Valve Guides Loose????

cpac

CPAC
Joined
Mar 21, 2006
What Is The Maximum Stem To Guide Clearance You Can Run On 109 Ported Heads With Bronze Liners Before It Affects Performance
 
Hi,
With bronze guides, you can go a little tighter, but I would say 0.001 is your benchmark. If you are doing a cheapo job, and don't care about valve wobble,and subsequent oil control problems,may be as fat as 0.009 is acceptable.
 
.001" is way too tight on a turbocharged application especially on the exhaust. With the heat the exhaust valve sees it's possible to stick the valve in the guide with less than .0015". If you shoot for .0015 -.002" on the intake and approx. .0025" this should work fine.

Neal
 
Yep!

.001" is way too tight on a turbocharged application especially on the exhaust. With the heat the exhaust valve sees it's possible to stick the valve in the guide with less than .0015". If you shoot for .0015 -.002" on the intake and approx. .0025" this should work fine.

Neal

X2..:biggrin:
 
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