Thread: Maximum head can be milled?

http://www.nasaproracing.com/rules/performance_touring_rules.pdf

ooo ok i found it page 4

check ebay, i cant recall what brand but im almost posative they sold a .9 hg.

stratton.

A lot of local guys here mill the DE heads 1.5mm without issues.

Not condoning it, but hopefully that answers the OP's question about how much he can go. Heck some guys have taken it to 1.8mm. This is on 10:1 CR high port DE motors. No P/V interferance issues. The DE's have lots of room there since the stock cams aren't particularly high in lift.

Thanks for the info everyone!!!!

Well, I pulled the head off and found that it was indeed warped past the limits outlined in the service manual. So I cut the mess out of it!!!

I ended up milling .030" off the head. I reinstalled and it didn't like that very much. Ran very poorly. Put in a call to my resident SR expert (Thanks Eric96Ser!) and he put me onto a set of adjustable cam gears. An hour or so later we're back running in tip top shape!!

I'm not sure if it's a placebo effect, but it seems like it revs quicker with more authority now..... Haven't driven it yet to see if there's a definitive power difference.

Next up is a way to tune this sucker and to stick it on my dyno!