430 air cooled head mod.

Has anyone machined the sealing lip out so that it is flush with the combustion chamber?

I'm having the squish area machined on my 500 because it's flat, promoting an area for detonation. Are you talking about machining the combustion chamber to extend to the sealing area?

No, just removing the sealing land so it transitions smoothly into the combustion chamber with no step.My current squish measuring with solder is .090.

I'm machining mine 2 degrees. to direct combustion more into chamber. Suppose to help alot with detonation prevention.

At 2 degrees how wide is the sealing land after lapping the head in?

Its from the inward edge of the sealing land towards the combustion chamber.

Exactly, so when you lap the head to the cylinder how wide is the area that is acually sealing?

Is it the full width of the cylinder sleeve?

Yes it is. My machinist actually asked me about machining a "o-ring" on top of the cylinder for better sealing.......? Something to think about if it was a problem. I'm going to use a decompression valve also. I used them on my Husky chainsaws when I was logging, they work good.

Are you going to use the Vulcan Valve?

O-ring plus lapping,HMMMM

Sounds like a wining combo to me.

Do you have any pics of the modified head?