Valve clearances - which is better?

[GrimJack]

Just rechecking my valve clearances after the last rebuild, I've let it heat cycle several times now.

The manual says .006 - .010 for the intake and .008 - .012 for the exhaust when cold.

Question is, what's better, and why? Right in the middle? On the tight side? On the loose side? I've got enough spare shims by now that I can fit it pretty much any way I like.

 

[ms07s]

What I was told is that too tight will lead to burnt valves and too loose leads to valve tapping. The reason for the burnt valve is it holds the valve open a little durring the combustion cycle when it needs to be closed. Better too loose than too tight. I would aim for dead center.

 

[IJ.]

Dave: For my Cams I have em set to 15 then this will allow them to close a touch due to valve recession (I aim for 13 once everything is broken in)

As 07 said I'd prefer some slight noise than burning a valve.

 

[GrimJack]

Appreciate the input guys!

IJ, are you running the same clearance on both sides? I'm still running stock cams, and expect to stay that way for a long time to come.

 

[IJ.]

Dave: Intakes are a thou tighter but due to the non adjustable shimless buckets I don't get too anal about a thou or two either way
(serious PITAS to adjust my motor)

I run it a little looser than the stock spec as I do quite a bit of sustained high rpm driving and it tends to heat the valvetrain quite a bit which closes the clearance's down some and I don't want to risk burning a valve.

I tried a multi/multiangle valve job and found it was leaking on all 24 within a few months so have gone back to a 3 angle with wide seats.