First motor rebuild questions.

[Petescj]

Ok , I have this AMC 258 i6 / 4.2l that I plan on rebuilding and throwing in the http://www.jeep-cj.com/forums/f98/600-salvage-cj-7-a-3095/. Other than the 4.0 head upgrade , a cam , and a small 4 barrel holley I havent really planned the whole thing out yet.

My questions are:

1. How far can I tear it down knowing it will sit for at least a few months until I get back to it.

2. Special cautions to take being it will be in the garage. The garage gets cold and damp in the winter months. Will just oiling it down and bagging it be enough?

3. Advice ,with some part numbers if you could, on a nice thumping cam that I can still use at 65 mph with 4.56 gears , maybe 4.88s

Any help or comment from guys who've rebuilt the AMC 258 i6 / 4.2l is greatly appreciated.

Im out of cash right now and have this on my engine stand:

 

[Niedhogg]

I say, if you're going to do the 4.0 head swap, and you seem to have plenty of time, then get all the EFI stuff from the donor vehicle that you get your head from. I would think you could still upgrade to a mild RV cam without having to invest in bigger injectors or a new computer, and that would give you dependability on the trail that you've probably never known before...

 

[Old Dog]

Ok , Special cautions to take being it will be in the garage. The garage gets cold and damp in the winter months. Will just oiling it down and bagging it be enough?

Yes it should be, either oil or greese.
I asume you will get the block at least honed so a little rust should'nt be any problems there. If your getting the crank turned than little rust wouldn't be a problem there either.

 

[Sasquach]

Hesco Inc. - High Performance Engine Service

X2 on the junkyard mpi system. Find the right donar and you can get your head, tubular factory header, intake manifold and injection system with computer and harness.
The Hesco link above sells all the goodies needed to adapt. which amounts to a crank position senser set up.

 

[CJ007]

I agree with old dog, if you break it down completely use a soft cloth to wipe some oil on the cylinder walls and crank and bag them up to keep air out, may be check every couple weeks. I don't have the dampness so don't know how long it would take but those would be my biggest concerns.

Now, let me apologize as I am about to go on and on as I am bored .

You can get it vatted, scoped and bored (will need new pistons too if bored), crank turned, cylinders honed and cam bearings removed and replaced by a machine shop. It can end up several hundred dollars or more for their work plus parts upwards of $500 low end for a rebuild kit with pistons, cam, all bearings, timing chain, gaskets etc. See ebay for ideas on kits. Also the machine shop should have parts or someone to refer you to.

As long as you can't really feel any scoring (fingernail catches= bad, slight catch should hone out) on cylinder walls you are prob ok to just hone and not be forced to bore. Unless they are burned (really discolored). Machine shop would typically advise..... or......... for a redneck rebuild you can pick up a hone for like $10, put new crank bearings, rod bearings, rings (under $100 or so) and rent a tool to pull cam bearing if you decide to do. Full gasket kit is prob under $50.

The cylinder walls will be pretty much glazed and the new rings will need to seat. Search honing on internet on how to hone. You can use a special oil or you can redneck it =regular oil. It should be criss cross with hone done one direction on drill, then reversing drill and doing it again. This just has to be done long enough to get glaze off and establish pattern. Not too long or hard, keep oiled. Also inspect your crank , it will have some lines in it but if its not too bad it will get you by too. It just depends on how little or much you want to spend and whether it appears you need to get bored or crank turned.

Unless I was doing the full machine shop inspection and machining, I might not even do the cam. If you don't do the cam and are keeping the same lifters, make sure they go back in the same holes as they wear in to that hole. If you are dong a new cam, don't put the old lifters in or it will ruin the new cam (should come with in most kits anyway). My brother once did this.

Last, be careful not to scratch your crank or cylinder walls when removing rods down through or when reinstalling and pushing pistons down in, use a cloth or something on the journals so the bolts won't score the crank when you put the piston back in. You will need a ring compressor (also about $10) to get the pistons back in (unless shop does). Make sure you read the marking on the ring boxes, they go a certain way and the openings need to face away so oil/gas do not get by.

There is a alot you can choose to do, or not to. The fully rebuilt way is not cheap, but is peace of mind. Although many times it's like anything else, you could do just the basics and and it could last forever.
Hope this helps.

 

[Kane]

Buy some silica packs and throw them in the bag with the motor. IT should handle the moisture issue. Like the other said, if you wipe down all machined surfaces with oil the motor will be fine.

 

[CJim7]

Buy some silica packs and throw them in the bag with the motor. IT should handle the moisture issue. Like the other said, if you wipe down all machined surfaces with oil the motor will be fine.

Yep. I kept my torn-down 401 in the garage this way over winter when I got it back from the machine shop. Wiped down all the machined surfaces with oil, threw some silica packs in with it and bagged up the crank, cam, pistons, block, and heads. A few months later, all was well.

 

[CJim7]

Unless I was doing the full machine shop inspection and machining, I might not even do the cam. If you don't do the cam and are keeping the same lifters, make sure they go back in the same holes as they wear in to that hole. If you are dong a new cam, don't put the old lifters in or it will ruin the new cam (should come with in most kits anyway). My brother once did this.

Likewise, It isn't a good idea to use new lifters with an old cam. They dont tend to break in properly and will wipe out a cam lobe. I know from experience.

Last, be careful not to scratch your crank or cylinder walls when removing rods down through or when reinstalling and pushing pistons down in, use a cloth or something on the journals so the bolts won't score the crank when you put the piston back in.

I used a couple short pieces of rubber fuel line over the connecting rod bolts to get them over the crank bearing surfaces without scratching them...worked great.

 

[Petescj]

I say, if you're going to do the 4.0 head swap, and you seem to have plenty of time, then get all the EFI stuff from the donor vehicle that you get your head from. I would think you could still upgrade to a mild RV cam without having to invest in bigger injectors or a new computer, and that would give you dependability on the trail that you've probably never known before...

Hesco Inc. - High Performance Engine Service

X2 on the junkyard mpi system. Find the right donar and you can get your head, tubular factory header, intake manifold and injection system with computer and harness.
The Hesco link above sells all the goodies needed to adapt. which amounts to a crank position senser set up.

This will definately take some investigating. I do love the idea of having efi , Im just a Neanderthal and havent even got my carb totally figured out yet. Alot will depend on where the 4.0 head comes from.

 

[Petescj]

Yes it should be, either oil or greese.
I asume you will get the block at least honed so a little rust should'nt be any problems there. If your getting the crank turned than little rust wouldn't be a problem there either.

There definately will be a machine shop involved. The level thats taken to will depend on what I find after shes opened up. Im not even sure of the mileage on the motor. Im pretty sure the Cj she came out of rusted out way before her time.

I agree with old dog,
Now, let me apologize as I am about to go on and on as I am bored

Do not apoligize!! I only reduced your quote to save a little space. I appreciate the info. I dont think I'll be taking any redneck ways with this motor. Id like it to power the CJ7 till its demise ... or next rebuild.

 

[Petescj]

Buy some silica packs and throw them in the bag with the motor. IT should handle the moisture issue. Like the other said, if you wipe down all machined surfaces with oil the motor will be fine.

Hadnt thought of the Silica packages. Im sure I'll come up with some around X-mas. Seriously though good idea

Yep. I kept my torn-down 401 in the garage this way over winter when I got it back from the machine shop. Wiped down all the machined surfaces with oil, threw some silica packs in with it and bagged up the crank, cam, pistons, block, and heads. A few months later, all was well.

Likewise, It isn't a good idea to use new lifters with an old cam. They dont tend to break in properly and will wipe out a cam lobe. I know from experience.


I used a couple short pieces of rubber fuel line over the connecting rod bolts to get them over the crank bearing surfaces without scratching them...worked great.

All good info there. Ive actually been putting my little brain to work as well. If it comes down to me just sending the block out for some machining I'll be able to move all the other components into the basement. I'll just oil and bag them then. Theyll be in the same room as my furnace. Wont be damp.

 

[elwood blues]

Hadnt thought of the Silica packages. Im sure I'll come up with some around X-mas.

Amazon.com: desiccant pack

Desiccant is cheap to buy, don't wait for Christmas presents, those one's are generally cheap and all used up by the time you get them anyway.

 

[Petescj]

Amazon.com: desiccant pack

Desiccant is cheap to buy, don't wait for Christmas presents, those one's are generally cheap and all used up by the time you get them anyway.

That was an attempt at a joke. I usually chew on the Xmas present ones anyway. Thanx for the link. :drool:

 

[elwood blues]

That was an attempt at a joke.