head decking

[hbhallett]

What would you guys think is the maximum amount of head surface which could be milled off a cast iron head? :confused:

[UBFJ #454]

Depends on the type head, valve sizes, cam lift, piston type/compression, etc..
[ August 11, 2003, 08:19 AM: Message edited by: BEAR_454PE ]

[hbhallett]

454 rectangular port 118cc head with standard valve size and edelbrock performer rpm cam. Pistons are forged trw at about 8.5:1 compression ratio.

[Moneypitt]

We're talking thousanths here. Most machine shops just take enough to "clean up" the surface, usually less than .020. I've ran heads that were cut .045 for performance reasons,(340 Mopar) but I would discuss your question with a well know machine shop for the pros and cons concerning the BBC. Again .010 , .020 , and maybe .030 , would seem within useable limits. The increase in comp. ratio will be minimal, and even .030 shouldn't affect piston to valve clearence enough to be a problem. Be sure to verify that the dist bottoms out on the intake, and not the oil pump drive shaft, as the heads will be a little closer together,(lower) on the block........Moneypitt

[hbhallett]

Money- thanks for the insight!!!

[UBFJ #454]

Agree with money's comments ... why do you want to mill your heads?

[058]

Don't forget to have your intake manifold milled too, There will be a mis-match at the bolt holes.

[Infomaniac]

Most heads can be milled more that you might think. Serious mill jobs are done at an angle.
Small Block Chevy heads can be angle milled to 48 CC's and less. 13:1 compression with flat top pistons.
As mentioned intake manifold machining may be necessary with big amounts.