What Size Head Gasket To Use With Rb25 With Rb26 Internals

[skozza711]

Hey guys just wondering if anyone could tell me the correct size head gasket to use for rb25 with rb26 crank, rods and pistons and I will be running maby around 25psi maby a bit more, I'm wanting to push this engine pretty hard. Thanks

[DR 32R]

RB 25 gasket, then depends on overbore if done. Eg 87mm bore gasket for 86mm rebored to 86.5mm. Thickness depends on calculated compression ratio after ccing the head, and measuring how close the pistons reach the top of the engine block deck. This will depend on the rods and pistons you chose etc.

[Aberax]

I recently had all m parts machined up, RB25 Block, RB26 Crank, CP RB26 86.5mm Pistons. The pistons were protruding from the block by 0.015" on a dummy fit, the machine shop then decked the block which took off 0.004", so now the pistons protrude by 0.019". I think I will be looking at a 1.5mm 87mm head gasket as they don't make 86.5mm.