carlvr

Now that I have vented a little, let me describe what happened
Maybe its not the cars fault, maybe it is.. Let see
I am fairly new to the Z06 and have owned it for about a year. it has 40 k miles on it, its a 2006.
Engine has been built by a reputable company 2 years ago.. Full engine job, Scat Chevy Ultra Q-Lite Stroker Rods, Manley Pistons, Ported heads, valve job, valve springs. Basically everything.. The engine should be bullet proof. Conservative cam, only 500 whp, but good torque

Fast forward to yesterday. Car is all set to hit the the track.. Brakes ready, tires ready. Everything seems fine. Track is Inde Motorsport Ranch.. 100 mile drive there, everything good. Hit the track at 8:00.. But the last lap, the last few turns, start hearing some odd intermittent noises, almost like the tires picked something up or maybe splitting tread and smacking against the fender (at least in the helmet thats what it sounded like)...

no such luck. As I make the last few turns to go into the pits, I get a low oil pressure light and the car shuts off. 45 min later I got it started, awful noise from the engine, oil pressure about 15
There was a metal to metal screeching sound too for a little while which went away. not its just a very heavy knock. needless to say in needs an engine rebuild.. oil pressure cool is about 40


So I start pulling out my hair, thinking how this could have happened..

Here is what I know..

Oil level fine before and after the run

Now, after just a little reading I see that the 8 quart dry sump system can cause an oil starvation problem when pulling lateral Gs on turns. Obviously when running an engine hard on a track, oil starvation is a very very bad thing. This is what I am leaning toward right now. I did not know that before getting to the track. I would have never even thought of that! Isn't the whole point of the dry sump system to keep the engine oiled up on a track?? How the hell did GM screw this one up too?

The more a learn about this car that I really wanted to like, the more disappointed I get. Super expensive engine, with exotic materials, perfect for the race track that is dropping valves, overheating, and blowing up after a few high G tuns..

So for those reasons I would like to start with a big F.U. to GM

Now I need to decide what to do

Any advise would be greatly appreciated

mtomlin1

Bad luck I think I have tracked my 06 many times do u run slicks ? I was told I wouldn't reach the limits of stock set up on road tires.

I have tracked mine for along time never had an issue, I'd say open engine check what's happened. Might be something linked to the work you have had done, how long ago did h have the work done ?

Hib Halverson

If you were generating 1.2g lat. for any length of time on a regular basis, that's at the limit of the LS7 dry sump's performance.

Plus, you had the early system with the small dry stump tank which makes any oil pressure fluctuations caused by 1.2 g even worse if the high-g also happens at high rpm.

It's certainly possible that you starved the engine for oil. This is why track only cars either have a racing type dry sump or an oil accumulator.

Coolant temp of 245°F is pretty high. Oil temp of 245°F is on the high side but not dangerously so.

Hard to say anything more until you get the engine apart.

carlvr

Yes, we'll be looking at the engine soon.
tires are pretty sticky. worked really well.

Here is the track.

The high G turns were not at high RPM.. around 4k I would say

carlvr

The work was done more than 2 years ago.. I did not do it, but I do have receipts. It was done by Larrys Engine and Marine in AZ, a very reputable shop.

Racingswh

My thought as well.

Also from my personal experience it's rare for an LS to have oil temps similar to water temps. In ours when flogged on a hot day I typically see water temps in the 220's and oil temps in the 260's. Nothing a decent oil can't handle. If you were seeing 245 water I bet you were nearly 300 oil.

I say starvation and excessive heat lead to a rod bearing failure. Pure guess but think it might be a decent one.

Needs a bigger radiator and a proper dry sump system to withstand real track duty. The larger capacity newer factory system at a minimum.

FWIW Lou Gilotti at LG has an engine that will work for you ready to go right now. If you did that and any parts from your engine, like the heads, are salvageable you can sell them and recoup some of the cost of the new engine and install.

https://www.corvetteforum.com/forums...7-f-s-dfw.html

C5 Hardtop

I can tell you what happened. That motor broke your trust. Like a cheating wife, you just have to rebuild, move on and hope for the better.

carlvr

Your right.. Oil was hotter.. Not by much though.. Coolant temps were around 230 until the very end. When the car shot off, I turned on the accessories and that when I saw coolant temps around 245.. I think the oil was actually 260ish.

When run hard, the temps shoot up pretty quickly so I was actually taking it pretty easy, Only revving out 3rd gear on the long straight

carlvr

any race engine builders in AZ want to chime in, i'll be happy to hear from you

HOXXOH

My first thought would be to ask the engine builder if they knew the car would be used on a road track. If that was known, what was the reason to not provide better a oiling system. Regardless of the answer, you'll still need a teardown to verify the problems, which will confirm the cause. No accusations being made here, but only fact finding.

AzDave47

The oil starvation issue at 1.2 G's is primarily in high-load long left turns (~4 seconds for the 8 Qt. system). Turns 12 and 13 are the likely culprit. OP, best of luck on the issues.

My 09 has the 10 1/2 qt. oil system that can take those hi G's for ~ 5 1/2 seconds. There is some good research and data documentation on this forum (search).

Stock I would see 245* water temps and 285* oil temps so I swapped to M1 0W-40 which can handle the higher temperatures better. I think GM is OK with water temps up to 260* with good OEM coolant mix, but I'd back off at anything over 245* water temp.

My first time out with HCIE and DeWitts IOC I saw 245* water temps and 290* oil temps using Amsoil Z-Rod 10W-30, certainly higher than I'd hoped. Ambient that day was 98-106* at Wild Horse East in Chandler AZ.

Dirty Howie

Yes too bad you were not aware of the oil starvation issue (which can happen with street tires). The first thing I did (and before my first track day) when I got my '08 was to put the larger external tank in. Sorry for your motor, at least you didn't put a hole through the block like many of us have.


DH

Racingswh

Sorry for the aggravation. Losing an engine is no fun. Can happen to any engine no matter what the manufacturer. LS7's are reasonably priced compared to many other's and not much gives you this level of performance for the dollars spent.

When you put it back together look at the AVIAID oil pan trap and baffle as well as the tank insert to combat starvation or the ARE complete stage 2 dry sump system from Katech. Should help to solve any oiling issues you may have.

Unreal

Never seen or heard anything good about Larrys. In fact seen just the opposite.

With the vast number of pure crap tunes in Arizona, I would have check that out too. I've only seen 1 tuner in the state that can actually put a tune in the car that can survive some lapping. The rest of them are lucky to make it to the track, let alone be beat on. Wouldn't be surprised if there is signs of lots of detonation which beat the bearings to death.

carlvr

Thanks for the help everyone.. Nick D did my tune, came recommended. It was actually a pretty conservative tune. It was really a hot that day, about 118 degrees in Phoenix so we took it easy..

I already know there was a major oil starvation issue.. The engine literally sounded like there was zero oil in it even though the tank was full.. I am sure I will be told what I broke but why is what I'm wondering..

BTW*** at cruising speeds and operating temperature rpm the oil pressure was about 30-35 psi which I was told was normal. Cold was way above 50.. Is that normal???

carlvr

I guess I need to figure out if dropped oil pressure was the cause or the effect

C5 Hardtop

Looking at the track map, T1 would be the widow maker.

RamAir972003

After seeing map and this is a question I have seen in past peoples z06 low on oil when I go to meets, I always check and express to my buddies and 70% are always low why blow by. They tell me the car has been driven only so many miles, I tell them check it exactly now they are 3 quarts low and wonder just always check oil. Good luck

Unreal

Nic D is good. If it was anyone else I would be affraid but he knows, especially if you told him it was setup for a road course.

I don't buy this was a left hand turn issue. Plenty of z06s from AZ run indy with stock oil tank, and don't have issues. Unless your race tires/suspension is that much better. The tracks that were seeing pressure drops, and not even enough to hurt a motor were banked turn nascar style tracks.

carlvr

Interesting...... I have no suspension mods. Only tires which were not racing slicks but did feel really good and were able to surpass 1G and holding 1.2 on a few turns