New World Datsuns...

Congrats! 30mpg is pretty impressive -- even if it's just a guestimate at this point.

DRIVEN wrote:Congrats! 30mpg is pretty impressive -- even if it's just a guestimate at this point.

Guys that drive these little diesel trucks 60mph or less get 35mpg plus, but I drive too fast and normally get 27/28pmpg.
My 720 has only been getting 20mpg which is terrible, I have never understood that as it don't blow black smoke, but I also have never driven it on a hiway trip of any significant distance either, only around town trips for that one so far, but 20mpg is just awful, I have always got 25mpg in the city in the past.

I got around 30.2mpg on that trip, that is the best I have done in years, there was maybe 30 miles of city driving in that, but the thing is that I didn't change the way I drive.
If I drove slower I would bet the mileage goes up.

It got a new exhaust system today, now I can hear other noises that I could not here before.
I am hoping that I am losing a U-joint as if it is not that then the transmission might be losing a bearing, it makes this rattling/vibration sound like a piece of sheet metal is lose in first, second, and sometimes third gear under certain conditions and it has me worried, it sounds like it is coming from the front, but I cannot find anything rubbing, but I got under the truck and found the middle drive line u-joint makes a sound something like the tone the rattle/vibration sound, tomorrow I will likely replace that section with another one I have and see if anything changes, it was raining today so I didn't want to lay on the wet ground, tomorrow is supposed to be better weather wise.
I like driving this truck again and now I don't like driving the 720 as it has that vacuum issue, I plan to change the 720 turbocharger setup to the same way I did the 521 and am hoping for the same results, but even if it works the same, this 521 kingcab is still my favorite diesel truck.

I changed the rear drive line section and it made no difference, I then noticed that the tube venting the crank case wasn't connected to the shorter piece just above the starter and it was resting on the frame and possibly the down pipe from the turbocharger, so I lifted the front of the truck up and noticed that the 10mm oil pan bolt holding the vent pipe up in position was almost ready to fall out, so I tightened that up, still no difference, I had this idea, I hit the hood release and drove it down the street and the noise was gone, so I started adjusting everything under the hood and shortened the intake tube and the upper water outlet on the turbo, no difference or to tell the truth it may have got worse, then I looked at the underside of the hood and figured it out, the driver side rib under the hood was actually resting on the highest point of the turbocharger, now I had looked at this area over and over, the water fitting going to/coming out of the top of the turbo was higher so I didn't think that part of the turbo would hit, but the hose initially helping hold the hood away that I adjusted down is what made it worse, so I notched out a section of the rib leaving the base of the rib there, closed the hood and no more noise, that was the issue all along, I have no idea why it didn't make noise at first, the hole trip to Olympia was made without a rattle, it likely was caused by me tidying everything up, as the water outlet was higher before and the rubber part was likely dampening the noise till I lowered it and changed the position of the hose clamp holding it on so the turbo high point was then touching the hood rib.
At least it wasn't the transmission, I wasn't looking forward to pulling that out.
The more I drive it the less powerful it feels, I guess I am getting used to it and now I want more power, it's never ending, but I can hear the radio now, that is a plus.

Congrats on finding the noise. I've never been that good at that. Luckily I'm deaf enough that most rattles and squeaks don't bug me.

Same here. And the loud stereo ensures I won't hear anything important.

I made a brace that goes between the front head bolt and the turbocharger flange, and now I hear this tick when I turn it over, so now I wonder if the brace was just barely not the right size and when I tightened the nuts down it pulled up or forced down the exhaust manifold to the point where it has a slight leak, I can only hear it when I am turning the engine over before it starts, once it starts I cannot hear anything wrong.
If it does it again the next time I start it I will remove the brace and see if it goes away, if it does I will leave it off, I just made the brace to take some of the turbo weight off the exhaust mount bolts, but the 2 threaded bolts I put the brace on are at different angles and it was hard to make a brace that would even fit when slid down on the threaded studs sticking up, the holes needed to be oblong but I didn't think of that till just now.
I might have to make another 2 piece brace that bolts on both ends separately and then has a bolt in the middle to tie them together.
It sure does drive nice now, the turbocharger is basically worthless in 1st and 2nd gears, but 3 gear it starts to go, but on the freeway in 5th gear is where it counts the most, it's like a different truck on the freeway now, it actually has power.
I have been thinking again about a bed cover, but aluminum is so expensive, so maybe I will put some kind of bed liner in it and carry the jack and spare tire in the cab behind the seats and just have the bed empty all the time, it's getting kinda rusty back there, as I didn't pay much attention to it until I turbocharged it, it had a pile of leaves in the front of the bed that held water all winter, and what a winter it has been and appears to still be.

How are your fiberglass skills? Probably wouldn't cost too much to build a light wood cover and glass over it for strength and weather resistance.

DRIVEN wrote:How are your fiberglass skills? Probably wouldn't cost too much to build a light wood cover and glass over it for strength and weather resistance.

For that kind of work my fiberglass skills are crap, but I have thought of cutting down a larger fiberglass cover to fit if I could find one, but one has to be looking for one to find it and I have not been looking.
I have just gotten to the point to where I am enjoying driving this 521KC again, it was great to drive for a long time, then I bought that turbo engine and put it in the 720 and could see that being better, but it had issues, so I got that 720 to the point where it was derivable for me and then learned another way to do it, that is when I decided to try and get the 521KC going with a turbocharger and pipe it the way I thought it should be piped, it turned out great, so I piped the 720 the same way and it drives good also except it needs some waste gate tuning to get the boost down on the freeway which I have not done as I am driving this truck.
I did have a cover way back but it was so heavy that I tried lightening it up and goofed and ruined the cover, but it was easy to see it was backyard made also, I would like a nice one that keeps the bed dry, or just por15 the shit out of the bed inside, then put some kind of roll on liner in it that is textured to hide all the shit like rusty spots and flaked/scratched off paint areas.

I am a little worried right now, this truck engine has been making a weird clicking noise when I start it and I am beginning to think it is the starter which will be a big problem now, as the turbocharger is in the way along with the head pipe.
It actually might be easier to drop the transmission and flywheel or pull the engine to replace it, tomorrow I will jack the truck up and see if the starter is loose again, if it is then the mount holes are likely stripped and I will have to drop the transmission to fix that anyway.
This sucks, although I might just convert over to a long shaft just to get the shift lever closer to me, I have the driveline already.

It's always something.

Well the starter was loose, but I can only get to the bottom bolt now, I added a thicker washer and lock washer to the lower mount bolt, tomorrow I might see if I can figure out how to access the top bolt from the bottom as I know where it is, but the turbocharger has definitely created access issues.
I have not started it yet but I have to go to the store tonight for food, I want to know if the clicking has stopped.

Well it was awful sounding, it started but I shut it down and used the 720 to do the shopping.

OK, so I went out there this morning and looked at that starter for quite a while, there is no way to even see the top bolt holding it on, I decided to try and do it by feel from the top, there was just enough room to get an extension with a 9/16ths socket in there, but I could not feel/find the bolt head, so I looked at my spare starter and realized I was searching in the wrong spot, so I went out and tried again and found the head, I then removed my arm and looked down in there with my flashlight and I could see the end of the extension straight line, so I went and got another longer extension with a wobbly and I was able to get the two connected, I put the ratchet on the end and carefully started turning it, it was indeed loose, so I kept turning and turning and finally realized the hole was stripped from front to back as I can see the bolt coming out of the back of the transmission housing, I hit the starter and it sounded way better, but I knew it was not going to last long.
So I decided to put off the inevitable and try something, I found a block of wood about the right size and pounded it in between the motor mount bracket and the starter, it didn't go in easy, but then I wanted more pressure so I made a metal wedge, I slipped and the grinder hit my finger:(, I then pounded that wedge in between the motor mount bracket and the end of the starter, that block is in there tight, it might be touching the frame slightly, but it is really in there between the bracket and starter, I started it and it sounded great, no clicking this time, we shall see how long it lasts.

When it comes time to remove the transmission to replace the front case with a good one that has two good starter mount holes I am considering changing over to a long shaft transmission, I am also considering removing the whole engine/transmission and cutting the tunnel out and making it removable with captured nuts and bolts like the 320, I just don't see an easy way to separate the transmission from the engine with the new exhaust in there.
Maybe this fix will out last me, but I am not going to hold my breath.

My neighbor gave me a used chair that swivels and has rollers on the legs, it sinks when I sit in it and it is comfy, it also has arm rests, I have never had it so good.

I am driving to Hoodriver Or in the morning, and back to Vancouver Wa in the afternoon, hoping for an uneventful trip, hoping to get around 35mpg hiway/freeway as I plan to not go over 65mph, I filled it up today and got around 25mpg city driving which is what I always got with a stock 1982 Datsun 720KC with an SD22 diesel engine, so I am not unhappy as there are a lot of traffic signals and vehicles around here now days.

My pre-filter(fuel) started plugging up around 10 miles from home, I barely made it home, changed the filter and all is good again, but that filter only made it 3 tanks of fuel???
I don't know my mileage yet as I have not drove it anywhere since getting home, I need to get to the station to fill it up and see what my hiway/freeway mileage was.
Other than the fuel filter it was an uneventful drive, the only observation I made was maybe I need a larger radiator as the coolant is a little warmer than I like at freeway/hiway speeds, my EGTs are low, under 800 degrees the whole trip, maybe the radiator just needs flushed out.

I have been having issues with missing at freeway rpms lately, bad issues, I cannot seem to figure out the issue.
Today I changed out the lift pump/fuel pump and blew out all the lines, made a few new lines and it is better, but it still has a miss at freeway speeds.
Tomorrow I am thinking about bypassing the hard fuel line with a rubber fuel line to see if that is the issue, I have been trying to figure this out since that drive to Hood River, as I have had issues since when I get on the freeway.
The last few pages in the thread/link below are about the issues and what I have done so far.
http://nissandiesel.dyndns.org/viewtopic.php?f=5&t=3380

It's too hot to do anything on this truck, and it is getting worse every time I drive it.

Park it. Sometimes it's best to just walk away for awhile.