Pulled Head

[Tin Medic]

Pulled the head today and the back cylinder was BLACK. A little overflow into the 5th cylinder so I am hoping it was the head gasket. Clean everything and put it back together. The block has been rebuilt, the pistons are marked .030 and the top of the head looks really clean. The head number is 3235480.

 

[tarry99]

What was the "original reason" for pulling the head in the first place?

With that Piston having as much Carbon on it what would make you think it was a Head Gasket?............How is the exhaust port on that cylinder is it oily?

Looks more like Rings or maybe valve guides..........did you do a leak down test before you took it apart?

 

[Tin Medic]

The exhaust port wasnt to bad but it wasnt good either. The head gasket had split in the back hence the black firewall. Already thinking rings due to the last plug always fouling up but I was hoping it wasnt. Everything on the top of the head looked fairly new and there was no sludge anywhere.

 

[Tin Medic]

Going to replace the rings and add the 7120 head so it will be down longer than I wanted but I'll be better off in the end unless I just go with a total rebuild.

 

[tarry99]

Going to replace the rings and add the 7120 head so it will be down longer than I wanted but I'll be better off in the end unless I just go with a total rebuild.

Thats a tough call............If you don't really have any history on the engine since it was last done.......the others could be right behind #6.

Probably should have done a leak down on the motor but it is what it is!. The head had to be loose for it to do what it did IE: the compression leak , also if you look at what the water passages looked like in the head confirms that water was migrating around up there............
So if your going to replace the rings I assume you mean them all? That's what I would do.........pull the motor and get the block honed and have the crank checked and or ground , new bearings and rings , timing gear & chain............hopefully the cylinder wall clearance to Piston skirt is not excessive and if your lucky you can reuse the Pistons!.....the top deck of the block will have to also be checked...........sometimes when a head has been allowed to dance around up there it kills that sealing surface and may have to be decked...........of course the head should also be rebuilt or at least looked at.....valve guides, valve job, and springs.

 

[Tin Medic]

Been losing compression on the last cylinder.

 

[1986cj7]

In my opinion I would rebuild the whole motor. I think in the long run you would be better served to go this route. I also think you would be more pleased with the results after rebuilding the whole motor. But of course as always time and money will also come into play.

 

[Tin Medic]

Got the head back today. I stuck with the stock head but gave it a complete overhaul.











She starts going back together this weekend.

 

[Tin Medic]

Pulled Head, It's back

The block itself was in good shape. No damage to the cylinder walls or pistons. The rings were really worn and the connecting rod bearings had seen better days. The PO had stuffed the head with random oversize valves along with some other questionable parts.

 

[Scooter402]

Glad you're getting it back together! Are we cruising yet?

 

[thiswontbetooexpensive]

Looks great!
That thing is a lot heavier than it looks, dont drop it on your foot.

(It is kinda wierd that these pics of your engine parts get me almost as excited as pics that would get me kicked off of this forum...)

 

[Tin Medic]

Need the oiling procedure for firing the jeep back up. New head and rings and don want to destroy anything.


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[csuengr]

Usually its just priming the pump. Need a tool that can go in an electric drill and fit the pump drive. Turn the pump till oil starts flowing and roll the engine over by hand. One thing to be looking for is oil coming out of the top of the pushrods. They are at the end of the oil path.