Aaannnddd POP!

[F-127]

Well, by the title of the thread can you guess what happened? Between the extremely loud pop and white smoke out the tailpipe it might be enough of a clue. I also had projectile mystery(well not really a mystery) material in the engine compartment, only found one piece, good chance its my problem.








Head gasket anyone?

[907DAVE]

Wow....had me worried there for a minute.

That sucks man, but its not the worst thing that could have happened.

Any coolant get into the cylinders?

[F-127]

Yeah I guess I could of had projectile engine block material, so its not the worst scenario. It blew out right at the back of the driver's side head. I'm kind of amazed at how that gasket made it from there up above the A/C line. Head is still on, but I'm guessing there was coolant that made it to the cylinder just from the smoke out the tailpipe, the rest of it just poured on the ground.

Engine kept running, it was a definite POP when it happened. It was the first real WOT run with the pickup and current setup, as I was usually satisfied with performance at half throttle or less. Comp 910s were waiting to be installed so I though I might have lost a rocker arm as well but they all checked out. I had just changed the oil after hauling a smaller tractor on a bumper trailer. I went to unhook the trailer and then only a few miles before putting it down. Probably about 10 minutes from the oil change... I did not even THINK of it being a cold engine with such a recent oil change and possibly cooler oil until after it happened. I'm not sure if that had an effect or not.

Pretty full day of work at the shop, so it'll probably be after hours before I dig deeper. Might hear from me late tonight.

[F-127]

Update time, I knew that headgasket at the back of the cylinder head had blown out, so that's the first picture, #8. Star pattern from some too advanced timing? Its really the only cylinder with a definite pattern.




Prior to head removal I had noticed that the gasket had also pushed out slightly on the front cylinder of the same bank, #2. There is a very minute star pattern, I can only see two "points."



Figuring I've been flirting with disaster running new stock springs(supposedly around 20k since replacement), yes its true. Everything looked fine in the valvetrain when removed, but I'll be taking a much closer look.





Figuring on stock headgaskets with new ARP or H11 headstuds, probably throwing on a 68/74 modded H2E and turning down, knowing the high HP that the sledgehammer would provide is kinda out of reach with fresh headgaskets and the local street diesel class is 2.8 anyway. Going to check piston protrusion on 2 and 8 compared to the rest. Had the 910s to install for a while now, just didn't think I'd be doing it with the heads off. YAY! Can't really justify a complete engine build quite yet. Need a few more $$.

[cleatus12r]

Originally Posted by F-127

Update time, I knew that headgasket at the back of the cylinder head had blown out, so that's the first picture, #8. Star pattern from some too advanced timing? Its really the only cylinder with a definite pattern.

That'll buff out....

Sucks to see it but as Dave pointed out, it could have been worse.

[F-127]

Picture time, once again. Despite have quite a few 7.3s in the family and working on several others as well, it's the first time I've had a cylinder head off. In the process of getting the head real clean I noticed some machining. Anyone know if this is an OEM head surface? Supposedly rebuilt about 20k miles ago, so it could have been resurfaced sometime. With all the tractors and other vehicle heads I have never really seen anything like it, in fact I can lightly feel the machining with my finger. I've been taught that if you can feel something on the head or the block, it isn't clean enough yet. Unfortunately I can't really scrape that off... lol. Probably going to call the machine shop in the morning to get an opinion too. Might post on a higher traffic site like PSN, but thought if any vistors here could chime in that'd be great.