Let the rebuild begin.......

[CRASH]

As some of you may know, I finished off my rig a couple weekends ago (details here)http://www.naxja.org/forum/showthread.php?threadid=4593

In any case, I need to rebuild my engine pronto. Anybody have any recommendations regarding brand/retailer for a full engine rebuild kit? I'll need a master kit.

I've done some quick searches, and the going rate on a master rebuild kit with premium pistons (moly coated hypereutectic) and name brand gasket set is $550 or so.

Comments and experiences welcome......should I just buy a long block and be done with it?

CRASH

[CRASH]

And no, I don't want to build a stroker, I just want a nice reliable 4.0 to get my junk down the road.

CRASH

[Stoney]

302 302 302!!!!!!!!! YEAH DO A 302 andy that b sic!!!

stoney:D

jk

[CRASH]

Beezil, can we get someone to invent a Stoney translator? I usually only understand about 5% of any given post.

CRASH

[Maximus]

Andy, I have a 99' HO with 50,000 on it that you can buy real cheap, it will also have the computer. It only needs the flex plate and I think someone in our club has an HO plate laying around somewhere. You can PM if you are interested. It would only be a couple hundred more than the rebuild kit.

[Handlebars]

Originally posted by CRASH
Beezil, can we get someone to invent a Stoney translator? I usually only understand about 5% of any given post.

CRASH
This helps out alot:
Originally posted by Stoney

This person is on your Ignore List. To view this post click [here]

[CRASH]

Andy, I have a 99' HO with 50,000 on it that you can buy real cheap, it will also have the computer. It only needs the flex plate and I think someone in our club has an HO plate laying around somewhere. You can PM if you are interested. It would only be a couple hundred more than the rebuild kit.

Hmmmmm......would my RENIX head bolt to the 99 block? Does the 99 block have provisions for a knock sensor?

I really want to keep the RENIX to keep the emissions and wiring simple. The trouble with switching to the late model stuff is that the whole wiring harness is different. I want to try and make the Swamp LAke trip, so I have to keep custom stuff to a minimum.....

In short, Rob, I'm interested in the motor if my RENIX junk will bolt to it. Anybody know?

CRASH

[Maximus]

You know I don't have any knowledge on that. I just bought it in case my engine went someday but who knows when that will be. I can see about how much of the wiring I can get from the donor vehicle if you wanted to do the wiring, but hopefully someone will have the info on the swap.

I may even try to look at a dealer shop manual and see of the block has the same provisions.

Just think you will have that cool intake manifold that everyone wants:D

[CRASH]

Yeah, but I'd have to figure out how to make the manifold work on a Renix head, or use the 99 head and figure out how to make the Renix computer work with it. Then there is the problem of the EGR......99's don't have this provision, and the smog man is not going to be pleased if I show up without one.

More questions: would the aftermarket headers designed for my 88 fit on the 99 head......something tells me no????

CRASH

[Maximus]

Good point, may be way more hassle than it is worth

[REDXJ4FUN]

Hum theres a few good questions posted. I'm not sure if the 99 block has a knock sensor spot or not. But as for the HO head and intake they will work with the renix. you just need to do alittle work with the TPS to work on the HO TB. That in its self is a great mod. Not sure how to work with the ERG. But any header for an HO will work in and 88 with an HO intake and head.I'm sure theres a way to fool both the computer and the smog ref with out and egr set up.

[Gary E]

I would go for a used low mileage motor like Rob has a hook up for. A 4.0 is not a great motor to rebuild the thin cylinder walls make it hard to keep cool, boreing it out only makes it worse. I have a buddy that works at Kragen, he says he won't sell any reman 4.0s because all the ones he knows of have cooling issues, also he says the mopar longblocks are pretty reasonable, we have a Mopar parts guy in the club, maybe he could hook you up. Plus I think it is more cost effective to go the junkyard motor route.

Use the Renix controls on the HO head and intake, it takes a little jerry rigging but a Renix TPS can work on an HO TB, Keven tried it with little luck but others have had good luck. Keven is a good one to talk to about the downfalls of the swap he hit about all of them :) I will email you a Cached webpage on some of the mods.

[Goatman]

Too much trouble to make it smog legal for CA. You would need to switch everything over to the HO computer and harness. I know an article was refered to recently about someone who put an HO motor in a Renix rig, and adapted the Renix computer to the HO intake and exhaust, but it wasn't done in CA. You need the EGR valve and the heat riser off of the exhaust manifold, among other things.

[Gary E]

Thats true I forgot about the EGR stuff, the HO intake still looks like it has the EGR mount so I was going to bolt it on and run vac lines to it, thats all they care about is that it matches the little schematic. My jeep smogged cleaner with the EGR blocked than it did with it functioning for some reason. When I was planning on usings Matts stroker motor I was just going to bolt the EGR valve on.

If its all to much of a pain you can use your renix intake on the HO head its not a perfect port match but its a jeep not a race car. Otherwise you are paying for a rebuilt head or putting on a 200k mile head on your motor. Of course you could probably sell that fancy 99 intake on JU for a good portion of the rebuilt head.

[CRASH]

So, if I wanted to get a short block, will any of the years of 4.0 work, prior to the distributorless system? The thing I'm most concerned about is the knock sensor provision and the head bolts matching up. It would be pretty cheap to rebuild my RENIX head, and I actually like the extra torque down low of the RENIX motors. Byusing my old head, I eliminate the concerns of the headers and the intake.

Also, any aftermarket cam recommendations? Mopar stage II grind or similar? Remember, this needs to pass smog.......

CRASH

[Beezil]

I'm sorry, crash, i don't understand you.

[CRASH]

Count on Beezil for penetrating insight.

CRASH

[simonsxj]

Hey Beezil too much of that swaybar thing again huh? :)

[simonsxj]

Go and buy a motor rebuilt and ready to go. The time of rebuilding would probably outway the extra cost of the motor. I will be building a stroker motor but that would be over a period of a year until I kill the other motor.

[Beezil]

stoney makes sense though

[Gary E]

so does the turbocharger make it on stage 1 or does it go on stage ? :D

[CRASH]

I'm saving the turbo for the buggy......I just want to get back on the trail. Summer is a tough time to be rebuilding stuff.

CRASH

[Rev Den]

This is what I did....Just an idea, a thought, thats all, may not be your cup-o-oil.

http://www.jasperengines.com/

Rev

[CRASH]

Hmmmm.....the more questions that I have answered, the more form up in my gray matter.

Will Renix intake and exhaust manifolds bolt to an HO head? Are the ports different shapes? Bolt patterns different?

CRASH

[Beezil]

curious, how far away are you on that buggy?

[CRASH]

Well, the rear got linked up, the tub is stretched, the frame extended (4"x 2" x .120"), drivetrain done (4.3 TBI, SM465, Dana 18), axles are close (rear: FJ80 full float, 13" disks, electric locker, front D-44, ARB).

Still needs a cage, fuel cell, wiring, front links and steering.

CRASH

[rsalemi]

The 99 block has all the prior bolt holes and even one for the knock sensor. The header ports are similar and any header should fit - the tubes are bigger than the ports in the head.
The Renix manifold should fit - people have reported using it as is - but I'd try to match the ports by moving it down slightly.
Otherwise the 91 - 95 HO manifold has the bolt holes for the EGR
and I doubt that any Government Employee at the smog station cares much? Or would notice!!

[CRASH]

Hmmmm......OK compression tested my motor this weekend (warm motor, all plugs out, very good compression tester), and this is what I got:

1 125#
2 136#
3 147#
4 145#
5 132#
6 127#

What do you all think of this? The motor had very little water in it, which is a good thing. I really think the main bearings are shot, but it seems like the cylinders may be salvageable, according to the numbers. Maybe a .030" overbore would do the trick, and keep the thing cool in the hot California sun?

What was the compression supposed to be on a 1988 4.0?

CRASH

[Gary E]

15% spread not bad for a 200k motor, a 10% spread is typical of a decent running engine. Just change the oil and run the thing, worry about a rebuild over the winter. Why do you think your main bearings are bad?

[CRASH]

The clickety-clack that is a sure sign of main bearing outage. It's not horrible, and it still makes 60 pounds of oil pressure under load and 40 psi at idle.

Lately, the rig just felt like a dog. The o2 sensor was going bad though, so a new one might help.

CRASH

[Gary E]

yeah clickity clack is a sound better reserved for trains. A stethascope (sp) might be a good thing to do to make sure the noise is from that general area. It would suck to install it in the phoenix and then take it back out to rebuild it later on.

If its any consolation I get 20 psi at idle and about 40psi a little higher up. Not that my motor is a super fresh by any means.:D