94 Galant GS pistons

[Joel91GS]

Yeah, same one. You think the Sonata head is less than 47 cc in the combustion chamber? It would be cheaper to get it milled down maybe 1mm than to buy those expensive pistons.

[mysticj]

Yes, just CC's the head to confirm it.

[Joel91GS]

You know theres not alot of room to work with on that, the valves are right at the edge, almost looks like if it were milled the blade would hit the vavles...

[mysticj]

Well, try a .027" head gasket from Comestic, it should raise compression by .3 and see if you could let .020" milled off the head. If you could, your total compression should increase by .5

[Joel91GS]

Well, try a .027" head gasket from Comestic, it should raise compression by .3 and see if you could let .020" milled off the head. If you could, your total compression should increase by .5

And bring it up to about 10:1!

[mysticj]

And bring it up to about 10:1!

That's if you are not using the Hyundai head.

[Joel91GS]

That's if you are not using the Hyundai head.

So what exactly is the 4g67 head? What model and year is that from? Did mitsu ever use a piston that was higher than 9.5:1 in recent years or are they all pretty much the same like the 2g?

[mysticj]

4g67 = G4CN. Hyunday 93-95 Elantra 1.8L

All Hyundai DOHC heads from 92 to 98 have a smaller combustion chambers than the 4G63. So your Sonata head is just fine.

[Joel91GS]

My car that I sold, had the 10:1 gs pistons that I was lucky enough to get from someone, but I ended up using the 1.6 head.........it worked well, and barely pinged with 87 octane, so I was using medium grade fuel with good results. I really couldnt see a VISIBLE diff from the 1.6 head to the 2.0 or the 1.8.

[Joel91GS]

Check out this site, these are mitsu pistons for a newer model, but see how flat they are. Bet I could get some CR increase out of these huh? I know a guy that has a machine that will mill out a recess of my choice, even can do valve reliefs. I already calculated about how much he would have to take off these to get my 10.5:1, about 1.5mm. I guess as long as the pin fits my rods. 200.00 as opposed to 550.

http://cgi.ebay.com/ebaymotors/ws/eB...m=260575504533

[Galanttuner10]

link didnt work for me

[Galanttuner10]

i found something for ya. a member on here got pistons and a full headswap on here and the pistons read 64SA on them and they were stock on the GS, then i saw a picture of a kid doing the DOHC swap and his pistons say 64SA as well and look exactly the same, granted in the pictures you cant tell every nook and cranny but they have the same exact markings, so i think that the GS pistons got obsoleted part number wise becuase the 96-98 are the same. now the 94-95 have the marking 64S so there may be slight difference between those, but i bet as said before my myself and others, the pistons all have the same compression ratio

[mysticj]

i found something for ya. a member on here got pistons and a full headswap on here and the pistons read 64SA on them and they were stock on the GS, then i saw a picture of a kid doing the DOHC swap and his pistons say 64SA as well and look exactly the same, granted in the pictures you cant tell every nook and cranny but they have the same exact markings, so i think that the GS pistons got obsoleted part number wise becuase the 96-98 are the same. now the 94-95 have the marking 64S so there may be slight difference between those, but i bet as said before my myself and others, the pistons all have the same compression ratio

94 GS has 64D on the pistons, I should know ;)
94-98 Galants have 64SA as well as the Fed Spec Galant for 99-00. 99-03 Cali and 01-03 Galants have 64S.

94 GS=10:1CR
94-98, 99-00[Fed]=9.5:1CR
99-03=9.0:1CR

[Galanttuner10]

its funny, even though there was one year GS they have 2 different blocks used, maybe 64D in one 64SA in the other. all i know is both blocks are now obsoleted from mitsu and can only be found used.


now the GS does have the 10.0:1 compression ratio, but why once we do the head swap do we go from 9.5 to 10.0 then if there was any true difference.

also, the 94 and 95 had one piston, the 96-98 another.

also, i would think that if the GS pistons were special, they would be more expensive, but looking back at how much they charged for them the was a good 10-15 bucks cheaper than the other pistons, so i dont think there is any real advantage to it at all by getting gs pistons.

and that info you gave about the 64S markings is weird as these came right out of a stock 95 galant.

so maybe the markings and maybe little design things here and there, but i believe the overall compression ratio is the same and it is the design of the chambers on the different heads that leads to the ratios.

like you guys were saying about how to bump up CR by different heads with the same pistons that gave that 10.0:1 would be the same idea. i bet if we took the stock gs pistons and put it in the SOHC setup it would retain the 9.5 CR

[Joel91GS]

I just bought them, so as soon as they get here I will try to get a pic of them in here or somwehere you can see them.

[Joel91GS]

Wel no go, they are flat becuase they shortened them to avoid a recess and valve reliefs so no go. Those 500.00 Wisecos are lookin better and better.

[Galanttuner10]

what pistons did you have the GS? as the gs should have 4 reliefs instead of just the 2 on the intak side as the SOHC has. i am going with JE or ross pistons as ive been reading too many piston slap issues with the wisecos but ive always wanted wisecos

[Joel91GS]

These were flattops for newer 4g64 applications. But they ended up being shorter cause they eliminated the reliefs. I just put them on craigslist for 60.00. They look like this

http://img820.imageshack.us/img820/3233/flattops.jpg