Turbo charging SD23 engine

[Taylorjacksun]

Hello, i bought a 1982 Datsun king cab 3 years ago and i finally have enough money to give the truck some love. Everything runs fine but i do want to get a little more power and efficiency out of it. Would it be possible to turbo charge the SD23 engine and if so, would it be worth it? I can upload photos of the engine tomorrow 

[datzenmike]

wayno on here has done this and doesn't recommend it. He says the SD25 is a better option and on the SD22 it didn't make that much more power. Maybe he'll chime in about his experience with the SD22.

 

Nice truck!

[Taylorjacksun]

Okay. Thank you. There are other things i need to fix or upgrade on this truck. Should i start a new thread or keep it here?

[wayno]

Where do you live in Washington?

 

As I recall the SD23 had 5 main bearings, I have two turbocharged SD25 engines and have turbocharged an SD22 engine for my friend, I was not impressed with the result of the SD22 turbocharging, it did not seem like it had much more power at all, but it might have been the turbocharger used, it might not have been what was needed, I used a 1985/86 Subaru XT turbocharger on my daily driver, they are very rare, and are gas turbos that spin up fast(low RPM turbocharger) the result on my truck was incredible, I suspect I went from 71hp to 120hp, I can walk away from a Z24 powered 720 on the freeway at freeway speeds.

 

What injection pump do you have, inline or VE type?

 

[Taylorjacksun]

I live in Silverdale and i am not sure which injection pump i have. I have photos but its only giving me the option to insert image from url. 

[Taylorjacksun]

https://www.dropbox.com/scl/fo/ssqytyzm9lk7q920b8qfu/h?rlkey=6a2rnbrpvc5w42wnz4bnpzber&dl=0

 

Here is a dropbox folder with photos of the engine. I just put a new air filter on today and next on my list is fixing the steering pump or switching to a manual steering box. Then i have to fix the RPM Gauge and maybe after that... a turbo. But this is my daily so i have to maintain reliability. 

[Crytek89]

On 2/24/2024 at 6:17 PM, Taylorjacksun said:

I have photos but its only giving me the option to insert image from url. 

You can upload images freely on imgur and copy the URL to use here.
Copied from your dropbox link for easy viewing.

 

 

 

 

Edited February 26 by Crytek89

[Taylorjacksun]

turns out i have an SD25 injection pump, SD22 block, and maybe a SD23 head or just the cover is a 23. 

[wayno]

What makes you think you have an SD22 block?

 

What makes you think you have an SD25 injection pump?

 

You have an inline injection pump just like I do and all the DD22 engines in this country sold in the 80s, it is possible to turbocharge it, I just do not know how good of a result you will get, like I said I used the 1985/86 Subrau XT turbo on my SD25 engine, they are very rare, my SD25 engine in the 720 dually I have uses some other turbo, but the former owner had the injection pump messed with/changed, made to run richer I think, it also has more power, but it is different, it has more torque but is not as freeway friendly, I have to put my foot into it to go above 65mph even with 3.3 gear in the rearend.

 

I am outside the library using their WIFI and freezing my ass off, I am out of here.

[Taylorjacksun]

SD22 is engraved in the block and when i looked up the part number for the injection pump it said it was for an SD25 engine. 

Thank you for the insight, i'm not going to turbo it for subpar results, but if i do then i will let you know how it went.

[wayno]

23 hours ago, Taylorjacksun said:

SD22 is engraved in the block and when i looked up the part number for the injection pump it said it was for an SD25 engine. 

Thank you for the insight, i'm not going to turbo it for subpar results, but if i do then i will let you know how it went.

 

You need to understand how to do it, no one has ever turbocharged one of these SD engines with an inline injection pump and posted about a positive result except me, not even on the Nissan Diesel Forums, when I posted how I did it on that forum they questioned me, asked how I did it and still did not understand, then I drew a diagram of how I piped it(every line) and I am not sure they actually believed me.

 

It is really simple if you understand how the vacuum throttle works with the diaphragm inside the injection pump, simply both the rubber hoses that go to the injection pump(vacuum and vent lines) need to see the same boost for things to work properly.

 

There are other things involved like making the piping(intake/exhaust/vacuum/turbocharger mounting), but there is a lot more room in the 720 engine compartment, that photo I posted is of my engine compartment of my 1969 Datsun 521 kingcab with my turbocharged SD25 diesel engine, it has power steering and power front disc brakes, there is not a lot of room left in that engine compartment, the photo below is of my 1980 Datsun 720 engine(SD25) compartment which also has an intercooler.

 

 

Like I mentioned, it may have been the turbocharger picked that resulted in a less than favorable result, I just know that the turbo I have in my 521 kingcab gave me a great result.

[Taylorjacksun]

If you had to turbo the sd22 again without a budget would you buy a different injection pump? Or is it just a matter of doing it properly and both pumps will yield the same results? Because i would rather spend the money to do it the best possible way with the most reliable option available. (Without swapping the engine) Also, if you’re in Washington then i would love to see what you’ve done to your engine before i start tinkering with mine. 
 

http://nissandiesel.dyndns.org/viewtopic.php?t=2900

 

Also, i would love to get your thoughts on this turbo setup^^

[620slodat]

Where at in Washington are you? East of the Cascades, or west? He is close to the Columbia, in Vancouver (which is on the Columbia River by itself). He will have to go from there as I don't have his permission to give you how to get there. 

 

Don

[wayno]

On 2/26/2024 at 9:06 PM, Taylorjacksun said:

If you had to turbo the sd22 again without a budget would you buy a different injection pump? Or is it just a matter of doing it properly and both pumps will yield the same results? Because i would rather spend the money to do it the best possible way with the most reliable option available. (Without swapping the engine) Also, if you’re in Washington then i would love to see what you’ve done to your engine before i start tinkering with mine. 
 

http://nissandiesel.dyndns.org/viewtopic.php?t=2900

 

Also, i would love to get your thoughts on this turbo setup^^

 

The VE injection pump is the one the factories use when turbocharging an engine even on American engines, but I heard they only last about 60,000 miles, while these inline pumps last 300,000 miles plus, I like the inline pumps like you have, I actually imported an engine from Australia with a VE pump that was wore out, just after receiving that engine I called and talked with a guy that was selling an SD22 turbocharged engine locally on Craigslist, his username on the Nissan Diesel Forums is/was Knucklehead as I recall, he is the one the that posted a photo of a bright red diesel engine with a turbo on it, at that time I had successfully made a draw thru turbo setup, but it had issues, one important issue was when I let off the pedal the air got cut off(butterfly closed in the carb looking thing on the intake), since the turbo is spooled up this created a lot of vacuum, so much vacuum that oil was pulled thru the turbo seal, in theory if you were going down a pass you could empty the oil pan of oil pumping it into the engine, I made a vacuum release valve and got it down to less than 2psi vacuum, but it still sucked oil thru the seal, just not as much, keep in mind that they make turbos that the seal will not leak under vacuum, but they are expensive, that said when talking with the guy with the engine on Craigslist he told me how he did it(piped his engine), it was complicated and required an extra vacuum pump but I listened, I then told him how I did mine as a draw thru, he suggested that mine was running lean, likely because the carb thing on the intake was so close to the turbo, and I should add vacuum to the vent line which would move the spring/diaphragm in the injection pump to a richer position, the way it was as a draw thru I could only get to about 70/73mph almost completely floored(I am positive it was getting really good  mileage), so I did just what he suggested and took it on a test drive, it easily went a 100mph, but it still had the vacuum issue, I thought about it for a little while and thought what if I made it a blow thru and piped it so both lines to the injection pump seen boost, the rest is history, it worked great, I even figured out a way to make it run richer and get me more HP, but there is this ragged line between more HP and having the engine start to try and run away(uncontrolled RPMs), I piped it that way and I thought about for a while, it had enough power without doing that so I just leave that valve closed now, it will still easily do over a 100mph as it is now, but redline is 4000rpms on that engine, and I am really close to 4000rpms at a 100mph.

 

I read that guys thread and even messaged that guy in Australia with that drift truck, I made a setup just like he did and came to the same conclusion he did, it worked fine for drifting(floored on the gas pedal or brake pedal), but it did not work well for normal driving, he moved on to a VE type injection pump as I recall.

 

I live in Vancouver WA near Interstate 205, you are west of Seattle, I bought a couple diesel 720s near where you are and drugged them home back in 2011ish, that is a long drive to look at an engine.

 

You need to know how to weld to make the exhaust from the exhaust manifold outlet to the turbocharger, then you need to make the exhaust pipe from the turbo outlet to the rear of the truck, good thing is no muffler is needed as the turbo is the muffler, bad thing is it is very expensive to pay to have someone make that stuff for you, either you need to know how to make this stuff yourself, or you need a buddy that can make it for you, I made a couple completely new exhaust manifolds from scratch so I could mount the turbo directly to the exhaust manifold, but that is a lot of work, it is just easier to make a pipe going from the exhaust manifold to the turbocharger and mount it where you have room, but either way it starts getting tight in the engine compartment on the driver side.

 

My 521 kingcab SD25 diesel engine was found on the side of a guys garage in the mud, it had this turbocharger connected to it that was too big, I never tried it with that setup, but they had someone that knew how to weld cast iron exhaust manifolds so what I have is the turbocharger mounted to the exhaust manifold between number 1 and 2 cylinders and the stock exhaust manifold outlet was cut shorter and welded closed to make room for the piping of the exhaust from the turbocharger, I sent 3 exhaust manifolds off with a member here to have the same thing done to them and the scumbag likely thru them away and he would not answer his phone anymore, do not deal with anyone named Darren/Darrel/Derek or something like that.

 

I will never have/drive a diesel engine without a turbocharger, I got 25mpg in the city no matter what, but I only got 27mpg on the freeway because I was almost floored all the time trying to go 70mph(without turbo), now the city mileage is the same(with turbo), but I only get 30mpg on the freeway because I drive 75mph+ all the time, if I could drive 55mph/60mph I suspect I would get close to 40mpg, the guy I bought the SD25 turbocharged engine from in my 720 says he got 48mpg with propane injection driving 55/60mph, but he had it piped wrong and the exhaust gas temps were very high, but he was very close to having it piped the way I do.

 

 

Edited February 29 by wayno