good or bad idea to mill the head .020 off? how much compression gain am i looking at? <br>

97 cav RS...16.6 @81...having traction issues...need help!

Not sure...I know that on the DOHC, you could run into timing chain tensioner problems...the tensioner has to take too much slack out of the chain. Not sure about the 2.2 though. <br>


99CavyZ ~ Black ~ 5-Speed
"If It Bleeds For A Week Straight, How Come It Doesn't Die!?"

i asked a man working at an automotive machine shop, and he said that he won't ever take more then six from stock on aluminum heads. that is .006 of an inch. that is all i know about it, and twenty thousandths sounds a bit high anyway. but i could be weird.

I am looking into it. I would like to take at least 40thou off hoping to jump .5 in compression. I havent heard of anyone on here doing this as of yet. I would love to get a little feedback if anyone has done it.



<br>

I feel sorry for people who don't drink. When they wake up in the morning, thats as good as they are going to feel all day. ~ Dean Martin

by milling the heads on a cavalier, you might only see 5hp, Its not worth it. If you want to raise compression, get different pistons.

i machined 30 thou. off mine . . . and have had nothing but problems with timiing ever sense . . . . it destroyed a brand new set of pistons and rings by 230km!! dont machine the head!

natedawg.... I think that my situation is a little different... I have a 2200 not a 2.4.



<br>

I feel sorry for people who don't drink. When they wake up in the morning, thats as good as they are going to feel all day. ~ Dean Martin

I'm pretty sure that even if you are milling it for a rebuild, you should only take off as much as necessary to make it flat. I would go with pistons to up the ratio. <br>

Graden wrote:I am looking into it. I would like to take at least 40thou off hoping to jump .5 in compression. I havent heard of anyone on here doing this as of yet. I would love to get a little feedback if anyone has done it.

You haven't heard of anyone milling the head by .004 because no one is dumb enough (so far) to destroy a head intenionally like that.

If you want some feedback, look in a Haynes, Chiltons, or GM factory service manual. The specs for warpage are listed in each one of these manuals.

<br>

Randy
1995 2.3HO Swap Turboed Z24 220.2HP,208.3TQ @the wheels, 7psi
1995 2.3HO Swap Sunfire GT, destroyed by an old lady R.I.P. 2/5/04
2002 Rally Yellow LS Sport Coupe Ecotec 5-speed

cut this out of an article. Here is your answer.

A maximum of .020 can be removed without compromising the effectiveness of the tensioner, claims Olds literature. Be cautious though: a 2.3 head on a 2.4 block can send compression skyrocketing without a custom set of dished pistons; carburetor conversions or ECM modifications can also help a stock 2.4 bottom end live with a 2.3 head.

if you are interested in taking the head off and not milling the head then you should find a place that offers a thinner head gasket, that will pick up the compression a little

95nosz24 wrote:

Graden wrote:I am looking into it. I would like to take at least 40thou off hoping to jump .5 in compression. I havent heard of anyone on here doing this as of yet. I would love to get a little feedback if anyone has done it.

You haven't heard of anyone milling the head by .004 because no one is dumb enough (so far) to destroy a head intenionally like that.

If you want some feedback, look in a Haynes, Chiltons, or GM factory service manual. The specs for warpage are listed in each one of these manuals.

forty thousandths of an inch is .04. you wrote four thousandths.
anyway, i do agree with you. that is stupid and would be destroying a cylinder head.
go for the pistons. don't mess with the head unless it got hot and ya warped it. just my opinion.

dont mill to increase compression, mill only to clean up and change pistons for compression...

if its a z24, dont make it into more of an interference engine than it is...

and if its a 2.2 ohv, dont turn it into an interference engine to begine with... <br>

My bad, I meant .04" not .004"

2.3's are interference engines
2.2 OHV and 2.4's are not interference engines

<br>

Randy
1995 2.3HO Swap Turboed Z24 220.2HP,208.3TQ @the wheels, 7psi
1995 2.3HO Swap Sunfire GT, destroyed by an old lady R.I.P. 2/5/04
2002 Rally Yellow LS Sport Coupe Ecotec 5-speed

95nosz24 wrote:My bad, I meant .04" not .004"

2.3's are interference engines
2.2 OHV and 2.4's are not interference engines

the 2.4 IS an interference engine....

the 2.2 ohv isnt, but if you mill the head too much, you can easily make it into one. <br>

General Schwag (Event) wrote:

95nosz24 wrote:My bad, I meant .04" not .004"

2.3's are interference engines
2.2 OHV and 2.4's are not interference engines

the 2.4 IS an interference engine....

the 2.2 ohv isnt, but if you mill the head too much, you can easily make it into one.

Wrong, 2.4 is not an interference engine, check your specs.

The valves sit up higher in the 2.4 head due to the larger combustion chamberthan a 2.3. Along with the cam lift being shorter than any 2.3. Open an intake valve all the way on a 2.4, lock the cam gear and turn the crank by hand, the pistons won't hit the valves.




<br>

Randy
1995 2.3HO Swap Turboed Z24 220.2HP,208.3TQ @the wheels, 7psi
1995 2.3HO Swap Sunfire GT, destroyed by an old lady R.I.P. 2/5/04
2002 Rally Yellow LS Sport Coupe Ecotec 5-speed

ever change the water pump on the 2.4 engine?

if you dont do it right, the 2.4 pistons WILL say HELLO! to the valves....

email Denny Boyles and ask him...

from my understanding, and interference engine is when if the chain breaks, they pistons and valve will interfere. denny;s 96 2.4 L certain did that with the water pump install. <br>

General Schwag (Event) wrote:ever change the water pump on the 2.4 engine?

if you dont do it right, the 2.4 pistons WILL say HELLO! to the valves....

email Denny Boyles and ask him...

from my understanding, and interference engine is when if the chain breaks, they pistons and valve will interfere. denny;s 96 2.4 L certain did that with the water pump install.

Re-read my last post.

Yes, I have changed water pumps, cams and built 2.3 and 2.4s along anything else you can think of with a 2.3/2.4 We have 4 2.4's and 3 2.3's in our shop right now. Just stick to playing with your 2.2.

Call your local GM Dealer and argue with one of their hacks, or better yet read a manual and interprete the specs.

Off to Tennessee for NHRA, have a good weekend.......

<br>

Randy
1995 2.3HO Swap Turboed Z24 220.2HP,208.3TQ @the wheels, 7psi
1995 2.3HO Swap Sunfire GT, destroyed by an old lady R.I.P. 2/5/04
2002 Rally Yellow LS Sport Coupe Ecotec 5-speed

I was told that milling a head to increase compression no matter what car you have is never a good thing. <br>

2004 Grand Prix GTP (Competition Group)
SOLD-->1999 Z24 5M-#30 to register on JBO
"You can please some of the people some of the time but you can't please all the people'
all the time

way to be a dick randy... good job! sorry, but i have seen things go wrong.... hence the reason i said what i did.

if its not then its not.

Quote:

Just stick to playing with your 2.2

if you only knew.... but nice guess <br>