compression Test Results

[FuddyMucker]

Wow Moncha your brother-in-law really knows his stuff, impressive!
I don't remember it running hot but can see where he means (now you have pointed it out).
So a full rebuild is in order then, sounds expensive but fun, I do like tinkering although it would be nice to get to drive it more than 50 yards before I get yet another problem.

So what you are saying I need to do is

1. remove the other head
2. remove all 4 cams
3. remove all 24 valves
4. remove all guides
5. remove all seats
6. get both heads skimmed
7. buy new valves, guides, seats and headbolts
8. rebuild both heads
9. buy complete gasket kit
10. rebuild engine


Surly if I am going to go that far it would make sense to drop the bottom off the engine and replace the piston rings and main engine bearings.
******Then I would have a new engine******

[FuddyMucker]

Roy, I actually had to read that 5 times to fully understand what your were saying (dosen’t help I’m working nights at the moment), very interesting stuff.
I guess you also think, if one valve hadn’t been seating well for a while then it is probably not the only one getting to your well described condition..
I am also guessing that its a 50/50 chance of the chip being blown out as it is falling back into the engine and destroying the cylinder lining?

[Moncha]

So what you are saying I need to do is

1. remove the other head YES
2. remove all 4 cams YES
3. remove all 24 valves YES
4. remove all guides YES
5. remove all seats YES
6. get both heads skimmed YES
7. buy new valves, guides, seats and headbolts
8. rebuild both heads YES
9. buy complete gasket kit YES
10. rebuild engine Maybe

Surly if I am going to go that far it would make sense to drop the bottom off the engine and replace the piston rings and main engine bearings.
******Then I would have a new engine******

The heads, go without question, do them all and do them right or you are headed for another failure. The weak point in the head, and block is where the center cylinder meets up with the two outer cylinders, as there is a lack of water jacket between them. The engineers are relying on convection to keep it reasonably cool but when there is an overheat, those valves will be the victims for sure. The valves, especially the exhaust, rely on contact with the seat to cool by convection, in this case, that valve, whether it was a weak spring, guide galling, or gross mal-adjustment, stuck open, causing hot gases to constantly blow by, thus overheating the valve, thus burning it (Like Roy said) then causing the tell-tale 45deg notch break.

Depending on what your low end looks like. From the pics, it is quite impressive that you still have crosshatching on the piston cylinders after that many miles/kms. If there was an overheating situation, then there would be quite a bit of crap floating in the oil (however microscopically) so the bearings, rods and mains, could have some wear or galling. You won't know unless you look. If it looks good and clearances are in range than you could get by without. But........

[lasturbo]

Did the burnt valve chunk that is missing disintigrated cuz I did not see any damage to the piston and wall in the pics?