tollway bandit 1

iTrader: (2)

This winter I am going to put rods and pistons the my motor. Its a C6 with a procharger on it. The stock short block isn't going to take much more. I already has 6.100 CompStar rods. I want to put Wisecos in it for sure. I don't want a low CR. I would like to stay in the 11.to 11.5 range. Can this be done with a off the shelf piston or will I have to have a custom set made?

Dark Shadow

you have a supercharger and you want a high CR is this a joke? y would you want to do that

Tom@SpeedInc

iTrader: (5)

Certainly, what we have done often, use a 1.304" compression height wiseco piston and deck the block .020" in conjunction with a .030" or .040" head gasket. We've built plenty of boost motors this way.

With a flat top piston (wiseco) you would maintain the 11:1 compression

let me know if you have any questions

Sales2@Texas-speed

iTrader: (5)

I'd sell the 6.100" rods and get some 6.125" to make this easier on yourself. Wiseco doesn't have a great assortment of pistons for use with stock stroke and 6.100" rods. Most all of them will need you to deck the block a ton as Fraser stated (who wants to deck the block .020" anyway?).

tollway bandit 1

iTrader: (2)

I would think it would be good to have the piston pin lower in a FI motor, so the ring lans can be thicker? Thats why I have the 6.100 rods.

tollway bandit 1

iTrader: (2)

No joke and it will take less boost to make the same power.

Sales2@Texas-speed

iTrader: (5)

That's good theory, but the pin will still be at the same place in the piston not moved down (unless you go custom piston) because Wiseco doesn't have a piston for this exact application as shelf stock. That's why you'll have to deck the block so much, because the pin is placed for the 6.125" rod and without decking the piston will be way in the hole.

Full-Force

iTrader: (11)

thats crazy, hell the extra boost you can run is going to far outweigh the benefits of higher c/r

in the end, cylinder pressure is cylinder pressure so you can go either way

i still think lower compression ratio and more boost is better because under normal driving is where you spend 99% of your time and i would much rather be driving around on a low compression motor than high

tollway bandit 1

iTrader: (2)

Thanks, thats what I was thinking. So, if I went with a custom piston with the 6.100 rod. The piston would be very strong?

tollway bandit 1

iTrader: (2)

I have driven cars that have 8.5/ 9.5 motor and they are a dog intill the boost gets there. The air charge should be better with lower boost, so that should it less likely to get detonation. Your right about the cylinder persure.

JL ws-6

iTrader: (50)

If you want to order a custom piston, you can run any rod lenth you want within reason.

Wiseco may not have a shelf piston that will work, maybe Diamond does, possibly mahle or jE does.

I'd do some more looking around. You certainly don't want to deck the hell out of the block, doing that is moving everything lower in the block, towards the bottom of the sleeve which isn't a really great idea, also decking that much off the block is bound to cause some alignment issues with the intake on the heads, pushrod lenth is gonna change, all that crap.

And to answer the question about how strong the piston will be with a 6.1 rod, yes it will be strong that's not a problem, with a 6.1 rod you'll have a good bit of room to put the ring lands down on the piston, the pin will be farther away from the bottom ring too, which never hurts.

Sales2@Texas-speed

iTrader: (5)

Yep, that might be the way to go! Diamond also doesn't have a shelf stock piston that will work unless you bore thew block a good bit (.030" IIRC).

tollway bandit 1

iTrader: (2)

Thanks for the info. Looks like a custom set it is. Who can I go threw for them?

Sales2@Texas-speed

iTrader: (5)

We can help. Diamond can take care of it by modifying one of their shelf stock pistons (compression distance). Were you planning on a 4.005" bore??

Tom@SpeedInc

iTrader: (5)

Its good when you have someone bringing you a used block, get the deck straight and fit the pistons at the same time.

Sales2@Texas-speed

iTrader: (5)

I find it fairly rare to have a used block that needs .020" to be flat.

racer7088

Yes if all you want is a CH change Diamond can do it but you have to wait for it. I do this with Diamond a lot. There is a charge but it's not like a full custom.

NemeSS

iTrader: (127)

if a really strong piston was needed,
wouldnt a on center 6.0 rod
1.425 compression height and stock stroke be a better option for strength
all lh pistons

tollway bandit 1

iTrader: (2)

What the cost of a custom piston set?