Roar

iTrader: (2)

Hi, maybe this have been covered but I have searched for hours without finding what I need...

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?

raymond mckinney

iTrader: (4)

Diamond makes a no balance piston. I would like to know who and how much power people have broken the stock pistons also.

Roar

iTrader: (2)

I have found that JE makes a piston that will fit straight onto the stock rod, bore and crank.

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.

dimetweaker

iTrader: (1)

I started with a L92 myself and thought I would test the power limits then build it. I read plenty of times people were getting ridiculous power and couldnt find much LS3 breakage on stock parts. BUT... Then I started pricing it out. Pistons and rods from wiseco for $1500, and a little machine work and gaskets, bearings, cam, etc I was in about $3000 for my build using the stock crank. So, now think about if you run it stock and blow it up, same price as my build, AND if you trashed the block, $1200, and if you trash the heads, $800 ( okay, usually just one head, so $400 ) , oh, and the crank? and maybe an oil pan depending... you see where im going. if you have deep pockets, run it until it blows and then build another. But for me, I decided to just spend a little money up front for insurance and not have to spend that, plus more later on a block etc once the thing pops. I was thinking about "that one bad tank of gas" or just some little hick-up and your spot on tune doesnt mean so much. Forged rods and pistons will be a bit more forgiving.

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

allblowdup

I have a set of brand new diamond pistons that are dished 9.5 cc for the ls3.

Roar

iTrader: (2)

I was not planning on running it on the edge, but the "limit" of these parts is interesting because of what I have read the LS3 rods and rod bolts were completely redesigned compared with the LS1 rods. (full floating piston pins and 4340 bolts)

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...

cam

iTrader: (9)

I have no idea of the power limits of the LS3 rods but I can tell you this much. They look to be at least 3 times the quality of LS1 rods on a visual beefiness factor. In fact so far everything I've seen for LS3 internals looks stellar in comparison.

smokin91rs

iTrader: (16)

im looking for more on this too. im running a l92 bottom end, looking at putting a 200 shot on my g6x3/ prc heads or possible boosting it 700rwhp ish goal. everything i see is these ls3 are living well at 6-650rwhp ? if i boost it it will be e85 tuned my car is a weekend warrior. about 5kmi a year and it gets driven.

Roar

iTrader: (2)

That was my thinking too. Also since they have upgraded to full floating pins and 4340 bolts with a special design to reduce bolt stress they should be hell of a lot tougher???

hellbents10

iTrader: (10)

With a good tune and good fuel the rods will let go first at about 950hp at the crank.

cam

iTrader: (9)

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.

Roar

iTrader: (2)

Thank you

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.

Gordon0652

iTrader: (4)

I ask this myself the same thing as the OP when i read about these 750rwhp builds on stock LS3 short blocks. Seen above "rods will let go first at about 950hp at the crank" thats great and all - and the LS1 can make 750rwhp on a stock short block also. But here is the question For how long?
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?

Mike454SS

iTrader: (4)

Too new?

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.

Roar

iTrader: (2)

The block gives me no worries at all- from what I can gather the LS3 block is identical to the LS9 except for the oil squirters and steel caps. The strength should be way greater than the LS1

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....