Huntr

As discussed above I recently had to drop a second block off at the machine shop. To get the other block I pulled the original engine from the comanche and stripped it down. Pulling and engine/transmission/transfercase alone was...fun. Very doable but definitely took a few hours. Interestingly enough, this Comanche block has "BT" cast all over it. No one on the internet seems to know why. It's also got an AMC logo cast into it which is kinda neat.

I agree. They explained it as being gouges near the top of the cylinders where the ridges form. I could definitely see someone accidentally boring over the .03 I requested but I am going to hold off on judgement for now. They are a reputable shop that most people know of in the stroker world so I won't call them out just yet. I work in a machine shop currently so when I get my original block back I will check the bore size and report back. They are working with me on the price and not charging me for boring the first one since they are doing another one for me right now. The only other thing that made me question them was when I discussed freeze plugs with them today. They told me they would only press in steel plugs. They refused to do brass stating that they will leak and I would have to do it myself if I wanted them. Seems to go against everything I've read online. I will report back about the shop when I get my blocks back. Here's hoping everything else goes as planned and I'm not stuck looking for a THIRD block!

Yeah it's pretty cool I just don't know if there are any significant changes in the block like how the freeze plugs are different. Since I'm going to stroke it I'm wondering if the dimensions are all the same on the deck height and bore. Interesting at how many variations there are over the years of this engine!

I just pulled the block from my 87 Comanche and noticed some differences between my 88 cherokee. There are multiple "BT" castings all over the block. There are also different size freeze plugs, both 1in and 2in. They are also steel plugs. Anyone seen these early "BT" blocks before? I can't find anything about them on the internet. I am looking to build a stroker out of the block so are there any major differences I need to be aware of? Is it okay to use this block in a stroker??

Weird right? When I looked at the cylinders when I took it apart they looked pretty good to me. Could still see crosshatching on all the walls...

Call from the machine shop this morning. Apparently the block I dropped off has to many deep gouges in the cylinders to be worth saving. They bored it to .040 over and it still has deep ridges which means the "working well maintained HO" that I drove to Nevada to pick up turned out to be a POS Renix block that someone tried to bolt an HO manifold to and never did an oil change on. What a waste of time and money that was. Now I'll be pulling the existing Renix block from my Comanche out this weekend and dropping that block off at the shop which is what I should have done from the beginning.

Today I swung by a Pic A Part down in Ogden and was able to pull a 7120 head for a pretty good price. I also located a horseshoe style intake that I'll be going back for in the next few days. As of right now here are the planned specs for the build: Renix block New 4.2 Crank Russ's Racetec Pistons 0.030 over Russ's Rods Comp Cam (still need to spec one out) 7120 head ported with LS valves and springs 99+ Horseshoe intake with matching TB modded for Renix TPS 24lb Bosch Injectors on 91-97?ish fuel rail with vacuum pressure regulator I am hoping to use the full Renix system to control ignition etc. I don't have the time or space to do an OBDII swap right now. Anyone have experience with Renix controlled strokers? This budget stroker got expensive real quick....

This week I sent the block and head off to Clegg Machine to get them hot tanked and inspected. I've been really struggling with which way to take this engine rebuild and after talking with Russ Pottenger I think I've been persuaded to go all out. I'll be doing the 4.2 crank with Russ's pistons and rods to bring me to basically a 0 deck with little to no decking of the block. I am struggling to justify going all out with the head and cam right now. Right now I have the Renix head at the machine shop but am considering either swapping to the 7120 head or the fully ported/LS valved head that Russ offers ready to drop in. I worry that the Renix head and intake won't breath enough and thus cause me some disappointment down the road. I might have to see what the local junk yards hold in terms of intakes and cylinder heads.

Here's a short little update on the past month. Between finishing up my last few weeks of college and work I haven't been able to get out into the garage much. On top of that I just received my EAD to Sheppard AFB at the beginning of August which is much earlier than anticipated. Once I start out at Sheppard I doubt I will have the time or the space to work on this thing during the next 2 years of training. This puts me in a time crunch to get this thing running! This weekend I was able to pull the valve springs and valves off the head. The damn things were so stuck on that it took PB blaster and some persuasion with a mallet to get the keepers to separate from the retainers. This was after trying the trick of hitting the tops of the springs with a socket and hammer to unseat them. I don't have a solvent tank to clean the head or the block so I'll be having the machine shop take care of that. The block and head don't seem to show signs of cracking or warping so here's hoping that the machine shop doesn't find any surprises. Hopefully by the end of the week I can have the block disassembled and the head, block, and crank off to the machine shop. The current plan is to use the existing crank and camshaft and just rebuild the engine to stock depending on their condition when I remove them.

Awesome thanks!

Anyone have that Mopar part number for the pump? All I'm seeing is a pump for a 2001, not a Renix. Are these interchangeable?

Oh god who let you on this forum I'll try and have it ready sooner than later, but no promises.

I thought about it. But I don't want to be taking tools on and off all the time when I fold the table down. My tool storage is also pretty good right now, lots of empty spots in my large roller toolbox (which must mean I don't have enough!)

I've been wanting a big table for garage projects for awhile. This engine rebuild gave me the perfect excuse to design and build one. I wanted to maximize the area of the table but currently only having a two car garage really limits me on space. I decided to design a table that uses a full 4x8' sheet for the table top, but collapses down to be pushed up against the wall when I'm not using it. When folded up, the base doubles as a workbench. So even though it is taking up space along the wall, I can still use it as a bench. Here are the drawings for the table if anyone is interested in dimensions. FoldingTop Drawing.pdfFoldingBase Drawing.pdf

Glad to hear you guys think its not too far gone. I think you're right and I'll finish tearing down the bottom end. I really need to find a machine shop up here. The only one I know of is like 3 months out before they will even look at your engine.

Shortly after getting the Jeep home came the first bad news. A loud knock (LOUD) started emanating from the bottom end of the engine accompanied by very low oil pressure. Around this time I figured it would be fun to undertake rebuilding an engine so I set out to find a HO to rebuild and swap in. The BA10 was also shifting poorly and is just all around bad so when I stumbled upon a HO/AX15/NP231 combo for a good price I jumped on it. Without asking too many questions or looking very closely at the pictures I was on my way down to Nevada to pick it up. The kid had told me on the phone that it was a 91 HO that he had planned to drop into a wrangler. He said it ran when he pulled it out of a cherokee and had just been sitting in his garage since. The crank turned over just fine and the engine and trans looked to be in fair shape (despite being an internal slave AX15) and having another NP231 around is never a bad thing. I loaded her up and made the 6 hour drive back up to Utah. When I got it home and got it up on an engine stand is when I started noticing all the issues. Lots of things were just cut off to get it out of the donor vehicle. A bracket on the intake manifold it broken. I still need to check casting numbers to be sure, but there seems to be some mismatches going on, it may just be replacement parts that someone had put on the Cherokee thats throwing me off, it definitely looks like the newer HO throttle body and thermostat cover. The real surprise came when I took the head off the engine.... Unfortunately I was too surprised to remember to snap a picture, but sitting on top of one of the pistons was a screw! Someone had dropped a screw down a spark plug hole at some point where it lived for who knows how long. Fortunately it looks like it hadn't been started with the screw inside, but its a good thing that someone didn't buy the engine with plans to just drop it in and fire it up! The build up in the pistons looks to be pretty bad, I don't have experience with the carbon build up in these engines so maybe someone can chime in. Right now the engine is just sitting disassembled in my garage while I try and figure out what direction to go. The original plan was to take the block and head down to a machine shop to be magnafluxed and inspected. Now I am stuck between just rebuilding the Renix or moving forward with this one. I don't plan on a stroker build or anything crazy right now, just interested in the experience of restoring the engine. If I want more power down the road I may look at doing an LS or V6 Vortec swap but thats years away.

Plenty of cool trails up here! (Although I am a southern desert guy myself) I'll try my best to keep everything up to date! Lots of high quality pictures will accompany everything! I'm currently finishing up the last few months of school so it might be a slow start here.

I figured as much. I just need it for personal use but was trying to avoid modeling as much as I could. I will just start modeling the bits and pieces as I go and try to make them available to anyone who needs it.

Hey guys, Wondering if anyone knows of a solid model of the MJ frame. It would be super helpful for modeling bumpers and stiffeners and such. I did some digging and someone had mentioned they were making a model but that was like 6 years ago and the thread seemed to die off. Figured I would ask before spending a few weeks trying to model it myself. -Hunter

As all Jeep builds tend to do, this Journey started off in a highly compulsive jump off the deep end. But first, some back story. 'Way' back in 2015 I started my obsession of throwing cash at a old crappy cars. After selling my perfectly good Toyota Sequoia I got my very first XJ. I developed a love hate relationship with it but fell in love with its ability to never leave me stranded despite abusing it through thousands of miles of California mountain and desert trails. When I moved to Utah for school it was the car that came with me to get me through the Northern Utah winters and explore the endless expanse of trails. Despite all of its chronic problems (over heating, belt squeak, lifter tick, oil leaks, and other 'normal' jeep things), I continued to upgrade her turning her into what I consider a moderately capable rig. She sits on 33's, ford 8.8 rear w/aussie locker, 4.56 gears, disks all around, 4.5 in lift, 3 link long arm, trussed front/rear, winch, RTT, Fox reservoirs, among other things. This Jeep started an addiction which I expect to plague me the rest of my life. The moment I realized what I had was an addiction and not a hobby was the moment I pulled the trigger on buying my first MJ. Within one hour of this 1987 Jeep Comanche being posted on KSL I was in the car on a 5 hour drive headed to Oregon to check it out. Did I mention that I hadn't even thought about buying a Comanche until one pulled into the parking lot at work not 1 hour before this? The jeep was everything I expected except noticing a pretty good leak from the radiator that the owner said he had never noticed before. 4x4, long bed (damn this thing turns like a semi compared to the xj), no visible rust (haven't checked the floorboards yet, that's first on the list), and no dents. By pure coincidence it turns out that the guy I was buying it from actually went to high school with my girlfriends dad. He was very hesitant to let me drive it the 300 miles back with the radiator leak and it took some convincing to get him to sell it to me. With the truck now in my possession we made the 300 mile drive home without incident. I was pleasantly surprised at how much quicker it was on the highway compared to the xj with its lift, tires, gears, and aw4 trans. Here she is in front of my house after making it home. Notice the tramp stamp someone added to the tailgate (Hence the lame title!) One of my biggest regrets with my XJ was not documenting the build. I told myself I wouldn't let it happen again so we will see how long this lasts. In the next few posts I will bring the build up to speed. Hopefully over the next few months I will get some more free time to put into the Jeep after I graduate and am waiting to head off to more training.

Nice! He will definitely be able to hook you up with something then. I'm finishing up my last few weeks of Mechanical Engineering up here at USU. Can't wait to be done. Buying two jeeps just means twice the headaches... I am probably sacrificing the XJ to build the comanche though. Going to take the long arms, axles, etc. out of it. I can't really have 3 cars while I'm moving around the country.

Not sure on your situation but most colleges offer student licenses for programs like Solidworks. If you are going to school I would poke around and see if you can find an educational license offered by your school. If you aren't in school then I'd try and find a friend who is who can get you a copy! Thanks! I figured I needed at least one of my jeeps in it.

That's why I've got the RTT I definitely don't plan on taking more than about 8 or so inches off. It's not so much the dragging the a$$ it's more about disliking the look haha. Just download a CAD program and get drawing! I've had 2 years of CAD classes and honestly you learn much more doing personal project then they can ever teach you in a class. There's also tons of awesome free lessons online. Goengineer on Youtube has great free resources for Solidworks. If you ever have any questions about Solidworks just shoot me a message and i'd be more than glad to help!

Planning on shortening it? Not right away, but eventually. I need to get it running and all my suspension moved over from the XJ first. I'm up against a time crunch because I might be moving in the next 6 months so realistically it'll be a year or two haha

Awesome to see some other people with Comanches so close! Might have to meet up one day after I get my truck further along and driving again. Any plans on cutting down your bed at all? I am highly considering it before I paint mine.