["coating","tbc","texture"],"value":{"max":0.8,"unit":"mm"}},{"id":"shot-peen-note","kind":"note","tier":3,"title":"Shot peening rods and cranks: what was found","summary":"Rod makers list shot peening as routine after heat treatment. No Almen intensity or coverage was published in pages opened, so state it as a drawing note with the vendor spec, mask finished bores and threads, and keep the peened surface unmachined afterwards.","applies":["connecting rod","crankshaft"],"basis":"SRC: Manley for routine use. EST: masking and no later machining are general practice.","sources":["manley-rods"],"tags":["peen","gap"]},{"id":"test-leak-down","kind":"test","tier":2,"title":"Leak-down test at TDC","summary":"At TDC compression, pressurise through the plug hole. Online figure is 9 % or less; 11 % is fine if cylinders agree; about 30 % everywhere is a problem. Air at exhaust = exhaust valve, intake = intake valve, breather = rings. Needs one accessible port per cylinder.","applies":["race engine","cylinder head"],"basis":"SRC: EngineLabs; a relative test, compare cylinders. EST: the access requirement.","sources":["el-leakdown"],"tags":["test","leak-down"],"value":{"max":9,"unit":"%","note":"commonly quoted, not a standard"},"see":["standards-testing/test-leak-pressure"]},{"id":"test-mpi-steel","kind":"test","tier":2,"title":"Magnetic particle inspection of steel parts (ASTM E1444)","summary":"ASTM E1444 finds surface and slight subsurface flaws in ferromagnetic steel only, not Ti, Al or austenitic stainless. Rods and cranks get 100 % magnaflux at Manley. Radius holes and keep faces open so bath and field reach the fillet.","applies":["crankshaft","connecting rod","piston pin"],"basis":"SRC: ASTM scope page, Manley. EST: geometric advice from how the method works; ASTM limits are paywalled.","sources":["astm-e1444","manley-rods"],"tags":["mpi","magnaflux"],"value":{"value":100,"unit":"%","note":"one maker sampling"}},{"id":"test-penetrant-nonferrous","kind":"test","tier":2,"title":"Dye penetrant for Ti rods and aluminium (ASTM E1417)","summary":"ASTM E1417 finds surface-open flaws such as cracks, laps, cold shuts, porosity. Use it on Ti rods and Al heads where MPI fails; peening can close surface flaws, so inspect before peening (EST). Leave surfaces drainable, no blind pockets holding bleed-out.","applies":["titanium rod","cylinder head","forged piston"],"basis":"SRC: ASTM scope page. EST: sequence and drain advice.","sources":["astm-e1417"],"tags":["penetrant","fpi"],"value":{"value":"E1417","unit":"text"},"see":["turbomachinery/fpi-inspection-test"]},{"id":"test-xray-castings","kind":"test","tier":2,"title":"X-ray and CT of heads, blocks and wheels","summary":"Cast race parts and turbo wheels get X-ray, 3D measurement and penetrant. Radiograph heavy junctions against ASTM E155; thin 3 mm cores and thick seat regions are the risk. CAD: keep junction inscribed circles small and mark critical regions on the drawing.","applies":["engine block","cylinder head","turbocharger"],"basis":"SRC: PBS foundry QC list, Honda on 3 mm cores; ldd entry carries E155. EST: where the risk sits.","sources":["pbs-turbine","honda-42"],"tags":["xray","ct","casting"],"value":{"typical":3,"unit":"mm","note":"core thickness cited"},"see":["load-driven-detailing/ldd-test-cast-radiograph","turbomachinery/ct-porosity-inspection-test"]},{"id":"test-dyno-durability","kind":"test","tier":2,"title":"Dyno durability: what published runs looked like","summary":"MAHLE printed pistons: 200 h bench, about 135 h full load, 25 h overrun, near 6000 km. Honda: 1500 km bench targets, F1 2006 life 1350 km, Cup up to 800 miles. Parts must survive their rule distance, not an infinite life: size to the target.","applies":["race engine"],"basis":"SRC: MAHLE, Honda, EPI. Break-in schedules were not sourced; ring maker bedding wears Rpk, not Rvk. Fatigue margin is the team's call.","sources":["mahle-3d","honda-51","epi-cup-f1","el-honing"],"tags":["dyno","durability"],"value":{"typical":200,"unit":"h","note":"MAHLE bench run"}},{"id":"test-compression-ratio-hot","kind":"test","tier":2,"title":"F1 2026 compression ratio check hot and cold","summary":"CR max 16.0 at ambient and, 1 June to 31 Dec 2026, also at 130 C; devices raising CR in operation are banned. Procedure defined by each maker under FIA-F1-DOC-042. CAD: carry chamber volume at both temperatures, including rod and piston growth. Issue 21 text.","applies":["f1 power unit","piston"],"basis":"SRC: FIA Issue 21 C5.4. Dated rule; later issues may change it. EST: thermal volume modelling as the response.","sources":["fia-sc-i21"],"tags":["compression","f1","test"],"value":{"max":16,"unit":"ratio"}},{"id":"test-ring-gap-bore-square","kind":"test","tier":3,"title":"Ring gap and ring form checks","summary":"Square the ring in the bore (0.500 in down on a 4.00 in bore), torque plate on, feeler check, file in steps, deburr lightly. Each 0.001 in of bore adds 0.00314 in gap. Honda checked ring taper on a jig to 6 arcmin. Rings fit a bore: CAD bore tolerance feeds gap.","applies":["piston ring","cylinder liner"],"basis":"SRC: EngineLabs, CP, Honda.","sources":["el-ring-gap","cp-rings","honda-51"],"tags":["ring","gap","test"],"value":{"typical":3.14,"unit":"ratio","note":"gap change per bore change"}},{"id":"test-bearing-clearance-check","kind":"test","tier":3,"title":"Bearing clearance check, tools and method","summary":"Zero a dial bore gauge on the journal mic; read the torqued housing with shells vertically, normal to the parting line. Instruments must read 0.0001 in; 0.001 in tools are too coarse. Check journals in 2 places per journal; overall accuracy 0.0002 in or better.","applies":["bearing","crankshaft"],"basis":"SRC: EngineLabs, one builder's method. Plastigage not covered.","sources":["el-bearing"],"tags":["bearing","test"],"value":{"value":0.0001,"unit":"in","note":"tool resolution"},"see":["race-engines/bearing-clearance-rule"]},{"id":"recipe-wet-cylinder-liner","kind":"recipe","tier":2,"title":"Recipe: wet cylinder liner with collar and O-ring grooves","summary":"Revolved 80 mm bore wet liner, 5 mm wall, 130 mm long, 6 mm top collar, two lower O-ring grooves and a bore lead-in. Liner sizes are worked-example values; bore matches the 2026 F1 figure.","applies":["cylinder liner"],"basis":"EST: wall, collar and groove sizes are a worked example, not published data. SRC bore 80 mm from FIA C5.4.","sources":["fia-sc-i21"],"tags":["recipe","liner"],"recipe":{"prompt":"Model a wet cylinder liner for an 80 mm bore engine with a top collar and two O-ring grooves","steps":[{"tool":"cad_revolve_profile","args":{"profile":[[41,0],[45,0],[45,8],[43.2,8],[43.2,11],[45,11],[45,14],[43.2,14],[43.2,17],[45,17],[45,124],[50,124],[50,130],[40,130],[40,1]]},"note":"Section about Z: bore R40 with 1 mm lead-in, OD R45, grooves 3 wide, 1.8 deep, collar R50 x 6. Bore finish and tolerance go on as PMI."}],"expect":{"volume":179407.27,"faceCount":15,"watertight":true,"note":"measured 2026-11-04: first pin"}}},{"id":"recipe-piston-blank-pin-bore","kind":"recipe","tier":2,"title":"Recipe: piston blank with ring grooves and pin bore","summary":"Revolved 79.8 mm forged-piston blank with three ring grooves, pin bosses across X, a rod slot and an 18.5 mm pin bore. Skirt form, pockets and ovality are left to later ops. A blank, not a finished design.","applies":["forged piston"],"basis":"EST: every section size here is a worked example. SRC: bore 80 and pin 18-19 mm from FIA C5.4. A real piston needs skirt form and FEA; 2026 F1 pistons must be steel.","sources":["fia-sc-i21"],"tags":["recipe","piston"],"recipe":{"prompt":"Model a piston blank for an 80 mm bore with ring grooves, pin bosses and an 18.5 mm pin bore","steps":[{"tool":"cad_revolve_profile","args":{"profile":[[33,0],[39.9,0],[39.9,26.8],[36.4,26.8],[36.4,28.8],[39.9,28.8],[39.9,30.3],[36.4,30.3],[36.4,31.5],[39.9,31.5],[39.9,32.8],[36.4,32.8],[36.4,34],[39.9,34],[39.9,40],[0,40],[0,32],[33,32]]},"note":"Cup about Z: 8 mm crown, 79.8 OD, grooves 1.2, 1.2 and 2.0 wide, top land 6"},{"tool":"cad_cylinder","args":{"r":12.5,"h":68},"note":"Pin boss bar, built along Z"},{"tool":"cad_transform","args":{"of":"$1","rotate":{"axis":[0,1,0],"angle":1.5707963267948966},"translate":[-34,0,13]},"note":"Lay it along X at pin height Z 13, compression height 27; ends sink 1 mm into the skirt wall"},{"tool":"cad_boolean_union","args":{"of":"$0","tool":"$2"},"note":"Join the bar to the skirt wall"},{"tool":"cad_box","args":{"dx":24,"dy":40,"dz":32,"origin":[-12,-20,-1]},"note":"Rod slot tool, 24 wide"},{"tool":"cad_boolean_subtract","args":{"of":"$3","tool":"$4"},"note":"Leave two pin bosses"},{"tool":"cad_cylinder","args":{"r":9.25,"h":100},"note":"Pin bore tool 18.5 mm"},{"tool":"cad_transform","args":{"of":"$6","rotate":{"axis":[0,1,0],"angle":1.5707963267948966},"translate":[-50,0,13]},"note":"Along X at pin height"},{"tool":"cad_boolean_subtract","args":{"of":"$5","tool":"$7"},"note":"Cut the pin bore through both bosses and skirt"}],"expect":{"volume":91882.6,"faceCount":35,"watertight":true,"note":"measured 2026-11-04: first pin"}}},{"id":"recipe-valve-spring-retainer","kind":"recipe","tier":2,"title":"Recipe: valve spring retainer","summary":"Revolved retainer: tapered collet bore about 7 deg per side, inner spring pilot, outer spring seat. Dimensions are a worked example for a stem near 5.5 mm; take the collet angle from the collet maker.","applies":["valve spring","retainer"],"basis":"EST: all dimensions are a worked example. Collet angle and spring diameters were not sourced.","sources":["motor-valves"],"tags":["recipe","retainer"],"recipe":{"prompt":"Model a valve spring retainer with a tapered collet bore and spring pilot","steps":[{"tool":"cad_revolve_profile","args":{"profile":[[4,0],[8.5,0],[8.5,5],[14,5],[14,8],[10,10],[5.2,10]]},"note":"Section about Z: collet taper R4 to R5.2 over 10 mm, pilot R8.5, seat at Z 5"}],"expect":{"volume":3226.78,"faceCount":7,"watertight":true,"note":"measured 2026-11-04: first pin"}}},{"id":"recipe-poppet-valve-blank","kind":"recipe","tier":2,"title":"Recipe: poppet intake valve blank","summary":"Revolved 33.5 mm intake valve: head, 45 deg seat, tulip and 5.5 mm stem, 95 mm long, sized inside the 2026 F1 limits. Tulip segments are a blank form; replace with blends and add a keeper groove later.","applies":["valve"],"basis":"SRC: head and stem limits FIA C5.4. EST: 45 deg seat, tulip and length; seat angles were not sourced.","sources":["fia-sc-i21"],"tags":["recipe","valve"],"recipe":{"prompt":"Model an intake valve blank with a 33.5 mm head and 5.5 mm stem","steps":[{"tool":"cad_revolve_profile","args":{"profile":[[0,0],[16.75,0],[16.75,1],[14.5,3.25],[6,10],[3,22],[2.75,30],[2.75,95],[0,95]]},"note":"Section about Z from the face up: margin 1 mm, seat, tulip, stem"}],"expect":{"volume":7509.57,"faceCount":8,"watertight":true,"note":"measured 2026-11-04: first pin"}}}]}