My 1969 Datsun 521 kingcab

[waynosworld]

I for sure will be waiting anxiously for when you make that diagram so I can know just how you plumbed the lines. I can attest to just how difficult it is to picture how you plumbed the lines for a successful turbo install. When you do get the time to diagram the install please note the direction of flow for the air, or vacuum.

Don

Everything is stock except for that vent line, there are two rubber lines that come from or go to the inline injection pump depending on how you look at it, one of them lines is the injection pump control line that goes from the throttle body to the injection pump, it is a vacuum line that is controlled by a venturi in the throttle body, when the butterfly is closed in the throttle body while the engine is running that venturi creates vacuum in that line which pulls against the diaphragm spring bringing the injection pump to the idle position, now you must understand that the diaphragm spring in the injection pump wants to be in the floored position when there is no vacuum, the other line is the vent line that basically goes to the airfilter, the air in that line goes back and forth just enough to let the diaphragm move back and forth, so what I did was tap into the intake tubing between the turbocharger and throttle body and I put that vent line there along with the line going to the boost gauge, so when under boost the vent line is under boost, but the injection pump control line is also under boost, so when one has their foot deep into the pedal the diaphragm spring wants to be floored, but when you let off the pedal the venturi in the throttle body creates a lot of vacuum pulling the injection pump back to idle.
If the butterfly in the throttle body is only a little open, the venturi creates less vacuum so it only lets the diaphragm move a little towards a richer position, if I didn't pipe the vent line to boost, the injection pump would be floored most the time because of boost, and the engine would run very hot EGTs(exhaust gas temperatures) because of being rich all the time which is the issue I was having with the 720 turbodiesel when it was piped as a blow thru, it ran stinking hot all the time.
It's complicated, but it is not complicated as except for the turbocharger being there all the lines except the vent line are not changed, only the injection pump vent line is piped to a boost source and it sees boost when there is boost same as the injection pump control line, when there is boost it sees boost, so when there is boost, both sides of the diaphragm see the same boost and cancel each other out, so then the venturi in the throttle body works as it should.

[waynosworld]

Ok, so here is how I piped the lines.

[handcannon]

Thank you very much for the reply AND diagram. That really helps me understand what you did. I was wondering if this is what you did, but there was still some question and confusion on my part.

Without going back a ways and re-reading I'm remembering that you used a turbo sized for a 1600 CC gas motor. Is this correct? I just want to make sure before I start looking at Craigslist, and other places, for a turbo.

Don

[waynosworld]

Thank you very much for the reply AND diagram. That really helps me understand what you did. I was wondering if this is what you did, but there was still some question and confusion on my part.

Without going back a ways and re-reading I'm remembering that you used a turbo sized for a 1600 CC gas motor. Is this correct? I just want to make sure before I start looking at Craigslist, and other places, for a turbo.

Don

The turbos I am using are supposed to be for around 1600cc engines, I have SD25 engines I use them on.
Every thread I have read recently(5 yrs) about an SD series turbo build had too large of a turbocharger and they could not build any real boost, they maybe could get 2/3psi, that was it, the home made turbocharger setup that was on the engine I bought has a 2 1/16th inch intake throat on it and the waste gate was wired shut when I inspected it, but it was not really that pretty of a setup either, it was backyard made, that is why I didn't even look at it for 5 years, as far as I was concerned there was nothing worth using on that setup, but when I removed the turbo and adapter, I thought that maybe the home made turbo exhaust manifold might work as the flange hole was huge, so I made my own back yard mechanic adapter for the Subie AWD turbo and it worked great.
Keep in mind I have 2 different SD series turbo engines now, but the one Larry built was modified, he put a larger inlet vane in the German turbo so it built boost at lower RPMs, he also had the injection pump turned up(made richer), and I have had nothing but issues with that setup, it ran hot all the time till I made it a draw thru, but that created other issues, but I didn't know then what I know now.
This turbo engine is using a Subie AWD turbo I found in a wrecking yard several years ago, as I recall it was a 1600cc engine, it was a small SUV looking vehicle, sorry I don't remember the year, but this one is unmodified and it works great on my SD25 engine, it doesn't have the grunt that Larry's turned up injection pump has, but it goes down the freeway awesome, it acts like a normal SD series engine off the line, but once it start building boost it like a different engine, on one of the test drives my friend rode with me, he has a 720 diesel, he said it was fast and now wants to do the same thing.
To get the numbers off the Subie turbo I will have to take the front compressor cover off, I really am not interested in doing that, it runs great so I want to eave it alone and enjoy it, but I did take the inlet hose going to the airfilter off and I measured the inlet size, I was very surprised to see it measured out at 1 7/8ths inches inside diameter, but I recall it being on a 1600cc engine.
Here is a couple photos of the German turbo numbers I have on the 720, it builds plenty of boost but the one on my engine was modified, the Subie turbo exhaust vane appears to be larger than the German turbo, I never really noticed this before.
The aluminum intake pipe is from the Subaru AWD turbo I used on the 521, I wonder if that will help identify the Subaru I got the turbo from.

[waynosworld]

My starter started having his clicking sound ever since I put the turbocharger on it, in other words since I started driving it more, well it started getting real bad recently, I lifted the truck up and wiggled the starter, so it was loose, I tightened the lower bolt but could not get to the upper bolt and tried the starter, it was not any better, it was late so I called the day.
Today I went out there and lifted the front again, crawled under the truck and I could see no way to access the upper starter bolt from the bottom.
I lowered the truck and started looking thru the small openings left on that side of the engine, I could not see that area of the starter, but I got an extension and a 9/16ths inch 6 point socket, I started trying to find the bolt head and could not find it by feeling for it with the socket on the end of the extension, so I went inside and looked at another starter then went back out and tried again, I found it, so I looked thru a crack and could see the end of the extension sticking out just past the end of the starter, I went in and got a longer extension, ratchet, and a wobbly, I was able to connect them together and I started twisting carefully and I kept turning and turning and it never got tight, the hole is stripped out as I can see the end of the bolt coming out the other side of the transmission case, I sighed and hit the starter and it sounded better.
So I thought about it for a while not looking forward to pulling the transmission, I lifted the truck again and found a block of wood that fit and I pounded it between the engine mount bracket and the end of the starter, once that was in, I made a metal wedge and pounded it in between the motor mount bracket and the block of wood, it took a while but I got it in there, I then dropped the truck and started it up, it sounded great, so until I have no choice it's staying the way it is for now.
This really isn't a surprise, that bolt has always been hard to get in but it started the engine without issues until just recently, I remember tightening the starter bolts when I had the intake/exhaust off to convert over to the turbo exhaust manifold, but it didn't just keep turning, I guess that time was the straw that broke the camels back.

[plenzen]

Is it the road draft tube that's in your way ? Seems I've heard of this "bugger bolt" before. Mine does not have that road draft tube but rather a little box with a baffle in it. That bolt is "doable" from the top with only a bit of fiddling. Also. I have the reduction type starter so not as fat at the DD one.

[waynosworld]

This engine has the big boy direct drive starter in it, it is huge compared to the gear reduction starter.
Everything is in the way of me getting to the top starter bolt now, but the big thing in the way is the exhaust pipe going from the turbocharger to the underside of the truck, but the turbocharger and the booster/master brake cylinder are in the way also to get the starter out of there, you can see in the attached photo there just isn't any room.
I can remove the engine case breather tube from the housing from the bottom, that is not a big deal, but the frame and torsion bar are an issue to drop the starter out the bottom, it has to come out the top, but you just made me think..............
What if I remove the torsion bar on that side, I wonder if I would have the room to drop the starter out, but the starter is not what is bad, the top bolt hole in the transmission case that holds the starter in position is stripped out, I will have to remove the transmission to fix that, which is not something I am looking forward to.
I have even thought about removing the interior and cutting the tunnel out in such a way that I can remove the transmission from the top, then bolt the tunnel back into position once the transmission was replaced, but that is a lot of work to do it right, I would have to gut the interior, even remove the dash/heater so I could cut high enough to slip the transmission straight back, it would be a lot of work for something I may never have to do again.

[plenzen]

That's definitely a full toy box you have there for sure. I was able to take mine out the top I believe. Had to get under it to fiddle that inboard bolt out once loosened.

Does your stripped starter bolt go right through the bell housing. Can you put a longer bolt on it and maybe a nylock nut ?

You will have to release the tension from the torsion bar and I believe there is a ride height adjustment measured from a fixed point on the frame. I saw that in my FSM for my D21. I guess you could take a baseline measurement of what it is now and count the number of turns on the cam nut. Might want to look into the GR starter as an option. After taking mine out a couple times I know I could not use the DD one as it would not go past the motor mount. The oil return from the alternator is in the way now and I have to remove it.
It's kinda PITA. But doable

[handcannon]

This starter topic brings up a question I have. Does anybody have pictures (or links to pictures) of the two starters side by side? I don't know what I have, DD or gear reduction. Currently I don't have the motor in the pickup, and now might be the time to make changes, if needed. I keep saying that I will get the motor in this summer, for the past two summers. I'm actually at the point of taking a lot of measurements, so hope is much higher for this summer. I'm planning to put the SD-22 into a 1973 Datsun 620 that my Dad bought brand new.

Don

[waynosworld]

Direct drive is on the left, gear reduction on the right in both attached photos.

[waynosworld]

My engine in this truck came out of a 620.
The diesel engine mounts are farther forward than other 720 engines, so i would imagine that they are also going to be farther forward than the 620 mounts also, you are likely going to have to cut the stock L block mounts off the chassis/frame and make new ones farther forward, I would mount the transmission to its mount and then make the engine mounts if possible, that way the only thing needed is the engine mounts, otherwise you have to make everything including a custom driveline.
I don't know for sure as I have never actually measured a 620 engine bay, but I suspect that the 620 engine bay is bigger, I do know the 521 bay is very very tight when fitting the SD series diesel engine, I had to change a few things to get it in there the way I wanted.
Also the 1973 Datsun 620 is a kingpin chassis/frame, that makes things harder also, the cross member for the transmission mount is not removable like the later ball joint chassis/frames, it would likely be in your best interest to make a short shaft 5 speed transmission, that way the shift lever will come out the stock shift lever hole, I have wrote an article about this subject, I am not a writer, but here is a link to the article, you will use your front diesel transmission case on a 1985/86 Nissan 720 regular cab/short box truck 5 speed as they are short shafts and the shift lever is 5 inches farther forward like the stock 1973 Datsun 620 4 speed transmission, you will also likely need a custom transmission mount, I have made them for the 521, don't know if the early 620 is the same, I only attached one photo as the files seem to be large.
http://www.nwdatsuns.com/viewtopic.php?f=35&t=72

[waynosworld]

That's definitely a full toy box you have there for sure. I was able to take mine out the top I believe. Had to get under it to fiddle that inboard bolt out once loosened.

Does your stripped starter bolt go right through the bell housing. Can you put a longer bolt on it and maybe a nylock nut ?

You will have to release the tension from the torsion bar and I believe there is a ride height adjustment measured from a fixed point on the frame. I saw that in my FSM for my D21. I guess you could take a baseline measurement of what it is now and count the number of turns on the cam nut. Might want to look into the GR starter as an option. After taking mine out a couple times I know I could not use the DD one as it would not go past the motor mount. The oil return from the alternator is in the way now and I have to remove it.
It's kinda PITA. But doable

I looked at the bolt coming out of the transmission case, but the hole/bolt in the case actually comes out the angled part of the bellhousing, I would likely have to have it come out 2/3 inches before I could get a nut on it, and then if I did tighten it down hard, it would likely bend the bolt and make it impossible to get out if the threads are stripped in the case, I thought about running a stud in there with the nut as tight as I could get it and mount the starter on the stud with a nut, but it is so tight in there it would just be easier to remove the transmission and put another front case on it, and then have that hole fixed in that case for the next transmission change.
I have done the torsion bars before, I understand them, but they don't always come out easy, right now I am going to live with a block I have jammed in there, if the starter dies, then I will have to do something about it, if the transmission dies I will have to do something about it, but a stripped out hole, I will work around it.

[handcannon]

Thank you for the pics. Now I will go out later this morning and see which one I have.

So far in my measuring I have found that the 620 engine bay must be slightly shorter than the 720 engine bay. If I place the motor within a quarter inch of the firewall the motor will fit, but I am concerned about how much clearance I will have to the stock 620 radiator. I might be able to enhance this clearance by going to an electric fan (may even help a little bit in the power area). I will definitely need to make changes to the motor mounts. My plan so far is to remove the stock 620 rubber mounts, place the diesel mounts on the engine block, and place the motor in the engine bay to see just exactly what I will need to do.

The stock diesel transmission is definitely longer than the 620 transmission. Although I haven't measured the exact amount I knew it was somewhere close to five inches. The transmission cross member for the 620 is going to need to be moved back for the diesel transmission. Being that it is a bolt in cross member will make that much easier. It looks like the gear shift lever will fit in the stock 620 opening in the floorboard, but it will be directly in front of the stock 620 bench seat with clearance in question for the lever to move into the rear most positions. Initial practice placement of the motor will let me know just how much, or how little room there is to work the shift lever. I will read the article, and keep in mind your solution for transmission space.

At one point you stated that the transmission cross member is not movable, then you stated that you moved the transmission cross member. Did you mean that the frame member between the king pins was not movable, instead of the transmission cross member? That would make sense to me anyway.

Thank you for the information you provided. It is very good to have that!

Don

[waynosworld]

Thank you for the pics. Now I will go out later this morning and see which one I have.

So far in my measuring I have found that the 620 engine bay must be slightly shorter than the 720 engine bay. If I place the motor within a quarter inch of the firewall the motor will fit, but I am concerned about how much clearance I will have to the stock 620 radiator. I might be able to enhance this clearance by going to an electric fan (may even help a little bit in the power area). I will definitely need to make changes to the motor mounts. My plan so far is to remove the stock 620 rubber mounts, place the diesel mounts on the engine block, and place the motor in the engine bay to see just exactly what I will need to do.

The stock diesel transmission is definitely longer than the 620 transmission. Although I haven't measured the exact amount I knew it was somewhere close to five inches. The transmission cross member for the 620 is going to need to be moved back for the diesel transmission. Being that it is a bolt in cross member will make that much easier. It looks like the gear shift lever will fit in the stock 620 opening in the floorboard, but it will be directly in front of the stock 620 bench seat with clearance in question for the lever to move into the rear most positions. Initial practice placement of the motor will let me know just how much, or how little room there is to work the shift lever. I will read the article, and keep in mind your solution for transmission space.

At one point you stated that the transmission cross member is not movable, then you stated that you moved the transmission cross member. Did you mean that the frame member between the king pins was not movable, instead of the transmission cross member? That would make sense to me anyway.

Thank you for the information you provided. It is very good to have that!

Don

As far as I know the early 620 frame/chassis is different than the late 620, the early frame has the transmission mount bolted on to the permanent welded in cross member, the late frame has a removable transmission cross member, I don't know a lot about the 620 other than early frames are drum brakes all around, while late models have front disc brakes with ball joints instead of kingpins.
I also know that the late 620 4/5 speeds are longshafts like the 720 trucks have except they have different gearing.
I have gotten real deep into the 5 speed transmissions, I know without question that the long shaft and short shaft 5 speed transmissions have the transmission mount in the same spot, the only difference is that the short shaft tail housing is 5 inches shorter and the shift lever is 5 inches farther forward, they both bolt into the same spot.
Does your 620 have a solid steering column from the steering gear to the steering wheel, if it does, then your transmission mount likely bolts to the cross member, you can get a long shaft in there without removing that cross member, and you need that cross member because the torsion bars are mounted and adjusted in that cross member as far as I know.
Another thing I know is that if you have the solid column and the transmission mount is bolted to the welded in cross member, then that mount is off around an inch forward and it mounts the transmission a few inches higher also, that is why I posted the photo of the mount I made, my mount uses a 720 transmission mount, and it is adjusted around an inch farther back as well as being lower.
What your doing is not easy, your going to have to fabricate several things, it's easier to fabricate parts that work with the frame you have rather than changing the frame itself.
I made the SD25 diesel engine fit in my 521 engine bay, I am using the stock 521 radiator and the stock SDD25 cooling fan with the fan tips/blades shortened so that it didn't hit the lower and upper hoses, I had around an 1 1/2 clearance total to work with, a half inch in the back, an inch in the front, as I said, it is tight, that is why I have been whining about the starter recently, since installing the turbo I have no room to work on this engine anymore except on the outer parts, even changing the oil filter is difficult, I can get it loose, but getting it out of there is a bitch.
Another thing I should tell you is that I used a 1982 Datsun 720 kingcab diesel frame for my 521 kingcab diesel project, I wanted power steering and front disc brakes, it was just easier to do it that way.

[handcannon]

Thank you for the pics. Now I will go out later this morning and see which one I have.

So far in my measuring I have found that the 620 engine bay must be slightly shorter than the 720 engine bay. If I place the motor within a quarter inch of the firewall the motor will fit, but I am concerned about how much clearance I will have to the stock 620 radiator. I might be able to enhance this clearance by going to an electric fan (may even help a little bit in the power area). I will definitely need to make changes to the motor mounts. My plan so far is to remove the stock 620 rubber mounts, place the diesel mounts on the engine block, and place the motor in the engine bay to see just exactly what I will need to do.

The stock diesel transmission is definitely longer than the 620 transmission. Although I haven't measured the exact amount I knew it was somewhere close to five inches. The transmission cross member for the 620 is going to need to be moved back for the diesel transmission. Being that it is a bolt in cross member will make that much easier. It looks like the gear shift lever will fit in the stock 620 opening in the floorboard, but it will be directly in front of the stock 620 bench seat with clearance in question for the lever to move into the rear most positions. Initial practice placement of the motor will let me know just how much, or how little room there is to work the shift lever. I will read the article, and keep in mind your solution for transmission space.

At one point you stated that the transmission cross member is not movable, then you stated that you moved the transmission cross member. Did you mean that the frame member between the king pins was not movable, instead of the transmission cross member? That would make sense to me anyway.

Thank you for the information you provided. It is very good to have that!

Don

As far as I know the early 620 frame/chassis is different than the late 620, the early frame has the transmission mount bolted on to the permanent welded in cross member, the late frame has a removable transmission cross member, I don't know a lot about the 620 other than early frames are drum brakes all around, while late models have front disc brakes with ball joints instead of kingpins.
I also know that the late 620 4/5 speeds are longshafts like the 720 trucks have except they have different gearing.
I have gotten real deep into the 5 speed transmissions, I know without question that the long shaft and short shaft 5 speed transmissions have the transmission mount in the same spot, the only difference is that the short shaft tail housing is 5 inches shorter and the shift lever is 5 inches farther forward, they both bolt into the same spot.
Does your 620 have a solid steering column from the steering gear to the steering wheel, if it does, then your transmission mount likely bolts to the cross member, you can get a long shaft in there without removing that cross member, and you need that cross member because the torsion bars are mounted and adjusted in that cross member as far as I know.
Another thing I know is that if you have the solid column and the transmission mount is bolted to the welded in cross member, then that mount is off around an inch forward and it mounts the transmission a few inches higher also, that is why I posted the photo of the mount I made, my mount uses a 720 transmission mount, and it is adjusted around an inch farther back as well as being lower.
What your doing is not easy, your going to have to fabricate several things, it's easier to fabricate parts that work with the frame you have rather than changing the frame itself.
I made the SD25 diesel engine fit in my 521 engine bay, I am using the stock 521 radiator and the stock SDD25 cooling fan with the fan tips/blades shortened so that it didn't hit the lower and upper hoses, I had around an 1 1/2 clearance total to work with, a half inch in the back, an inch in the front, as I said, it is tight, that is why I have been whining about the starter recently, since installing the turbo I have no room to work on this engine anymore except on the outer parts, even changing the oil filter is difficult, I can get it loose, but getting it out of there is a bitch.
Another thing I should tell you is that I used a 1982 Datsun 720 kingcab diesel frame for my 521 kingcab diesel project, I wanted power steering and front disc brakes, it was just easier to do it that way.

Thank you for your reply.

I just went out and double checked the 620 frame to make sure I was remembering correctly. There is a welded in cross member for the torsion bars, and a removable cross member for the transmission. The removable cross member is forward of the torsion bar cross member. The transmission cross member has two bolts on each end, and three holes in the pocket welded onto the frame. The cross member was bolted onto the front two holes, and because of the third hole, although not measured, I'm assuming that the cross member can be moved back about 1 1/2 to 2 inches. It is a king pin style front pivot, and drum brakes.

I don't know any visual difference between the short shaft and long shaft transmissions. But, what was stock (4 speed) I'm assuming was the short shaft transmission as it was several inches shorter that the 5 speed that came with the SD-22. The rear end ratio, according to specs I found, is 4.375. This will need to be changed in order to get the highway RPM into a more optimum range. Stock SD-22 ratio is somewhere around 3.9, but I haven't found definite confirmation on the actual ratio. Most driving I plan on will be highway and freeway speeds, so I'm wondering if something in the 3.5 to 3.7 range might be better. Or, maybe an overdrive like what was used in the 70's Volvo, if I can find/afford one. My big reason for all this is fuel MPG, not for hauling anything.

My 620 does have a solid steering shaft from the gear box, although a future mod may include changing to a shaft that will compress on impact. The solid cross member that the torsion bars attach to does also have adjustment available for the torsion bars. However, with the removable transmission cross member I'm counting on being able to use it easier for the rear transmission mount. One of my requirements is that any modification made be easily removed.

I am able to weld, although overhead and vertical are problems for me since I don't do enough welding to have picked up that expertise. I do know someone who spent several years as a professional welder, so if some welding that is beyond my comfort zone is needed I may be able to talk him into some quick help. However, I'm really hoping that any mods can be done out of the vehicle and bolted into place.

I checked the vin tag on the left inner fender (very faint and very hard to read) and could only easily read two stamped in numbers. The numbers are in two lines, one above the other, in the lower right corner. The upper number is 767349, and the lower number is 297723. There is an emission tag in the center of the upper firewall that states 1973 as the year of manufacture. Sometime in the future I will go online and see if I can find a picture of a 1973 vin tag so I will know what info originally was on it. I'm assuming that the second number listed is the vin and was preceded with PL620. The actual month of manufacture would also be nice to know, although not absolutely necessary.

The swap will most likely proceed slowly due to time and money available. Although it would be great if it can be finished before summer is over (lack of work space under a roof is the reason).

Don