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WAS WONDERING WHAT KIND OF.clearence`s..
on a BBC... blown alky/nitro 6-71 STD
magIII 30-35 LBS BOOST
steel crank,..steel block,...aluminum rods, forged pistons

main bearing clearence ? oil
rod bearing " " oil
piston to cylinder wall
rod side clearence

thanks
Vic

Vic, I would have to check back in my notes. If I remember correctly the cyl walls to piston are around 26-28 thou.

You want all the clearances a little looser with the Nitro in the mix.

Rapid, That sounds like an aweful lot of clearance to me.

i agree solid,..maybe more like .006-.008 ???
on the piston wall ??

That's what I'm thinking Vic. I'll check my records later today on what I have and post them.
I can't see getting any ring seal with .026 piston to wall clearance. The piston will be rocking in the bore too much to seal.

Good thing we don't build engines from my memory,,,I have it in my notes, but it is in the race book at home. I know I checked it when we were having some Piston scuffing way back with the BBC. Now you have me wondering and will have to look at my notes!

Plus,,,I am on meds for this cold so I do have an out!!

p/w=usually .008 depends on the manufacturer

main=.004

rod= .003-.0035

side=.045-.060 depends on the manufacturer

You are right Wheelz!

With no great suprise, Leon is right. My numbers match his range, except my notes say piston to cyl wall: 8 was normal, with nitro 10-12, and we ran 11 on ours.

I am blaming it on the cold medicine!!

DAY TIME THERA FLU,..NOT NITE TIME NYQUIL...

THANKS GUYS I GOT A GOOD IDEA NOW.

VIC