Inliners International Forums General Discussion Hi Performance Flow bench day for the 848 head

Back in the day, they ran huge clearances to cope with the RPM and oil quality. You have to remember these engines have forged steel cranks with a journal diameter of 2.7 on the mains and 2.3 on the rods. Roughly the same as a big block Chevy (bigger on the rods!). Some folks do run BBC 4-bolt main caps. Harmonics are the killer of all sixes. If you can't dampen them, run above or below their ranges. There are Wayne 12 ports out there, you just have to find them. Charlie Yapp gets $3,650 plus shipping for a Riley Model A head, worth every penny if it makes you happy.