[cduemig]

After my 3rd attempt at stopping this massive oil leak and low oil pressure in my engine that already has a dead cyl, I've decided to rebuild it. I also bought another engine that I know at least started, but know nothing other than that. I now have two complete, but what I want is a new rebuilt reliable engine and while I'm at it, why not update it a bit. I can get on ebay the 4.0l conversion head already machined ready for install for 420. I have no idea how much it would cost to get a rebuilt head welded... I figured get my shortblock done. I've been considering taking my 70,000 and reringing her and replacing the head and calling it a day, but if I do all that, just rebuild the whole thing and be sure. I need to do this quickly. The money to do this job is the 94 ranger I have that I need to sell so I have a 3 week window before my roommate comes back and I can no longer use his car to put around in. My jeep would leave about a quart everytime I drove to work so that's def out unless I replace the rear main seal which I really don't want to do, I've already dropped the pan twice at 6 hours per in the last week. I should have just done it then, but I was pressed for time. I have a lot of options in front of me and wanted to know if you guys have any tips or ideas.

Option 1: buy a complete shortblock (I found one in TX for 471, but have to pay shipping twice...) I live in Norfolk, VA so it'd add up.

Option 2: rebuild my engine myself allowing only the minimal work done by the shop

Option 3: rebuild my engine by the machine shop.

It's starting to look like a rebuild done myself wouldn't save me much... What do you guys think? Know any places to check out for the work / parts? Thanks...

[jadams68]

Well this sounds like me about a year ago.
And this is what I did.

http://www.bustedjeep.com/projects/rebuild.asp

Here's some tips based on the writeup I did.

1) The head on ebay is from Clearwater cylinder heads right? If so, keep moving because their quality control is lacking. They sent me a head that was so screwed up that it was unusable. They did refund me without any fuss tho, so it could have been a fluke. I spent the extra cash and got it done right from Hesco.

2) If I were to do it again, I'd buy a remanufactured shortblock from ATK for about $600 unless you can find a machine shop that will do everything for around that price. I made a mistake and took it to a machine shop that does race engines and they were insanely expensive.

3) Buy a Cloyes timing chain. They are the best and the machine shop will be able to degree the cam more accurately.

4) Don't buy a header, use a 4.0 exhaust manifold unless you're ok with a little fabrication (see my writeup).

My engine has so much power with the 258/4.0 head combo..

If you need anything, let me know.

- James

[86cj74.2L]

What do you mean by getting the rebuilt head welded?.

I thought all one needed to do was press plugs into the unused water passages.

I also thought you used a 4.2l head gasket because of the unused water passages.

I plan on trying to do this head swap this winter. I think I have a line on a HO head from a friends parts Cherokee, He is making sure it is a HO motor this weekend.

[jadams68]

Wrong and wrong...

You can use shipping peanuts to stuff the holes and then use epoxy to seal the water jacket, but the best way is to have a qualified welder who can weld iron do it.

Secondly, you use the 4.0L head gasket.

[GPER]

I had mine drilled, tapped and plugged maybe this year I will finish the motor. James what valve springs and retainers did you go with???? Nice site.

[jadams68]

I actually don't know because Hesco refurbed the head. Most likely they are stock 1996 Cherokee parts. All my other parts were Crane, Mellings, Cloye, ARP and Mopar stuff....

With fuel injection it's such a hot combination... I'd expect some serious power gains with a carb as well tho.

[rjcj-8]

I went with the following
valve springs Mopar Performance #5249464
retainers Mopar Performance #4452032
locks Mopar Performance #4529218

I I'm running these with a crane CRN-753901 with the following lift
Valve Lift with Factory Rocker Arm Ratio: 0.456 int./0.484 exh. lift.


I broke several of the stock 4.0 springs before switching to these

[86cj74.2L]

Originally Posted by jadams68

Wrong and wrong...

You can use shipping peanuts to stuff the holes and then use epoxy to seal the water jacket, but the best way is to have a qualified welder who can weld iron do it.

Secondly, you use the 4.0L head gasket.

Welding would definitely be more permanent than brass freeze plugs.

GPER, Are those 3/8 npt pipe plugs welded in?

[GPER]

They are the pipe plugs threaded in the holes then the head and plugs were milled down.

Thanks rjcj-8 for the spring numbers and that is the cam I going with also.