Wondering about flat top pistons

[JH]

I am just wondering if there are flat top pistons that will work with a 91 3.1 and if they do is there anyone who makes them?

[RacerX11]

Which heads? Your best bet is aftermarket. Venolia, JE, Ross, Wiseco, or Cosworth all make custom forged pistons to any spec you want. Plan on spending ~$500-~700 for a set.

Marty

[JH]

i hope to put gen3 top end on the gen 2 block

[RacerX11]

You don't want flattop pistons. With gen2/3 heads and flattops, you will get a compression ratio over 15:1. I assume you are asking because you want to raise the compressin ratio. Here are your options using off-the-shelf pistons and gaskets.

stock gen2 pistons, stock gen2 gasket ~8.9:1 (stock 3.1 comp)
stock gen2 pistons, iron head gasket ~9.3:1
gen3 pistons, stock gen2/3 gasket ~9.6:1
gen1 pistons, gen2/3 gasket ~11.1:1
gen1 pistons, iron head gasket ~11.8:1

There are several whom have mixed and matched the stock pistons and gaskets to get higher compression with good results. With custum pistons, you can get any compression ratio you want.

Marty

[JH]

Cool thanks man i guess 15:1 is a bit to high lol. So if i put the old gen 1 pistons in my 91 3.1 block i could get 11.1:1 compression? how much do the gen 1 pistons cost?

[PIKACHU]

I am wonder in that question too!
So I cant find the cheap answer for it...
But the combination of RacerX11 are interesting...

[JH]

Does anyone know what years and cars the gen1 pistons were in?

[JH]

If i did change the pistons and got the compression up around 11 the
computer wouldn't try to compensate by setting the timing back or
anything would it?

[EspanolaGuitarista]

I had no idea...

raising compression could be that simple. Can I go to the local auto parts store and order gen I pistons? I have gen II. I'm not sure. Is the 1995 3100 Gen II? I would suggest thermal coating. This will gaurantee running 11:1 with no problems on pump.

[RacerX11]

The gen1 3.1 pistons were used in the '90-'92 Camaro 3.1, and the early 90's Lumina APV's with the 3.1 iron-head TBI engines. I'm not 100% sure on the exact years, but if you order '92 Camaro 3.1 pistons you should be OK.

Marty

[v6h.o.]

Re: I had no idea...

raising compression could be that simple. Can I go to the local auto parts store and order gen I pistons? I have gen II. I'm not sure. Is the 1995 3100 Gen II? I would suggest thermal coating. This will gaurantee running 11:1 with no problems on pump.

GEN1 90-95 3.1L U-van engine code "d" 90-92 Camaro/Firebird 3.1L engine code "T"

Sealed Power Piston # 562CP
Hyperutectic Coated Skit pistons, available in .5mm, .75mm, 1.0mm, 1.5mm oversized. These Pistons retail for about 330$ canadian$ so i'd imagine they're likely in the 170-250 US$ retail range.

all "3X00" engines are GEN3 Richard.

[RacerX11]

Re: I had no idea...

90-92 Camaro/Firebird 3.1L engine code "T"

Just a note, the gen2 FWD 3.1's were also indicated by the VIN T, but are not the same thing as the Gen1 Camaro engines.

Marty

[JH]

So can you order 3.1 camaro/firebird pistons that have thermal coating?

[v6h.o.]

So can you order 3.1 camaro/firebird pistons that have thermal coating?

why do you think i posted the part number for you....

[JH]

Ok cool thank you just wanted to make sure