Originally Posted by CRX_stg3
The B18C5 is basically just a B18C1 with a B16 head.
That's not the half of it.
Originally Posted by honda_pilot
and thats that. Well done CRX this should be now closed, and used for future archive reference.
Haha, yeah, right. I could write a few paragraphs about what hasn't been included yet. I'll keep it basic:
The C5 has higher domed pistons which bump up the compression enough to still yeild a well higher compression then the B18C1, despite the smaller combustion chamber in the P72 head. The camshafts have a slightly more agressive profile to them, along with upgraded valve springs to prevent float. The B18C5 PR3 head received a very light port job, also helping overall flow. The C5 is given a fat, short runner intake manifold vs. the C1's dual stage inverted manifold, and the ITR also uses a slightly different exhaust manifold. I've also heard from a few sources that the B18C5 oil pump and timing belts are different.