Milling heads and getting thinner head gaskets
 

Hey all,

I'm getting my heads milled and getting some thinner Cometic head gaskets. What's the limitation where I'm going to start running into issues with intake manifold fitment? I'm going to .040" head gaskets from the .054" stockers. I'm assuming that the thinner the head gasket the less I can mill. If that's true, then what's the maximum amount I can take off between the two?


Thanks in advance for any help! :)

I have mine milled .024 and run the .040 Cometic gaskets. Everything fit just fine. How much of a mill do you have in mind?

my heads were milled about .040.and i went with a cometic .045 gasket.no fitment issues.but i'm sure it will vary from motor to motor....

We run into problems with .055 milled on stock gaskets.The intake doesn't sit right.

I was hoping to mill about .040" off the heads and run the .040" gasket (thus taking off another .014". Based on what Slowhawk is saying, that's pushing it. Perhaps taking off .030" would be safe with the .040" gaskets? (Total of .044" taken off)

thats what im doing :)

Have you actually done it yet? Any success?

Can anyone tell me what I can safely mill off my heads with .040" gaskets? Is .030" off the heads and a .040" gasket (thus .014" off the stock gasket) acceptable? I imagine that would be the same as milling .044" off the head with stock gaskets.

im in the process but car is off road till spring

there is a maximum and someone will answer soon i am sure. This question has been asked b4. and it seems like .03 was the max witha stock gasket but i can't remember.

Bump because id like to know also

I called TSP today and asked them. Zack told me that I could safely mill .040" and use the .040" gasket. I (to clarify) asked him if he was sure it was okay to take a total of .054" off the bottom of the heads. He said yes.

Anyone want to comment on this? I'm doubtful, and I need to let my machine shop guy know how much to mill pretty soon.

Even if it doesn't line up, take a cartride roll to the intake manifold and a carbide bit to the runners and make them line up.

Ben T.

Im also goin 030" mill and .042 gaskets. Im goin to use the mr gasket gaskets. ET performance told me they have taken .030 and .040 off before, typically they do .030 though.

I'm not sure what exactly you mean. I was wondering if the manifold could be modified to deal with fitment issues, and I'm definitely willing to do a little modification.

When you have fitment problems, how do they usually manifest themselves? Bolts won't go in the bolt holes? Manifold won't sit down all the way? Intake ports on the heads won't line up with the manifold? All of the above?

What exactly would you do with the "cartride roll" and the carbide bit to make it fit properly?

I'm sure I could figure all this out when the time comes and have it work out for me, but I'd like to be prepared and know what to expect.

he means port match the heads to the intake.

whats the largest cam one could run without flycutting the pistons with the heads milled .040

You might have to "shrink" the alignment pins a little to get it to line up, but the intake bolts should go in. If not, don't force it. If the ports don't line up well, they could be adjusted by port matching the two.

tbick, there will be no black-and-white answer for that question.

Ben T.

Is port matching something one can do for himself? Or does this require special equipment? Can you give me a brief description of how it's done?

Ive got .040 off my heads with a .054 gasket. Rule of thumb is that at around .050 you run into intake gasket fitment issues, but then again simply replacing the smooshed and cooked rubber will likely fix that easily enough. Once you get past .050 you may start to hurt head flow according to some big name porters. I wouldnt think it would plummet, but something to keep in mind.

For portmatching, I made a rubbing of the head ports and marked where the edge of the head sat. Then i placed the intake on and marked where that sat on the other side of the paper. Then pull the intake and you can line up the paper to where it sat on the intake and kind of feel if the ports are aligned with the rubbing marks on the paper. sorry if thats confusing, but its actually quite easy. I dont think youll be far off enough to make a big difference.