No compression on 1 - burnt valve? Topic is solved

[volvolugnut]

That video is hard to stop watching.
volvolugnut

[Sveedy]

Oh nice, you're going to crush it!

A few pics would be great

Choice of words could be misinterpreted here...

Just think of what kind of " interesting " machine we would have, if this was coupled with robotics and AI

[scot850]

The question of the match up will depend on our conversation later today. It will depend on their knowledge and enthusiasm. Also their ability to seek help and research issues as they arise.

The easier option is to start small(er) and fix the burnt valve on the NA and get confidence on that first. Then strip the other car to figure out how to remove the engine and stuff like that. Then work forward from there.

Anyway I will see later.

Neil.

[songzunhuang]

So I realized that I have a boroscope I hardly use. Could my no compression issue be due to a bad piston? Well, we will know for sure when we remove the head, but until then I can check it out with this nifty tool. Here's what I saw. Ignore the date stamp, it's not set correctly. This was 2 days ago.

Top of piston on 1.

Piston Top.png (1.64 MiB) Viewed 582 times

The top of piston one looks to be in great shape. There's nothing looking worn and even the cross hatched marks on the cylinder walls were still visible when I moved the scope around. Those notches on the right are reliefs for the valves. It does look a bit oily, which may be due to failing valve seals that also may have led to a burnt valve? The major takeaway was that my piston looks fine.

So I put on the 90 degree mirror at the end of my boroscope to see if i could somehow make out the top of the valves. It was really tricky, but I finally caught a glimpse of what I think is an open exhaust valve. In the picture below, I outlined it since it's hard to make out in a blurry picture. I think I see a chunk gone from the edge of the valve. Of course this would be consistent with a burnt valve.

Side view of valve?

Valve Chunk.png (1.84 MiB) Viewed 582 times

So that's all I have for now. I'm thinking I'll remove the head this weekend, but I won't be able to complete the job for at least a week afterwards since I've got some commitments at work. It'll give me time to have the machine shop do their bit and also time for my parts to arrive. I'll update when something interesting happens.

[abscate]

I think I got the head off Elizabeth in 4 hours in, uh, sub-optimal work conditions …

[songzunhuang]

Ok, I took 5.5 hours to do this as I had to run to the store when I broke 2 x 14mm sockets trying to use a 3/8" socket. Well, don't wast your time, use a 1/2" socket and a long cheater bar for leverage. Things went pretty much as planned, otherwise.

Here's the first big milestone when the cam cover came off. Everything looked to be in really good shape. I checked all my lifters and they actually all checked out. I may go ahead and replace them since I already bought new ones.

All looks good, lifters good

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Here's the 1/2" cheater with a 14mm socket that finally got the bolts off.

Use a 1/2" Cheater bar!

Cheater Bar.png (1.47 MiB) Viewed 532 times

Whoa, the first time I have ever removed a head off a car!

Head is off.

Head Off.png (1.67 MiB) Viewed 532 times

And here's the main event! I did in fact have a burnt exhaust valve on cylinder 1. You can see the chunk gone here.

Well, burnt exhaust valve on 1

Burnt Valve.png (1.58 MiB) Viewed 532 times

I labeled and laid out the parts in the trunk in the order that I removed them. This should help me when it's time to reassemble.

Trunk full of parts.

Trunk Parts.png (1.43 MiB) Viewed 532 times

I did come across a few issues that I'll leave to the machine shop. For example, I could not get all the screws off the thermostat housing. Some won't budge an I am afraid I'll break them. Then there's a stripped screw hole in one of the intake valve holes. And finally, when I removed my exhaust manifold screws and studs, all but one of my studs came out of the head with the nut. I'm trying to figure out if I really need to get all the nuts off the studs and put the studs back in the head for installation.

So next steps is run the head to the machine shop. We'll report back after that. So far, pretty good!

[volvolugnut]

Well done! It is very satisfying to remove the head and clearly identify the problem. Think of the satisfaction you will feel when you restart the engine you repaired.
volvolugnut

[abscate]

Get new exhaust studs and bolts and have the shop take them out for you.
Can you add more to the stripped intake valve hole screw? Not sure I understand where you are

[BlackBart]

That’s a lot of work. I did the exact thing in my trunk with parts in order!

What caused this? Too lean?
Is this a significant comment here?

Then there's a stripped screw hole in one of the intake valve holes.

[abscate]

Age. The valves on these cars last 200-250k miles , especially if the stem seals let oil in.

Song and I are,playing in synch while I do Shagg valves on Long Island

The Kat is burning oil ftom stem seals but that is off in the future