My 1980 Datsun 720 diesel dually

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wayno
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Re: My 1980 Datsun 720 diesel dually

#141

Post by wayno » Sun Dec 17, 2017 7:54 pm

A little less power off the line, but being I am turning 330 gears in the rear it has a shitload of power, what really counts is on the freeway with the trailer.
Keep in mind that I put tires on it that are 3 inches shorter, it is like dropping the gearing to 350 gears, I really have not driven this truck much, it has been more or less a test engine to try and sort out the turbo which finally happened last spring.
The issue I have with this truck/engine/turbo is that the guy I bought the engine from had machined the intake vane side of the turbo to except a larger vane so that it spins up at lower rpms, well that has a down side, at freeway speeds it wants to be at maximum boost, when I let off and then step on the pedal slower it still goes right up to maximum boost which I set around 15psi(I have seen over 20psi), I don't want to set it at 5/6psi because when I am accelerating it will only get to 5/6psi, I would rather it act like my 521 turbodiesel where it can get up to 15psi speeding up, but on the freeway it averages 5psi going 75mph, this truck will peg 15psi and stay there at 60mph, but I don't do a lot of freeways for long around here working, so it will make a good backup work truck.
Being he did modify the turbocharger the way he did(he also turned up the injection pump), it has a shitload of torque, way more torque than the 521 turbodiesel being they are the same engine, it might make a great work truck, but everyone knows my 521 truck I have now, I plan to keep it my work truck until I retire.
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Re: My 1980 Datsun 720 diesel dually

#142

Post by wayno » Mon Dec 18, 2017 10:17 pm

Well this evening is the first evening that I don't have band-aids on my fingers. :lol:
I have quite a pile of them now, every time I changed them the pile grew.

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I cleaned out gutters today and pressure washed a steeper driveway so it would not be slippery over the winter, I guess i am going to survive. :lol:
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Re: My 1980 Datsun 720 diesel dually

#143

Post by wayno » Sun Dec 31, 2017 6:32 pm

So I put some helper leafs on this truck today, they likely raised the rear of the truck at least 4 inches. :(
I took it for a drive, it will do for now, I suppose it is time to check the trailer wiring and if that works properly it will be time to start the 521 conversion/frame swap.
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Re: My 1980 Datsun 720 diesel dually

#144

Post by wayno » Sun Jan 07, 2018 10:59 am

I made a removable ladder rack, front one is full width of the cab angled with the sides of the cab, the rear is a stand alone rack made for an extension ladder, that one can be put on either the passenger side or driver side, it will not drop into the 2 center stake pockets as they are farther apart.

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Re: My 1980 Datsun 720 diesel dually

#145

Post by DRIVEN » Sun Jan 07, 2018 11:52 am

Looks sturdy enough. What's that black knob in the background? Liftgate control?
When the only tool you have is a hammer every problem starts to look like a hippy.

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Re: My 1980 Datsun 720 diesel dually

#146

Post by wayno » Sun Jan 07, 2018 7:36 pm

The black knob sticking up in the second and third photos is the control knob for the Tommy Gate, but unless the thing has power it will not raise back up after lowered, that switch is in the cab, the knob has to be on top as one has to be able to control it standing on the ground or standing on the Tommy Gate while raising/lowering it.
This is all temporary, while I am changing the 521 cab to the new frame I need something to do work with, once the work truck is back in service, the 720 long box will go back onto the truck, I will likely try to sell the flatbed with the Tommy Gate first while it functions.
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Re: My 1980 Datsun 720 diesel dually

#147

Post by wayno » Mon Jan 08, 2018 2:17 pm

So I had to cut these 5 inch long pieces of metal off the bottom sides of the 2 inch square stakes to get them to fit in the stake pockets, I welded them pieces to the sides of the horizontal rack tubes to keep the ladder on the rack.
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Re: My 1980 Datsun 720 diesel dually

#148

Post by wayno » Mon Feb 26, 2018 5:05 pm

So today I replaced the 1980 Datsun 720 brakes with the brakes I had on the 521 work truck(1990 Hardbody V6 2wd dual piston/vented rotor brakes), it stops way better now, I bled it and bled it and I had to continue to pump the brake pedal twice to get it to the top, it turned out all I had to do was adjust the rear brakes and all appears to be good now, the pedal stays the same no matter how many times I pump it, once or 3 times it doesn't matter.

I did have to fabricate a short piece of brake line on the passenger side front brake line, that rubber hose has a block on the end of it instead of a brake line fitting, for some reason I thought the brake assembly would just bolt right in, but in this chassis year they put this NLSV that connects into the right front brake circuit, what a pain, I just made a 3/4 inch brake line that went in between the 2 rubber hoses, it works fine and so far has not pulled one way or the other while braking, I suppose I should now make something that holds that area of the brake line in one place as right now it floats and I expect it could find a way of wearing a hole in the brake line or brake hoses somehow.
Here is the brake line section I made, you can see the brass block also, I was hoping the photo would be in better focus.
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I thought about putting one of the sets of drop spindles I have in this truck and likely will in the near future, but it was more work than I wanted to do today, I am trying to use all the stuff I have around here for my rigs as I am going to start cleaning up around here again, I make a little more progress at cleaning up every time I clean up, I get rid of a little more than the last time I cleaned up, one day it will be cleaned up meaning I will not have even 10 percent of the Datsun parts stored that I have stored right now. :lol:
“The difference between genius and stupidly is that genius has its limits” Albert Einstein

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