New here, just bought '90 ZR-1

[A26B]

Looks like the broken cam chain has some rollers that are badly worn and at least a couple that are missing. With roller(s) missing the chain pitch no longer matches the sprocket pitch which probably precipitated the link breaking. You should have several pieces of broken rollers in the pan also.

Hard to say whether a sprocket on the drivers side chain went bad first or the chain did. Regardless of what failed first, all of the sprockets will also have to be replaced too, as you already know.

Oil pump has a few battle scars, but nothing bad. Good news is no damage to the block.

Will keep my fingers crossed for minimal damage when you get the head off. Not too bad so far!

[bdw18_123]

Driver's head is off! Man, those head bolts are really, really hard to get off. Even with a 5ft cheater bar. I busted one socket (craftsman, free replacement, hehe ) getting them off.

Here are the pics. While it is incredibly filthy in there, the damage seems minimal, I think I got pretty lucky considering how bad it could have been. Total of 4 bent exhaust valves, no intake valves appear to be bent. Although as you can see in the pic, in cylinder #5 the intake valves contacted the piston, but they seem to close ok.

I told ya

You should send those pics over to the original owner. Demand some money back.

[bdw18_123]

I guess the next step is getting the bent valves out. There seem to be a whole lot of special (and probably extremely expensive) tools to work on this engine. Where can I get the valve removal tools? If they are really expensive, is there anyone here that has them that wouldn't mind letting me borrow them?

I also need 4 exhaust valves and maybe 2 intake valves in case they are slightly bent.

The cam cover for the drivers side unfortunately is a little damaged. There is a small hole in the side where he tried to pry on a stuck screw (I have the piece) and some deep gouges on the top (don't know how those got there). Would an experienced aluminum welder be able to repair it? I could just JB weld it, but in the future, I will want to get it powdercoated and I don't know if JB weld will hold up to the powdercoating process. Here are some pics of the damage to the cover:

[-=Jeff=-]

you MIGHT.. be better off with a head from Johnny, with a Cam cover

depends on cost to fix this one

[A26B]

Cam cover can be repaired by a good welder with a tig machine, followed up with a bit of hand work to smooth everything back like it was, then powder coat. Heat can be controlled easier with a tig and the damage is essentially cosmetic, not structural.

No visible head damage that I can see apart from bad valves and you may run into more after they are all out.

Looks like coolant leakage into the #3 cylinder. Any sign of a bad head gasket? Water in the oil?

My question is; are you going to tear it down and rebuild completely since it has 145K miles? The thing about an LT5 is that you can pop rod caps to look at crank & bearings, but you can't check the mains with out doing a complete teardown.

[bdw18_123]

Originally Posted by A26B

Cam cover can be repaired by a good welder with a tig machine, followed up with a bit of hand work to smooth everything back like it was, then powder coat. Heat can be controlled easier with a tig and the damage is essentially cosmetic, not structural.

No visible head damage that I can see apart from bad valves and you may run into more after they are all out.

Looks like coolant leakage into the #3 cylinder. Any sign of a bad head gasket? Water in the oil?

My question is; are you going to tear it down and rebuild completely since it has 145K miles? The thing about an LT5 is that you can pop rod caps to look at crank & bearings, but you can't check the mains with out doing a complete teardown.

No, there did not appear to be any water in the oil and the head gasket looks ok, no tears or anything. But I'll probably get new head gaskets anyway.

I don't really have the money at the moment to replace everything. Since there are some ZR-1's with 200K+ miles on them, this one should make it too. I'm just going to clean everything up real good, replace what has to be replaced and put it all back together.

[kirkstingray]

Good luck hope all goes well to get her on the road.

Kirk

[QB93Z]

Thank you for taking the time to post these pictures and findings about you engine. It is a great learning experience for me. I appreciate it.

Good luck getting it all back together.

Jim

Originally Posted by bdw18_123

No, there did not appear to be any water in the oil and the head gasket looks ok, no tears or anything. But I'll probably get new head gaskets anyway.

Cylinder #3 does look like it has had coolant flushing around in it. otherwise it should be solid black like all the others. I see a small imperfection at the bottom of the gasket, but can't really make it out with out having a better picture. Typically cylinder 7 is where a head gasket will give out first. And there is no re-using old head gaskets.

I don't really have the money at the moment to replace everything. Since there are some ZR-1's with 200K+ miles on them, this one should make it too. I'm just going to clean everything up real good, replace what has to be replaced and put it all back together.

This is where you come to the cross roads. You have a good opportunity to do some clean up, porting etc. You have already done most of the dirty work. I would be worried about the condition of the bottom end. You should take a peek and see what is going on.

The cam cover is repairable, but you need to take care in not overheating it. Otherwise it does become garbage.