Found a LT5 at the junk yard with fire damage

[2poor4aZR1]

Howdy all!

So, as the title states, I managed to snag a LT5 from my local pick a part this weekend that looks like it was pulled from a 1991 ZR1 with fire damage. I paid just under $2100 for the stripped engine with a 90 day return warranty.

Normally, I wouldn't think twice about picking up an engine with fire damage, but I've always loved the LTx motor family and when the opportunity to purchase this was right in front of me, I jumped. Now that I have it in my garage and on a stand, I'm having concerns about it, and wanted to post here and see if anyone had any advice. Ignore any of the oil on the engine/valve covers, I have this engine on a stand and rotated it 360* and made a mess.

Bad:

1st concern is the most troubling. With the plugs removed, when I turn the engine over, there is a "popping" noise from the drivers/both valve covers. I removed the drivers side valve cover and found that while turning the engine over, the timing chain will get tight, appear to skip a tooth. After skipping a tooth, the timing chain has a concerning amount of play. Turning over by hand has drag to it, but that may be related to the issue above. Plugs looked good with only one really being a little dark. I can't confirm if its both cams that have this issue, as I didn't pull the drivers side valve cover.

2nd concern is what looks like some light bluing on some of the piston wrist pins. My garage doesn't have the best lighting, and this may be an optical illusion. There is also some front to back play in the connecting rods, but I haven't looked up how much clearance is allowed and what is normal.

3rd concern is the obvious fire damage. As I said, under 99% of circumstances, I wouldn't touch an engine with fire damage. While I don't think the engine got hot enough to warp it, I honestly don't have any points of reference. If the engine/heads are warped, then this might be more than I want to take on. The engine does have the forbidden milkshake inside (oil mixed with water), but doesn't have any rust.


4th concern isn't really anything major but worth noting. LKQ did a number pulling this engine. There is a "sawzall" kiss on one of the heads that should need fixing. Nothing terribly major, but I question what sort of moron tries to cut off exhaust manifolds right at the head. Additionally, drain plugs are hard and the same moron decided to drill a hole in the oil pan. Both should be fixable by someone who is capable of properly TIG welding aluminum.

Good:

Filters/spark plugs are AC Delco. At some point, someone did love this car/motor

Cam lobes and bearing surfaces on the driver side looked brand new. No scaring, pitting, or rust. Couldn't get a great view of the lifters, but they looks excellent as well.

Inside of the intake doesn't look like it has very much oil. While not scientific, possibly little blowby.

The fire looks to have been on the back/driver side only. The passenger side is rather untouched. I have pictures in the Imgur album below, and you can see the PCV elbow and AIR tube both have heat/fire damage to them. The passenger side looks perfectly okay.

While the coil packs and other "stuff" that sit at the back of the engine was missing, the fuel injectors and "ignition module" were not melted. Had the fire really heated the engine, I'd think both of the above would be a mess of melted plastic. Additionally, the rear main seal is still in one piece and doesn't really look to be affected.

The oil pan didn't have a ton of sludge in it, and zero metal. The sludge may be the result of oil/water mixing or a 30 year old car that sat for most of its life.

PICS:
https://imgur.com/a/1UxpKe0
**********

I plan on pulling the front timing cover tomorrow night to hopefully see what the timing chain issue could be. Something on the front of the engine was leaking badly, and I'm going to need to spend quite a bit of time power washing the crud off of it to prevent any of it getting into the motor.

With all this said, I don't have any real plans for this LT5. I have an LT1 (1996 Trans AM), and SBC (1969 Stingray) in my collection, and would absolutely love the idea of slowly rebuilding this LT5 for a future project, as I've always wanted to be apart of the ZR1 family. If I were to ever swap this into another chassis, I would most likely go with a standalone modern engine management system, so the lack of the original harness/sensors isn't a concern. If the engine's mechanical bits are salvageable, then I'd love to strip this down completely, clean it, and re-assemble it. If I decide not to return it, I'll most likely have a machine shop check that the block/heads are true (I've read ya'lls posts, I promise not to have them do any "work" to it. Just checking that there isn't anything I can see).

Please ignore all the paint marks on the outside/rod bolts, they were "required" by LKQ to warranty the engine. Yes, they made me pull the oil pan in a dirty junk yard, with the engine hosted over my head secured only with a seat belt run under the intake.

[JG95ZR1]

What color is the chevy emblem on the valve cover? Block Should have a serial number to trace down some history


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[2poor4aZR1]

Where is the serial number located on the LT5?



I figure to ask now before I spend hours pressure washing the block

[WARP TEN]

Originally Posted by 2poor4aZR1

Where is the serial number located on the LT5?



I figure to ask now before I spend hours pressure washing the block

Here are a couple of pictures of the VIN and engine number on the block. The VIN "409" is lightly stamped and just barely visible above the number "11". The larger engine picture shows the location of the VIN stamp pad; it is in the lower left of the picture, on the passenger side at the rear. The engine number is on the opposite side of the block. Hope that helps.--Bob

[2poor4aZR1]

Originally Posted by JG95ZR1

What color is the chevy emblem on the valve cover? Block Should have a serial number to trace down some history


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Both emblems are missing unfortunately. Someone might have taken them as a souvenir , as the "CORVETTE" lettering is still visible on both (after a very heavy cleaning).


As for the serial number, happy to say I think I found it on the driver side of the block above the oil pan. It was coated in many many layers of gunk.

10ZTK X10415006

[phrogs]

If the motor is poping as it's turned over I'd say its the chain tensioner because lack of oil pressure from sitting for so long pull the cam covers pull the timing cover.

[2poor4aZR1]

Originally Posted by phrogs

If the motor is poping as it's turned over I'd say its the chain tensioner because lack of oil pressure from sitting for so long pull the cam covers pull the timing cover.

A friend of mine said the same thing. I will have better answers tomorrow, I ended up spending the last three hours with a pressure washer, oven cleaner, and a tooth brush cleaning years of oil off the engine. Its far from perfect, but clean enough to pull the timing cover now.

[JG95ZR1]

That is a mercury Marine Tracking number . 91 engine built April 15 and it was the 6th build of the day. See pic for vin location
IMG_0751.JPG


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[2poor4aZR1]

Hard to read, but here is what I can see:

M580 059 ?

112790 13

Pictures attached, I can try to clean it up further tonight if this isn't complete.

[WARP TEN]

Originally Posted by 2poor4aZR1

Hard to read, but here is what I can see:

M580 059 ?

112790 13

Pictures attached, I can try to clean it up further tonight if this isn't complete.

Interesting how different these look compared to mine on my '95. I wonder why these appear stamped on a very rough looking piece of aluminum and the stampings look like a slightly different font. Were castings and stamps from different years different? Curious.--Bob