Should I take on this project? 50s Cat D4

Those eccentric adapters were used on later units that had the "buzz bomb" pony motors or factory direct start. The flywheel access hole was larger than the drive end housings of the starters.

Old Magnet said:

Those eccentric adapters were used on later units that had the "buzz bomb" pony motors or factory direct start. The flywheel access hole was larger than the drive end housings of the starters.

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Yes sir, and I learned a hard lesson with it. There was no gasket between either when I started working on mine, which explained why water from pressure washing got into clutch housing. Old Magnet, you truly amaze me with your knowledge sir!

Following Old Magnet's advice, I removed the starter and cranked on the flywheel a bit with a bar and got it moving a tiny bit. Then I turned it back the other way, and found that I could turn the engine by hand, but only by about 30 or so degrees each way before something stops it. Injectors are still out and I poured about a cup of oil into each cylinder just to keep things smooth.

I am suspecting a stuck valve...when I say "suspecting" I really mean "hoping". I guess there could also be something like a mouse nest in a cylinder. I will pull the valve cover off tonight and see if I can get it to budge. If they are in good shape and not stuck, I guess I will be pulling the inspection covers off the side to see if I can see what's going on. Or maybe I should pull the head?

I'm getting a good workout wrenching on this thing. Every time I need a tool I have to climb off the track, walk 50 feet to my shop, walk back and climb back onto the track.

More than likely it is rust on the liners that's stopping the rotation but could be a number of things. Stuck valve is easy to check but you will probably need to pull the head if you can't get passed the stoppage.

Lumberjack Matt said:

Following Old Magnet's advice, I removed the starter and cranked on the flywheel a bit with a bar and got it moving a tiny bit. Then I turned it back the other way, and found that I could turn the engine by hand, but only by about 30 or so degrees each way before something stops it. Injectors are still out and I poured about a cup of oil into each cylinder just to keep things smooth.

I am suspecting a stuck valve...when I say "suspecting" I really mean "hoping". I guess there could also be something like a mouse nest in a cylinder. I will pull the valve cover off tonight and see if I can get it to budge. If they are in good shape and not stuck, I guess I will be pulling the inspection covers off the side to see if I can see what's going on. Or maybe I should pull the head?

I'm getting a good workout wrenching on this thing. Every time I need a tool I have to climb off the track, walk 50 feet to my shop, walk back and climb back onto the track.

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Welcome to Yellow Iron Disease!!

Oh boy, are we getting into it now. I just keep repeating to myself: "it ran when parked, it ran when parked!".

I pulled the valve cover and checked out the valves. The #4 back valve is definitely not returning when I push down on it, but the other seem fine. Some surface rust sure, but can't really not expect that. This is after i hosed it down with penetrating oil, so it doesn't look too bad.


The real problem is when I turn the crank. I see no movement whatsoever on the valve train. Check out the two pictures showing the amount of crank travel (around 30 degrees). Nothing is moving on the valves. Yikes! I guess I'll be pulling out the radiator next so I can get the camshaft out.

I'm assuming this is an interference engine, so the root of my problem is either the cam gear is jacked up, the camshaft has sheared off, or some other form of torture I can't even come up with. Stay tuned!

And the money pit opens wider.
Bob

Lumberjack Matt said:

Oh boy, are we getting into it now. I just keep repeating to myself: "it ran when parked, it ran when parked!".
I pulled the valve cover and checked out the valves. The #4 back valve is definitely not returning when I push down on it, but the other seem fine. Some surface rust sure, but can't really not expect that. This is after i hosed it down with penetrating oil, so it doesn't look too bad.
View attachment 240127

The real problem is when I turn the crank. I see no movement whatsoever on the valve train. Check out the two pictures showing the amount of crank travel (around 30 degrees). Nothing is moving on the valves. Yikes! I guess I'll be pulling out the radiator next so I can get the camshaft out.
View attachment 240128 View attachment 240129
I'm assuming this is an interference engine, so the root of my problem is either the cam gear is jacked up, the camshaft has sheared off, or some other form of torture I can't even come up with. Stay tuned!

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I would say the answer will be revealed once you get the timing cover off . Stay positive even though it doesn’t sound good, it could be something simple.

Oh boy, are we getting into it now. I just keep repeating to myself: "it ran when parked, it ran when parked!".

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I always tell people that if it truly “ran when parked” it wouldn’t have been “parked”

JD955SC said:

I always tell people that if it truly “ran when parked” it wouldn’t have been “parked”

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My previous dozer was running fine before the crankshaft broke,,,,,,,,,,,,

The Titanic also ran when it was parked.

I wouldn't panic quite yet. I'm not the expert, but that amount of movement not showing valve movement doesn't surprise me that much.

First, have you tried tapping that stuck valve down a tiny bit at time? Not to compress the spring the whole way, but just enough to get it moving and maybe it will pop back part way, then you can work it loose.

Then keep working the engine back and forth until you go all the way around. A breaker bar on the front of the crankshaft is the only way to go about that. You're not going to ruin anything that isn't ruined already, if you pull the pistons and clean it all up, you're going to get new parts anyway most likely.

Very rare to have valve train failure on these old beasts. As stated I don't think your getting enough flywheel rotation to really tell. At this point I'd say it's either head off or remove the #44 hydraulic control to get access to the crank. Other option is to rig up a hand crank affair in place of the starter although that will require a RH helical drive gear.

Old Magnet said:

Very rare to have valve train failure on these old beasts. As stated I don't think your getting enough flywheel rotation to really tell. At this point I'd say it's either head off or remove the #44 hydraulic control to get access to the crank. Other option is to rig up a hand crank affair in place of the starter although that will require a RH helical drive gear.

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Yeah I am hoping you are right. After some more thought this morning, I think the best plan of attack is going to be to remove the rockers and let the valves all fully close. Then if I can freely turn the engine, I know what to do next (remove timing cover). If not, then remove the head.

I watched your video, and think Old Magnet is hitting on something there. I'm not sure the crank is being turned enough to determine if the cam is moving much. But you are on the right track though.

Likely piston is hitting valve that is stuck open. Free valve, free engine. Don't waste time on timing gear.

Update?

on any old engines if i suspect mouse or water intrusion, i pull the exhaust manifold to verify. stuck valves can be tricky. lots of penetrating fluid and carefully tap it down about 1/8" then carefully, with two pry bars opposite each other under the retainer, attempt to pry it up. the exhaust valve stem on most old engines is usually visible through the exhaust port after the manifold is removed

Kyfarm said:

Update?

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Sorry, had 2 solid weeks of in-laws visiting, and the weather has been rough.

I pulled the valve lifters off the side and a few lifters were stuck and the valve train is covered in surface rust. Also looks like the rods and non-machined surfaces of crank are covered in surface rust. Judging by the rust pattern on top of the head, its clear that water was getting into the engine through the valve cover studs (the seals were toasted). Surface rust also might be due to long term exposure to sulfuric acid from diesel? Not sure.

Once I took the lifters out of the block, the engine rotates about 180 degrees now. So I am suspecting rust buildup in the cylinders is the final (of several) culprit. I'll confirm that when I pull the head. I have all the bolts off the head but it's pretty stuck so I need to get a big prybar on it.

Trying to decide now if I want to clean up the rust as best as I can with the engine still in it, or should just bite the bullet and pull the engine, disassemble and clean up. I am going to have to pull the radiator to get the cam out to clean it up, so it might be just best to pull the entire engine. It would also nice to be work on the engine in a clean shop instead of next to a blackberry bush outside. I guess I will decide when I get the head off. When I get to this point in a project, I like to take a few days off to think about it before I do anything drastic.

There is definitely going to be pitting on the surfaces of the lifters/cam/etc due to the rust build up. Not sure I want to replace all that stuff though, Hoping I can just clean it up as best I can and smooth it back out and go from there.

Some of these pictures are pretty bad, might be considered NSFL. Don' look at them if you have just eaten. Just about every non-machined surface is covered.

This is about par with blackberry rescue tractors .
Bob