How much can you mill a stock head?

[gold408fox]

i just picked up a WB1 with a fresh 61X and a protec pipe. I want to bump the compression by shaving the head on my mill.
Anybody out there know how much I should or can take off?

 

[mikidymac]

You really can't just cut the head down. You also have to recut the domes to get the proper squish clearance.

 

[WB800BLASTER]

buy a ADA head from jetmaniac. this way you know its right and you can change the domes for more or less compression.

 

[badvinny]

You can cut the head down, measure with solder first for your actual squish clearance, then mill and be sure to leave .040" squish clearance when your done.

 

[gold408fox]

You really can't just cut the head down. You also have to recut the domes to get the proper squish clearance.

I can recut the domes if necessary I have a CNC mill. I hadn't thought about it really. Thanks this is there sort of input I'm looking for.
Like why shouldn't I spend ten minutes taking the head off to machine it again?

 

[kevbo]

You can mill it down to the edge of the squishband if a stock head gasket is used. You need to make sure the squish is at least parallel with the piston. Many like to cut the squish a degree or two more than the piston crown.

 

[long beach local]

^

You can mill it down to the edge of the squishband if a stock head gasket is used. You need to make sure the squish is at least parallel with the piston. Many like to cut the squish a degree or two more than the piston crown.

I have milled stock heads and use an oem head gasket for my surf motors and they prove to be very reliable setup. Straight cut the stock head maybe .020-.030 thousandths making sure your fingernail will still catch on the lip. Pretty sure I had machinist cut .030 which got me using a stock head gasket about 190 psi compression at 83mm bore. I run 91 octane pump gas but this is short bursts playing in the waves not long full throttle runs.