1982 Datsun Diesel SD22 Turbo

[TommyBsolid]

Just got this sweet little datsun.
1982
SD22
152,000 mi

5 speed manual

planning on slapping a turbo targeting 8 psi

will post pictures/videos later

[datzenmike]

[]2eDeYe]

Sooner is better :)

[620slodat]

It's my understanding that because of the type of intake system used in the SD-22 it is not easily turboed.  Look up wayno on this forum and use his diagram as he is one of the few who have successfully added a turbo to the SD-25. The SD-25 is a bigger version of the SD-22, and uses the same intake system.

 

Don

 

[wayno]

Hi there TommyBsolid, we both live in the same town, Vancouver WA, we should talk before you go buy a turbocharger, the thing is that I have read a lot of these Datsun 720 diesel turbo conversion threads and not one has ever posted a happy ending in a thread except me.

If I were to guess, almost all of the failures are do to too large a turbocharger, likely the reason is by the time they reached the RPMs needed to spin one up you will already be way over the red line for these diesel engines which is 4000rpms, and these diesel engines don't like it up there, I rarely go over 3000rpms except in 5th gear(3200/3300rpms max).

The other reason for failing is they cannot figure out how to pipe the injection pump vacuum hoses, that had me stumped for a while, I figured out how to do it as a draw thru, but there were issues, mostly I had the wrong turbocharger, it ran great that way except it ran lean, top speed was around 64mph, but I got there pretty quick, and when I let off the pedal it would suck oil thru the turbocharger seal and feed it into the engine, in theory you could empty your oil pan going down a pass where you are coasting a lot, now there are turbochargers out there that have a seal in them that will allow them to be used in a draw thru system, but I bet they are expensive.

I figured out how to turbocharge my SD25 engines as a blow thru system, and my turbodiesel truck is my favorite vehicle to drive now, but I helped my friend turbocharge his Datsun 720 SD22 diesel engine and I was not impressed, he built up plenty of boost but it didn't seem to have a lot more power to me, he also built up exhaust gas temperatures(EGTs), so he was getting fuel, so I am kinda baffled about the result, it seems to me there should have been a better result.

 

There are people out there that have turbocharged their SD22 and they were happy with the result, they just never had a thread about it that I have ever read.

By the way, you will never build up boost revving the engine in your driveway, you have to drive it under load to build up boost, I have seen as high as 20psi, but I have it adjusted so it never goes higher than 15psi anymore and it normally is at 4/6psi on the freeway going 70mph with the EGTs at 600/700 degrees.

 

PM me, you could come over to my house and see my stuff and how I did it, it's easier to show you than explain how I did it here in a thread.

Here are links to both my threads on how I did it and all the stuff I dealt with/did wrong.

http://nissandiesel.dyndns.org/viewtopic.php?f=5&p=24529&sid=b7300c2798676623d16a711993196650#p24529

 

http://nissandiesel.dyndns.org/viewtopic.php?f=5&t=3474

[TommyBsolid]

Waiting for somewhat clear weather to take some quality photos. In the meantime here are photos of the previous owner's post:

Album: https://ibb.co/album/hY4t8v

The exterior is covered in Rhino bed liner 😉

The previous owner had removed the tailgate along with the tailgate strikers and bolted on a canopy. I have the matching tailgate but cant re-attach it until I find a pair of tailgate strikers (brackets that bolt into the sides of the bed allowing the tailgate to latch onto and stay up).
 

7 hours ago, wayno said:

Hi there TommyBsolid, we both live in the same town, Vancouver WA, we should talk before you go buy a turbocharger, the thing is that I have read a lot of these Datsun 720 diesel turbo conversion threads and not one has ever posted a happy ending in a thread except me.

If I were to guess, almost all of the failures are do to too large a turbocharger, likely the reason is by the time they reached the RPMs needed to spin one up you will already be way over the red line for these diesel engines which is 4000rpms, and these diesel engines don't like it up there, I rarely go over 3000rpms except in 5th gear(3200/3300rpms max).

The other reason for failing is they cannot figure out how to pipe the injection pump vacuum hoses, that had me stumped for a while, I figured out how to do it as a draw thru, but there were issues, mostly I had the wrong turbocharger, it ran great that way except it ran lean, top speed was around 64mph, but I got there pretty quick, and when I let off the pedal it would suck oil thru the turbocharger seal and feed it into the engine, in theory you could empty your oil pan going down a pass where you are coasting a lot, now there are turbochargers out there that have a seal in them that will allow them to be used in a draw thru system, but I bet they are expensive.

I figured out how to turbocharge my SD25 engines as a blow thru system, and my turbodiesel truck is my favorite vehicle to drive now, but I helped my friend turbocharge his Datsun 720 SD22 diesel engine and I was not impressed, he built up plenty of boost but it didn't seem to have a lot more power to me, he also built up exhaust gas temperatures(EGTs), so he was getting fuel, so I am kinda baffled about the result, it seems to me there should have been a better result.

 

There are people out there that have turbocharged their SD22 and they were happy with the result, they just never had a thread about it that I have ever read.

By the way, you will never build up boost revving the engine in your driveway, you have to drive it under load to build up boost, I have seen as high as 20psi, but I have it adjusted so it never goes higher than 15psi anymore and it normally is at 4/6psi on the freeway going 70mph with the EGTs at 600/700 degrees.

 

PM me, you could come over to my house and see my stuff and how I did it, it's easier to show you than explain how I did it here in a thread.

Here are links to both my threads on how I did it and all the stuff I dealt with/did wrong.

http://nissandiesel.dyndns.org/viewtopic.php?f=5&p=24529&sid=b7300c2798676623d16a711993196650#p24529

 

http://nissandiesel.dyndns.org/viewtopic.php?f=5&t=3474

I concur with the assessment of large turbos not being suited for such an engine, for #1: diesels don't rev high (especially these ones) and will not pump enough air to spool up a large turbo maximizing its effectiveness. #2: high boost levels will tend to send these engines to the scrap yard due to not being designed for boost (even SD33T engines are notorious for cracked pistons & heads).

 

Before committing to buying one of these old school diesels I searched for threads related to the topic of turbocharging an SD22. I came across a thread on this forum (although I fail to find it again, the title was something like 'This is the bomb... SD22 Turbo!') I read through the entire thing in the span of about 4 hours. 15 pages dating up to 8 years ago. While reading, one thing became very clear. Properly setting up the injector pump is the biggest challenge, due to the combination of vacuum & boost fundamentally changing the characteristics of the injector pump vacuum lines. I started thinking how to go about integrating boost into the vacuum lines to calculate how much fuel is needed at any given RPM & PSI. I remember reading one of your posts where you stated getting rid of the throttle body all together and converting the injector pump to be mechanical rather than working off vacuum would be best case scenario. I read on and it seems the SD engine family has interchangeable injector pump governors. An SD33T injector pump governor is designed for turbo applications and seems like it would be a near perfect plug-n-play in this case.

I managed to find an SD33T Injector Pump for sale on ebay: https://www.ebay.com/itm/SD33T-diesel-injector-pump-Nissan-International-Scout/333428815791?hash=item4da1e7f7af:g:T0kAAOSw901dUFFy
Album: https://ibb.co/album/e52PFa

[wayno]

I talked on the phone with that guy that wrote the bomb thread about my draw thru setup, he actually succeeded but his way was kinda complicated, he had a belt driven vacuum pump instead of using the one on the back of the alternator, and he said something about valves in vacuum lines, that made me think of something I had not thought of, this lead to me getting the draw thru past that wall I mentioned, I used a valve and added a little boost to the throttle control vacuum line and that made the injection pump run richer as a draw thru.

Well that was how I figured out how to pipe it as a blow thru, my 521 kingcab diesel was not turbocharged, but I decided to try setting it up the way I figured out in my head, well it worked perfectly, that truck screams now, all I did was put the turbo on and I piped the boost straight to the intake of the throttle body/snorkel, I left the injection pump vacuum that has the venturi in the throttle body alone, then I left the injection pump vent line in it's stock position also(on the snorkel, with the turbocharger supplying boost to both them lines now going to the injection pump they cancelled each other out , the truck drove normal except it had a lot more power.

I did figure out a way to get a little more power, I put a tee in the vent line that has boost(both vacuum lines have boost), and when I open the valve it releases some of the boost in that line and that makes the injection pump run richer as the diaphragm has more boost on the injection pump control line side now, but there is a point that I cannot go past, if I release too much boost in that vent line the truck engine starts trying to run away because it is getting too much fuel.

My injection pump on my 521 kingcab turbodiesel is not modified, as far as I know it is stock(I bought the engine used), it is a SD25 engine, from what I can tell all SD25 engines came with turbo pistons, they were sold with turbochargers in other countries, but with a VE type injection pump.

In the end all I did was put the turbo between the snorkel and the air filter housing leaving everything else alone and it runs great, if you vent that injection pump vent line the engine sorta runs away.

 

It's really simple, but everyone wants to leave that vent line vented, and the boost makes the injection pump think it is floored all the time except when you let off the pedal, and the EGTs get stinking hot that way, both them injection pump vacuum lines need to have close to equal boost.

 

By the way, my Datsun 521 kingcab has a 1985/86 Subaru XT turbocharger, that one is awesome, my 1980 Datsun 720 has a 1999 VW Passat turbocharger, both are made for 1.9 liter gas engines, the Datsun 521 kingcab is awesome in the city and on the freeway, the 1980 Datsun 720 has a lot of power around town, but it's not as nice on the freeway, both trucks have 3.3 gears in the rear.

 

[TommyBsolid]

I found the thread I mentioned: http://nissandiesel.dyndns.org/viewtopic.php?f=4&t=495&start=105

It was Knucklehead who was talking about removing the throttle body, as well as IP governors being interchangeable on in-line pumps.

Quoting him on the topic of modifying the IP in order to be able to delete the throttle body:

Quote

Either:
1.) Get the RLD governor from the turbocharged SD33T which will fit the pump perfectly,
2.) Get the RSV governor from a forklift model and modify it,
3.) Adapt a rotary pump from an SD25 (or any other pump for that matter)
4.) Modify the existing RBD-MZ governor to to be mechanical.

@wayno Do either of your trucks have a VE style IP? What are the differences between in-line and VE? Could you fit a VE pump onto an engine block designed for an in-line?

 

I read up on SD22 engines and it seems later models (1981+) received 3-ring pistons (not sure if this constitutes it as a turbo piston) rather than 5-ring, as well as 5 main crank bearings rather than 3. Sources: https://en.wikipedia.org/wiki/Nissan_SD_engine ; https://www.engine-specs.net/nissan/sd22.html

 

I would prefer to remove the throttle body and have a mechanical IP, though I'm not sure if its worth the trouble. What do you think?

 

As for what turbo I'm thinking of getting, I will most likely look for a VW Jetta 1.6-2.0 L at a junkyard. I'm not looking to make big power, just enough to bring the HP up to 100-120.

[wayno]

100-120 HP is big power for a SD22 engine, that would almost double the the HP of the SD22 engine, I might be in that range with my SD25 engine but I started out with 71hp, also my 521 kingcab is lighter than a 720 cab, I also have a step side box with fiberglass fenders, my truck is just lighter which in the big picture counts as it felt like a big jump in HP to me.

 

The 1980 SD33 block that came with a turbocharger is the only block that I know of that might have had SD22 sized turbo pistons, but I don't know they are any different, but I suspect they are different.

Personally I don't know anything about changing out the rear of the injection pumps, if Knucklehead said it was possible then it likely is, but he did not do that to his engine, he turbocharged the inline pump like I have, he was the one I talked to on the phone as he was selling a turbocharged SD22 engine at the time on craigslist in the Portland area, he explained how he did it over the phone which sounded complicated to me, but I was talking about my draw thru and he was talking about a blow thru, he started talking about valves on vacuum lines and that gave me an idea.............

What my issue was for power on the draw thru was there was so much air being sucked thru the throttle body that the venturi was creating vacuum when it was not supposed to create vacuum, this caused a lean condition in the injection pump(the wall I hit at 64mph), so I used a valve to add a little boost to that vacuum line from a boost source and no more wall at 64mph, I had it almost going a 100mph once on a straight flat 4 lane freeway, this was on my 1980 720 kingcab turbodiesel truck, at the time I think I had 3.7 gears in the rear, I was turning around 3500rpms in 5th gear.

This success with the 720 diesel as a draw thru gave me an idea, what if it was set up as a blow thru, when one puts a turbocharger on one of these diesel engines with an inline pump the injection pump thinks it is floored because of the boost and it tries to run away, this is because of the diaphragm having pressure on it when normally it either sees vacuum or atmospheric pressure(neutral), vacuum pulls it to a leaner position like when at idle, the more pedal one gives it the less vacuum it has the richer it runs, when boost is built up the diaphragm sees this boost via the venturi and moves to the floored position, even if you are barely pushing on the pedal(run away), this is happening because only one side of the diaphragm is seeing boost, so my idea I thought of was what if I put the vent line to boost also, it worked great, when both sides of the diaphragm see the same boost they cancel each other out and the venturi works properly again, it drives normal, fact is anyone can drive it as long as they are not hot dogging it as that causes EGT issues.

 

I see over 12psi all the time when I am going thru the gears, but on the freeway when I am going 70/75mph it runs at about 4 to 6psi and when I come to a hill I see up to 10psi on rare occasions depending on how steep the hill is, I have drove it this way for a few years now and taken several trips with it that were around 300 miles round trip without any issues except for the pre-filter issue, this truck is awesome, you should take a ride with me.

 

I have a VE type injection pump setup on a spare rebuilt SD22 engine, I had an engine imported from Australia just for all the stuff I needed to convert over to the rotary type injection pump, but it was for an SD22 engine, by that time I had found a SD25 engine, I also have a rebuilt VE type injection pump for an SD22, I almost turbocharged that engine but I bought that turbocharged SD25 engine I mentioned from a guy before it happened, he said it ran great but it was just another failure, the EGTs went over 1400 degrees just trying to get on the freeway and do the speed limit, that guy told me I drove it wrong on the test drive but I had already committed to buying it, top speed for him was 55mph, I tried a lot of things to get that engine to run cooler but none of them worked, so that engine sat for a few years until I made it a draw thru, once I figured it out on the 521 kingcab I copied that setup on the 720 and it runs properly also, but it has a different turbo and is not as fun to drive although it has a shitload of torque, the injection pump was turned up also, at least that is what I was told by the guy I bought it from.

 

I don't know what the results will be on your SD22 engine, like I mentioned before I was not impressed with the result of my friends SD22 turbo conversion I helped him do.

Also I learned that to convert over to a VE type rotary pimp you need all the gears on the front of the engine, the inline pimp gears are not the same as the VE type pump gears, I supposed you could buy a VE setup somewhere like I did and have it imported or buy a used engine from one of them engine import places, I also believe that you could weld up the inline injection pump gear to make it solid and put it on a VE type injection pump, but I have never done any of this myself as I figured out how to turbocharge my SD25 engines without issues with the inline injection pump and i don't even need an inter-cooler.

 

Again, Knucklehead in the end used the inline injection pump, he never posted to that thread what he all did to make it a daily driver(the happy ending), he used WVO in his engines so the injection pumps didn't last that long, personally I would go with the inline pump as that is the easiest/least expensive way to turbocharge your SD22 engine, especially if you can make everything needed(turbo manifold and associated piping), I actually have a couple setups already made that you could look at, but you would need to come over to my place to see them.

[TommyBsolid]

Just getting around to changing the Transmission & Differential fluid. While driving I have noticed a 'clunk' when shifting. I decided to check out my driveshaft joints. Center bearing has been replaced fairly recently and is in quite good condition. Turns out my center U-joint has 45 degrees of 'clunk' and will be no issue replacing. What worries me is the transmission has about 20 degrees of play, and the driveshaft about 30. Is this fairly normal for an older car as such?

 

I won the bid on the SD33T IP I posted a link to. I will look for a spare 4 cylinder in-line IP and attempt to Frankenstein them together. If it fails to run ill have the original IP with the pneumatic governor as a backup. I met with Wayno and he explained how he managed to successfully pipe the vacuum & vent lines with a blow through setup (Air Filter>Turbo Compressor>Vent Line>Throttle Body>Vacuum Line>Intake Manifold) Essentially keeping the lines put and adding a turbo past the air filter.

@wayno Correct me if I'm wrong.

I'm going to attempt deleting the throttle body... for science

[datzenmike]

Have someone hold the differential flange from moving and try the U joints again. I think you are just bumping back and forth on the differential gear lash. 20^o of turning is wider than the U joint cup and trunnion.

[TommyBsolid]

Taking a second look the numbers I gave were highly inaccurate. I put the transmission in gear and there is maybe 1° , basically nothing. U joint behind the center bearing is shot 5-10°. Differential is around the likes of 8-10°~ with the parking brake engaged and transmission in neutral. The previous owner had not tightened the parking brake line, it was loose as a goose. He told me he parked it in gear everywhere he went, who knows how long ago the parking brake stopped working. I imagine having the drive line holding the weight of the car constantly can loosen some things up.

[datzenmike]

U joints should allow the drive shaft to turn and that's it. No other movement should be possible nor felt. No up/down or side to side... nothing. If you can feel a movement of one shaft while the other is still it's bad, if you can see movement that's really bad. Don't be afraid to 'lean on it' to check for any play. It handles a hundred HP... you aren't going to hurt it. 

[TommyBsolid]

Center joint needs to be replaced. The other 2 joints trans and diff are tight and in good condition. Question is how much backlash is acceptable in these differentials, its got about 8°

[wayno]

I don't know what degrees are in inches of movement, but if the pinion flange has more than an eighth inch play I would be looking for the reason, when I was at the wrecking yard I found an LSD that had a quarter inch play in the flange, I bought it anyway, but once it was out and I looked at it real close the ring/pinion were fine, the slop was some where else, I put it in my axle housing in my 521 kingcab and it had only a 1/16th inch play at the most, it was fine.

What color was the gear oil in the rear axle when you drained it?

 

[TommyBsolid]

The flange is about 3" in diameter

3*3.14(pi)= 9.42" circumference

9.42/360= 0.0262" per degree

1/8" = 0.125"

0.125/0.0262= 4.77°

 

so 1/8" is close to 5 degrees
It's somewhere in that range, not too much more. I'm not gonna worry about it as I am likely going to swap the diff out for a higher gear ratio after the turbo.

I haven't gotten to draining it yet

 

[TommyBsolid]

I was able to break the drain bolts loose for both trans and diff. Transmission had quite a bit of tiny metal fragments in the oil, I'm not sure if anyone had ever changed it. Differential had coffee brown fluid with a side of white cream, hardly any fragments. I tried getting the fill bolt on the transmission loose (soaked it in wd-40), what an odd square bolt Nissan decided to use (I'm measuring 17mm). Tried using a wrench but it slipped, had to file off the excess on the sides of the bolt to get it back to somewhat square. I realized a socket is my only option, its deadly tight on there and a wrench will just end up rounding the corners. I hacked together a 17mm square 1/2" drive socket using some stock pipe and scrap metal, it fit very well and I was confident it would work...

 

This bolt is on tight! Didn't even budge.

[MaxChlan]

Holy shit... heat heat heat. I would be scared of snapping the head off the bolt at this stage. 

[datzenmike]

I use a pipe wrench. It tightens it's grip as you turn it. Jack the car up so you can slip a 2' length of pipe over the handle to increase leverage. Use anti-seize on the threads when you install. 

[wayno]

This is one of them all or nothing situations, do what Mike suggested, get a pipe wrench if you can and a piece of pipe that will fit over the pipe wrench handle, get the best grip you can once the pipe wrench is ready to go, and pull/push with everything you have in you, don't ease into it, it has to be like you using an impact, I personally have never heard of anyone breaking the end off, but I have heard of people rounding it, when I put them back in I don't normally go that tight,  I just use an adjustable crescent wrench and get it snug. 

[datzenmike]

There is a tendency to over tighten. It's a pipe thread which self seals not a screw thread that needs to stretch the fastener. Snug it up and clean it off with de-greaser....... check back in a few days to see if seeping. Usually it won't. Don't forget anti-seize.

 

Differential bungs also fit. Most have the 1/2" square hole that a breaker bar fits. I also use a drain bung in the fill hole on the side because they have magnets on them.

[TommyBsolid]

I ordered an impact socket off of https://www.mcmaster.com/drive-sockets (the company I work for gets free next day shipping)

The socket is 11/16" (17.4mm~) 4 point 3/4" drive but I fabricated an adapter for 1/2" using stock tube and scrap metal.

I heated the bolt/thread with propane and cooled it with water. Came loose like butter with 1/5 of the force I used last time. I figure I could have gotten away with making another scrap metal socket but I had already ordered the socket, only $25. Thank you all for the suggestions, they are much appreciated. Back on the road! 🙂

[datzenmike]

Aluminum expands twice as much as steel. Warm the case the hole gets larger. Cool the bolt it gets smaller. It's very small but sometimes enough. I try to take the plug out when the transmission is hot from driving before it cools down.

[TommyBsolid]

Recently bought a 1985 720 ST Z24, has a coolant leak and smokes like a chimney. I got to pulling the head off today to see whats up. No doubt the head gasket is blown, the oil has mixed with coolant so much its become thick like molasses. What has me scratching my head is it seems cylinder 3 is the only one affected by coolant making its way into the combustion chamber. The intake valve on #3 is covered in coolant, the chamber clearly has been burning coolant by looking at the head, the spark plugs are fouled. But this chamber seems to be the only one compromised. I can see coolant passages running through the intake directly under the runners, though I'm not too sure on how its piped. I'm guessing Nissan designed the intake this way in an attempt to raise the intake air temp to promote a more complete combustion in an effort to reduce emissions? I see 2 pipes coming off the radiator, lower one to the water pump which is attached to the block, upper one to the thermostat which is attached to the intake, and then a coolant pipe coming strait from the block to the center of the intake. This has got to be the strangest design I've seen so far. Any experienced veterans care to fill me in on what Nissan was thinking I appreciate it 🙂

 

 

Cylinder 3 intake runner, the others were dry. The hose directly in between 2&3 is attached to the coolant pipe coming off the block.

 

 

 

Ive got big plans for this truck, its got a bright future 😎 

 

EDIT: moving this post to a new thread: https://ratsun.net/topic/76978-z24-naps/

 

[TommyBsolid]

My transmission started to make quite a bit of noise while in neutral clutch out. Talked with wayno and he helped me figure what it is, must be a bearing wearing out. I’ve decided not to push my luck and go ahead with taking it out and repairing it. I just got done taking it out this evening and boy was it a learning experience. Everything was going smooth until it came to actually dropping the gearbox. Without rotating the box there was no where near enough space for the bellhousing to clear the clutch. Because the crossmember (the one the center driveshaft bearing sits on) is part of the frame, this means you have to angle the box forward pivoting on the crossmember. I took a good look and figured if I rotate the box counter clockwise (from driver perspective) having the starter location on the bottom of the box it might give me enough room, it worked and i’m almost certain this is the intended way of removing/installing the transmission. Though the reason it worked isn’t all because of the starter position, its because it gave me much more clearance having the shifter fork sideways instead of banging straight up on the underside of the floor panel.

 

To clear things up this is an SD22 (starter is on the left side of the engine (driver’s perspective)

This is a manual 5 speed

 

I’m curious if you have to do the same on the Z engines?