Steel head shim ???

[art leong]

The pistons are domed with valve reliefs. I sent them back to the manufactureer (JE) To lower the compression. (originally 17 to 1) They cut the valve reliefs as deep as they could without weakening the piston. (only picked up .020) and shaved the dome to reach 12.75 to 1 with the .074 gasket.
With the shim the total thickness will be .105. So I'll pickup about .030, and lose a little quench and compression.
I've used copper shims a lot. And never had a problem. But never used the steel ones.

[Bub Whitaker]

Art... generally if you move the cam, you pick up .005 to .007 per degree/ advance loose on the Intake pick up on the Exhaust.. retard pick up on the Intake lose on the Exhaust. Another solution would be to machine the valve face, combustion chamber side , for additional clearance. My experance on the flow bench has shown that the margin thickness on the intake valve doesn't affect flow...Exh is a different.So if your cam is in the happy place and the int valves are just kissing and your worried about it, then top those intake valves what you think they need...

[art leong]

Originally Posted by Bub Whitaker

Art... generally if you move the cam, you pick up .005 to .007 per degree/ advance loose on the Intake pick up on the Exhaust.. retard pick up on the Intake lose on the Exhaust. Another solution would be to machine the valve face, combustion chamber side , for additional clearance. My experance on the flow bench has shown that the margin thickness on the intake valve doesn't affect flow...Exh is a different.So if your cam is in the happy place and the int valves are just kissing and your worried about it, then top those intake valves what you think they need...

Thanks. If the valves are bent (I don't think they are). I'll have the front side dressed a bit. I don't think they are bent(will pour alcohol in runner to make sure).
I'm running a dual cam motor. The intake cam is a couple of degrees advanced. the exhaust is straight up.
Thats what it liked on the dyno.
If the valves are good I'm just going to throw the thicker head gasket in and race it. I can't run a bigger cam till I design a new piston. (Over the winter)

[Woodro Josey]

Yep excuse me Bub, i am not saying thats the right thing to do, but the amount of flow lost to having bent valves, i think i would face the valves if all else has been tried, either on top side or with a valve refacer, whatever he has access to,! But then what do i know!!!!!!! lol

[Bub Whitaker]

Originally Posted by Woodro Josey

Yep excuse me Bub, i am not saying thats the right thing to do, but the amount of flow lost to having bent valves, i think i would face the valves if all else has been tried, either on top side or with a valve refacer, whatever he has access to,! But then what do i know!!!!!!! lol

You know too much! hope I can retain as much as you've forgotten, but your correct that is the easy quick fix... I'm just use to doing these stocker engines and makin the heads fit the shortblock after it's assembled

[art leong]

Thanks guys. I can't do much with my existing pistons The cam I'm running would check legal in a stocker.
And I'm running a modified production motor class. I talked to JE and they can make a piston for me that will take up to .500 lift with a normal head gasket .045 and have 14 1/2 to 1 compression.
But that will be over the winter.
For now I'll just try to learn the ins and outs of this combo. Then build a killer motor and really learn how to go slow(but I have a head start in knowing how to slow it up)
Thanks again.

[Woodro Josey]

Art, if the valves just lightley kissed the piston, i believe i would look at facing the Valves about .015! Be sure and reshim the springs! You could retard the cam a couple degrees and pick up .005-.007 more clearance!

[Woodro Josey]

Sorry Bub, i hadn't seen your post!

[Bub Whitaker]

no problem Woodro.. however you don't want to face the valves for more clearance as that does affect flow / changes te back side- under head radius- been there...