My 720 Resto

[wayno]

Do they have different height pedestals?

[720inOlyWa]

Pardon my lack of nomenclature understanding here, wayno, but by ‘pedestal‘, I reckon you mean the flanged collar doohickey that the distributor bolts up to? I did glance at them, but not too closely. That is a very good point- maybe the base plates of the pedestals are different thicknesses.  That would make things much easier, if correct- I could just swap them out and stick with the plug and play! Thanks, wayno!

[wayno]

Pardon my lack of nomenclature understanding here, wayno, but by ‘pedestal‘, I reckon you mean the flanged collar doohickey that the distributor bolts up to? I did glance at them, but not too closely. That is a very good point- maybe the base plates of the pedestals are different thicknesses.  That would make things much easier, if correct- I could just swap them out and stick with the plug and play! Thanks, wayno!

I am just asking, I don't know, I know very little about the Z24 other than if you put a Weber on one that I need to make sure the ground wire is still connected to ground near the carb harness of the wiring harness.

[720inOlyWa]

By the way... for those who will read this because they also had to wrestle the timing chain and tensioner into perfect alignment. The job is SO much easier if you put a tie wrap around the tensioner assembly before you mount things up. I didn‘t tie wrap the tensioner the first couple of times I did this job and getting the tensioner and chain in right was like a money fucking a football. Just a nightmare. A tie wrap keeps the plunger pressed in all the way as you mount it up and you just cut it off when everything is done. I was  probably the last person ever to figure this out, but who knows- there could be dimmer bulbs to follow me who can use this great tip. I did this job twice before I got wise. It sure helps to get that 0.0 gap in the tensioner if you use the tie wrap trick.

[720inOlyWa]

Shit. Well that didn’t get it running either. I am back to square one-without a clue as to what I am doing wrong. I feel like I did everything correctly and to back that up, I triple or quadruple checked everything again. 

 

One thing does not make sense to me. On the dizzy drive shaft, the drive dog is supposed to be at 11:30, with the engine at TDC. The small side of the drive shaft dog is supposed to be forward, and the rotor is supposed to be pointing to cylinder #3. Well, I don't care how you set it up, if the small flat on the drive dog is forward, the rotor is going to point to 7 o'clock. It just does.

 

I should say, the first two timeI replaced timing chains on my 720s, I took a pic of the drive dog as I disassembled the front of the engine, to make sure I got it right. In both cases, the drive dog was at 11:30 alrightie, but the small flat was to the rear, not the front. I posted this out on another forum  and datsunmike assured me I had it in 180 degrees backwards, but that it should rise fine that way too. I am still confused as to how that was possible, especially on two trucks, but what really confuses me is how you get the rotor to point to umber 3 plug with the small flat facing forward.

 

Man, that is the only I can point to where maybe there is a major gap in my understanding. Mind you, I drove the truck 15,000 miles with it in backwards.m And yeah, I tried it backwards too. Still no dice.

[wayno]

I don't know much about Z24 engines, but on the L20b when the dist drive cog/dog is at 11:30 the rotor is supposed to be pointed at number one plug wire, which is at 4pm when standing on the driver side looking down on the rotor.

[Charlie69]

When your timing marks are lined up are you on the compression stroke?  The easiest way to tell if you are on compression stroke is put your finger over the spark plug hole over not in, and turn the crank when you feel compression then line up your timing marks and you will be top dead center.  you can also watch the rocker arms to determine compression stroke.  if using a socket as desscribed above to turn rhe crank be sur you are turning the crank the correct direction.

 

Scroll down about a lttle past half way and you will get into intelegent information.

 

http://720world.com/forum/topics/z24-timing

[Draker]

If you are at 7 oclock at TDC, you need to pull the oil pump and rotate the drive spindle.

[Nissan_Boy85]

There is marks that line up on the oil pump side too. I know I've spent an evening making new colorful words attempting to line it all up before I understood those lower marks.

[720inOlyWa]

Okay. So I took it all back to square one and set the timing up again. This time, the engine started, but only when I retarded the ignition to the limit of the slot on the dizzy mount. (I turned it fully counter-clockwise.) It started and it was lumpy. I threw the timing light on it and it showed it was firing at about 10 degrees After TDC.

 

So, I must be a tooth off, right? I am having a little difficulty working through which way I need to rotate the drive spline, so I‘d like opinions. Here is what I am thinking, correct me if I am wrong: I need to retard the timing by one tooth. Therefore I need to rotate the spline shaft counter clockwise a tooth (looking at the shaft from above). Is this correct?

 

If I recall correctly, you rotate the shaft i the direction you want the distributor to move. In this case, counter clockwise.

 

 

Thanks. This is screwing with my head, but I think I am close to running okay if I can just pull the oil pompon more time. It sucks doing it in the rain.

[720inOlyWa]

All‘s well that ends well, I suppose.

 

We are off the ramps and doing our test drives now. It seems to be running fine so far. Timed up nicely, idle is smooth, acceleration is good (so far- I have not ht the freeways yet).  Parked it to cool it off so I could check the coolant levels. It has to run for a few minutes with the heater on to purge any air pockets in the cooling system. 

[Charlie69]

Good to hear!  Your next one will go smoother

[LTJ]

Great to hear it is on the right track!

[720inOlyWa]

You know, I don‘t make a big enough deal about the people who helped me out here with sound advice AND the good folks who just give a little encouragement along the way. BOTH were the absolute key ingredient for a guy like me who has never really been through this process before. Man, that was so important, I cannot tell you. And I cannot thank you all enough, but offer my deep and sincere thanks anyway. I owe you all the debt that I cannot possibly hope to repay.

 

I took the Fudgecicle to coffee this morning. That is sort of the big daytime street test. I go to a stand on the west side of Olympia, and you have to pull a rather long and steep hill to get over there. The hill is preceded by a roundabout, so you have limited ability to build momentum before heading up. with the old motor (bless its heart) if I slung through the roundabout just right, would just pull that hill in third. If you asked with a little force, and the bed was empty, it could even gain a little speed up that hill in third. This morning, without asking at all, it moved right up that hill in third. I touched the accelerator pedal and it was happy to go faster, no problem. What a damn thrill!

 

With the entirely new drivetrain in place, I feel like I am getting to feel a new 1985 Nissan truck at its freshest. It has such a pleasant feel and solid drivability. I really feel like I could go pick up a stack of plywood and head off to the job site, no problem It has a nice, tight, ‘trucky‘ utility feel to it that has been wildly improved- rediscovered- by the thorough rejuvination.

 

I did‘t feel this way at this time yesterday. Instead, I was considering deleting my thread altogether. I felt hopelessly inadequate as a Ratsun forum contributor, even at the novitiate level. I had failed to get the simplest of operations correct for four tries before the fifth was correct. I was certain that I was unfit for my build thread. On that fifth try, I had firmly decided that if I didn’t hit the jackpot this time, I was going to roll it off the ramps, cover it with a tarp and wait for spring to attack it again. I was sick and tired of laying in my wet driveway all day. But the fifth try was the charm, and all‘s well that ends well, my wife says. Only it isn‘t. I still have no damn idea why the fifth try was any different than the four previous. I did not discover my mistake, I just failed to repeat it. There is no learning in that, which makes me nervous.

 

The hood is up in the driveway and the engine is cooling off now. I heard a tiny ‘chuh, chuh, huh’ in the engine noise that makes me thing that the exhaust manifold has a tiny leak, or a spark plug isn’t fully seated in.  The idle mixture probably needs fine tuning, and several other little items should be checked / tweaked / refined to finish up the job. But it isn‘t raining, and I even saw a sun break when I rolled home. At least these pleasant little mop up chores won't have to be done in the rain. Thanks again, everybody.

[Draker]

Nice work! Remember, YOU did this. We just guided you and provided feedback.

[Charlie69]

As far as I am concerned you owe nothing to anyone.  This is what we as people are supposed to do, "help each other".

 

You did the same thing I did the first time I set up the timing chain on an L motor.  I had to pull the timing cover 3 times cause I dropped the chain before I got the wedge in.  I misssed the timing by 1 tooth so I had to keep trying until I got it correct.  First time I did the small block Chevy timing chain it was easy, 

 

I am happy you are persistent.

 

Congrats!  Enjoy your Fudgecycle!

[720inOlyWa]

I used a bottle torch (unlit) to see if I was leaking anywhere around the carb and/or intake manifold. Eliminating vacuum leaks is the first step in Weber set up. Fair enough. Sure enough, I did find a little one and pinched the weber down a little harder to squeeze it off. That helped a little more. It is really running pretty good now, which makes the tiny exhaust flange leak -that has been there all along- more irritating. It is like the only unforced error left. The exhaust guy said he had a hard time getting the header to lay on the downpipe flange when he re-did the exhaust system. I believe that I am going back to have that re-done at some point soon.

 

I‘d like to find a connector and a rubber boot for the larger oil pressure sensor used for the oil pressure gauge. Anybody know where that might be found? I would like to have that connector locked to the sensor, and covered, than to have my current set up.  Thanks!

[Charlie69]

The boot and connecter for the oil pressure gauge I usually get from 720 4x4s as they have the gauge more often.  I find them in the wrecking yards.

[720inOlyWa]

It is on my wrecking yard list, Charlie. But have you noticed- they are showing up less frequently these days. My wrecking yard manager here locally said “Oh, Back to The Future Trucks. We can sell them whole.“ meaning somebody will likely save it.

[Charlie69]

They are real rare here in the Phoenix area. 

 

You will see caravans of Datsun, Nissan, Toyota trucks on the hiway to Mexico here on a daily basis.  It is not uncommon to see each truck towing another headed to Mexico.  It is sad that our mini trucks are going to Mexico in large quantities.

[wayno]

5 years ago there were 5/6 720s in the 4 wrecking yards around here all the time, I could go in there and remove a 1980 720 transmission and then remove a 1986 short shaft, put the 1980 front case on the 86 short shaft and walk out of there with what I wanted.

Right now there are two 85 Nissan 720s and they have been there for over a month, there is one 1986, but don't know if 720 or D21, there are no Datsun 720s at all and there have not been any for a while in the three yards we now have.

There used to be 620s in every yard, I have only seen one recently in the Vancouver yard, I pulled the dist. drive shaft off it for my LZ23 build, and now it is gone also, I have not seen any Datsun cars in the yards for a long time, but I don't go to the yards much anymore, they are too expensive, I can buy stuff on ebay/craigslist for cheaper now.

[720inOlyWa]

Now don‘t get all mad at me because this doesn‘t sound maybe so politically correct, but...

When I was a VW nut, ages ago, I had a friend who was a rodder with real car trend savvy. I had a 69 VW  square back and thought it was never going to be cool, no matter what I hung on it from Bow Wow. “No“, my savvy friend said. “I see the young Phillipinos tricking out square backs all the time now. Watch, they will be cool as hell soon.“ Sure enough, the ugly duckling became a swan over time.

 

Fast forward to today. When I bought the Fudgecicle a couple of years ago, it was not what I was looking for. My idea was the classic Ratsun wet dream of a souped up 521 sleeper. I just happened onto the Fudgecicle, broken down in the rain, for a stupid cheap price and could not say no. Now I was stuck with letting go of my tricked out 521 fantasy and challenged with seeing if I could transfer that enthusiasm somehow to this totally square looking 720 King Cab. It was a difficult adjustment at first, until I saw a young Phillipino dude driving a really nice 720 over in Lacey. I mean, seriously cool.

 

That‘s when I knew I was getting on the train just in time. So I bought another, an 86 4x4 720, just to have it both ways before I could‘t anymore. And now the wrecking yard calls them ‘Back To The Future‘ trucks, whatever that means, and they sell them whole. I gotta find me a short trans before it becomes impossible...

[Lockleaf]

 

Because of the Toyota from Back to the Future.

[wayno]

I like the 521 myself, although I have had as many as four 720s on my property at one time, I would buy Diesel 720s because I liked them, I put a diesel in a 521 and then thinned the 720 heard down to one, I still would rather drive the 521 diesel, but the 720 turbodiesel is fun to drive because of power, so I drive it a lot, but my 720 is not a normal 720, it has been waynoized. :lol:

[Lockleaf]

I've been a 720 guy from my datsun start. A 720 was my first datsun. I've daily driven 4 of them over the last ten years. I've owned 7 of them, 6 of them 4x4. They are my favorite mini truck. I'm in the market for one more for parts so I can get back to work on my 720 crew cab :).