danbo56

It seem that LS7 motors only fail in two ways:
1. Needle being on the rocker arms
2. Oil Starvation during hi-g corning.
These weak spots both pretty ease to correct.

Has anyone heard of a different cause on an engine failure??

thanks
Dan

dg144

OIl Starvation for me, GM stepped up with a fully covered replacement 2009 engine, 14 days I had my car back running great!

Joe_Planet

i thought the whole point of a dry sump oil system is to prevent the second point....

CanadaGrant

This is BS.
The needle bearing failure on a rocker arm is relative to a small period of time.
It does not cause an engine failure.
If you want to talk about oil starvation at G's just talk to any racer, Mustang, Corvette, or whatever.
Grant

Pistol Champ

Do not worry about the needle bearings I have had 3 failures and mine sill runs great. I'm happy with it every day. This is why they have the warranty.

allanlaw

A few engines have failed due to valve springs breaking. What role the rocker arm problems may have in valve springs breaking is unknown at this time.

Some have failed due to oiling problems, not necessarily related to high-g turns.

zeshawn

not some, 90% due to valve springs breaking, at least there are 19 Z's with NO engines currently in one dealer in Dubai, and about 15 of them due to broken valve springs, some due to oil pump failure.

Now, I think it would be a good idea to upgrade to aftermarket dual springs and rocker arms

Mopar Jimmy

BobDVC8

Allan is correct. VERY VERY few have failed. It is a GREAT powerplant

patton

i recall awhile ago reported valve spring failures but that seems to have died off.....some oil related issues from tracking but i wonder how many blew from OOF [owner occurred fault] not checking oil level

danbo56

I'm considering some mods. The first goal is to addreess the weak spots in the motor. Since a cam, tune and headers will violate the warantee. I'm not gonn try to weasel out of it being my fault if that happens. But, I'd prefer to not blow it up on the track. So, Were are the weak spots?....
Oiling...seems likely. ARE Stage II pan and LPE tank? hummm....
Cooling system? I dont' think ive heard of any issues?
Valve springs, rockers? Maybe good insurance since I'm changing the cam.

I don't know... that's Why I'm asking

Z06LINK

My 07 falls into the group that was having rocker arm issues. I upgraded mine to to some CHE Precision prepped ones for my own peace of mind.

nzk

from what i have read the oil starvation is not during cornering, but heavy braking = 2-4 Gs, much higher than you would see during cornering, which causes enough oil to remain in the heads so that the tank runs dry, hence the larger tanks in 09.

danbo56

Grant
Funny you should say that..... I used to race AS Mustang...now I HPDE a vette. I cant afford to race anymore. Blowing up motors is a fact of life in racing.

Cloaked323

It was and it hasn't totally , I have seen one blow first hand complete with flash fire which is .

C5 Frank

I know of 5 LS7s here locally that have broken a valvespring.... including mine! The other 4 dropped a valve and lost the motor... In mine I felt it right away and shut the car down. Saved the motor!
It is a real issue. Mine is a late production '06, it happened with 14k miles and 100% stock. I was cruising at 50mph in 5th when it happened. GM replaced the one broken spring.... left the other 15 as is. I was told there was a bad batch of springs and that it was not a serious issue.... so my car was proven to have spings from the bad batch.. yet GM did not replace any more springs....
Well I have a GMPP until 2012... so we'll see.

CanadaGrant

Same as the bad rockers. If you read the TSB's, for any other GM motor it says that if a rocker fails the dealer is to replace ALL rockers but on the LS7 they are to replace ONLY the failed rocker. Stupid and then some.....
Grant

CanadaGrant

I know what you mean. I used to be a drag racer but the smile on your face is quickly replaced by the fifteen thousand dollar bill on Monday morning. Especially when your wife sees it first....
Grant

allanlaw

The Harland-Sharp modified rocker arms would be a good thing to do (and fairly cheap) while you are working on the engine. Dual valve springs are certainly safer, but may lead to valve float at higher rpm. This is definitely something to discuss further with your builder.

As far as the oiling issues, I don't think we've had enough experience yet with the larger tanks and modified pans to know if they really cure all of the oiling problems. GM needed more oil capacity for the ZR1 for a variety of reasons, and I've wondered whether they put the same tank(s) into the '09 Z06 just to have the same parts in both models. GM did not change the pan in the Z06. There are various theories posted regarding the oiling problem, so you can believe whatever makes sense to you. Again, if you are working on the engine, then the added cost for the ARE pan and the larger aftermarket tank is not too great, and it certainly can't hurt. I don't know enough about aftermarket oil pumps to comment on that.

If the stock cooling system is working for you (works for me), then I would leave it alone.

CanadaGrant

I think Allan has a valid point here. GM decided to use a larger tank but didn't change the pan. I wonder if the problem is actually in the picpup as it only exists on the track under big G's.
I would install the H/S modified rockers in a heartbeat but I don't want any issues with warranty. The cost is minimal but if GM decides your dropped valve is due to your modification of their product....?
Grant