81 Datsun SD22 Swap to 83 Datsun 4x4

[wayno]

Hi there, so this is a turbo for a smaller displacement engine, correct? I was told that one for a 1600 cc gas engine would work on the SD22 diesel, but that is hear say, no proof or literature was provided to back that statement up. Let us know how it works out. wayno

[wayno]

Hi there again, I just looked at the picture, does it blow a lot of black smoke set up that way? How did you replumb the vaccumn lines, or did you? wayno

[firemedic]

Yes, but not real bad it's more heavy gray with a white puff when you first open the throttle body. I have the vaccum lines like this:

 

one to the inlet before the turbo, and the other where the TB opening is (the factory way except the turbo inlet)

 

 

firemedic

[wayno]

Here it goes, I am going to try to explain how I beleave the throddle body system works, in it's stock configuration there are two vacuum hoses that are connected to the throddle body area, one is connected to the air inlet breather housing, it is just a breather hose that needs to be open to the air with no vacuum or air pressure of any type. The other hose is important, that one that connects to the side of the throddle body, it is part of a small vacuum aperture, this vacuum is needed to pull the injection pump( IP) to the idle position, if the engine is shut off, the IP is floored because there is no vacuum, so if the engine is running at an idle, the butterfly in the throddle body is closed, maximam vacuum is being created and the IP is at idle, open the butterfly(floor it) and you loose vacuum so the IP goes to the floored position, maximam fuel delivery. The reason I asked how your vacuum lines are plumbed is, if the turbo is before the throddlebody, then the important vacuum hose is being pressurized, therefore floored all the time, that hose is supposed to create vacuum, not be pressurized. You can put the throddlebody on to the turbo inlet and plumb the turbo outlet right into the intake manifold, then the important vacuum hose creates vacuum again, but that creates differant issues. It will blow black smoke if the turbo is before the throddlebody, because the IP is floored. I have had a SD22 running with a turbo, the throddlebody was before the turbo, i was afraid that the turbo would pull oil threw the seal of the turbo seal when I let off the pedal, because it would be spun up, cutting the air off of a fully spun up turbo will make it cavitate, and try to pull anything in it can from anywhere. Can you imagine what would happen if oil started dumping into a diesel engine at 2000 RPM threw the oil seal in the turbo, I bet it would explode. The only way I can see to do a turbo on the sd22 correctly is to get rid of the throddlebody and figure out another way to control the inline injection pump, or buy a VE type injection pump that has a cable controling the throddle, NOT A VACUUM SETUP. wayno

[wayno]

Hi there Firemedic, I pulled one of my extra inline injections pumps from storage and pulled the side inspection plate, and the rear vacuum throddle control apart and inspected it to see how it worked, I beleave that some kind of manual control could be fabricated in time, but there are a few issues that could pop up over time. One of the big concerns is that there is a leather type partition that separates the two sides of the vacuum throddle control hoses, the front side(towards the radiator) is suppose to be filled with cod liver oil, if you take out the leather partition, the oil escapes, is the oil there to dampen the throddle response, or is it needed for lubrication, or both? If the partition is removed, there is a lever that can be connected to that I beleave will control/meter the fuel and the engine could still be shut off with the key, but I don't know this last statement for sure yet. It does not take much sucking on the vacuum hose to see how it functions. I still think that the easy way would be to connect the throddle body hose to a vacuum source, with a tee in it, put some kind of valve on the tee that is controlled but the gas:lol: pedal, and the more the pedal is pushed, the less vacuum there will be, the higher the RPM/power. Who ever tries this has to be gutsy enough to remove the throddle body before starting the engine,:unsure: and then start the engine. Do you see the problem, when the engine is off, the injection pump is floored, so when you start it, you have to wait for vacuum to be created to pull it to the idle position, and since the throddle body is gone/removed, there is no way to cut off the air unless there are provisions made ahead of time to do just that, A FULL PROOF WAY TO CUT OFF ALL THE AIR, in case it becomes a runaway, if vacuum is created fast enough it should just rev briefly and then idle, I floor mine to start it, and then let off after it starts, it should act the same.:unsure: maybe, hopefully, but I am just making an uneducated guess. A buddy of mine gave me a piece of plywood(6"X6") once just before he started his SD22 engine, and told me to to put it over the intake hole if it reved uncontrolably, I don't think he wanted to be near it if it did, I guess he thought if I was stupid enough to stand there and watch:lol:, I could help. wayno