blazin

Is this safe to do....I would normally run 10-14psi on the street but up to 20 psi at the track on C16 occasionally?Also do weisco 9:1 forged pistons have any known probs/weaknesses?Thanks

Speed PHreak

As long as you've got a standalone. Tuning is your friend, any detonation at that amount of boost = bye bye sleeves.

But it can be done. St00pid has run 20psi through a stock blocked LS engine. Then again he's a pretty nasty tuner.

333

I'M running 81.5 mm at 19 psi and 9000 rpm. No problems yet. pulled only 333 fwhp. Greddy 18 g

hybrid901

I'm running 19-20psi on a 81.5mm bore. Its just a matter of time.

blazin

servion

matter of time... before they go? Are ou talking in the sense of "the fact that we're using our motors for performance reasons makes tem wear quicker" or is it due to the overbore? I.E., what kind of boost (or should I say HP) can get from a unsleeved block with this overbore?

servion

any advice?

boostaholic

He means running at that horspower level, the slightest bit of detonation will crack the stock sleeves. People have ran 500whp on stock sleeves. It's just a matter of good tuning and good engine building.

ekb18c

It can be done but it wont last too long.

You can tune the **** out of the computer but remember cylinder pressure is still cylinder pressure. So eventually the sleeves will give way because they weren't built to handle all the pressure for an extended period of time.

You can play it safe by retard the time so much and then dumping fuel in to make it super rich but then you wont be making the power that you should be making at the boost level.

Remember it's not how many psi's of boost, it's how much hp can the stock sleeves hold up. You can be boosting 21 psi on a stock block but only make 300whp, in this situation the stock sleeves can hang maybe. However, if on a different block and your are still boosting 21psi but making over 400whp because you were more agressive with the ignition and fuel table then that's a different story because of cylinder pressure. There is more cylinder pressure from the later example as compared to the first example.

In the end it's a gamble that I wouldn't take if it was my daily driven car because I wouldn't be able to deal with the down time. If however you have another car to drive around while your car is down then go for it. Just make sure you have a good and experienced tuner that can do it.

servion

Is there a decided hp level that stock sleeves can handle (given proper tuning)?

Mr. Softee

at least throw a block guard in there or something if you want to boost that much

servion

well... when there are sleeve problems.... to they usually/ever happen up top? Will a blockguard do any good?

ekb18c

Get iron ductile sleeves from GE. end of story.

93LSivic

Or Darton

Darton has step decks now too!

servion

Well... I'm doing a mild build now.... I will sleeve it, but when $$$ is more plentiful. I'm just trying to evaluate what hind of power I can get out of a mild build until I build her again and do _everything_

E-Rok

I personally wouldnt bore stock sleeves, it just makes them weaker, as if they arent weak enough.