Meissen's LT1 Rebuild Thread

[meissen]

ill say this...i lost ton of power when my LT1 went.. it was soo slow it was not funny. but my engine had no shavings like yours at all.
did you ever do a compression test?

Weird... mine was running damned strong all the way to the end.

I've got a thread on CamaroZ28 and they said if the fuel was washing past the rings that the cylinder walls would be really effed up worse than the pictures look. That leaves me completely stumped - there was definitely fuel in the oil.. you could smell the fuel in the oil, in the heads, etc. The question is - what are the possibilities for fuel getting into the oil? I thought the only way was piston rings..

[Transamsfast]

hmm really? when you pulled out of AE it looked like you didnt move and minutes later it blew

[meissen]

Well OK almost all the way to the end. It was running really damn strong from 24 Mile Rd and Hayes until I got to about 16 and Dequindre.

[98blackbeauty]

Larry,

Ya, I agree, you need to try and figure out exactly what caused this failure, if at all possible. Otherwise, how can you be sure to avoid the same situation again?

Main bearing # 5 had wear and scouring not turned. the worst wear and damage was Rod journal #8 bearing turned and rod journal worn down .020 -.025. Odd part is same Journal, is rod #7 didn't turn and hardly any wear. Understand I'm being visual, not using a micometer.
Main bearing 2,3 turned worn, rod bearing 4 turned. the other rod bearing and journals look great.
All the piston, wrist pins and rings look fine. Cylinder wall appear fine.
From your experience would you think problem stated at rod bearing 8 and the rest was a result of that damage escalating. the worst main was #2 then 3, the crank journal for #2 was really scoured. none of the other journals were scratched or scoured.
So, let me know what you think.

[meissen]

Pictures:

[meissen]

BTW - before anyone says anything about the cam - I ran my fingernail over each surface and you can't feel any scoring - it's perfectly smooth all the way across.

[Lucky SOB]

nice work! and wow your sig and avatar are very distracting!

[WMCC Doug]

BTW - before anyone says anything about the cam - I ran my fingernail over each surface and you can't feel any scoring - it's perfectly smooth all the way across.

Brian, at the risk of sounding harsh, do you really want to trust your engine to how it feels with your finger nail? I sounds like you are desperately trying to convince yourself that you don't want to believe what your eyes are seeing.

The lines and marks you see on the cam lobes and bearing journals are from those metal particles that were in your oil being crushed under the lifter rollers and getting squished in the cam bearings. What you see is the beginnings of a breakdown of the surfaces. This will not heal itself, it can only get worse.

If I found that kind of wear indication in a part of a machine I was fixing at work, I would definitely replace it. I know that's not what you want to hear. But, in the end, it's your engine and you will have to make the final call.

Larry,

It looks to me like the problems started with a lubrication issue. But, it's really hard to tell. Once one bearing surface started to go, the metal contamination started and it progressed from there.

I would be concerned about that bearing cap in pic #20. The new bearing insert needs to fit properly.

Once the crank gets ground and the new bearings go in, then it's all about cleanliness during assembly and making sure the oil galleries and passages are clear and unrestricted. Make sure the oil passages in the crank journals are clean and clear, as well.

Don't forget to pre-lube the engine by spinning the oil pump before you try to start it. (I'm not exactly sure how you do that on an LT-1) It's pretty easy on an old style small block.

[98blackbeauty]

Larry,

It looks to me like the problems started with a lubrication issue. But, it's really hard to tell. Once one bearing surface started to go, the metal contamination started and it progressed from there.

I would be concerned about that bearing cap in pic #20. The new bearing insert needs to fit properly.

Once the crank gets ground and the new bearings go in, then it's all about cleanliness during assembly and making sure the oil galleries and passages are clear and unrestricted. Make sure the oil passages in the crank journals are clean and clear, as well.

Don't forget to pre-lube the engine by spinning the oil pump before you try to start it. (I'm not exactly sure how you do that on an LT-1) It's pretty easy on an old style small block.

When we put the engine together I was concerned, we used lub on cam and even the cyl walls. Then when we had the engine in the car, we pulled the fuses for the injectors, and the coil wire, and cranked the engine over for a number of times to pre lube the engine. On the LT1 I am also not sure how else you would do it. the only access to the oil pump drive is under the intake manifold. I have rebuilt numerous engines of various types and understand the cleanly issue.
I am slowly accepting the not tuned for the injectors theory, definately smelled gas in the oil, and that would explain the lubrication problem. Still keeping open mind though.

[Phantom409]

I would replace that cam B!
Like Doug said, that cam isn't going to heal it's self.

A line hone is needed for sure on that block.

[meissen]

We're taking the cam to the machine shop tomorrow to see. I'm just trying to convince you guys that haven't physically held the cam or seen it in person. Pictures don't do the cam justice - everyone that has seen the cam in person has said that the machine shop should be able to polish the cam to good as new and that it just looks like the pattern where the lifters are rolling against the cam.

Please keep your fingers crossed tomorrow everyone...

[MunsterZ28]

its easy to sit on this side and give advice B, but when its your engine and your money your going to think diffrently. now im not saying anything either way hear because i dont know enough about all this to say you need a new cam but there is alot of experience in this crowd. and its hard to listen to everyone and hey they maybe wrong they maybe right but all in all i think everyone is just trying to help because this situtation sucks, you worked so hard to get this done, everyone is just pulling for a 2nd start-up that last you as long as you have the car, so chin up boy, your six feet up and not 6 six feet down its a great day, now as the late great rob dyrdek would say "Do work son!"

[meissen]

I know - and I do appreciate everyone's advice. I think what's killing me the most right now is that I spent my inheritance money from my grandparent's estate getting this project done. It was supposed to be saved for Angie and mine's wedding but I thought "No biggie, I'll just put the money back in the bank once the car's all done." I feel like my grandma is rolling in her grave right now knowing the money I blew just for it to break down like this. I've been trying to stay numb to it all since Friday night but it's just hard. This LT1 project as a whole has been stressing pretty much all areas pretty thin and I was really getting to the point where it was a huge relief to see that light at the end of the tunnel because I didn't know how much longer things could go the way they were before something went wrong. Grades in school, relationship, bank account, work performance, for awhile there I was even starting to think it was making me physically sick. I just really wasn't prepared for the engine to break down like this. I'm just hoping the light at the end comes soon because I don't know how much more of this I can take before I just say "eff it" and give up working on the car for the season.

[bigjon88]

b it will get better dont freak out to much yet wait til the machine shop sees everything

[WMCC Doug]

Hang in there, Brian.

Fred is right. We're all just trying to help someone that we care a lot for (You!)

I think everyone on this site took your troubles on as our own.