1988 4.0L Renix Rebuild

[avnsteve]

I'm curious if anybody has an informed opinion on the wear pattern on my cam in the above pic. I'd really like to know if it's something to worry about replacing the cam, or do you think a machine shop could polish it out, and why would it wear so unevenly?

 

[xjtrailrider]

I'm curious if anybody has an informed opinion on the wear pattern on my cam in the above pic. I'd really like to know if it's something to worry about replacing the cam, or do you think a machine shop could polish it out, and why would it wear so unevenly?

Just put a new cam in it, any wear at all and it will not perform as good as it should.

Go with the stock grind, stay away from the RV cams and such, I think you will be disappointed.

My $.02

 

[avnsteve]

Just put a new cam in it, any wear at all and it will not perform as good as it should.

Go with the stock grind, stay away from the RV cams and such, I think you will be disappointed.

My $.02

thanks, I think I will, do you have the specs for a stock cam for a 1988?

 

[xjtrailrider]

thanks, I think I will, do you have the specs for a stock cam for a 1988?

Nope, someone on here will though.

 

[Shorty]

thanks, I think I will, do you have the specs for a stock cam for a 1988?

don't have specs, but Federal Mogul markets a factory replacement cam under
theie Sealed Power line part number is CS809. It retails for about $150.00 on
Partsamerica.com, but I'd be willing to bet Ebay will have it cheaper.

--Shorty

 

[Bored400]

Excellent thread! I'm going through my 89 as we speak! I've always been told that unless you're building a high end engine that a new stock cam is best. I'm wondering how much bore you guys are getting or got? I dont have any major gouging, so I probably dont have to go big...but is there any advantage to boring it bigger? I've done big block v8's bored over big (hence my screen name!) and I've been really pleased, but I really love the way these little Renix motors run stock so I'm wondering if it would really be any better to change that much? A port and polish on the head is a must though I think. JMO.

 

[xjtrailrider]

Excellent thread! I'm going through my 89 as we speak! I've always been told that unless you're building a high end engine that a new stock cam is best. I'm wondering how much bore you guys are getting or got? I dont have any major gouging, so I probably dont have to go big...but is there any advantage to boring it bigger? I've done big block v8's bored over big (hence my screen name!) and I've been really pleased, but I really love the way these little Renix motors run stock so I'm wondering if it would really be any better to change that much? A port and polish on the head is a must though I think. JMO.

The 4.0 that I pictured in an earlier post has been punched 40 over, the head was milled 20 and the block decked 20.

Runs better than my 3 HO XJ's in my opinion. I put 4.10 gears on my trail rig 96' XJ with only 30" tires(30" tires makes every obstacle a challenge!) and I love the torque, mileage is good as well. I think I'm going to set-up some 3.73's or 4.10's in this XJ as well just for that extra punch when towing my bass boat.

 

[avnsteve]

I'm wondering how much bore you guys are getting or got? I dont have any major gouging, so I probably dont have to go big...but is there any advantage to boring it bigger? A port and polish on the head is a must though I think. JMO.

the point to this particular thread is a bread and butter stock rebuild, no overbore, no stroker cranks, just dependability. I'm trying to see how high a quality motor i can build on the least money and remain essentially stock.

 

[Bored400]

the point to this particular thread is a bread and butter stock rebuild, no overbore, no stroker cranks, just dependability. I'm trying to see how high a quality motor i can build on the least money and remain essentially stock.

That's essentially what I was getting at with my response. I have no problems with the basic package that I have, and have no desire to punch, stroke or otherwise modify what I believe to be a solid little engine. I look forward to seeing how things go with your project!

 

[Wa Woody]

I rebuilt my '88 in 2002 and have been very pleased with the results. I had a local shop do most of the motor work. I did replace the exhaust manifold with a Borla header, 2.5" pipe, high-flow cat, and a Flowmaster muffler. I had welded the stock exhaust manifold twice and it was cracked again when I pulled the motor and the Borla was cheaper than the OEM manifold at JEEP. I also install a K&N conical filter and a new inlet pipe to help the motor breath a little better. Since installing the motor I have added a Art Sound 59mm throttle body and a adjustable MAP sensor to do a little fine tuning. The only thing I would have done differently if I had it to do again would be to have had the header ceramic coated and the head flow-ported while I had the motor down. With my setup, I get good gas mileage and no pinging, although I run mid-grade when pulling anything. Good Luck

Woody

 

[90Blue_XJ]

that's xjtrailrider's engine in the pics, i haven't posted mine yet, but I am using stock because that's what i have, and upon inspection, there's no cracking, nor warping, so penny saved... I do plan to have the exhaust coated (ceramic) to help keep temps down in the bay a little...it's only about $100 here locally from what i understand

I'll ask again. Where have you found in Central Texas to ceremic coat an exhaust header for $100. Not too difficult a question. I have checked around here (Rio Grande Valley) and no shops here do that. I would ship my spare up there to have it done if I had a name and address. Thanks

 

[VAwheeler]

Just put a new cam in it, any wear at all and it will not perform as good as it should.

Go with the stock grind, stay away from the RV cams and such, I think you will be disappointed.

My $.02

I am going through my '90 now. I had to bore it out 0.060" due to the DUMB @$$ that had it before me. When I bought the "master rebuild kit" it came with all new pistons, rings, bearings, lifters, timimg gears and chain, oil pump, gaskets, and cam. I paid $365 for it through a guy that has an ebay store.

http://cgi.ebay.com/ebaymotors/AMC-Jeep-87-95-242-4-0L-Master-Engine-Rebuild-Kit_W0QQcmdZViewItemQQcategoryZ33620QQihZ019QQitemZ8073463623QQrdZ1QQsspagenameZWD1V


The only problem I have found with this kit is that he sent me the wrong freeze plugs which he gladly took back and even refunded me my cost for shipping the box back to him.

Good luck and keep us posted!:eyes:

 

[VAwheeler]

Ohh and another thing. You asked for tips and guidance. I am going to show my ignorance but don't make the same mistake I did. Pay attention to the valve springs if you go to replace them. I purchased the wrong ones from an online store that won't take them back now. I purchaced the "Cylindrical Valve springs for an 87-94 Jeep Cherokee". Come to find out I was told the 1990 jeeps where a toss up whether you had the "Cylindrical" or "Conical" spring. I am not sure about 1988 but pay attention to the top two coils on the springs. The "conical" springs will be a little smaller at the top.
Now everyone knows I am an unattentive Dumb@ss but at least you won't fall into the same catagory.

 

[avnsteve]

I'll ask again. Where have you found in Central Texas to ceremic coat an exhaust header for $100. Not too difficult a question. I have checked around here (Rio Grande Valley) and no shops here do that. I would ship my spare up there to have it done if I had a name and address. Thanks

Mike, sorry it's taken me so long to reply, I really was looking for my stuff I had on the topic, it turns out, it was not local. I'm basically looking for a coater again, here's what i've got so far:

[email protected]
Phone920) 458-3790

Toll Free: (877) 398-9388
Fax:
(920) 458-3748
809 Wilson Avenue
Sheboygan, Wisconsin 53081

Engine Ceramics Header and Industrial Ceramic Coatings
Dallas, Texas 214-352-4931

 

[scca28]

the point to this particular thread is a bread and butter stock rebuild, no overbore, no stroker cranks, just dependability. I'm trying to see how high a quality motor i can build on the least money and remain essentially stock.

Just wondering how you made out with your rebuild. I just got mine up and running last week, posted a little about it in this thread: http://www.naxja.org/forum/showthread.php?t=930988
Took pictures all along the way, both to document my work, and to make sure everything went back in it's place when we installed it. Followed lots of advice from the other guys here, learned a few new things I might not have thought of myself, and also passed along some info I thought might be helpful to others.

When I pulled the head off the engine I was driving with for the past 3 years, I found rust on the cylinder walls. All of the pistons had chunks of carbon laying on them, most of the lifters and rods were blocked with sludge. I haven't even gotten into the crank area yet, but I can't believe this engine ran as good as it did, or even started for that matter, considering the condition it was in. Actually, the junk yard motor I used for the rebuild looked better the day I pulled it than the one that I had been using....I guess that's a testament as to how reliable the 4.0 really is!

Now that I am finished, all the tools are cleaned and put away, spare parts from the original engine boxed up, old block and head wrapped up for future use, there is nothing to do.... I must be having post-partum depression. The dirt under my fingernails is even starting to clear up! I'll probably grab some wrenches and tear into the rest of the old block to see what other gremlins I can find in there.
If anyone has any questions about the rebuild, I'll be glad to help out where I can.

 

[avnsteve]

ok, so it's been a good long while, here are some pics of progress thus far.



this strypeeze is the most effective engine cleaner I've ever used. I just happened to have it lying around and decided to give it a try, awesome!

any opinions on which is the best valve cover to use? this is a pic of a 92, I think I like it better because the PCV fittings fit better




don't ya just love new machined parts?

sorry I didn't take pictures of the piston and crankshaft install, I was so excited to do the job, I forgot the camera!

what color should I paint the block? I was thinking a flat tan/sand color, opinions?

 

[scca28]

what color should I paint the block? I was thinking a flat tan/sand color, opinions?

Here's a small group shot of some of my pics.



This was my choice of colors, just wanted to brighten up the engine bay. I stuck with the stock aluminum valve cover, but just couldn't get it any cleaner than what you see here. The nasty looking block is the one that I had been driving with. Like I said, the salvage yard motor was actually cleaner when I opened it up!
After I removed everything from the new (salvage) block, I soaked it down with a degreaser I got from a Dollar General store. Then I hit it with the garden hose hooked up to our wash tub, so we had steamy hot water. As I sprayed it, I also hit it with some cheap scrub brushes and bottle brushes, also from dollar stores. Next I ran pipe cleaners through all the oil passages, and finished it off with blasts from the air gun and a soaking of WD40. My machine shop guy (installed the cam bearings, and piston pins) told me I did a good job, so that made me feel better. Never though of using a chem stripper. I do have some, maybe I'll try it on the old block when I tear that one down...

 

[avnsteve]

looks good, my rig is red, so i think a red block may be too much, the main reason i'm thinking tan is to show up any oil leaks etc. it'll also help brighten up the bay when i'm working on it later (I hope)

 

[jk333]

Yes that's my daily driver that I am doing a resto-mod on. Its basically stock(4.0,AW4,NP231), but it will get a few goodies which include 3.73 gears, a 29 spline 8.25, posi-lock front disconnect, and HD rear springs and a spacer in the front to level it. I already have a HD tranny cooler, tranny temp gauge, and a few other goodies. It runs good enough I don't need headers. I still run the stock manifold in all of my XJ's, I've found that the money is better spent other places. But everyone has a different opinion.

I have 4 XJ's so I wanted one of them to be nearly as stock as I could allow myself to go. This 90 used to be my Dads that he bought brand new, he passed away a few years ago so it is a tribute to him.

Some before and after shots

I also replaced all of the RENIX input/output sensers/devices etc. and the fuel injecters/pump, distributer, pressure regulator, if you can think of it it is new under the hood or under the Jeep.

Here is another shot of the finished motor, I've got 8k on it now, it runs great.

that's a great looking Jeep. it looks to be i really nice condition. :worship:

 

[xjtrailrider]

that's a great looking Jeep. it looks to be i really nice condition. :worship:

Thanks, My dad bought it new and drove it untill he died a few years back. My stepmom sold it and it took me about 3 years to find it and buy it back. The engine was blown and a homeless person was living in it. I found it at the back of a wholesale lot getting ready to go to the junk yard. I'm doing a resto mod on it now. The engine is done, it has some new interior(some of it was just cleaned good), it has a 29 spline 8.25 in it, a 2" bastard pack/spacer lift, its getting new paint this weekend. I'm also going to use emblems from a 00 XJ and the "Laredo" emblems from a 02 GC. The lower portion, flares and bumper caps(flares and caps are new) are getting the brighter metalic silver like the 96 "Country's" have. I also have the factory silver and grey stripe kit to put back on it.

Here is pics from today at the body shop;