LS3 Pistons and Rods limit
I have purchased a low mileage LS3 shortblock from a 2010 Camaro to replace my current turboed LS1 (347 cui). I am making just over 850 crank HP with my current setup. Stock crank, Eagle rods and Mahle pistons on E85 fuel.
Going to run LS3 heads and L76 intake with 92mm TB on the new engine.
I see people are running over 700 rwhp (which should be around 800 crank hp) on a stock LS3 with just a cam and supercharger. With a perfect tune of course.
Are the pistons and rods on the LS3 THAT good? I know the rods and the bolts are way better than on the LS1...
I was thinking of just putting in forged pistons and maybe a set of ARP rod bolts.... Do you guys think it will hold up at this power level?
I cannot find a suitable piston at Diamond or at Wiseco, most of them are for .927 piston pin and not for .945
I am counting on rebalancing the rotating assembly anyway so the weight is not an issue for me.
If I was going to run something stock on the edge, id do it with a cheap iron block. blowing up a few 4.8s sounds like a hoot
If the limit of the rods is 600 rwhp then I wont run them, but if the limit is say maybe 750 rwhp then they will be enough for my application.
I do understand that forged parts are more forgiving, but if you have a failure in - say the fuel system - it does not matter what internals you have.
My current LS1 was all forged until I had two injectors crapping out on me. The result was one damaged piston (Mahle) and two spun rod bearings that damaged the rods (Eagle) and bent the crank (Eagle).....

I totally agree that it is better to be safe than sorry, but then again it is not needed to replace parts that are good enough?
BTW, this is an Offroad race only vehicle that does not see a lot of running time and the maintenance level is fairly high...
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Wow thats up there for stock components and good to know too thanks. I was researching a boost build a while back and found the consensus of 550 whp to be about the limit for the stock LS1 rods so thats around the 6-700hp at the crank.

Exactly what I was thinking - these rods are strong as hell and there is no reason to replace them (OK, maybe for peace of mind) at power levels below 850 crank hp - at least as long as I am running a turbo which puts a "softer" load on the rotating assembly than a high static compression or nitrous use.
The LS3 is to new to know what the longevity of the engine is at that level. They have seen some impressive levels of power so far but how long will they last?
The LS3 is to new to know what the longevity of the engine is at that level. They have seen some impressive levels of power so far but how long will they last?
LS3's have been out for a few years now...and people have done a LOT to them...10-15 years ago, people weren't messing with "new" cars nearly as much, and info didn't spread as fast...and the ability to make LOTS of power wasn't as attainable to everyone...10-15 years ago, yeah, nobody knew much about a 2-3 year old engine.
The LS3 has enough in common as far as architecture with the Gen 3 and 4 engines before it though, that it hit the ground running with the aftermarket, and has been put through the ringer since day 1 for a lot of people...I disagree that it's too new to know enough about.
The crank har proven itself to 1000+ hp i several LS1's (this is basically the same crank)
Rods: This was my first worry, but it seems that this has been answered.
Pistons: I am not going to push these up there. I believe on the 700+ rwhp stock builds we see these will let go sooner or later. (Probably sooner)
For my application I am not too worried about extreme longevity because it is a race only vehicle.
I am going to run this setup and promise you to post pictures if it breaks apart....
Last edited by Roar; Oct 7, 2010 at 01:16 PM.







