My 1969 Datsun 521 kingcab

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waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#16

Post by waynosworld »

plenzen wrote:I have a question for you.

Can you not just eliminate the throttle body all together ?

Or do you need the vacuum source from it for the fuel pump diaphragm and all that "magic" that happens there ?

I have a throttle body on my SD 25 but have the VE style pump.
I have adjusted it so it's open all the time.
Only thing I can think of why it was on this truck was for noise abatement as it was originally adjusted to open at about 1/2 - 3/4 throttle and then the engine noise was enough you couldn't hear when it opened anyway.
It's made no difference whatsoever as to how the engine performs.
I kept it there in its open position merely to keep my air cleaner in place. My air heater is mounted under it.

I would think that getting rid of that thing would give you more air flow and a bit easier to seal the boost to.
You could use the base of it or make a flange with just a piece of 3 inch ( or whatever size it is ) pipe and shoot it straight in.

However
If you need it for proper fuel pump diaphragm function then I guess your stuck with it.

Or has someone mentioned this already elsewhere ?

Just curious is all
P
The throttle body is needed with an inline injection pump, there is no way around it that I know of.
I understand what you are talking about, I truly do, if I just found and bought an SD25 VE type injection pump with the front plate, cover and all the gears that make it work it would be a lot easier, but one has to find an SD25 with a VE type pump first, then you have to convince them to part it out, and then you have to talk them into pulling all the parts needed and send them to you at a reasonable price.
I actually have a SD22 VE type pump and everything else needed, but it is for an SD22 not an SD25, and I have not given up yet, I am on a mission now to see if I can get this to work as a blow thru, I know I can get it to work as a draw thru, but I have that vacuum issue that I have dealt with the best I can, but only I can drive it that way, and it drives real good and is very powerful.
What do you have adjusted open all the time?
I know the voices are not real,
but they have some really good ideas.
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#17

Post by waynosworld »

I drove it today in a couple different configurations, but I am getting ahead of myself, here is what it looks like right now.
Image
This is what I did for the air filter housing, I cut the inner fender and made it fit in front of the battery.
Image

Image

Image
So here it is piped.
Image
Notice the front brake reservoir being turned sideways.
Image

Image
The pyrometer probe installed.
Image
The turbo compressor intake to the air filter neck, it's just two stock hoses put together, I am lucky I had these parts in good condition.
Image
The hood does close, I was going to make this work with a stock hood without any holes in it.
Image
And I have boost and pyrometer gauges.
Image
So I drove it today, the first time I drove it I had the waste gate piped to the compressor outlet, I had the boost in that line, I also piped the injection pump vent line into that same line, so all these lines are connected to the compressor outlet that goes to the waste gate, the throttle body vacuum line is untouched, in it's stock configuration, so it drove fine, I could hardly get 7psi boost and it takes time to build up boost, fact is that going one speed there is no boost as I recall, even on the freeway, but when I put my foot into it even a little it starts building boost, it also blows black smoke when accelerating, I am only using the top half inch of pedal also, this I am not used to when driving this truck, I was planning to see what the EGTs did on this hill I drive up, but my pre-filter plugged up before I could get to the hill, I made it more than half way home before the engine died, lucky for me I had a filter in the glove box and the one tool I needed to change it out, I primed the system and it started right up and all was good, I drove home.
So I wanted more boost, so I removed the line going to the waste gate, plugged it and took off again for another test drive, around the neighborhood it drove fine, had a little more power, but when I entered the freeway I could not hold a steady speed, it was surging, meaning I would hold my foot in one spot and maybe 5/10 seconds later it would just start taking off even though I didn't move my foot, I would have to let off to get it to stop accelerating, I tried over and over to hold a steady speed but I could not do it, but it has more power like this.
My theory is that when the waste gate is hooked up it gives the rack steadiness, I had no surging issues on the first drive on the freeway before the fuel filter plugged up, but I did on the second drive, it is the only thing I changed, so I put it back the way it was on the first drive and I am now going to wait for the 2 valves I bought last night on ebay, one of them will go between the compressor and the waste gate to make that adjustable, the second valve will go between a boost source and the rack vent line, this line will be piped differently, I am going to punch two holes in the ABS piping, one for the boost gauge, the other for the vent line, I am going to have the waste gate/compressor line clean except for the valve.
It has more power than it had before, and on the freeway I normally have the pedal half way down and don't get that great of mileage, this time I barely had my foot into it, I also noticed my RPMs once while entering the hiway, normally I shift at 2500/2600rpms, anything more and it sounds over revved, well I looked down while entering the freeway and seen 3300rpms and it didn't sound over revved, but my exhaust pipe is dumping right under my seat right now, and I was looking at my boost for the most part.
I need a better exhaust system as everything including the flange connected to the turbo is just tacked on, it's leaking at that flange, leaking where the flex pipe is connected to the head pipe, the pyrometer probe is leaking as the mount bung is only tacked on, all that is temporary in my mind as I want to use an exhaust pipe that is the size of the turbo flange, the one on it now reduces in size an inch out of the flange.
All in all I am neutral about the results, I need the control valves before I change anything else, as the second drive was a fail but was easily reversible, I really need to fix the black smoke coming out when I am accelerating, it's not terrible, but I could see getting a ticket if I ignore it, I am hoping the control valve fixes it.
I know the voices are not real,
but they have some really good ideas.
plenzen
Posts: 891
Joined: 16 years ago
Location: Cochrane Alberta Canada

Re: My 1969 Datsun 521 kingcab

#18

Post by plenzen »

I guess in the automotive applications they use that silly diaphragm on the fuel pump. Marine and industrial applications its not on there. No throttle body either.

I have the butterfly in my throttle body open all the time. I reread what I posted and it was a bit "cryptic".

Actually I lied a bit.
It's adjusted to the proper "closed" amount at idle so that on a really cold day start up the amount of -15 - -30C air is restricted somewhat so the air heater can work a bit better.
As soon as I give any throttle at all it opens all the way. There is an adjustable switch on the fuel pump linkage.

I admire your determination/stubbornness/resolve. call it what you will, to get this little guy performing.

I suspect that you may build a bit more boost once you plug up some of the exhaust leaks you say you have.

Edit

Just looking at your engine room, and reread some of your previous posting about a different brake booster.
I wonder if the booster/master out of a D21 might work in there. It's a single reservoir and a lot shorter than the one you have in there now. Maybe ?
Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#19

Post by waynosworld »

You don't even need the throttle body with a VE type injection pump.
I have a marine type injection pump also, I installed it on my 720 engine trying to fix the running to hot issues I was having with that blow thru turbocharged engine, I finally gave up on that injection pump as I could not get it to run correctly, that is when I gave up and changed it to a draw thru, it runs great and it is pleasant to drive, that is why I am turbocharging this engine/truck, I know more now and am hoping to keep this a blow thru, that way I don't have the vacuum issue the 720 has, although I have driven that one quite a bit now and don't see the oil level dropping, so the oil being pulled thru the turbo seal is minimal.
The turbo piping clears the brake master reservoir, so I will not worry about that, it works fine the way it is.
If I cannot make this work as a blow thru it will become a draw thru also, but my first drive it drove fine except for the black smoke when accelerating, I hope to fix this issue with one of the valves I have coming, if I can get the boost in the vent line right it will keep the rack from moving so far to the rich position because of the boost in the injection pump control line, I am trying to find a happy place with a valve.
The valve worked on my draw thru engine, I could not get enough fuel, so I added boost to the injection pump control line thru a valve, I had a wall I reached at around 2500rpms, no more wall after that boost line was added, but my fuel mileage suffered, but now have lots of power, and it doesn't run hot EGTs either.
I am waiting for the valves to arrive, I may talk to an exhaust shop Friday to see if I can get an exhaust system made, the one I have now is temporary.
I know the voices are not real,
but they have some really good ideas.
ziper1221
Posts: 25
Joined: 8 years ago

Re: My 1969 Datsun 521 kingcab

#20

Post by ziper1221 »

What is wrong with replacing just the diaphragm mechanism with a mechanical linkage to the throttle?
1982 720 SD22
Florida
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#21

Post by waynosworld »

ziper1221 wrote:What is wrong with replacing just the diaphragm mechanism with a mechanical linkage to the throttle?
A guy in Australia did that, he used the truck for drifting or burn out competitions, he said it was basically floored or not floored, in the end he converted over to a VE type injection pump.
I mocked one up with a mechanical lever, but the total usable throw was a half inch, that injection pump is touchy, and shut down is an issue, I never put that mechanism on an injection pump that was on an engine to test, it was just going to take too much work to make the engine shut down with a key, and that is very important to me, it must start and shut down with a key.
I know the voices are not real,
but they have some really good ideas.
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#22

Post by waynosworld »

I put a longer exhaust pipe on it today and it is a lot quieter, I also added a boost controller valve between the waste gate and the turbine outlet, I now have almost 10psi boost when accelerating and I have not even tried to adjust it yet, I guess I had it adjusted close after pulling it apart to see how it worked.
I didn't even see 1000 degrees EGTs today and I had it on the freeway, and I do have 4/5psi boost holding a steady hiway speed, but I was only on the hiway a few miles, the 720 has at least 8psi going the same speed.
I am planning on driving it 220 miles total tomorrow going to a small get together near Olympia, at least that is my plan tonight, I am hoping I have no issues and that I get a better understanding of the engine generally speaking, it appears to idle rougher now and when I shut it down it shuts down fast and it shakes the whole truck when it stops, I have it idling at 700/800rpms, it just feels different, I didn't expect the idle to be effected, very strange.
Oh and I washed it today. :lol:

I am not sure how much difference it makes temp wise, but I am sure there is some difference, my EGT gauge probe is on exit pipe from the 521 turbo, while the probe on the 720 is a few inches after exiting the exhaust manifold a couple feet before the turbo exhaust turbine, I am not sure that I can measure them the same side by side, as they would both have to be in the same place to be accurate side by side, this 521 exhaust turbine is a lot closer to the valves than the 720 exhaust turbine by a couple feet, I suspect that it will be easier to melt the 521 turbo vanes.
I know the voices are not real,
but they have some really good ideas.
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#23

Post by waynosworld »

I drove this truck to the Jrock shop get together today, it was around a 220 mile round trip, the engine ran flawlessly, I should have done this years ago, but I only learned how to do it the way I did it in the last year.
This thing ran awesome, I mostly went 75mph, I was turning 2800rpms, my exhaust gas temps were at 700 degrees, and I was at 5psi boost on level ground, if I slowed down to 65/70mph the EGTs went down to 650 degrees, and I had 3psi boost, if I wanted 80mph I had to start putting my foot into it and the EGTs went up to 800/900 degrees and I had around 8/9psi boost, at the faster speeds my water temp went up a little, almost 3/4 of the way up the gauge when normally it is just past half way, but when I backed off it slowly dropped to normal.
What was really awesome was how it drove, where ever my foot was is how fast I was going, if I was going 75mph at 5psi boost and I came to a hill, I just kept my foot right there, and as I started up the hill the boost would slowly climb higher depending on how steep the hill was, but it kept up 75mph no matter how steep the hill was without even moving my foot a little, but the EGTs raised when going up the hill, but they never got above 1000 degrees, when I went down hill I had to keep my foot still also, it kept going 75mph, but the boost dropped to 3psi and the EGTs also dropped, but it kept going 75mph down the hill, a cruise control would work great on this truck now, normally when I would come to a hill I would have to start getting deep into the pedal to try and keep my speed up, most the time I would end up being floored and slowing down, but when the EGTs got to 1300 degrees I would start letting up, and when it got to 1400 degrees I would let way up, to go 75/80mph in this truck I was almost floored all the time and it was hot all the time.

This thing is awesome, I could even speed up going up hills, I had it at 90mph once, but backed off because this was a test drive and I wanted to get there and back without breaking down, I forgot to write my mileage down when I filled it up yesterday, but I think I used around a half tank, maybe slightly more, I believe I got real good mileage, 6/7 gallons for 250 miles of driving between yesterday and today, I will fill it tomorrow to check, even if I used 8 gallons I still got over 30mpg going 75mph.

I will drive it a little more before making my decision on the 720 turbodiesel that has the draw thru setup instead of the blow thru like the 521 above has, but I am pretty sure that one is going to get changed back to the way it was and I will pipe it like this 521, I didn't know 6 months ago what I know now, otherwise the 720 would never have become a draw thru even though it helped me learn what works and what doesn't work.

This thing drove awesome today, I don't believe I am going to change anything on it, sure I can turn the waste gate control valve to give it more boost, but right now I don't want to screw up a good thing.
I know the voices are not real,
but they have some really good ideas.
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#24

Post by waynosworld »

Well I filled it up today, I figure I got at least 30.2mpg on that trip going 75mph most of it, I did have maybe 30 miles of that in the city, I have never gotten that kind of mileage going that fast before.
I also had no EGT issues at all, I never got above a 1000 degrees the whole trip, normally I am flirting with 1300/1400 degrees when I come to hills, as I start flooring it trying to keep my speed up on the hill, I had no such issues this trip.
It's such a simple thing that I did to have this engine run awesome other than using a turbo for 1600cc gas engine, all I did was pipe the injection pump vent line to the intake system between the turbo and throttle body, so when I have boost, I have boost on both sides of the diaphragm, so basically the venturi in the throttle body works like normal as both sides have boost when there is boost.
I did put a control valve in the waste gate circuit, I am able to get around 10psi boost now instead of just 7psi, but most the trip I was at 5psi anyway except on the hills.
I am fairly certain that the 720 is getting re-piped in the near future, if the result is the same then it is not a fluke.
By the way, I don't have a blow off valve as when I let off the pedal the boost goes away right away, maybe the waste gate has something to do with that, and I checked my pedal, I am only getting the butterfly in the throttle body open three quarters of the way, maybe in the past I have pushed so hard on that pedal assembly that I bent it trying to keep my speed up on a hill before I had an EGT gauge. :lol:
I know the voices are not real,
but they have some really good ideas.
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#25

Post by waynosworld »

Well i have been driving this and I don't even look at the EGT gauge anymore, it's never very high so I lost interest in it, but I am always looking at the boost, it's not like the 720 turbodiesel, this one has to build up boost while that one with a larger intake vane has boost from the moment I let out the clutch, the 720 has way more low end grunt.
I am also thinking that transmission bearing is going away, I get this weird noise in first and second, but the engine moves more side to side when in them gears, and I have the exhaust piped with a solid hanger in one spot just under my seat, so next Friday it gets a new exhaust system and everything should be isolated when it is done, if I still have the noise I will know it is not the exhaust hitting/rubbing/transferring noise thru the body/frame, transmissions seem to be heavier and heavier every time I have to change one out, one of these days I am not going to be able to change one out myself.
I know the voices are not real,
but they have some really good ideas.
plenzen
Posts: 891
Joined: 16 years ago
Location: Cochrane Alberta Canada

Re: My 1969 Datsun 521 kingcab

#26

Post by plenzen »

Sounds like you hit the sweet spot with this one.
I would love to have about 5 lbs. boost on my D21 and that's about all it would need here at 4000 ft.
I have a hill about 3 km long to get out of town. 3rd is too short and 4th is too tall to get me out at speed limit which is 80Kp/h.
I just hold 60 Kph in 3rd with my 4 ways on and people just go around me and give me " the stare" when they do it.
Oh well.
Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#27

Post by waynosworld »

I am in the process of negotiating with a guy to build me at least 3 turbo exhaust manifolds, from the sounds of it they will not be that expensive, and the exit flange will be tight against the intake exactly in the same place the home made one is but I still have not decided if the flange should point sideways or farther out and up, it will have a generic flange and whatever turbocharger is used will need an adapter piece that bolts to the generic flange, I can make my own adapters, but making the actual exhaust manifold is more than I want to try and tackle.
It's kinda depressing for me when I know that the truck cannot get up the hill even in forth, that is why I have moved from the SD22 to the SD25, that 10 extra HP does make a difference, my issue has always been that I drive fast, I always have, and I likely always will, I am always on the ragged edge of almost going just fast enough to get a ticket, and if someone passes me I follow behind them a quarter mile.
So this is why I am chasing the turbocharger for my diesel trucks, when I had a 1982 Datsun 720 with an SD22 I always drove it 70mph when I could, I got terrible mileage for hiway travel, it was always somewhere between 27mpg and 29mpg, and half of the time I was doing 60mph because it would not go any faster because of head wind and other such things, the SD25 allowed me to go almost 80mph most of the time except on the hills and I still got the same mileage.
Now driving the same truck going a steady 75mph up or down hill and have been getting over 30mpg, this is a win/win for me, I am still going fast and getting better mileage.
Now from what I understand, all the SD25 engines came with turbo pistons, while the SD22 engines did not come with turbo pistons, the way I look at it, with the turbocharger I am running cooler than I ever ran without the turbocharger and I am not even running an inter-cooler as I am never floored, while without the turbo I run hot because I am almost floored all the time, if this is the case, then having a turbo would seem better because the engine will not be as hot all the time, so it might be alright to turbocharge an SD22 as long as it runs cool like my 521 does.
The guy that made the Red SD22 engine in the upper left of each page on here built his turbodiesels with SDD22 engines, he says he has had no issues with blowing them up, he is the reason that I piped my 521 SD25 diesel engine this time the way I piped it, he said something in an email that made a light blub light up in my head, he is the reason my 720 has power because I ran into a wall power wise, he made me think about that vent line the injection pump has, I never really gave that line much thought before I talked to him via emails, he started talking about that vent line and control valves, I did get lucky though, when I put that control valve in the lines between the boost and the injection pump control line to help the injection pump to a richer position, I didn't know that the valve only works properly one way, so I had a 50/50 chance of getting it wrong, but I got it right, and that is why I started thinking about the injection pump diaphragm and how it works, and that is how I thought of piping the vent line to a boost source to cancel out the boost on the injection pump control line when it is under boost in the blow thru configuration and giving the engine too much fuel and making it run way to hot.
I sure hope you guys like reading, as I don't know what a short reply is. :lol:
I know the voices are not real,
but they have some really good ideas.
plenzen
Posts: 891
Joined: 16 years ago
Location: Cochrane Alberta Canada

Re: My 1969 Datsun 521 kingcab

#28

Post by plenzen »

I like reading it/them.

I bet you have some "Ah Ha" moments while lying in bed at 0345 and are even tempted to go out to the garage to have a look or try your "Ah Ha" revelation don't you ?

Only reason I ask is that I have them, and in fact, have seen me go out and look to confirm and may even start the repair or modification or whatever.

It might even be a form of OCD.,,,,,,,,,,,,,,,,,,,,,,,,,,,,, maybe.
Retired Pauly
Problem with being retired is that you never get a day off.
1987 D21-J SD25 KC
KJLGD21FN
waynosworld
Posts: 571
Joined: 11 years ago
Location: Vancouver Washington USA

Re: My 1969 Datsun 521 kingcab

#29

Post by waynosworld »

Actually I don't have them at night, I go to sleep right away and sleep without dreaming and have for the most part since I was a kid, long story short, I was given a drug that I should not have been given, and I have not dreamed since except maybe twice a year since I was in the sixth grade.
My Ah Ha moments come while I am talking to someone or reading something, that's why for the most part I have not done anything original, my kingcab 521 was done before, trying to turbocharge SD series engines is not anything new, but happy endings on them builds are rare.
My thing in life seems to be to buy others failures and make them work, this SD25 engine I turbocharged was turbocharged when I bought it, but it looked like a failure to me, and I was just so happy to find an SD25 that I took the turbo stuff off, put the stock stuff on it from another engine and put it in my 521 kingcab and I called it good for several years, getting the 720 turbodiesel going was one of the bought failures, but Larry will never agree that what he made was a failure, he drove it the way he drove it, I could not drive it that way, it just got too hot for me, I floored it once to see what would happen on the hiway, nothing happened, but I was over the max RPMs as far as Larry would have been concerned, he drove 50/55mph max.
The Ah Ha moment on the 720 truck was when the guy that built the Red engine in the top left corner of each page on this forum said something about having a valve between the boost and the vent line(I read this in an email he sent me), I thought that if that could be done, maybe I could add boost to the injection pump control line itself to try and move the injection pump diaphragm to a richer position, keep in mind that I had it set up as a draw thru and I was running lean the way it was, that worked great, but the vacuum issue has and still is an issue having that engine as a draw thru, so this time I tried this 521 kingcab truck as a blow thru again, but this time I piped boost to the vent line coming from the injection pump, I was going to add a valve to control how much boost the vent line seen, but I went for a test drive and it worked great without a valve, so I took that trip to Olympia WA and it drove great, so this is a happy ending as far as I am concerned, but again I didn't think of this, the guy with the pretty engine is the one that mentioned it to me in an email, but his thread on here doesn't have a happy ending either, he never mentioned what he did to make it work in his thread.
I am waiting to have a turbo exhaust manifold made that will allow me to remount the turbo in my 720 lower like it is in my 521 so I can put the good stock hood back on that doesn't have a hole in it, I then will put the 720 back to a blow thru like the 521 is now, I hope to have the same result the 521 has had, Larry said that the injection pump has been turned up on that engine to make it richer, if it runs hot again like it did before even piped the way the 521 is piped, then I may have to remove it and take it to the injection pump shop and have them put it back to stock(turned down) unless someone on here can tell me how to do it myself, but I am going to try it the way it is first.
One of these days I will draw up a diagram on exactly how I piped the 521 showing every line so that everyone can see what I did so that they can do it if they want as it is hard to make people understand what I did as for some reason, even though most know what the injection pump vent line is on an inline injection pump, they do not get it when I say I piped that line to a boost source, when there is boost of course.
I will never daily drive a SD series engine without a turbocharger again. :)
I know the voices are not real,
but they have some really good ideas.
handcannon
Posts: 58
Joined: 8 years ago

Re: My 1969 Datsun 521 kingcab

#30

Post by handcannon »

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
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