2 - Drivetrain

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Isuzu 4BD1t > GM 4L80e > Dana 300 > Dana 44

After learning about the different motors I have, the 89 is more efficient and quieter. That's the one I want. I also want to make sure that the motor runs before I put all the time into installing it into the Wagoneer. I strapped the motor to the cart I've been wheeling it around on, got some fuel, found a couple batteries to borrow and Wham!

Runaway engine!

I was prepared to bleed lines and coax this thing into life. What I was not ready for was a runaway engine. If you don't know what that is, I started the motor and once it fired up, it went to max RPM > full throttle. (there is no throttle on a diesel, but imagine pedal to the floor). I pulled the fuel lines out of my 2 liter bottle, still going. There's enough fuel in the filter to blow this thing up, or there's a leak in the turbo and it's feeding itself on motor oil. It's like a vampire drinking it's own blood. I stood there for a second wondering if I should run away or keep trying to shut it down. The fan was blowing so hard I couldn't see when I was close to it. The fumes were filling the shop quickly. I could feel the heat coming off the motor. I was imagining motor parts flying out the side of the cases when the engine finally gave up.

I finally went to grab a 2x4 to put over the intake and it sputtered out. I stood there with weak knees. The dipstick had gotten pushed out and oil was on the hot side of the turbo making it smoke. Vapors were rising out of the water pump housing. My eyes were watery from all the exhaust and air. It was also about 95F in the shop, which is hot for an Oregonian.

Next day I pulled the intake tube from the turbo to the motor and there was no oil. OK, the turbo was not feeding the engine. I fed tranny fluid into the pump and let it sit overnight. Next day I made some adjustments on the IP (injection pump) and had a nice piece of aluminum channel in my hands to block the turbo inlet in case of another runaway. Started it again and same thing. Instantly to wide open. Here's a video of the turbo inlet mostly blocked. This is not good for a diesel. Lean is ok, rich is bad. But it was only for less than 60 seconds at a time, and I needed a running engine to test.

I thought about going to the 86 motor, but as I started looking at the two, it seemed like the IP on both is the same exact part number. All the parts swap, so why not the whole IP? And I really want the quieter, more efficient, stronger of the two. It took me several hours to swap them over. Timing marks are critical. Leaks are bad and cleanliness important. One little grain of sand can block an injector port.

Repeated the whole startup process again Friday after everyone left for the day and Voila! We have a running motor!!! After getting so freaked out by the runaway motor, and thinking that I had bought a hunk of useless steel, this was highly gratifying. Hearing it run and bumping the RPMs was awesome.

Expenses Recap:

1800 72 Wagoneer - Jeep

800 4BD1T Motor - Isuzu

600 4L80E Transmission - GM

650 Transmission Adapter - dieseladapters.com

492 Transfer Case Adapter - Advanced Adapters

499 Transmission Controller - DIY Autotune/MicroSquirt

20 TPS - Throttle Position Sensor

20 MAP - Manifold Absolute Pressure Sensor

4881 Total so far

Credits Recap:

200 dead 88 350tbi motor

300 700r4 Transmission

400 Novak Transfer Case adapter

350 Painless wiring kit

100 GM ECM

1500 Isuzu 5sp manual Transmission MSA-5D

2850 Total so far

2031 Net cost so far

Now that I have a running motor, I can move on to actually putting the thing in the rig. I have to make all these parts from different countries, metric and SAE, all work together. Luckily it's been done before, and if you look really hard, you can find info on the internets.

The transmission adapter requires that you grind out the center hole of the flywheel so the adapter can pass through and mate directly with the center hub on the crankshaft. I could grind it out, but a more sophisticated method would be to machine it. It just barely fit on my little lathe, but it made for nice work.

My tooling wouldn't reach so I used a boring bar to enlarge the hole from 35 to 40 mm.

Now she fits

Everything is bolted up and it's time for a test fit to see if this is actually going to work.

I think it's going to fit.

1. might have interference with the fuel tank. Not sure if I'll be able to trim/move it.

2. dipstick is going to have to move as it's hitting the firewall/brake booster.

3. probably have to relocate oil filters. They're going to hit the front diff.

4. oil pan looks like it will clear the axle just perfectly.

I've never done a repower before. Actually, I've never pulled an engine before. Going from gas to diesel adds another challenge to the task. It is really fun.

Next up is motor mounts.

When I was removing the motor mounts that the PO (previous owner) mounted, I noticed that the 72 Jeep frame was not a super strong bit of engineering. I'm just an armchair engineer AND I've never done this before, but I do realize that I'm putting in a motor that's probably 300 lbs more than what was in there. I'm also going to guess that this one will shake a bit more, and maybe some day have a bit more torque coming out of it. The isolator creates a pivot point that's leveraged off the frame about 6.5" inboard. No matter how strong you make the frame side mounting, it's going to want to twist the frame members. Add to that twisting from pure weight a little shock loading of diesel startup and/or diesel torque, and I'm imagining body mounts getting torn, frame breaking, etc.

By building a cradle instead of independent mounts, the force on the frame rails will be straight down with the weight of the engine, and better distributed from the torque/shaking of the motor. Again, this is just me, not knowing really what I'm doing, shooting from the hip, making S up as I go. I don't think I'm way off base here as the design I'm copying is the one that Isuzu used to mount these in the NPR trucks.

So here's my start:

Got some 1.5" Sch 40 pipe out of the scrap bin and started bending it with the dies that came with our angle rolls that I've been waiting to use.

This is my CAD software at it's best (Cardboard Aided Design) If you noticed, the above pic I have the work mounted backwards. This pipe is pushing the limits of the machine, and I couldn't go as tight with the radius as I wanted. So there was a lot of tweaking and adjusting. Now that I know the radius the machine will do, I could go back and do it again a little cleaner... but other than you guys here online, not too many other people are going to see this work. A little ripple in the metal isn't going to hurt in this application... I think. Oh, and I didn't have another piece of scrap that long. And I'm not cutting into new material.

If you look hard, you can see the new Advance Adapters section between the transmission and the transfer case. I picked this up at 2p and had it on the drivetrain by 4p. Awesome bit of kit. Comes with an extra Reluctor Ring and sensor because the 2nd one in the transmission might be a ghost connector. I'll need this to feed wheel speed to the transmission controller and it would give me an electronic signal for a speedometer if I had one.

An added benefit of the engine cradle that I made is that I can slide the whole assembly fore and aft right on the frame rails. Right now the transfer case end is supported by a floor jack, but I think I'm going to do the same with the tranny support. Until I have all the other components in place, I'm not sure where the final resting place of the engine will be. Exhaust routing, intake tube, AC compressor, fuel tank interference, and then hood, firewall, and tranny tunnel will also play a part in positioning. I'll be hugely surprised if this spot is the end spot. I fully plan on cutting my tacks and re-welding the height on the motor mounts.

I'm a little concerned about where I'm going to put the AC compressor. My plan was under the alternator; there's already some bolt holes and a mount for it (that wouldn't work with the compressor I have) and it would be an easy run to the belt drive. I'm running out of space quickly. I will have AC. I'm also concerned about how close the turbo is to the brake reservoir. I've seen a heat shield on other motors, I might have to make one that keeps some of the radiant heat off the brakes.

One other note: I wanted to get the motor/tranny/TC in the frame and supported by the mounts so I could see how much the rig would squat under the weight of the diesel. I don't think it moved 1/2". I was kind of shocked.

I have to figure out where the engine/trans/TC will live before I go any further. I've got a big problem. In order to figure out where it needs to go, I need to assemble the rest of the parts around it. If I re-assemble all the parts around it and I have to move it, then I have to tear everything back out again. Is that called a paradox?

My battle of the day is mounting the cross member for the tranny support. Where the engine is now, I'm about 6" aft of the support. That means I have to box in the frame further back and remount the cross member. In order to box in the frame, I need to pull the body off. Ugh. +

I don't even know where to begin putting the dashboard back together. I have shelves of parts and buckets of bolts, and I'm having a hard time getting started.

For instance, do I assemble the steering column first, or put the dash frame in first?

PO took apart all the pedals, everything. What makes it worse is he was going to use some GM parts (like a tilt steering wheel) so I have a bunch of other parts mixed in the mess. I spent a hour cleaning up and painting a gas pedal only to figure out that it's a GM part when I found the Jeep pedal.

I've found some exploded parts diagram manuals online that are going to help a lot, but sheesh, this is daunting.

I've run into an interference problem. I was looking at the intake tube from my 85 motor the whole time assuming they were interchangeable 85 to 89. Nope. Not only is the 89 much bigger, it takes up a bunch more space behind the motor. I'd have to move my motor about 3 inches forward to make it work, which creates all sorts of other interference. I immediately assumed that I should make a new intake tube and all the fab work that's going to take.

Maybe I should just get the turbo I'm going to eventually use anyway, since I'm going to have to do all this custom work for the exhaust and intake. Hummmm. I wasn't planning on adding power until phase 2 when I detail the motor and maybe put a year on it having fun.

I'm just having a hard time swallowing the idea of spending $750 for a turbo. Of course I want to think ahead to where I'm going to mount and route the Charged Air Cooler. All this stuff is holding me back on actually mounting the motor in it's final position because I don't know where stuff is going or how I'm going to do it. I'm suffering from Analysis Paralysis.

On top of that, I don't even know if this whole thing is going to work. It's hard to start adding "go fast" parts to a truck that hasn't even turned a wheel yet. I'd hate to spend $1000 on a turbo only to find out I wish I would have used that money for the whole engine rebuild when I find out it has cracked pistons/head/cylinders, etc. etc.

I have a 1998 Dodge Cummins Flatbed for work, and I went out and looked at the motor bay again. It makes so much sense.

Hot side comes out of the engine, into the turbo and straight back... where it should be heading anyway.

Intake comes from the filter (up front where the cold air is) into the compressor (cold) side of the turbo and exits up front to the CAC (Intercooler is technically wrong, it's a Charged Air Cooler) back on the other side to the intake.

Setting it up the way it is in an NPR truck is so silly. All these 180* turns crossing over each other going around the engine and over it???

It doesn't make sense for packaging, airflow, simplicity... Maybe it does in a cabover truck. Yes it does. Just not in a Jeep.

Aug. 19, 2017

I just bought a used Holset HX221W for $325 shipped.

While I'm waiting for the turbo to get here, I have a lot of other things to get together.

I put together most of the dash, which I absolutely love:

Then today I wanted to accomplish two things with putting the front together:

1. See where the radiator goes so I know how much room I have. (I bought this rig in pieces, I didn't take it apart).

2. Get some ideas of what condition everything is in, and what parts I'm missing.

3. Psychological and motivational traction.

4. Show my wife that I'm not crazy and this will be a cool rig.

It's so sweet. I'm really happy. And I think the diesel is going to live just fine where it is.

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