NYOverlord

Hello all. I thought it would be good to have a consensus on what it the power/torque limit on a stock bottom end LS7.

NYOverlord

I have a stock bottom end LS7 C6 ZO6 and I'm putting out 690 hp and 736 tq to the wheels on a Dyno Jet. With the new blower-friendly cam, I should be somewhere around 710 hp.

Is this too much? Where is the horsepower/torque cut-off for a stock internals LS7 before it's in the danger zone and becomes a ticking time bomb waiting to blow up?

croatbob

mine was making mid 700s on pump only. i built b4 it blew. was going strong tho for the 2 years

NYOverlord

What do you mean "I built b4 it blew"? Are you saying you built the motor to be forged/forced inducted?

croatbob

i got a built forged engine and sold the stock short block. i didnt trust the ls7 to handle too much abuse at mid 700s so i got a forged engine built while the stock bottom end was worth selling

schpenxel

That's the smart thing to do for sure.

C6 Curtis

You're fine no one here has pushed it too far yet. They've been in the 800's just fine. The LS7 is forged from the factory besides the Pistons the rods and crank are forged. It can take alot. I'm getting dyno tuned this weekend. I'm going for 850-900 with a single turbo setup on E85.

-Curtis

427ZM

I'm interested to see how yours does on the dyno. I plan on pushing 800whp here in the next month on a 200 shot and race gas. Earlier this spring it laid down 753/771 on a 150shot. Pistons and thin liners are the weak points for sure.

EX1

The cylinder liners is what most are concerned with. I still haven't seen a single rod or crank failure. I've seen failed pistons, rings, and plenty of cracked cylinder walls in hard run LS7s.

Big thing to remember here is most guys making big numbers on stock short blocks only make the engine see that power for short spurts down the highway or some roll event. The question isn't how much power the short block can take, but how long the short block has to endure that power. This is where stronger internals and sleeves come into play.

NYOverlord

So you mean even after having a fully forged motor made and running mid 700 hp, it STILL blew after 2 years?

Black07c6z

No he said he was running mid 700hp for two years on stock ls7 block with no problems. (Pump gas only). But he built a forged block and swap out the stock ls7. Before it blow up.

croatbob

as above. you can sleeve and piston your stock block as they are the 2 weak points but i spent a few more bucks and started with a fresh block and sold my short block. not much more to do it that way then you can throw mad boost at it too. i went rhs but erl or lsx is a cheaper option.

screaminchevy

I ran mine hard for 2 years at 700whp, H/C/N2o and performed great. Even did a couple 1000 mile road trips still getting 30mpg. Anything beyond 750wheel seems to be sketchy territory. Might as well sell the longblock (if it's low miles) for a decent price and build an ERL or RHS if you want to make more power than that. I've heard of a couple LS7's doing mid 800's but I can't imaging those cylinder walls lasting long.

NYOverlord

I'm really hoping not to spend all that money on a completely new motor. I'm only planning on keeping it at 7.4 max PSI and about 710 or so hp at the wheels.
I feel like I will only get about $7,000 for my long block with 20,000 miles on it, and I'm being quoting by LME (Late Model Engines) about $27,000 for a fully forged Dart all aluminum motor with heads flowing 400 and the billet intake manifold. -That's a crap load of money that I'd rather hold onto.

screaminchevy

lol eesh. pretty sure you can come in well below that with ERL or RHS.

schpenxel

Sounds like overkill to me.

NYOverlord

No my friend. Only the crankshaft is forged. True, the connecting rods are titanium, but the position are most certainly not. They are cast aluminum and very susceptible to breaking with forced induction. Also the cylinder lining is another weak point. I'm just trying to figure out at what hp level is the limit. I know that 800 to the wheels is deep inside that "danger zone".
I can't believe you have a stock LS7 and you're making well past that. Only a matter of time. Even an amateur like me knows that.

Good luck and God bless with that set up bud!

NYOverlord

Can you please point me in the right direction? Who can set me up for much less than the $27,000 (including billet intake) for an all aluminum fully forged 427 motor?

Thanks in advance!

schpenxel

Why billet intake?

NYOverlord

LME said the $4,500 billet intake was the way to go because I'll pick up 80 up the wheels. Obviously I'm a bit hesitant to go with theirs when I can grab one from Wilson for $3,000-$3,500. But still not sure I believe those hp gains...