Got my stuff back from the machinist the other day and was calculating the compression ratio. I figured the pistons would stick out of the block and well they did by about 3mm.

My machinist said he couldn't find any 3.1 pistons @ .060 over so he gave me low compression 2.8 pistons that SHOULD work. They didnt Well my faith in him is now gone.

You guys have been very helpfull in the past so please help now.

Im looking for a 3.1 cast pistion that will get about 9:1 compression.
TIA

.060" over? Ever considered a new block?

Silvolite 1486's stop at .040's. They are 8.8:1 which is considered the Fiero 8.9:1.

Can you only go .040"? .060" is alot.

block is already back from the machine shop

He told me there would be no prob going .060

If I knew there may be problems I woulda opted for a new block but the cash is really tight so...

why is everyone so scared of the big bad 0.060??? my 3.1 is a screamer at high rpm's!! as for the pistons, it was my first engine so my machinist took care of all the details. wish i could help ya, but don't let people make you nervous on the overbore. it'll be just fine. just upgrade your cooling system for good measure. also invest in some dura lube or slick 50.

doing some more math. I think a flat 2.8 piston withn a 6:1 CR would do the trick. Does anybody make a 6:1?

Please help im getting very anxious to put the motor back together.

definitely flat pistons. i do remember that.

It's not fear, it's the availability of piston for that overbore.

Frankly, if he told you "no problem finding them", tell him to call you when his gets them in. It's his problem. Otherwise, have *him* buy a block from the wrecker (cheap)and bore it to something you can get pistons for. His dime.

The Fiero block is just the dime-a-dozen 2.8L/3.1L 67mm journaled block from 85-9?. Quite a few years. The block from the billions of MPFI A-cars 85 and up(Celebrities, 6000, Ciera's, etc) will work.

Terry

[This message has been edited by terryk (edited 06-15-2000).]

[This message has been edited by terryk (edited 06-15-2000).]

Well talked to my machine shop he said that if I bring my block back and a boneyard block that can be bored he will do the work and supply the pisions at no charge.

Still It would be much easier for me to get pistons to work with what I have.

Mike Calahan at JE Pistons can make you a set of pistons for any bore size and compression ratio that you want. They make all of my pistons for me. But be advised - there not cheap. If your interested let me know and I'll E-mail his phone number.

Arias, and Wiesco will make you a set... from $580-$700 for a set. any compression ratio you want... But if you plan on nitrous stay away from Hypereutetic pistons and stick with a good forged unit. If you gunna put a S/C or turbo on you'll want a lower compression ratio also...

He should pay for the block too, but I guess that's was good as it gets.

Unless you have some extraordinary need for custom pistons, use cast. Silvolite 1486's run about $20 each or less.

Look at www.kb-silvolite.com under Chevy. The 1486 is a 3.1L iron head piston. 8.8:1 compression.

Don't sweat it. Joe Wynmann of associated Auto out of Maryland sold me .060 over pistions with his 3.1 stroker kit. At .060 over, you have a 3.3 I think. He supplied PISA Corp. with their 3.1 kit. Try contacting PISA at www.cybercars.com
I can't complain about being .060 over.

Bad news... Depending how you look at it.

I went back to the 2.8 crank after having little luck at the boneyards

But the engine will be together over the weekend

so im set at

2.8 @ .060" over
ABOUT 9.1:1 compression (I dont trust his calculations anymore)
Crane compucam 2030
Comp Cams springs and retainers
Ported stock exaust maifolds

Just hope it turns out well kinda worried about the bottom end power with that cam and the 2.8 crank but the top end will be sweet

Aren't the PISA pistons 8.5:1 Camaro pistons?

Your 2.8L will run quite nice with that cam.

I don't believe they are Camaro pistons because they are hypereutectic pistons, not cast. hyperuetectic have more silicon in them and can withstand more heat. Also in an article her wrote for Fiero Owner magazine decribing the rebuild in detail he states that an .040 over bore would give you a 9.2 compression ratio and a .060 overbore would put you at 9.3... Even if they are camaro pistons, it's from a 2.8... stroking to a 3.1 should boost compression probably to 8.9 with no overbore.