I am going to buy the GM ZZ4 shortblock. I will need to mill my TrickFlow 64cc heads down to 58cc to maintain the 10:1 compression ratio. I want to know if anyone has had this done? I also want to know how much the intake manifold will need to be milled, if any. Do I need to have the heads angle milled? Or should i just change my pistons? Any feedback from you guys would be great.

 

I have seen a website that has a formula for determining the amount the intake needs to be milled to match with specific head milling amounts.

BTW: A lot of machine shops use a flat belt sander to surface and 'mill' heads.
I am not convinced of the precision of this method of doing the job.
A "real" milling machine is a better way of doing it.
You may want to talk to your machinist and get his input on this.

 

As a machinist myself I can tell you that if the shop has a belt sander for milling heads and intakes you need to run away as fast as you can and find a REAL machine shop that has spent the bucks to get the proper milling machines to do the job properly.

 

never heard of milling with the sanding belt machine. my shop uses it for cleaning up the surface and making it flat. the have a milling set up for really removing metal from the heads. guess i can see where some lesser equiped shops would do that to keep from turning work away.

 

You guys are right.

But, If you live where I do, they think that's the proper way to do it.

That's why I'm driving 150 miles Monday to take my heads to a 'real' machine shop.

Second biggest city in Georgia and NO machine shop here has a Bridgeport mill or any other brand mill.
They ALL (three) have flat belt sanders. How in the world can you do precision 'mill' work with that?????

Thanks for confirming my thoughts.

 

Listen carefully to Dart, ede, and King Arthur: "Run Away! Run Away!

The belt-drum sander approach is used in some places for "trueing" heads in a production line mode, as in "fixing" the typical warped aluminum Misubishi head/gasket failure problems. It might just get you back on the road so you can burn some more oil. It is NOT suitable for sufacing anything on a real engine that could actually have a chance of surviving a round of the odometer.

However far you have to drive to find a real automotive machine shop will be well worth the effort. You might be surprised at how many places will actually do it properly.