whats the most that can be decked off a head?

[asd_gst]

what are the specs on how much you can deck the head, ive read a few threads about decking the head and block and havent seen any specs on how much a head can be decked.

 

[DougR]

You can go untill a valve touches a piston.
But do you want to? When you mill a Head for example. You change the quench area of the combustion chamber.
You also change the way the air fuel charge enters and exits the chamber.

Its generaly better to deck a block then it is a head... Unless you are after a specific Combustion chamber CC. And the only way to check that is with a, Well shoot I forgot the name of the darn tool.

Now if your head is warped. Shure Mill that sucker, But remove as little material as needed to true the head. Im shure with DOHC head there is a warp limit , Due to the cams being on top of the head.

Decking is also the cheap way out of raising compresson. If you can't or don't want to buy high compresion pistons.
For instance, Way back when I built my 4.3 I did not have the funds to buy pistons with all of the other components I bought. So instead I had the head milled just enough to flatten it out and finish it so that I wont be popping head gaskets.
But I also had the Block decked so that the piston tops actually hang out of the block 10thousandths. this brought my compression up to where I was wanting. My builder estimated it at just over 10.8.
Its literaly so tight that Only the thickness of the head gasket keeps me from banging valves. We checked it with putty.
This engine is my whipping post, I beat the hell out of it on a regular basis. And have been for over 6 years now, Seeing rev's as high as 6500. With Zero problems or leaks. now that I say that, It will probly send a rod out the side of the block.

But as for spec's there really is none. That I am aware of.
I'm shure some of the more knowledgeable builders here will chime in and fill in any gaps or correct anything stated above.

 

[asd_gst]

the reason im asking is im building my motor, the head that was one the car is warped way to much to use car over heated which is why im just going to rebuild it. But the 2nd head i have is warped around .011 and i know there are some limits on heads and how much they can be shaved, also will the limit the head can be decked also determine on what cams i use due to the bigger lift from a cam?

 

[DougR]

The cam thing, I was thinking if a OHC head is warped bad enough it might through out the alignment of the cam or cam's causeing unneeded stiction or breakage.