No Juice

iTrader: (11)

I want to hear from the engine builders who build and tear these things down. Plan is to boost one with about 16-18psi, and I'm not concerned with the parts in the block, its more with the block itself.

Are the cyclinders moving around? core shift? warping?
Are you getting odd wear on the cylinder walls?

Lets hear it

Detoxx03

iTrader: (14)

A friend of mine has been pushing 1145rwhp through one for 3 years. Still running strong.

No Juice

iTrader: (11)

Any details on the build? Compression? Crank? Pistons? Boost?

How many miles does he have on it?

my bandit

iTrader: (10)

I was always told to stay stock stroke if you are planning to boost due to the piston skirts going too far out of the cylinder. If a 418 is just as reliable as a stock stroke, then I dont see why people wouldnt go with the extra little bit.

Cold Zero

iTrader: (1)

With the amount of boost you are looking for it will be fine using LS3 block but make sure :-

- Crankshaft 4" or lower
- Piston rings gap for FI application
- Correct quench area
- Proper head gaskets (Alot of FI guys are using the LS9)
- Aftermarket Heads for thicker deck or LSA/LS9 Heads

my bandit

iTrader: (10)

I agree on all but the bold. Why not the stock LS3 with head studs to prevent lift? Granted the LSA heads are rotocast so they are heavier and less prone to heat transfer.

Detoxx03

iTrader: (14)

His compression is at 9.5 and he's running a dragonslayer crank with custom diamond pistons. His highest settings hits 18.5 psi

Cold Zero

iTrader: (1)

Aftermarket castings are thicker (3/4" vs 3/8" I believe, and some as cast may go to 0.800"). And It is not about the thickness, but the material used in those casting which way better than OEM. LSA OEM heads have been proved to have better materials than other OEM castings.

Anyhow, nothing wrong with LS3 stock heads, but the OP is talking about "Durability/Longevity". To save the block you have do other things right.

Detoxx03

iTrader: (14)

For a blower setup I would absolutely stay stock stroke just because of the issues with snapping the snout of of the crank. Another friend of mine is running a forged stock cubed LS3 setup at 10.1 compression with a D1SC and 150 shot.

Ari G

iTrader: (25)

The tune has to be correct and they will last if done right on the machining and assembly part

Stock stroke cranks have more overlap then stroked ones and hold up to 1000hp,if you want to do things right get a center counterweight crank that is what most cheap out on and bites them in the *** later down the road.

The block itself Is allso a limiting factor at 1000hp mark with stock sleeves

Jimbo1367

From what I read, the better LS heads, LSA/LS9/LSX , have 5/8" thick sealing surface.
Whether this is true, who knows.

No Juice

iTrader: (11)

All good info here, but lets leave the head discussions out of it. Still looking for those who have torn them down after a few years of boosted abuse to see how they fair.

Ari - are you talking 1000 fwhp or rwhp?

thewrx

iTrader: (1)

i was thinking vehicle weight would be a factor in this equation.

Tuskyz28

Ari..... good info bro about the stock sleeves. Most guys don't think about the sleeves. On the other hand while you brought that up a darton sleeved 5.3 aluminum can take up to 1500 hp is what I been told.

Ari G

iTrader: (25)

There is no x number just an estimation some have 1000rwhp and last a while but after sleeving they can take more abuse but oem main caps are weak at that

A blower setup is harsher on the crank and you need to make more cyllender pressure with it to match a turbo setup for the losses so with that in mind

Cast iron blocks 5.3 and 6.0s are the best choice for boosted and nitrous stuff because of their rigidity in the cyllenders