'87 Grand National, unknown 10/30, 400 miles...motor let go

[JRHAWK9]

Hello, a friend of my dads had a shop build him a motor (3.8L turbo for the GN). The first one they built let go on the dyno right after they built it with no street miles. They built him a new motor and told him that they are not going to warrantee it anymore. Well, with only 800 miles on the motor, the oil pressure went to zero while driving on the street. He had yet to bring it to the track. He had his oil sampled and I thought I would post it on here for all you oil guru's to look at. He wants to see if he can use this oil sample to recover some of his expenses.

thanks,
Paul

ALUMINUM 0
CHROMIUM 0
CADMIUM 0
IRON 14
COPPER 30
LEAD 965 (!!!)
TIN 0
MOLYBDENUM 131
NICKEL 0
SILVER 0
TITANIUM 0
POTASSIUM 0
BORON 5
SILICON 6
SODIUM 0
CALCIUM 1611
MAGNESIUM 17
PHOSPHORUS 1078
ZINC 1156
BARIUM 0

TBN: not tested
Vis @100C cst: 8.8
Flashpoint: not tested
FUEL: WATER:
Tested by US Oil in Kimberly, WI

Here are there comments:
Lead level high. Suggest investigation for possible sources.
Viscosity below specified limits for weight of oil given.

 

[peakperformance]

I have a lot of experience with these motors and it sounds like whoever built was not using the correct cam and/or main bearings. The last/rear cam bearing is generally the determining factor for oil pressure and therefore the type of bearings and tolerances are critical to get sufficient oil pressure. Also, the crank bearings in these cars need to be "hard" and "soft" bearing will get chewed up from the crank load under boost. You can likely find all the details you need on http://www.gnttype.org (some basics http://www.gnttype.org/general/rebuild.html)

 

[Blue99]

Actually, the wear metals aren't bad for a newly rebuilt motor.

The high lead level is similar to what we have seen, recently, from a UOA posted from Georgia, where the owner got into some leaded gas & killed his catalytic converter.

Is this friend trying to run leaded Sunoco race gas in the Grand National?

 

[JRHAWK9]

peak, thanks for the info, I told my dad to have him check out this post.

blue, I have no idea what fuel he was running, hopefully he will visit this site so he can answer any questions.

 

[JD Green]

JRHAWK9:

Just a question, IF this oil was a 10W-30 and only in use 800 miles, with that amount of lead in it, shouldn't the viscosity of thickened rather than thinned out? This seems kind of odd to me. Am I out in left field with my thinking?

Sorry about your luck.

 

[benjamming]

Help me out here. If the shop couldn't get the 1st motor right & wouldn't warrany the 2nd one, why did he let them go ahead & build it? Didn't he pretty much expect it to die?

 

[Ray H]

What was the break-in procedure - "drive it like ya' stole it" as so many BITOGers advocate?

 

[T-Keith]

I would suggest looking into the shop. From what I've heard SBC builders who try and built a LC2 without experience don't usually do well. The oiling system is much different. Find out what they did to the bearings and oiling system. Also, what kind of power is he making with this motor. The LC2 block is pretty stout but you can overpower it quick with a turbo.

-T

 

[Drew99GT]

I'd imagine the owner did not use leaded gas as it would quickly contaminate the 02 sensor. Guess they could have inadvertently filled it with leaded. Lead is most definetally from a bearing that got chewed to bits.

 

[zoomzoom]

quote:

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Originally posted by benjamming:
Help me out here. If the shop couldn't get the 1st motor right & wouldn't warrany the 2nd one, why did he let them go ahead & build it? Didn't he pretty much expect it to die?

---

Exacly what I was thinking!!??

 

[drive it forever]

JRHAWK9, post the sorrya** machine shop on this board if you could.