TruckA's 1984 720 4x4 gasser conversion to SD22

#16

Here are some more pictures, I'm glad the tranny pictures were enjoyed, I just hope that the differentials and the transfer case don't have similar rust scale. A couple of frequent fluid changes will be due once the truck is able to drive.

The tranny is now assembled, engine and transmission are in the truck. I just need to finish up the driver side mount, and readjust the passenger side mount just a little. Next steps will be to wire and plumb everything up, change out the tank and drain any gas out of the fuel lines, and then mount up the AC compressor and power steering pump to the diesel engine.

Driver side mount almost finished:

Passenger side mount, I just need to shift the lower mount to center the middle bolt a little better:

The pan is close, but this shot is without the driver side mount installed, with the mount it looks like it will do just fine:

#17

Very resourceful your SD22 into the 4x4 720 truck. Looking at the front suspension reveals a 1984 or later model. Did the SD22 come from a 1982?

SDs use an engine mount bracket linking the engine block to the rubber mount. This bracket has offset webs and offset bolt holes. I just wonder ... what would happen if you reversed the left / right sides so that the bracket/mounts might align the frame better. Just a thought.

#18

Yes, the SD22 came from a 1982, and because I'm putting it in a 1984, I hope I don't run into problems when trying to re-register the vehicle as a diesel. It usually a no-no to put an older engine into a newer vehicle, I didn't even think about it before I bought the 1984 720. I read through the NC DMV statutes a few weeks back and didn't see anything, but I'll find out what to do when the time comes for an inspection to get on the road. Anything 1996 and older in NC only requires a visual engine look and a safety inspection, plus all stock emissions parts must be installed.

I tried a couple of different combinations with the gasser and diesel mounts, I'm finding that I need to use the bottom (frame) part of the Z24 gas mount along with the top (engine) part from the diesel to get everything close. Blending the mounts gets the bolt holes maybe 1-1.5" from lining up, and from there I've just drilled or expanded bolt holes laterally to get everything to line up. I'm not done with the mounts so I'll see if switching sides makes everything work better when I start working on it again tonight, thanks for the suggestion.

David

#19

Ok, new update. After wrestling with making and lining up brackets for pulleys and such over the past week or two, pictures of how the power steering and AC compressor are mounted are below. I ended up modifying one of the tensioner pulleys from the Z24 engine and was able to mount it below the power steering pump so I'll be able to take the slack out of the belts. The PS pump by far was the easiest to mount. I had a piece of angle iron laying around, and it all fell into place very easily. I ended up using a piece of aluminum I also had laying around because the bolts just so happened to line up very nicely with two unused threads down on the SD22. The AC compressor was a different story as you can see the crazy bracket I had to make. Its a pretty sturdy piece even though it may look a little weird. I did want to mount it as a part of the alternator bracket, but I figured I still needed to be able to move the alternator as a separate piece in order to provide enough tension for its own belt. I'm heading to the auto store tomorrow to find a belt long enough to work and I should finally be done with this stage. I also swapped out the gas tank for the diesel tank, and there's no obvious differences on the outside of the tanks between the two, but I posted pics anyways (BTW, the pvc pipe filler neck came with the 1982 720). The mounts were also finished, I used the urethane inside the mount which may or may not help, the starter fits very snugly along the driver side mount to say the least.

#20

I haven't posted an update in a few weeks because now the work has turned a little more tedious. It can't be too exciting showing me crimping every wire, but I almost have all the wiring done. Everything under the dash should be good to go, I just need to complete wiring the SD22 alternator and engine sensors into the Z24 harness really. I've also pretty much completed the fuel system plumbing, all that's left is to lift the bed and get the top few hoses on the top of the gas tank that I can't reach. I dropped in the radiator only to find that I didn't consider the top radiator outlet when installing the power steering pump, so after cutting up many random types of radiator hose I had laying around, I had to come up with a homemade solution. Now, I only need to do the same thing for the lower radiator hose, but I don't think it will be as bad and I hope to be able to use a few 90 degree bends and straight pipe to get around the alternator, the last picture shows the maze I need to navigate. I'm going to have to go behind the AC compressor and then underneath it to connect. And yes, I've been toying around with various brass/chrome plated plumbing pipe as photo'd in the first picture to get the cooling system completed, as long as it works I guess.

Here are pics:

David

#21

I don't think this is going to work at all. With the SD22, you will need to have 2" lateral flex at the top of the engine at a minimum, for startup and shutdown. If you've ever watched an SD start up in cold weather, you'll see why the OEM intake plenum hose is accordion-pleated, and why it's always cracked.

If you try to clamp that nifty adapter up, you'll break the radiator very quickly when you start running it.

#22

asavage wrote: I don't think this is going to work at all. With the SD22, you will need to have 2" lateral flex at the top of the engine at a minimum, for startup and shutdown. If you've ever watched an SD start up in cold weather, you'll see why the OEM intake plenum hose is accordion-pleated, and why it's always cracked.

If you try to clamp that nifty adapter up, you'll break the radiator very quickly when you start running it.

That's a bummer, I didn't consider that either. Well, back to the drawing board.

#23

Round two after a trip to the auto store, I think this will work okay even though its pieced together quite a bit from two hoses. I was able to salvage my lil homemade metal pipe for the lower radiator hose section near the AC compressor.

#24

Is this curvaceous upper coolant route to avoid the oil pump's pulley?

#25

Yeah, the pulley is in the way, I didn't consider where it would come out when I placed the power steering pump. I really didn't want to reshaped the mount parts I made, so I went around it.

#26

That upper hose looks great in terms of how it works. Lots of area to take the stress of engine movement.

#27

Well,

I worked on the truck alot this past weekend, just enough to be able to try and start to crank the truck today during my lunch break. I didn't have a large enough amperage battery last night and I needed a new primary fuel filter, so I picked those up and put them in and had a little time to try and start it up today. The glow plug light came on and off and the cab electronics seemed to work fine, so I gave it a shot. It turned over a few times on the first try and I let go of the key after a few seconds. The second round it started to turn and fire

, and I had some black smoke bellow out from underneath the truck from where the exhaust hasn't been connected all the way yet. And for the third try, it wouldn't turn over at all. I can hear the solenoid clicking, but the starter isn't turning over. Anyone have any guesses about the starter issue before I dig back into it?

David

Edit: I was researching for new starters when I came across this note on Advance Auto Parts website:

Reman; INSTALLATION ALERT! Replacement unit must be installed with a fully charged battery. Cranking at less than 9 volts will damage this starter.; See Tech Tip # 124; Test Chart Page # S-4

So, it looks like I may have unknowingly shot myself in the foot when trying to start it last night and now will have the joy of replacing the starter with the engine installed, and I have to pull out my engine mount as well since it rests right on the starter. Yay.

Final edit:

Took the starter to Adv. Auto Parts and it bench tested fine. I guess the solenoid got hung up but now it cranks fine! Its firing but it seems like only one cylinder. I pulled out the glow plugs and they all light up fine, so I think I don't have all the air out of the fuel lines. When I pump the primer, I hear air seeping into the primary filter, I bought it at Napa, and from reading another thread, it seems like I need an OEM Nissan primary filter so I'll be getting that today hopefully. This thing may be running and driving by the weekend! I need to get it running so I can pull the truck over in front of my shed to weld up the exhaust to connect to the manifold downpipe and to remove the catalytic converter and put in a straight pipe.

#28

Good news, IT is Alive! Check it out:

Photobucket made the video a little pixlelated. But, the bad news is that I have a few pinhole leaks in the oil pan, and I think I'll have to pull the engine to get at all of them

I can probably fix the leaks pictured below, but there are one or two small leaks above the part that sticks out and I don't think I can reach them with the engine installed. Oh well, at least the thing runs. I pulled out the Napa primary fuel filter I put in last week and put in the old Nissan filter that I tried to clean a little and purged out the air and it fired right up. I have three OEM primary filters on order so a new one will be on there soon. I also need to source a new dashpot because mine broke somehow. Onward and upward I guess.

David

#29

congratulations on it firing!

too bad the pan leaks. You sure you cant just drain the pan, clean it off with some brake cleaner and then try squirting some metal with it on the car? If you have a mig welder, it should be fairly easy to do.

If you clean it good enough and not care about how it looks, you can jb weld it too.

#30

Over the past few days. I was able to weld up most of the oil leaks on the pan. One leak was coming from where I stripped out a bolt up front, so I used a coil and put in a larger bolt. There are two other bolts in hard to reach places that are leaking, so those will be pulled and put back in with a coat of JB weld, it doesn't look like I'll have to pull the engine. I finished the exhaust and the AC lines, strapped the battery, and it took forever to get the driver side mount back in. So at 7pm I took it for a drive. It seemed to do fine, the tranny felt fine and I put it in 4wd with no issues. When I got home, the diesel dieseled and I couldn't get it to shut off. I ended up loosening the air bleed screw on the IP to get it to shut off. I thought later that it would have been easier just to make it stall out, it was the first time that I had an engine do that to me. Does anyone know if this is a common occurance with the SD22 or if I may have something not connected? Every other time I shut it off in the yard, I had no issues.

David

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TruckA's 1984 720 4x4 gasser conversion to SD22

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