Trimetal Main Bearings Porsche 911 GT3 4.0/4.2

ACL Race Series main bearing set (crankshaft bearings) for Porsche 911 GT3 flat-six 4.0L (3,996 cc) and 4.2L (4,194 cc) engines. High performance trimetal construction designed for high RPM conditions and the severe stresses of motorsport applications.

Technical specifications

• Manufacturer: ACL Race Series (Australia)
• Part number: 8M2435H
• Type: Main bearings / crankshaft bearings
• Construction: Trimetal (SAE1010 steel + copper-lead + nickel barrier + lead-tin-copper P76 overlay)
• Packaging: Complete set for 1 engine, crankshaft front support bearing included
• Weight: 0.7 kg

Designed to withstand high RPM conditions, ACL Race Series bearings feature several technical improvements over standard bearings: high strength overlay plate with reduced thickness for improved fatigue properties, increased crush for improved bearing retention in the housing, elimination of flash plating on the back to improve heat transfer and maximize grip in the housing, increased eccentricity to compensate for bore distortion at high RPM and assist in the formation of hydrodynamic oil films, 3/4 grooved main bearings (270°) to optimize bearing load carrying surface and oil flow to the conrod bearings, tight and consistent wall tolerances for uniform clearances, and enlarged ID chamfers to accommodate large fillet radii on performance crankshafts.

Applications

Compatible with Porsche 911 GT3 flat-six engines:

• Porsche 911 (991) 4.0 GT3 RS - MA1.76 (3,996 cc)
• Porsche 911 (991) 4.0 GT3 - MA1.77 (3,996 cc)
• Porsche 911 (991) 4.0 GT3 RS - MA1.77 (3,996 cc)
• Porsche 911 Speedster (991) 4.0 - MA1.77 (3,996 cc)
• Porsche 911 4.0 - MA1.79 (3,996 cc)
• Porsche 911 4.0 - MA1.85 (3,996 cc)
• Porsche 911 4.0 - MA1.86 (3,996 cc)
• Porsche 911 4.2 - MA1.87 (4,194 cc)
• Porsche 911 (992) 4.0 GT3 - MA2.75 (3,996 cc)

Available part numbers

• 8M2435H-STD: Main Bearing Set - Standard size
• 8M2435H-.025: Main Bearing Set - 0.025 mm Undersize (for crankshaft ground to -0.025 mm)
• 8M2435H-.25: Main Bearing Set - 0.25 mm Undersize (for crankshaft ground to -0.25 mm)
• 8M2435HX-STD: Main Bearing Set - Standard size with 0.025 mm extra clearance (wall 0.025 mm thinner than STD size), recommended for high power applications

All sets include the crankshaft front support bearing. ACL recommends checking availability of the required undersize with the distributor prior to grinding the crankshaft. Sold as a complete set for 1 engine. To complete your order, thrust washer sets are available separately under part numbers 1T2435-STD and 1T2434-STD (the latter specific to MA2.75 crankcase index B or C).