Piston to head clearance
 

Steel rod bbc street engine may see 6500rpm if the owner gets too happy some days.
How close have you ran this without tapping the head?
I usually shoot for .040 but this could run a bit closer.
Thank you

Re: Piston to head clearance
 

I run my race engine at .036. There would be no noticeable difference at .040. There is a lot of variables to this question. Bearing clearance, rod type, wrist pin stiffness, piston weight, piston to wall clearance. All have an effect on deck clearance.

Re: Piston to head clearance
 

In a street engine, I see no reason to
go any closer than 040. I run 050 due to
the fact that I will get carbon build up over
the miles of a street engine that I do not get
on the race cars.

Re: Piston to head clearance
 

Easily runs at 0.042. Might get away with 0.038, but not worth it. You can buy a Cometic to get it exactly right.