efficientkilla007

I'm in the process of taking the head off of my jeep. I'm doing this because I'm pretty sure my rings are bad. I've read alot about this and I know it's a stupid question, but what do you guys think the best way to go is, new motor or doing the rings? The work isn't an issue for me because I bought the jeep to learn on, but I do want to do whatever is more cost efficient. So what do you guys think? look for a motor, or man up and do the work?

cherokee90

Buy a junkyard motor

volaredon

have you done a compression or a leakdown test? You cant get at the rings by just pulling the head.

Cherockee

It's unlikely that you can "just do the rings". Most engines will require machine work, boring the block, new pistions, etc.
If you skimp you might be able to freshen it up for under a grand. Otherwise buy a used motor that you can hear run and do a compression test on first.
If you plan on buying a motor new you can go cheap for about $1600, middle of the road for about $2K, or all out stroker for about $5K.

Silly me decided to rebuild my motor and I'm over $2K so far and I'm just doing a stock rebuild.

efficientkilla007

I've done a compression test before. not since the actual motor went out on me. But when I did do the test I had really low compression in like 3 cylinders. Then I had all the pressure in my valve cover, which I read was the rings, and I ahd been burning alot of oil which I was also told would be the rings too.

413maxwedge

If your going to buy a motor in the end, buy yourself a short block and skip the JUNKyard motors. I rather put a good one in once, than put 2,3 or more bad one's in and out and in and out.

84zmyfavorite

Yes, All those nuts-n-bolts can get worn out with engines being swapped in-n-out. I would do the Rings you were talking about after you have had the block checked for cracks and coolant system corrosion, and then if the cylinder walls look decent, have a .020, .030, .060, etc overbore done with a good hone finish, check specs last time and then order your New pistons and Rings. While All this is being done, have the lifter bores refinished, Crankshaft measured, and Maby Port&Polish the cylinder head after teardown. I like a New HIGH Performance Cam & Lifter set along with new timing Gear and Chain set at rebuild time. Check everything for wear,...Rocker Arms, Pushrods, Valve seats and Stem clearance, Refurbish Everything or replace with Better Quality.

Caish

I've done lots of engines and just put rings and bearings in them.
At least you know what you have then vs a JY gamble.

Use an old rings as a scraper to remove the carbon from ring grooves.


On trick use some rubber gas line on the rod bolts, will keep the rod studs from scratching the crank. It also holds the bearing in place while your sliding the pistons back in.

leecarr

A low mileage used motor from a reputable yard is probably the cheapest way out. A decent yard will give you a warranty on the motor, you'll still have to do the work but I work pretty cheap for myself. Maybe not the perfect solution but the cheapest.

Caish

http://compare.ebay.com/like/1207916...=sbar&_lwgsi=y
Re-Ring kit for the XJ 4.0 $97.99+SH.
Your not going to beat that at any salvage yard and you've replaced the most common wear items in the engine.

Nothing wrong with it, just don't sell it saying its rebuilt and you can do it in a weekend without pulling the engine.
I'll be doing the same thing in a few weeks, wifes 95 was toasted last summer and cooked the rings at 255k miles. I'll gauge the piston clearance when I get it apart for if its close I'm not worried about replacing the pistons if they look good.

leecarr

It seems a shame to pull a head and not do a valve job and what about the cost of a gasket set. I don't know if any of these are but my son did a valve job on his Dodge hemi pickup and a lot of the bolts were torque to yield and have to be replaced every time.

highmileage

pay 3 or 400 for a wrecking yard motor take yours to a machine shop have it short blocked and you do the final assembly. you can get out possibly on the machine work for 1000 at the cheap. the wrecker motor gives you a way to get around while yours is in the shop, and bonus one to turn into a 4.7 monster after you put your new rebuild in.

leecarr

Very good plan, I plan on rebuilding a junker first then dropping it in before mine dies (236k).

highmileage

Dies, you mean 4.0s' die? When? I am at 422,000 and climbing.


90 cherokee sport

leecarr

I didn't say I was going to do it right away.