LS3s seem to have a problem on a race track

I don'ts got one of these, but this has come up in another forum I'm on and thought it might be helpful to those of you who do.

http://forums.corvetteforum.com/autocrossing-and-roadracing/2824807-let-me-ask-another-way-whos-ls3-hasn-t-blown-up-on-the-track.html

The root of the problem seems to be lack of oil drain back. On sustained high G corners, the oil gets trapped in the valve covers and heads instead of draining back into the pan.

Apparently you can't run and LS2 or LS3 (for long) without dry sumping. The LS6 is supposed to be OK.

The cornering forces of full slicks and high rpms both seem to aggravate the situation.

As I said, I have no first hand experience with this, but since so many seem to want to stuff an LSx into everything except the commode I thought this might be a good data point..

accusump?

LSx in the cammode....Brilliant!

Targa Miata seems to have held up alright, but it isn't a strait LS3, (it is a L33 with LS6 heads i think) and it might have some oiling mods.

Wondering if drainback hoses could run from the back outside corners of the valvecovers down to the top of the oilpan to let the oil drain back that way.

Accusump helps delivery, but not the drain back.

Yes, I'm surprised we haven't seen a commode pit bike powered by an LS

I wonder if external returns would fix it. Braided line that runs from the valve cover to the oil pan.

carguy123 wrote: Accusump helps delivery, but not the drain back. Yes, I'm surprised we haven't seen a commode pit bike powered by an LS

Challeng budget required the use of an LT1 :P

The L33 in the Targa Miata is more closely related to the LS1/LS6 than the LS3. 4th vs 5th generation, although I can't comment on the oiling issues. The Targa car doesn't see a lot of sustained high-g operation either. But we've had no complaints from any of the LS3-powered cars we've built, including Elvis. I'll look into it. I don't know if any of our customers are running slicks and seeing sustained 1.2g (!) as reported in that thread.

Oh L33 how you tempt total destruction of my wallet

pres589 wrote: Wondering if drainback hoses could run from the back outside corners of the valvecovers down to the top of the oilpan to let the oil drain back that way.

Toyota 4AGE.... had similar problems with sustained long left hand sweepers. The last generation 16V 4AGE had a secondary drain in the right rear of the head, then went to a drainport in the side of the block

Taiden wrote: Oh L33 how you tempt total destruction of my wallet

E30 with an L33 > wallet. Just sayin'

That thead might have been the most expensive trail of 1st person gentleman racer cash loss carniage I have read. Mayby I missed the post, but I think the OPs question, and I parphrase, "if you went fast with this motor did your engine NOT blow up?" failed to yield a positive answer. I wish I was the 1% and could post about that sort of loss. Pisses me off. I want to blow up expensive E36 M3.

If oil return is THE issue then it would seem the external return line would solve the problem. Now does anyone have an LS2-3 they'd like to donate so we can run it to death?

In reply to carguy123:

As pressed for time as I am, I'll bite the bullet and chip in my time for this experiment as well.

Yeah my brother has a new LS3 he's putting in his Super Stalker. Research did show a serious oiling issue during cornering, and the only right solution is to dry-sump it. Expensive, but but the only absolutely right way to fix it, and is pretty much the perfect oiling solution... did I mention that it was expensive?

Does this oiling phenomenon apply to all Gen III chevy v8s?

kb58 wrote: Yeah my brother has a new LS3 he's putting in his Super Stalker. Research did show a serious oiling issue during cornering, and the only right solution is to dry-sump it. Expensive, but but the only absolutely right way to fix it, and is pretty much the perfect oiling solution... did I mention that it was expensive?

THEY say the dry sump helps, but does not stop the issue. Oh, they also say the dry sump IS expensive.

Taiden wrote: Does this oiling phenomenon apply to all Gen III chevy v8s?

As I read it, it's only the LS2 & 3.

If an external return line isn't the fix, then perhaps an auxiliary electric pump would.

two lines from each valve cover converge at a pump, and a line exiting the pump leads to the top of the oil pan.

thats sorta like dry sumping.

Dry sump doesn't seem like it would help the top end accumulation issue, since the scavenge pump is still in the bottom of the engine. Maybe the reason it helps is the 12 quarts of oil in the tank you have to run through before it starves, means that it's got enough reserve for any corner.

I was trying to think if there was a way to increase oil capacity in corners only. A dry sump with the external tank would sort of be like that I suppose.

So if the issue is described as a drainback problem why are there so many comments in here about adding system capacity? It could help and may be easier but why not attack the root cause? Polish the lifter valley, add drainback routes like hypothetical tubes, and maybe some light machine work to add volume to drainback routes already in the motor. Right?

yea, what pres said

I'm not familiar w/ them but could there be a breather/ vent problem slowing drain back?

Maybe you aren't supposed to drive Vettes fast????

Campaigned my LS1 equipped 951 all season with no issues. 4 30 minute sessions a day, 6+ weekends...