Milled head?

[Jhughes7]

I've been doing some searching lately and talking to a few people, I have an oppurtunity to pick up a milled head .30 for my shee. I dont mind running race gas and I have read and heard the arguement both ways about reliability. Does it really affect it? I would like people who have a milled head or know First hand knowledge of them to answer.

 

What about power gain? Milled Head and straight race gas a fairly noticeable difference? Thanks for the answers guys.

[kawiking]

not sure if i know what your asking. i had my head milled .30, i think i needed a top end because i only had 120 compression. so,i ran pump gas !!! a .30 milled head is on the border of 20-19 dome. what u need to do is put the head on and see what your compression is. i had rebuilt mine motor this winter(after shee blew) and i went with a dragport. my compression is 152,so im running 50/50 race/pump... i could probably run pump but im running +5 timing and dragported . i had my buddies head shave .30 and he has 165 compression and he's running 50/50 (he needs to be).

 

so put it on and do a compression test to see where your at. race gas wont help how it runs ,it will hurt the power if you dont need to run it. high compression needs high octane. hope i helped alittle

[Jhughes7]

Yes I understand all that about compression, I am just assuming I will be in the race gas category since my top end is still fairly new and I am at sea level. The question I had is, Is a milled head still as reliable as a stock uncut head.

[5150banshee]

i milled my stock head a little more then that and i have had 0 problems with it i love it

[spike]

I've ran a .030" milled head for almost 2 years without a problem either, I ran 50/50 avgas/91 pump and +4 timing at sea level

its the best 40$ mod i've done to my shee. Go for it!

[blowit]

i milled my stock head a little more then that and i have had 0 problems with it i love it

 

 

You can generally get about .040 off with acceptable clearance but .030 is genreally max without considering race fuels. The major changes really come into improving the specs on the head, not just cutting the deck. The squish angle is criticle for proper performance. You would still be fine with -.030 with stock porting at sea level. More people are more conservative with the compression but we use knock sensing here and have pushed the banshee over 200 psi on pump fuel without detonation. Generally speaking though, 170psi would be max recommended compression for pump fuels and only 4degrees ingnition timing. We have plenty of happy racers using our stock sleeper heads. PM us if interested.

 

Brandon