Top End teardown

[Tin Medic]

Wanted: Advice and tips and anything else. Taking the head off tomorrow to install a new head gasket and I need to check the rings. What is the best way to go about this? The engine in question is my FI AMC 258 i6 / 4.2l . I know I have at least one busted ring on the back cylinder, how do I know what size the rings are when I pull them off, are they stamped somewhere? Any supplies I should have on hand? Looking to do this in one day hopefully.

 

[elwood blues]

When I tore my top end apart to put in a bigger cam, I ran into a couple of problems. I ran out of boxes/bags to store all of the nuts/bolts/washers etc, so I thought I would just remember... I didn't remember.

Take pictures, I swear that no 2 AMC engines were ever assembled by the same person, I don't think that 2 engines have the same bolts in the same places. The head bolts for example, some are just hex head bolts, there are 3 or 4 though that appear to be some kind of stud, I don't know what for, but I assumed that they needed to go back in to where they came out of to make sure the valve cover fit correctly.

The water pump bolts are all kinds of weird, again, some revolts, some are studs, but there's no rhyme or reason to why.

If you're going to replace your water pump, there are about 6 different variations out there, make sure you get the correct one.

Last one, that head is cast iron, it's heavier than a dang boat anchor, prepare yourself for that when you're getting ready to clean and jerk it off of the block, it's heavy

 

[elwood blues]

Forgot to add, it's definitely possible to get this tear down accomplished in one day. Sorry though, I'm no help at all with the rings.

 

[TroyaCantrell]

If you have busted rings you will be doing more the pulling the head off, you'll be headed for the bottom as well.

I read somewhere there are 2 at 5/64 and 1 @ 3/16, if they are stock.


Troy--
Steering rehab- http://www.jeep-cj.com/forums/showthread.php?t=4106
Build thread- http://www.jeep-cj.com/forums/f98/1966-cj-6-build-15075/

 

[IOPort51]

may I ask why you think you have a broken ring?? If it is because you are fouling plugs I would check the head for cracks before I started pulling pistons.

 

[IOPort51]

and the #11? head bolt goes into the water jacket so it needs a locktite/rector seal/Teflon seal on it when re assembled.

 

[mtnwhlr]

You can tell how much wear you have by the lip at the top of the cylinder. When new its the same top to bottem as it gets old the rings wear down the cylinder since the rings don't go all the way to the top you can see how much wear you have. A broken ring may leave a scratch in the cylinder. Hope this helps

 

[Tin Medic]

may I ask why you think you have a broken ring?? If it is because you are fouling plugs I would check the head for cracks before I started pulling pistons.

The plug on the back cylinder is fowling pretty bad. Can the fowling be caused by a bad head gasket? I also seem to have a small loss in power especially at takeoff.

 

[IOPort51]

AMC 258 i6 / 4.2l heads like to crack between the valves. Before I started pulling pistons I would do a die-pen test to check for this. This may be a very opportune time to do a 4.0 head.

The plug on the back cylinder is fowling pretty bad. Can the fowling be caused by a bad head gasket? I also seem to have a small lose in power especially at takeoff.

 

[Tin Medic]

what is a die-pen test?

 

[mtnwhlr]

what is a die-pen test?

http://www.google.com/url?sa=t&rct=...rICIAQ&usg=AFQjCNEdzMZZ3BhUL3XWFTM8H_OJXpGKNg

 

[Tin Medic]

So where can I get this stuff or is it something I would have done? It seems similar to magna-fluxing.

 

[mtnwhlr]

Napa might have it or Summit

 

[CJ]

Tin, I think you need to slow down and do a lot of investigation before you decide what to do. A fouled plug can come from many things, as you said - a bad ring, cracked head, faulty valve seal, bad valve guide, blown head gasket and more. If you do have a broken ring, do you have a ring compressor? How about a ball engine cyl deglazer so the rings will seat? Do you know how to stagger the oil / scraper / compression rings?

Just want to through a couple things at you so you can get this job done.

 

[Tin Medic]

Thanks CJ. Tomorrow I am going to pull the head and check that first. The rings will be the last resort so to speak. I am hoping all the problems are in the head, (seals, gaskets whatever). If the problems are not there I will probably go with a full rebuild or a rebuilt engine.

 

[CJ]

Glad to hear you have a plan, it just looked to me like you were jumping directly to the rings - didn't want you to put a bunch of effort into something and be disappointed at the outcome. Hope it is a very minor repair!

 

[Tin Medic]

My mind has a great plan but my typing, not so much.

 

[mtnwhlr]

Have done a compression test?

 

[Tin Medic]

Yes, cant find the numbers but they were all in the 135 range except the last cylinder which was 125.

 

[IOPort51]

the die-pen stuff can be had at a welding supply shop. been a long time since I have bought any but its not too expensive.