i am getting the head on my pinto rebuilt and people say that you can shave the head to boost the compression. but is this a good option, i am also replacing the cam with a roller cam. how will the bottom end hold up with more compression?? how much should i shave off??
and if you have any more info on things to do to the little 2.3l head it would be appreciated........
Another person asked this as well. I believe the response was.030. please someone correct me if i am Wrong on that
No more than required to make it flat.If your trying to raise compression every 30 thou you remove gives you about a half a point increase.60 thou is safe and on a 9 to 1 motor that gives you around 10 to 1.Hope that helps.
i just got my head off and correct me if im wrong but isnt the stock 2.3l in my 1980 pinto suposed to have flat top pistins?? and how hard will say 60thou be in the bottem end....the car only has 98,000mi on it, will i still get a pritty long engine life? and do i have to get shorter bolts?
you can take a lot off of these heads, all depends on what kind of fuel you want to run. the more compression, the more octane you need. I would think .030 if you want to run regular or mid grade. Also, don't forget about your cam timing. when you cut the head, the cam timing will be retarded, so any compression power gain you get will be lost and it will be a slug on low end. Read my post called "cam timing 101". A lot of people just refuse to beleive how important cam timing is and how much difference it can make in how your car performs.
You should have flat top pistons, turbo cars had dished pistons.
.060 won't hurt the bottom end unless you run cheap gas and it detonates or "pings"
Then your stock cast pistons are going to say bye-bye
You don't need to shorten the bolts until you get to around .125"
well i got the head off and the pistons are dished...i thought only turbo cars have the dished pistons???? and my pinto is not a turbo. ok well i think im going with .060 is there enything els that i will need to do if i shave the head???
The mini-stock boys mill up .150 off the iron heads. They stop when they get to the bolts for the intake. The more you mill, the better the gas has to be. Every thing in life is a trade-off.
Are your pistons a single dish that covers most of the top or 2 separate valve reliefs? With a 0.60 mill you will definitely need an adjustable cam pulley to correct timing. Also, have you priced the milling job? Most machine shops can't mill much more than 0.15 in a single pass, so multiple passes add up dollar wise. Ask first so there's no bill shock. My $0.02. JT
the pistons have 2 of the dishes. is that good or bad???
Sounds like valve reliefs but I don't remember the 2.3 having them. Can you post a pic?
Most all 2.3s had valve reliefs. 71-74 2.0s were true flattops. IIRC the 79-80 turbo 2.3s had two relief forged pistons with around 9.3 compression. Another $0.02.