MTFCA Forum

Need to know how much I can deck a high or low head. What is most can be removed and it still seal ok? If you do not want to post here you can send me a email at address in the picture. Thanks Dan

Lots of posts in the old forums

https://www.google.com/search?q=surface ... e&ie=UTF-8

I don't think sealing is the issue, rather piston to head clearance.
I took about .018" of my Jensen aluminum head with no problem yet.

I never could understand why people do that. It seems like a cheap and dirty way to accomplish very little at great risk to reliability. One can remove as much as a quarter inch from a head (I have seen it!), and gain less horsepower or performance than a dozen other minor changes (each) could make. One simple minor costly change to a high compression head will do as much as all those other things put together. The proper high compression heads not only raise the compression more, they also improve the flow of gasses which causes the the engine to gain even more power and high end speed.

How much can be removed? Depends upon the individual casting. The quarter inch I saw? Worked. I saw another one that removed about an eighth inch. And it lost connection to the combustion dome in one cylinder badly enough that compression could NOT be maintained. Significant portions of the web between the combustion domes and the bolt holes was gone all around the poor thing.

Dan, How much can you remove from the head surface is the amount of material available, Measure the thickness of the casting at the water holes. Measure as many places as you can as I have seen core shift were one end of an original head was less than 3/16 at the back and the front was more than 5/16 . I routinely cut them to 1/8 wall thickness at the thinnest with no sealing problems. After machining I always pressure test them because there might be thin areas were there could be local rust pockets that could result a pin hole.