My 1980 datsun 720 diesel dually

[wayno]

And this would be aftermarket black, this is the one I want to have chromed.

 

This would be the neighbor, he couldn't move fast enough to get out of the photo. :lol:

[wayno]

OK SD22 diesel guys, I seen something on the diesel engine forums that gave me an idea, so I am going to run with this in my spare time in the evenings when I feel like it.

I have an extra injection pump that never worked, so I am using it for mocking this up.

First photos are of the plunger shaft that controls the fuel mixture, this is what is controlled by vacuum, this is what needs to be controlled mechanically.

All the way in is full throttle, all the way out is off, just short of all the way out is idle.

 

The next photo is of the diaphragm that controls that plunger.

This is how the diaphragm is connected to the plunger.

OK. this is what I have done so far, I drilled and tapped the center of the diaphragm plunger.

This is how the shaft connects to the diaphragm.

I drilled the cover that holds the diaphragm in place and connected the shaft to the diaphragm, and this is where I am now.

 

I now have to figure out the throttle control, and a way of having the engine controller shut the engine off, this is going to take me some time to figure out, I have been thinking about this for a long time.

If I can get this to work properly, it will be easy to turbocharge these engines, as the throttle will be mechanical instead of vacuum.

The trick here is going to be the engine cut off, I have an idea, but I now need to make a bracket that lets the engine come back to idle without shutting the pump down, and then having the engine controller actually shut it down, I do have an idea that will use existing parts on the injection pump itself.

[wayno]

I played with this a little more this evening, the cable connection is not going to work on this side, as it only has an inch travel, I will need to make an arm that is taller.

This arm is perfect, I suspect I will have to weld it to the bolt.

This is going to take some time, and I might chuck all this and start over before it's all over.

[wayno]

I messed around with the new headlights today, I took a chance with these new headlights today.

At first I was a bit worried, as when I sprayed the headlights, at first it was milky, but it cleared up, and turned out just fine.

They turned out a slightly lighter tint when I diabled the flash on the camera.

I have another set for the main running lights, but I will not be installing these today, I want the paint to dry real good.

 

I also messed with the injection pump timing today, I am trying to figure out why it acts like a wore out engine, when in fact it is a fresh re-manufactured/rebuilt engine with new sleeves and pistons.

At the same time I believe figured out my starter issue, I am hoping it was just a bad connection.

[wayno]

I tried putting the tri-bar headlights on this project, but it was a total fail, the said headlight bulbs were to big for the headlight rings that hold them in position, so I took a small step forward, and put the amber bulbs that were in the 521KC project in this one, and used the tri-bar lights in that truck.

 

 

[Master-O-Turbonics]

After looking at your photos, and looking in my diesel service manual, I think all that needs to happen is to apply boost through the throttle body and have the pump breather connected before the turbo so that it does not see boost.

 

This would allow boost dependent enrichment, which would not interfere with any of the operation of the diesel controller.

 

A mechanical connection to the control rack would not need much travel, as it was only designed for slight movement from the diaphragm.

I think vacuum actuation is the most efficient method for fuel metering, since it is what fluctuates so much in a turbocharged engine.

 

Full throttle below boost would act just like a non turbo engine. Apply the same amount of fuel as stock.

 

Full throttle at boost applies max pressure to the back of the diaphragm for max rich mixture.

 

No throttle at boost pressure with a blowoff valve to divert pressure away from the throttle plate so the pump would move lean and decelerate the engine. the blowoff valve and throttle plate would be necessary to not bleed pressure into the pump diaphragm.

[wayno]

After looking at your photos, and looking in my diesel service manual, I think all that needs to happen is to apply boost through the throttle body and have the pump breather connected before the turbo so that it does not see boost.

 

This would allow boost dependent enrichment, which would not interfere with any of the operation of the diesel controller.

 

A mechanical connection to the control rack would not need much travel, as it was only designed for slight movement from the diaphragm.

I think vacuum actuation is the most efficient method for fuel metering, since it is what fluctuates so much in a turbocharged engine.

 

Full throttle below boost would act just like a non turbo engine. Apply the same amount of fuel as stock.

 

Full throttle at boost applies max pressure to the back of the diaphragm for max rich mixture.

 

No throttle at boost pressure with a blowoff valve to divert pressure away from the throttle plate so the pump would move lean and decelerate the engine. the blowoff valve and throttle plate would be necessary to not bleed pressure into the pump diaphragm.

 

All I know is that my engine in the 521KC diesel came with a turbocharger, there are photos of it on page one of this thread, I actually started it with that turbocharger, but I did not like the idea of letting off the pedal and having the butterfly close while the turbo is spun up, it will just cavitate(create a vacuum), it will try to suck anything it can from anywhere it can, it can suck oil threw the seal in the turbocharger, as far as I know, no manufacturer has ever set up a turbocharger like that.

The injection pump needs to be mechanical as far as I am concerned, no one one here or on the nissandiesel forum has ever succeeded in a pull threw turbo on a SD series engine, they have tried a bunch of times, it has not worked yet, but you can try yourself, as I said, the diesel engine I bought had a pull threw turbo on it, and it did run, but I never have had it in a vehicle.

As you can see in the photo below the exhaust manifold was welded shut, and a new hole was cut into the side of it, that is where the turbo mounted, the exhaust pipe goes out the rear, as you can see, the throttle body is put on in front of the turbo inlet, then that is piped strait into the intake manifold, it's actually very simple, but so far no one has succeeded except the guy that set this one up, but I have no idea if it actually worked, it's such a scabbed together setup, I really don't trust it.

Top view 

Side view

Exhaust outlet welded up.

Front view.

View of intake mount side.

Back view.

And the mount which was cut into the side of the manifold.

[Master-O-Turbonics]

That system will not provide any more fuel than a standard SD22.

If the vacuum port in the throttle body sees boost pressure, then it will shove the rack to full rich, which will add power.

Without a boost reference to the vacuum line, it crams more air into the engine but no more fuel than stock, maybe less.

Under boost there is theoretically more vacuum at the throttle body(in front of the turbo), and that would actually pull the rack towards lean. A diesel won't detonate like a gas engine, it just wont make any more power and will probably make less..

[wayno]

That system will not provide any more fuel than a standard SD22.

If the vacuum port in the throttle body sees boost pressure, then it will shove the rack to full rich, which will add power.

Without a boost reference to the vacuum line, it crams more air into the engine but no more fuel than stock, maybe less.

Under boost there is theoretically more vacuum at the throttle body(in front of the turbo), and that would actually pull the rack towards lean. A diesel won't detonate like a gas engine, it just wont make any more power and will probably make less..

 

It will not work any other way, i have seen videos of what it runs like with the throttle body between the intake manifold and the turbo, it runs alright, a giant black cloud comes out the exhaust 100 percent of the time, you will get a ticket the first time a cop sees you, people will complain and call the cops while driving down the road.

Why do you think I have not turbocharged anything yet, it's because of all the issues with the inline pump.

Here is a thread about all the stuff I have been talking about, somewhere in there is a jeep with the TB between the intake and turbo, it's not pretty.

They have a very slow server, it takes a long time to load, very aggravating.

http://nissandiesel.dyndns.org/viewtopic.php?t=495&start=0&postdays=0&postorder=asc&highlight=

I read more up to date stuff on this thread that has been added since I read it last, it doesn't sound like they have figured out how to turn it off with the key yet either.

They also say that the throttle is touchy, and should not be used for street use.

There are a lot of links on that thread, I have read every one of them at one time or another, it's where I got the specific idea for the mechanical throttle I have been playing with in this thread of mine.

I believe the best way is to find a VE style injection pump.

There is a guy that lives in my town that is playing with a SD22 engine, but he is using VW stuff, and talking about enrichment, and other stuff I don't totally understand, he has one of my injection pumps to mock up something or other, if anything comes from his tinkering, I will post it in this thread.

[Farmer Joe]

heres a turbo setup we did on a isuzu c223 engine. it was in a bagged 77 luv..

 

found the stock turbo manifold on ebay, found a perkins diesel replacement turbo, and turned up the fuel on the injection pump.

 

do the isuzu's have a differnt pump? this only made the smallest puff when youd take off, or really get off alot of boost.

 

[wayno]

heres a turbo setup we did on a isuzu c223 engine. it was in a bagged 77 luv..

 

found the stock turbo manifold on ebay, found a perkins diesel replacement turbo, and turned up the fuel on the injection pump.

 

do the isuzu's have a differnt pump? this only made the smallest puff when youd take off, or really get off alot of boost.

 

I don't know what type of injection pump the engine above has, but it is likely controlled at the injection pump with a throttle cable, datsun/nissan injection pumps(US models) are controlled by vacuum, so when you add a turbo in the mix, it screws everything up.

Basically the nissan injection pump(IP) has 2 vacuum lines that go to a throttle body(TB) looking carb from the IP, one is a vent that connects in front of the TB where no vacuum or air pressure is created, the other connects to the TB, which has this venturi that creates vacuum, when the truck is idling, the butterfly is closed which creates vacuum, this vacuum pulls the injection pump back to idle, when you step on the gas pedal a little, some vacuum is lost, and the spring inside the IP lets the fuel mixture get richer at the same time that you are giving the engine some air(butterfly is open), if you floor the pedal(butterfly is open all the way), all vacuum is lost, and the IP floors itself.

When you add a turbo, the only way to have the injection pump work correctly is to have the throttle body in front of the turbo, that way the venturi still works correctly, but let us say you are driving down the freeway and you let off the pedal, the turbo is wound up, the engine is trying to suck air, but you just cut off the air, so now you have a vacuum inside the intake manifold, eventually it is going to pull oil threw the seal, guess what oil is, it's fuel, under the right circumstances, you could drain your oilpan while driving down the freeway.

Normally there is no vacuum in the intake on a turbo setup, it is pressurized, so you have no issues with oil being pulled threw the seals, normal injection pumps have the throttle cable connected to the IP, so there is no need to be cutting off the air with butterflys and such, you just let off the pedal and that cuts/meters the fuel, with less fuel the engine loses power.

If one puts the turbo in between the airfliter and the throttle body(TB), then the TB is always pressurized, that venturi is always pressurized, so the injection pump is always floored, so one will be blowing clouds of black smoke all the time(it will be RICH), I have seen this in a video of a jeep with the turbo piped this way, it was a fail.

I hope this makes sense to everyone, I try to write what's in my head, but it don't always come out correctly.

It is best to just have a VE type injection pump(manually metered), or figure out how to manually meter these inline injection pumps, because so far, everyone has failed with a stock vacuum controlled throttle.

Mine ran with the turbo setup in post 32 in this thread(photos), but it scared me, the blow off valve was wired shut, it was a backyard setup, my buddy down the road says I should put it on my 521KC SD25 diesel and see if it has more power, but it scares me, and my truck runs good, so I am not going to mess with it, I will mess with the SD22 in my 1980 720 first.

[Farmer Joe]

ahhhh i seee...

 

yeah the isuzu was cable actuated on the IP. it had no throttle body, just the plain open intake as you see in the pics..

 

i guess its gonna be best to do it NA for the time being.

[w_datsun_a]

I have to say I have loved reading about this truck.  It looks great and is put to work!  Just curious - have you ever considered ditching the bed and going with a service body?  Dually + king cab + turbo diesel (hopefully!) + service body = awesome!  Not only would it look great, it would be really functional.  You could probably pick a used one up for pretty cheap, that along with your skills could make a used one look like brand new.

[wayno]

I have to say I have loved reading about this truck.  It looks great and is put to work!  Just curious - have you ever considered ditching the bed and going with a service body?  Dually + king cab + turbo diesel (hopefully!) + service body = awesome!  Not only would it look great, it would be really functional.  You could probably pick a used one up for pretty cheap, that along with your skills could make a used one look like brand new.

 

I used to drive this truck several times a week until it overheated and started smoking, I had to remove that engine, which now needs rebuilt.

I actually have a work truck, it does everything I need done, and is very reliable, although it is not a diesel.

This truck was my first datsun creation other than the work truck, it has a longbed, is a kingcab, and is a dually, the dually part is more for show than function, as I use adapters to hold the dually wheels on, it's not really meant to haul any kind of weight, but it does tow good, the reason I use adapters is because the true dually rearends do not have the gear ratio needed for the diesel engines, with 437 gears, the diesel engine would be revved out at 60mph, so I have to use the stock 389 geared rearends which are not compatible with the dually wheels.

My work truck.

[wayno]

The parts store says that the dually and non-dually use the same carrier side bearings, so it looks like i will be pulling a rearend apart for the carrier, I hope they are the same.

Nissan wasn't any help at all, all they could tell me was that Nissan did make a dually rearend between certain dates.

[Master-O-Turbonics]

After reading more, I think you are right about placement of the throttle body. If it is placed before the turbo the engine will act as normal. It just needs some sort of boost referenced actuator to take over throttle control(push toward full rich) when the engine is at boost.

 

It seems the diaphragm does not have enough travel to make use of as much enrichment (more fuel to go with the extra air induced by boost, more air+ more fuel= more power) When the throttle plate closes, it starves the system of air and loses boost.

I think this system will need a very good blow-off valve so that extra boost will be quickly vented to atmosphere in a quick lift off the throttle situation. 

 

A problem to think through is if you have a boost actuated enrichment, there has to be some kind of shut-off so that the engine does not just take off to max RPMs. Maybe figure out a way to only actuate the enrichment at full throttle and boost, and cut enrichment as soon as the throttle is not at 100%. 

 

After reading, I have my doubts that the diaphragm will be able to handle much boost pressure on one side and atmospheric pressure on the other side... so that is another thing against having the throttle body in the stock location.

 

 

I'm sure there is a way to make this work with no electronics added, just going to take some trial and error.

 

 

Full manual control of the fuel rack would work, but it would also be somewhat dangerous to the health of the engine, as your right foot is controlling the air/fuel ratio instead of the actual needs of the engine. EGT's may be hard to keep under control. 

 

I will post some of the information from the service manual that may spark some ideas.

[wayno]

All other diesel engines are controlled by manual control of the fuel rack, and the intake is nothing more than a hole hanging out in the air, that hole can have a turbo put on it without effecting the fuel rack, because the fuel rack is manually controlled, so basically the more you put your foot in it, the more fuel it gets, when you let off the pedal, it has no more fuel, so it loses power whether or not the turbo is spun up, no fuel, no power.

This injection pump has no way of giving the engine more fuel under boost like other turbo diesels, that is something that the guy I mentioned was going to figure out that has one of my injection pumps, I have not heard from him lately though.

I suppose that some kind of solenoid could be used if the pump was not manually controlled, but in the end, I believe that something else is going to have to be used, I have this other injection pump I bought on ebay, but it is made for a boat or water pump,vacuum pump, or a generator, I have the same issue with this one also, how to shut it off with a key, but it is a manually controlled inline injection pump of the same design as our vacuum controlled pumps.

I have thought about this for several years now, having a turbo diesel Datsun, but other projects get in the way, and I just don't drive this truck much anymore, so I just keep it operational, and one day I will find the time to continue on with this project, until then it will just sit in the driveway unless I find a need to use it, like one of my daily drivers breaking down.

[wayno]

Well I have not done much to this truck over the last couple years, today I started installing the injection pump in the photo of my last post, I went golfing today, and when I got back home I tore into it, it actually already has a turbo in it already, I bought a turbo diesel engine from a guy that did a lot of research when he built the turbocharger he put on the SD25 engine, I will bet his wife was happy to see the car go away, but the engine runs to hot, the inline injection pump just doesn't like to be turbocharged, I cannot go 70mph on the hiway, it gets to hot, so i decided to put the inline IP I have that is metered like a VE type pump, and I will say this, it barely fits.

He is what the engine looked like before I tore it down.

I tried an inter-cooler, it made no difference, it still ran hot.

Here it is all buttoned up.

Here the new IP is installed.

 

I had to install a remote oil filter setup, it just would not clear the oil filter.

 

I had to remove a plug on the side and put a plastic plug in it's place, I am hoping this is not a pressure situation, you can see it next to that big nut, it's blue.

I goofed when I started this project, I thought that the front gear can only go onto the IP one way as the shaft is keyed, so I marked the gear and the housing so I could put it back on exactly in the position it came off, well when it came time to put the gear back on, I checked the pump key position of the IP I took off, and then I checked the new IP pump position, they were exactly the same just sitting there, I thought that was great, well it turned out to be a major pain in the ass, what happened was when I removed the gear, the IP gear shaft had moved, what it had done was move to the bottom of the internal lobe, well when I would try to move the shaft to where I needed it to line up my marks and the key way, it would flip back like a spring to where it was before I moved it, this was a major problem, I could not get the gear on, the teeth on the gears, and the key way have to be aligned to get it to drop in where I had it when I pulled it apart, I didn't dare move the crank, I then would have to pull the whole front of the engine off to align everything, so after looking at the pumps for a while, loosening the IP and turning it as far as I could, I gave up, I had to think of something else, see the hole in the end of that shaft, well I tapped an easy out into it while on the engine, then I started to install the gear onto the IP shaft in the position it needed to be, then I put a tool I have for tapping holes on the end of the easy out, then I turned the injection pump shaft until the key way lined up with the gear and it dropped in, it took a couple tries, but I could do nothing else except pull the whole thing apart, it dropped in, and I put the nut on and tightened it up before it came off for some reason.

It started to rain on me, so I packed it up, and called it a day, I will work on it tomorrow, it is close to starting it up, I just want it to run, then I will pull the turbocharger off and lower it, I don't like it sticking out the hood.