im finally gonna start buying stuff to redo the bottom end and want to know something. i already have le2 heads and will be getting another cam when i rebuild. if i dont plan on using any nitrous do i really need forged pistons? will they help make more power then the hypers? more then likely ill build a 383 but was just wandering about this situation. thanks in advance for any info

 

If you dont plan on running any type of FI then I dont see the point in forged, but if you are building a 383, why not go ahead and get the forged pistons, they arent that much more, and then if you do decide to spray, you can do it without worries.

 

i used to spray the stock bottom with no worries but i doubt ill be spraying after the rebuild. i just want a decent amount of power for if i decide to try someone out every now n then. i bought a mustang(dont cuss me out) to toy around with a lil more since its easier to work on. ill be spraying it n racing it more then the camaro. so i was just wandering

 

If you're sure you're not going to use a supercharger or nitrous later then cast or the high silicone forgings (Mahle PowerPak or JE SRP) are the way to go. Much tighter bore clearances for less noise and better oil control and they last longer. I'd be a little more conservative on compression is I used a cast piston.

Michael

 

I agree with the above - go with a nice high-silicon forging like Mahle or SRP.

Rich

 

For some reason Rich and I seem to march lock step on most things but found the LTX can run much more compression than conventional knowledge would dictate.

Right now I'm in the 12.8 to 12.9 range on 93 octane and did to pull a little drivability timing out below 3000 rpm as compared to the stock timing tables, but above 3000 added more WOT timing with no issues at all.

They say "nothing like excess, to breed success" and wouldn't recommend anyone else to run that much compression, but with the proper tune you can run quite a bit of compression. Depends upon the cam and what your dynamic compression works out to also.

 

Forged.... as has been said the Mahle Pro Packs are the best deal out there for rings and pistons for high performance street motors.

As for the compression, the LT can handle lots of it and it does it quite well. Partly due to the lack of ability for the engine to attain high VE% and the fact that the chambers are not prone to hot spots and detonation.

Bret

 

Bret

Why would the LTx engine be different than any other 23 degree headed small block in the VE% aspect? The intake? Thought it was the reverse cooling heads that accounted for most of the compression increase.

As you well know, the book I get most of my technical data from is titled "trial and error." Somehow though error keeps comming up in caps and can't seem to find the chapter in it regarding VE.

 

ok guys thanks for all the replies. but, i thought it was safe to spray the srp's and mahle pistons? just curious

 

Bret, I noticed you specified Mahle Pro Pack, not the more commonly used Power Pak. Is that difference critical?

I know the Pro Series are a different alloy than the high silicon 4032 used in the Power Pak, and have gas ports. Are the Power Pak appropriate for high compression as well, say 12.5:1?

 

You thought right. Why else would the LS1 have less compression?