3.0 Head Milling, How much?

[dirkr]

Blown head gasket, and it looks like one of my heads isn't true anymore, so I'm going to have it milled. I want to boost my compression a bit, but don't want to go too far.

How much should I have them mill off?

-Dirk R

 

[Beef52751]

The machine shop should have a spec that says how much you can safely take of, im not sure about a 3.0 head but when we do SBC's we take it of untill we are about to the edge of valve seats.
Beef

 

[dorman68]

I would want to only do the minimal amount needed to obtain a true surface as these engines are prone to pinging.

 

[fixizin]

I'm no engine rebuilder, or metallurgist... but I've known a few, AND I've stayed in Holiday Inns...

It "sounds" like MAYBE this head *warped* due to overheating, perhaps due to air-bubble/low-coolant condition, and THAT caused the head gasket to leak...?

If so, merely planing the mating surface might not cure other warpage issues... like pushrod binding or other valvetrain issues?

RKIs please set me straight, but would this head be a candidate for Magnafluxing, or other crack-detection methods?

 

[Beef52751]

Good point fixin, have them magnaflux it for cracks first, no sense payin to mill a head and havin it be cracked.
Also mill BOTH heads, not just the cracked one
Beef