Noticed something interesting on my LT5...

[1989ZR1#74]

Originally Posted by A26B

I have friends at Mercury who were core personnel in the LT5 program. I'll ask them about rebuilds @ MM. Frankly, I would be very surprised if any engines were rebuilt at MM.

Let me ask then if not MM where would it go to?

as LGAFF said " took forever to get it back" back from where?

I have read in several sources (not available to me right now) that it was what they did. The LT5 was way too complex to rebuild at a dealer.

[1989ZR1#74]

From the registries archives:

"However, the question still remains: once an LT5 problem is diagnosed as being other than with engine management, what framework is in place to acquaint dealer service departments with the revolutionary technology of the LT5? At the press introduction of the LT5 at Riverside, California last June, that question was raised. Chevrolet said that training would commence a few months before the introduction of the ZR1 and until servicing ability is up to speed, any LT5 problem requiring the opening-up of the motor will be handled with an engine exchange. The dealer will remove the offending LT5, replace it with a known-good unit then ship the bad motor to Mercury for repairs. "

http://www.zr1netregistry.com/LT5tech.htm

[1989ZR1#74]

So #2299 has an LT5 with a deviation in the MM stamp/markings, and with the BG stamp/markings. Both correcting a previous mark/stamping. It was clearly done at two seperate points of manufature 100s of miles apart. It was delivered to customer on 11/22/1990. It has a block casting date of 03/07/90. It has a documented history of being off the road for a year early in it's life. Engines, at least in the early days of the ZR-1 were shipped back to MM for repair. The only point I can not foot note right now is my belief that the customer was given the option of repair their LT5 or replacing it with an available "core" from MM.

There is nothing in what I just typed that will ensure that that did happen, but there is also nothing as of yet to prove it did not happen.

Another thought/theory, "Mary" the inmfamous BG lot driver who in 1990 was cold starting ZR-1s at WOT and grenading the LT-5s must have taken out several LT5s. What process did Chevrolet go through to replace these engines? What did they do with the damaged blocks? when did Mary stop killing LT5s? Could #2299 have started it's life with a new block because Mary killed it? That would make #2299 an interesting footnote in the lexicon of ZR-1 history. Time to order your build sheet and invoice to find out when it was built and when it was shipped. If there was a large gap maybe it was waiting to get a new LT5.

[bdw18_123]

Originally Posted by 1989ZR1#74

... Time to order your build sheet and invoice to find out when it was built and when it was shipped. If there was a large gap maybe it was waiting to get a new LT5.

I do need to order the build sheet since the build date area is unreadable on the one I pulled out of the crossmember. However, I do have an original invoice which appears to document the transfer of the vehicle from GM to the dealership from which the car was sold from and lists all the options, pricing & other things. I can take a picture of it and post it if that will help, maybe you guys can help me decode it.

There are several dates on this invoice, listed as follows (I'm not sure what the last two mean):

INVOICE 5/24/90
PRICED 5/22/90
SHIPPED 5/24/90
EXP I/T 5/29/90
INT COM 5/29/90

So that means my car sat at the dealer for about 6 months before it was sold to the P.O. on 11/22/90. Since my block has a cast-in date of 3/7/90, that means the build date of my car should fall somewhere around March of '90 I would think. Are there any dates anywhere on the car itself that would give a clue as to what the build date was?

Originally Posted by 1989ZR1#74

...
Not that #2299 will ever be judged or need to justify the stamp, I am very curious how two stamps in two places were wrong.

I always like to try and wrap my brain around these even though I have no skin in the #2299 game.

Agreed, my ZR-1 is definitely not an NCRS candidate, but I like learning about stuff like this and I'm also very curious as to why both stamps from both manufacturers were redone. My Z might have an interesting history and I want to learn about it.

Originally Posted by 1989ZR1#74

... Another thought/theory, "Mary" the inmfamous BG lot driver who in 1990 was cold starting ZR-1s at WOT and grenading the LT-5s must have taken out several LT5s. What process did Chevrolet go through to replace these engines? What did they do with the damaged blocks? when did Mary stop killing LT5s? Could #2299 have started it's life with a new block because Mary killed it? That would make #2299 an interesting footnote in the lexicon of ZR-1 history. ...

Who was this "Mary" person and what kind of moron starts a car at WOT??

[A26B]

I just spoke with Chris Allen who was the man in charge of design & supervision of the LT5 assembly line at Mercury.

Chris said "to the best of my recollection, for the first year, dealers were not allowed to open an LT5 engine. He went on to say "I only recall one engine that was ever returned to Mercury. We opened it up and the only thing wrong with it was carbon buildup. We cleaned it up & sent it back to the dealer with no other work."

Chris also said that Mercury did not have any procedure for rebuilding LT5 engines and that he would have known about it if they did.

Apart from engineering development & test units, there appeared to be a couple of warranty replacement engines in the group of 30 engines I had that were remaining from the lot of engines GM sold off 2 or 3 years before I got them. As I understand it, what actually happened was that dealers did not rebuild LT5's. The dealer received authorization and was shipped a new crate engine from GM stock (not Mercury). The dealership returned the original engine to GM, in the same crate the new one was shipped in, where upon receipt, it was simply placed in a storage warehouse with all of these other test & development engines. The warrany replacement engines were never rebuilt as the cost to GM would have been greater than the cost of a new crate engine.

I probably have some photos of the engines I think were returned & recall some instructions to the dealer about what all to remove & return to GM. Those crates were different than the crates I've seen for crate engines offered for sale.

It seems probable to me that procedures & policies perceived to be feasible when written may have turned out in actual practice to not be practical.

[1989ZR1#74]

Good stuff Jerry, you have moved the ball forward and I learn more and more. Ok so if the block was replaced it would not have been restamped.

2 seperate issues:

So why was MM mark on #2299 restamped? The fonts on the MM restamp appear to be the same. They appear to have been done to document not to deceive (ie like a 63 Corvette Restamp) Perhaps you could send your friend the link for the picture and ask him what he thinks.

VIN stamp. This LT5 perhaps was destined for another 90 Corvette at BG but was diverted to #2299 that would explain the VIN restamp again to document not to deceive. At what point was the LT5 assigned to a ZR-1? how much time is there between assignemnt and installation?

It does not seem plausible that an outside repair shop would go through the effort to restamp the block. Nor would they have access to the correct stamps/fonts etc. So I would think this had to have originated at MM and BG.

[A26B]

Originally Posted by 1989ZR1#74

....... So why was MM mark on #2299 restamped? The fonts on the MM restamp appear to be the same. They appear to have been done to document not to deceive (ie like a 63 Corvette Restamp) Perhaps you could send your friend the link for the picture and ask him what he thinks.

Can do. He's on an extended weekend vacation, but will be home tomorrow. I'll work on an answer.

VIN stamp. This LT5 perhaps was destined for another 90 Corvette at BG but was diverted to #2299 that would explain the VIN restamp again to document not to deceive. At what point was the LT5 assigned to a ZR-1? how much time is there between assignemnt and installation?

Someone else can answer that better than me. I will recount a story that Ryan B. & I worked on a bit. He acquired a 405 new, crate engine with a build VIN stamped on the engine. We "acquired" the current owners contact info & found out the ZR-1 has a numbers matching engine, WITH THE SAME VIN AS THE CRATE ENGINE. Through a few phone calls we surmised that the first engine was VIN stamped @ BG (like all engines), placed in the car, but on final inspection may have had finish blemishes & was removed & replaced with another engine that was VIN stamped with the same VIN. The removed engine was sent back to MM, then back to GM crate engine inventory, still with the original VIN intact.

So, things do happen that are not in accordance with the standard procedure.

It does not seem plausible that an outside repair shop would go through the effort to restamp the block. Nor would they have access to the correct stamps/fonts etc. So I would think this had to have originated at MM and BG.

Agreed..

[1989ZR1#74]

Originally Posted by A26B

Can do. He's on an extended weekend vacation, but will be home tomorrow. I'll work on an answer.



Someone else can answer that better than me. I will recount a story that Ryan B. & I worked on a bit. He acquired a 405 new, crate engine with a build VIN stamped on the engine. We "acquired" the current owners contact info & found out the ZR-1 has a numbers matching engine, WITH THE SAME VIN AS THE CRATE ENGINE. Through a few phone calls we surmised that the first engine was VIN stamped @ BG (like all engines), placed in the car, but on final inspection may have had finish blemishes & was removed & replaced with another engine that was VIN stamped with the same VIN. The removed engine was sent back to MM, then back to GM crate engine inventory, still with the original VIN intact.

So, things do happen that are not in accordance with the standard procedure.

Agreed..

Wow that is again more neat info. So there was a history of LT5s being pulled after the VIN deravation is stamped and placed back in inventory. So that could be an option.

[A26B]

Well, I would hesitate going plural and counting this as a definite occurance, but after analyzing all the tags on the engine & crate and talking to GM personnel, it is the most likely circumstance. Fact remains, there are 2 engines with the same VIN, one is in the ZR-1, the other is a crate engine.

[1989ZR1#74]

Originally Posted by A26B

Well, I would hesitate going plural and counting this as a definite occurance, but after analyzing all the tags on the engine & crate and talking to GM personnel, it is the most likely circumstance. Fact remains, there are 2 engines with the same VIN, one is in the ZR-1, the other is a crate engine.

You are correct. Only theories, but it "appears" that an LT5 could have been stamped with a VIN deravation and then not installed in that same sequence numbered ZR-1.

I guess I would ask what if that crate motor was sent back to BG what would the VIN stamp look like?

What was the reason that the 405 LT5 was not installed in the correct ZR-1?