88 Jeep Wrangler re-power
 

I've had this Jeep for quite some time, and it has served me very well. We use it for exploring the back-country and having fun outdoors. It's seen countless iterations of builds including axles, tire size, suspension, and a motor swap. After some parts swapping in 2018 I ended up with a motor that would be a perfect candidate for the Jeep, so I had it on the stand until I had a chance to do something with it. Fall 2019 was that chance (yep, this is a retrospective thread).

Re: 88 Jeep Wrangler re-power
 

20 years ago, I pulled out the original carb-ed 258 for a TBI 305 (I was told it was a 350 when I bought it which I later found out to be false). Though it never had an abundance of power, it served my needs very well. In the off-road world, fuel injection with the ability for the engine to stay running is far more valuable than having loads of power. Now it was time to pull it and replace it with a 6.0, which is far more modern and the added power should mean it is more fun!!

Re: 88 Jeep Wrangler re-power
 

I decided that I would re-use the existing built 700r4 that was in the Jeep. It was built with all the upgraded components, and had a non-lockup torque converter so it needed no electronics to run. It also had very clean fluid and no clutch residue at all in the pan. I would later regret this decision to keep the old school transmission and hook it up to the newer school engine.

The engine compartment also was really in need of some work. It had dirt, a little oil, and 30 years worth of buildup on it, as well as 24 years worth of me drilling holes and changing things. My goal was to weld up everything that wasn't needed, and basically clean it all up prior to the new engine going in. Power washing was the first order of business.

Re: 88 Jeep Wrangler re-power
 

All the unnecessary holes were TIG'ed up, planished, and ground smooth.

Re: 88 Jeep Wrangler re-power
 

Some epoxy, some filler, more epoxy...

Re: 88 Jeep Wrangler re-power
 

Added some fresh blue and black paint, and I have what I wanted. A clean firewall ready for a new engine!

Re: 88 Jeep Wrangler re-power
 

I'm using the manage attachments feature and directly uploading the pics, any ideas on how I not get them to rotate or show upside down?

Re: 88 Jeep Wrangler re-power
 

The engine fit in just like a dream. Having smaller physical dimensions than the SBC it replaced makes that simple. I used adapter plates since I already had the SBC mounts in it and I liked where the engine had been placed. I had no need for the low-mount A/C pump so there were no clearance issues.

I had a little bit of a time getting the engine to line up with the transmission and not hit the firewall....that was weird. The old engine had a distributor and didn't come close. Oh wait, when I push back, the transmission is moving backwards too. Transmission mount was destroyed, that now makes sense. Not only had it torn the polyurethane, it had also broken the 1/4" steel capture inside the mount. I guess a new one was in order, as well as adding that to my preventative maintenance list to check on in the future.

Re: 88 Jeep Wrangler re-power
 

Looks good...
I'm not sure how to keep your pics right side up..I've seen where someone says to resize them...

How'd you overcome the 700r4 kickdown cable with the LS?

Re: 88 Jeep Wrangler re-power
 

And re-assembly. I used C6 corvette exhaust manifolds and a new dual pass radiator with both inlet and outlet on the passenger side to keep everything tidy and compact.

Re: 88 Jeep Wrangler re-power
 

OK, I was hoping I wouldn't have to do that because it takes 4x as long to upload the pics, and we all like pics!

Stay tuned, I'll be getting to that.....;)

Re: 88 Jeep Wrangler re-power
 

I wanted to keep my York compressor, so I ordered a Goat Built bracket to mount it on the passenger side. I also picked up the serpentine pulley for it because I think it is a lot cleaner than the adapter pulley I used on my old alternator. I experimented with positioning....hmm, can't be up and down without a large hole in the hood....

One thing I did learn with the York, everytime I changed the position it changed the belt length. Up makes it a different length than over to the right vs. different length than over to the left. Documenting it here for others to maybe benefit from someday.

Re: 88 Jeep Wrangler re-power
 

For about the last year I've been watching antifreeze leak onto the passenger side floor. Not a lot, but in a weekend of 4 wheeling it would definitely leave a wet spot. I knew this project would be coming, so I delayed fixing the heater core until it was all torn down.

The old heater core was the original 1988 one, and it was copper/brass. All the replacements are aluminum. This would be fine, but the new ones don't come with the bracket that the mounting screws bolt to. They rely it to "float" in the housing, and this didn't sit well with me. Especially since when assembled, I would have aluminum hose bibs coming out of the steel firewall, and with vibration that is guaranteed to be a pain in my ass at some future date! My solution was to duplicate the original bracket and weld it to the new heater core. I do NOT have enough practice TIG welding aluminum, and that is a goal that I have for someday in the future....but it seems to be holding (and more important not leaking).

Re: 88 Jeep Wrangler re-power
 

Exhaust was fairly easy, I had a single 3" before with a Flowmaster. I cut that off and made a new Y pipe to attach back to it. I used Holley band clamps, they seem to seal better than others I've used.

I took some extra time with a die grinder inside the merge after it was welded to ensure a nice smooth transition. In my head, that'll add .3875 HP!

Re: 88 Jeep Wrangler re-power
 

Fuel system. I don't like to spend gobs of money on AN anything, and stainless braided hoses. Instead, I wanted to use nylon fuel line like I did on my '49. This was a 2005 motor, so it was returnless. I also didn't want to use a corvette filter, so I decided to use the stock 2005 van fuel pump and mount it in the fuel cell. This would do several things for me. 1) when I'm out on an adventure and I need another one, I just pick one up for a 2005 van 2) it takes advantage of the fuel pump module benefits inside a non-baffled fuel cell 3) use a 2000 van fuel filter that I can get anywhere.

Here's how I did it. I had a machinist buddy turn me a clamping ring that would fit on the fuel pump and an accompanying threaded ring for inside the cell. I then had to make a spacer to take up the gap, use some fancy fuel-safe rubber sheet to make my own gasket, some nitrile bonded washers from McMaster Carr, and BAM....fuel system!

Disclaimer: I filled the cell with soapy water to within 1/4" of the top and did my cutting with an air saw. No explosions here.

Re: 88 Jeep Wrangler re-power
 

Because I've regretted not having a permanent fuel pressure gauge on the rail before, this project got one. Used the Holley setup, and I'm very happy with it!

Mounted the fuel cell back in it's place. Last time I did this build, the fuel cell was sunk into the floor behind the back seat. Everything cleared my "luggage rack" that sits on top of the cell just fine!

Re: 88 Jeep Wrangler re-power
 

Wiring: Nothing super new here. I wanted to remove any unnecessary wires from both the Jeep and the engine to make it clean and any future diagnostics easier for me. I also wanted the wires to wrap behind the intake vs. over it, and wanted the ECM mounted behind the dash vs. on an inner fender (I don't have inner fenders). I re-pinned 95% of the wires that go to the ECM, it turned out like I wanted.

Re: 88 Jeep Wrangler re-power
 

Here you go Mongo, the TV cable. This is the part that makes me regret running the 700r4. I bought the "TV made EZ" kit from Bowtie overdrives, and it has not been easy. It comes with a new TV cable, bracket, and plate that mounts to the throttle body. Despite multiple calls with their tech support and adjusting, and re-adjusting, I cannot get the transmission to shift in what I would call a "reasonable" way. It shifts very hard, almost violently now. My line pressures are good per their tech support. I still have to do some more messing around with it before I pass final judgement, but my advice to others is put a tranny behind an LS that is supposed to be behind an LS, and let the computer do the adjustments for you.

Re: 88 Jeep Wrangler re-power
 

I was just guessing , but I figured that may have been why you regretted it...

Re: 88 Jeep Wrangler re-power
 

I always wait until they run before I wrap the wires in loom. I cranked it over and over and over, and nothing. I had cleaned the injectors, had 58psi at the rail, held them up above the intake and saw the spray pattern while cranking. I had spark. The very last thing I did before pulling the engine out of the van was to do a compression test so I was confident that it had compression. HP tuners told me I wasn't getting a cam signal, so I bought new cam and crank position sensors. After scratching my head for quite some time I pulled a valve cover, and things weren't moving when I cranked it over. That led me to stripping the front of the motor back down and sure enough, the timing chain was broken. Another lesson learned, always replace the timing chain.

The best I can figure, the timing chain must have snapped the very first time I bumped it over after it was in the Jeep. After replacing the timing chain, all cylinders once again had good compression and no leakdown so even though with my scope I could tell that the pistons had tagged the valves in several holes, nothing was bent. Put it back together and it fired right up and ran perfectly! PS, I love the little plug in the side of the block for priming the oil pump!

Re: 88 Jeep Wrangler re-power
 

dang...was that thang under water?...sure is a lot of what looks like rust behind the timing cover

Re: 88 Jeep Wrangler re-power
 

And that pretty much brings me to current. I wrapped the wires in split loom, and finished up the intake plumbing. I also swapped out my dash lights for LED, swapped out the fuel gauge with one that matched the fuel module's ohm scale.

Like I mentioned, it does run and drive, but doesn't shift well. I have googled a lot but have yet to find a story of someone using the TV made EZ kit behind an LS and liking it....guess I should have done more research before starting. I'll either figure it out or change it.....

Re: 88 Jeep Wrangler re-power
 

Nope, carpet cleaner's van. Never left town, and probably didn't warm up to temperature much. That was actually the worst looking part of the engine, everything else looked great.

Re: 88 Jeep Wrangler re-power
 

Super nice! You will find some weak links in your drivetrain with that puppy thumping up front.

One the photos I open mine in Paint, make sure they are oriented correct. If not, I rotate them and re-save under the same file name or a new one. Regardless if they open correct or not, I re-save in Paint and that seems to clear up the orientation issue.

Re: 88 Jeep Wrangler re-power
 

Thanks!

So now you have me experimenting, and if I open the sideways pics in paint they open "right side up". They also appear "right side up" in windows explorer...the only place they don't appear "right side up" is here on the forum....