So I bought a used LS6 shortblock from a friend of mine, assuming it was ok. I went to pull it apart and found 3 cracked pistons between the ring grooves, so now I'm looking for new pistons. I thought originally that LS6 and LS1 pistons are the same, but I found out that the LS6 has the hyperuetectic (sp?) skirts on them. I have a chance to get a free set of stock 99 LS1 pistons from a friend and was thinking of running those. Is the LS6 piston with the coated skirt that much difference? I was thinking of running the LS1's in it, since it would be harder to find a used set of LS6 pistons.

Also, is there any factors, weight wise of swapping out stock pistons on stock rods? Should I weigh them to see if they all measure within a certain weight limit or something?

 

As for the weight question its always good to have them matched so that the crankshaft is balanced, and for the questions about the LS1 and LS6 pistons I dont know but im interested!

 

The Teflon coating was added to reduce piston slap. On an 18K mile motor that was disassembled the coating had signifigant wear on it already.

 

Both the LS1 and LS6 pistons were both hyper, however the LS6 was a slightly denser alloy. Are aftermarket forged pistons out of the question? I dont see much wrong with running the LS1 pistons, plenty of people are running plenty of power and rpm with them. I am not sure about any balancing differenced, but I dont think the cranks were different from LS1 to LS6.

 

sorry, forgot I posted

Aftermarket isn't necessarily out of the question, but I am trying to keep costs down. I don't plan on race it hard or any power adder, so I figured stock would do me just fine. Plus I don't see it being logical to put a forged piston on a stock rod, IMO, if you go forged piston, mine as well make the rod just as strong

 

So if you have an F-Body that came with an LS6 block do you have LS1 pistons or LS6 pistons?

 

well that's what I'm wondering. The LS6 shortblock I have came out of a 02 Firehawk, so I'm wondering if these are LS1 pistons or LS6? I have a set of 99 and 00 pistons and both don't have the hypereutectic skirt

 

People are pretty quick to jump your *** when you say your f body has an LS6 block, they can't wait to tell you theres no big difference over an LS1 block. Stronger pistons would be an advantage IMO.

 

well i called my local dealership ordering pistons under a 02 Z06 and the guy told me it's the same PN as an LS1? I will probably get some speed pro hypereutectic pistons and call it a day

 

Doesn't surprise me. The LS6 was essentially an LS1 with a diff. cam and intake. Plus, its more cost-effective for a manufacturer to not have to use different parts in the same engine line.

 

The blocks were different too. The LS6 has added oil passages for better cooling

 

True, but the blocks still came from the same casting, no? I think they probably machined out the larger passages and stamped those with the LS6 pn and left the rest as LS1 pn.

 

hmmm, not sure on the castings.

nice sig pic!

 

If your gonna buy pistons and your looking at the speed pros why not get the forged speed pros? they're not that much and it leaves room for you to grow in hp numbers, later on down the road if you choose to do so.

 

because this engine build has gone out of budget so I'm trying to save what little money I have left. Plus I don't plan on going big with the car anymore, it's just going to be a street car, nothing else. That and I think it's redundant to put a forged piston on a stock steel rod, if I went forged piston, mine as well do forged rod

 

ALOT of people make bad *** power with the stock rods, all they do is just replace the rod bolts. So I dont think its redundant, thats my 2cents. Hey more power to ya if your trying to save money, stock pistons work just fine if your looking to drive and enjoy the vehicle. I just think that since you already have the motor tore down just throw them in there. The HP bug can bite you outta nowhere.

 

What kind of power do you plan to make? the stock stuff holds up to 500rwhp pretty good.

But if something is wrong aftermarket will last longer. the main thing is scan it and don't knock it or run it lean and it will live. I have put 38k on my 04 gto spraying a bottle at 150 shot every other weekend since i bought it.

It did lose #2 rod bearing ONLY after putting in arp rod bolts at 37k and blew up at 38k.

Just put a 15k mile short block in last weekend and it has already seen 6800 30 time's and no problems. afr heads ,238/242 cam ,full bolt ons,lt's,fast

The way i see it gm did a damn good job on this moter.as long as you don't detonate it it will live a long time,let it warm up good first and give it hell and scan for kr

 

I plan on 430 to the tires. Like I said, it's got a 10 bolt in it, and will remain just a street car, so the motor doesn't have to be outrageous.

 

Well if you ever plan on taking that thing to the track and hooking that 430rwhp your stock 10 bolt is on borrowed time.

 

Does ne1 read????