safe minimum - Piston to valve clearance

[jauringer]

Title says it all. I've seen numbers that vary greatly on the intake side. Would like to get an opinion here. 304 non-e if it matters.

Thanks a bunch,
jason

 

[Robert Kenney]

Good question but in the IH sv it won't be possible to create a valve to piston interference issue. This assumes flat top pistons.

Map the over lap period before and after tdc with the 10-20deg after tdc being the most likely to have closer clearances.

.10-.15 is a safe number both vertical and radial..

It is very important to have the cam timing where you intend to run it. Advancing the cam will close the intake distances while retarding the cam will close the exhaust distances. Also floating valves throws all measurements out the window. Run good seat and open loads according to your application. I see 100# seat and 260-290 open reasonable.

 

[jauringer]

Thanks Robert, however, this is a contoured piston engine.

*edit* I misread your number...added a zero after the decimal in my head. .100" is what my machinist used and that's what I wanted to verify.

Your help is greatly appreciated.

Oh and btw: isky dual pattern cam, spring pressure 110/290.

Thanks,

jason