What killed this LT1?

My friend's stroker LT1 just went south on him. It had maybe 10,000 miles on the new motor.

When we tore open the motor we found:

8 forged pistons with scorched skirts on the side facing the cam.

1 spun rod bearing. King bearings used.

He has a Melling High volume oil pump and a stock size pan.

Why did the bearing spin? Why did the pistons scorch?

He did a burnout and raced and saw a drop in oil pressure immediately afterwards.

Oilpump sucking air. What viscosity oil was he running?

10w40?

what rpm did the motor see during the run/burnout? i would guess lack of oil somewhere, but i need more info on rpm. did the pick up come off?

i know this sounds really stupid, but did you install the oil pump pickup deep enough into the pan?

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Was there any overheating , or hight engine temps. With the bearing spun and scorched skirts, it sounds like something burned maybe because of oil starvation, or over heating.


What color are the bad bearing/s .... How do they look?

Was there any sort of windage tray on the studs or in the pan?

What did the other rod bearing on that crank throw look like?

Bret

durring a burn out?

may sound REALLY stupid but... was it running REALLY rich? was there an exhuast leak?

Strange that it burned all the pistons on the cam side. Did you happen to notice where the ring gaps were aligned on the pistons?
I would send the oil out for analysis.

There was no problem with the pickup.
Stock oil pan.
No oil scraper.
Rod showed burns as well where the bearing spun.

He says the car has never been overheated. He was revving to 6500rpm during his run. 6000rpm for the burnout.

My guess is the same as yours that he starved the engine of oil. I just wanted someone else to reach the same conclusion as me. :D

Would a thinner oil or synthetic have saved his motor seeing as how he was running 10W40 dino oil?

I've always thought it was recommended that you not run a stock pan with a high volume oil pump, for exactly this reason, oil starvation. Which bearing spun?

There was no problem with the pickup.
Stock oil pan.
No oil scraper.
Rod showed burns as well where the bearing spun.


You didn't have that stock plate/windage tray in there even?

I'm betting that's the problem, longer stroke with that and all that dam windage and no way to keep the oil in the bottom of the pan picked all the oil up away from the pickup during the burnout and boom there goes the bearing.

Get a Milodon Tray or a Canton Pan, something anything to keep that puppy from picking up all the oil in the pan and starving the pump.

Bret

I've always thought it was recommended that you not run a stock pan with a high volume oil pump, for exactly this reason, oil starvation. Which bearing spun?

Rod bearing #6.

Thanx guys I'll pass on the info. He's ordering a Canton pan as we speak.

hes prolly gunna need alot more than that lol

i also heard that u dont run a high volume oil pump with a stock pan...

i also heard that u dont run a high volume oil pump with a stock pan...


Hmmmmm....I did not know this. I have been running a Melling HV/HP pump with a stock pan for three years now, spinning the motor to 6500 and haven't had a problem.
:confused:

You have to be carefull running a stock pan with a HV pump because the pump can litterally suck the ALL of the oil out of the Pan. A good example is running a few Qts. Low of oil and stomp the gas.. The Oil Pressure will drop Drastically then Climb when you let off the gas, becasue the oil returns to where it was. And I've always known HP oil pumps to be bad...Especially on stock Clearenced Engines. If you have a loose clearence I can see a reason to run a HP oil pump, but not until then. Any way It really sounds Like starvation. I would check the cam for burnt bearings as well if the Insides of all the Pistons were burnt. Could mean there wasn't any oil on the top end at all.

Just an Idea

Chris

Did the viscosity if the oil have anything to do with the oil starvation? Its dino 10W40 oil.

Would synthetic have been better?

I do not think 10w-40 caused this. I burnt a rod bearing runnning 50wt racing oil in a stock 440 Plymouth. The 50 wt oil was only ment for race clearenced bearings. I have no experience with dino oil. I thought it was only for dyno runs??

Did the viscosity if the oil have anything to do with the oil starvation? Its dino 10W40 oil.

Would synthetic have been better?