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Oops, I did it again!


720inOlyWa

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That looks great, Charlie! Grandpa truck rated!

I did‘t go as far as you, but I like the thinking here. That motor will hose down nicely, for sure.  While I wait for the machine shop to call, I am out in the driveway, cleaning and prepping the engine compartment. And, while doing so, my neighbor (the one who borrows my truck from time to time) sauntered over  and made an offer on this one, when it is all done. We toured the trucks strengths and unknowns there in the driveway while he considered everything and reasserted his interest. Just an initial inquiry, but I thought it was intriguing that I could possibly pre-sell this project. He is the third person who has expressed a real interest in owning this one...

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Well, the head came back from the machine shop today, looking all clean and fresh. The long re-assembly march has begun!

 

MY TIPS FOR REINSTALLING THE TIMING CHAIN AND COVER:

I am not Nissan expert or anything. That much, you can gather from my thread. But I figured out how to reassemble the front end after doing a bit of research and getting a bit of repetition!

 

First off, we probably all know about the trick of using a tie wrap around the timing chain tensioner while you position and install everything. I was probably the last one to get hip to that trick, but it helps enormously! By compressing the tensioner with a regular old tie wrap, you can get all of the compression asked for by the shop manual (0.00"). By having the spring out of the way, it makes setting up your timing chain a snap. When you cut the tie wrap just before the cover goes on, it only pops out the thickness of the tie wrap which is WAY tighter than you will ever get it simply by jockeying everything around by hand.

 

Second, the timing chain cover. I did‘t notice this in the shop manual, but it might be there. The first thing I do before fitting the cover back on is to loosen all of the oil pan bolts about 4 or 5 turns, especially in the front. With a piece of wood and a hammer, I gently knock the front of the pan loose from above. Now I can fit the front cover easily, without screwing up the front of the head gasket. Those little squirts of silicone in the corners can go right on without being messed up as you wrestle the cover on. Instead, I can position those little side gaskets carefully and just slide the cover on cleanly, without damaging anything. The only caveat to this is that now you have to bolt up the cover completely- and especially down below, on the oil pan end. I only quit work when all of the cover bolts are in, the pan is inched up, and I have torqued the head from 22 pounds to 57.

 

I know it probably sounds pretty dumb to try to wrangle that timing chain tensioner on there without having the spring compressed somehow- but I have done it before I got hip to the tie wrap trick. And I realized that something must be terribly wrong if I am tapping the timing chain cover on with a rubber hammer and a putty knife- but I have done that before too!

 

These two tricks- the tie wrap and loosening the oil pan- turned front end work from a nightmare into a breeze.

 

Maybe you all knew this already, but someday, somebody like me is going to read this and have a holy shit moment.

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Between rain squalls, I hung a few clean parts back on the Z20. I surprised myself and got all the way to installing the fan belt.

 

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Now there is a nice timing mark that even I can see! and look at that de-rusted and clear coated marker plate, will you? Geeze...

 

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Given a sunny day, I can get all kinds of stuff done. Radiator, water pump, shrouds. What you can‘t see here is that the front anti-sway bar was hanging on by 2 threads of one bolt, with the other three gone missing. So I wrestled it back into position, made sure the mounting grommets were snugly in place, and tightened everything back down. I suspect that the tow bar anchors were tucked under the front mounting bolts of the bar and when they shit canned the truck in favor of something else, they nabbed the mounts off of the truck and didn‘t bother bolting everything back together. Another potential clue as to why this truck has 180k miles on the odometer but shows so little mechanical wear.

 

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While I am fabricating a custom adapter plate for this *W (Z20) intake manifold to fit a Weber 32/36 carb, I also took some time to start cleaning up the ‘east bay‘ of the engine well. The canister holder received the deep rust treatment, followed by paint.  While the paint was drying, I rubbed out the area under the canister and gave it three coats of wax. You can see it is a bit shinier than the rest of the area back from there, which has only received the hot soapy water and a washcloth treatment so far. 

 

I have a clean brake boost ready to go when I get up the steam for that project. In the meantime, I will de-rust  and paint the areas under the booster when the old one is out.

 

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Got the weber installed today. All I have left to do is to pour in the fluids, hook up a battery, drain the fuel tank and re-fill it, and turn the key. The moment of truth aint that far off. 

 

It occurs to me that all of the Z motor intake manifolds have an expansion chamber directly below barrel number one. The weber adapter plate that I received (which was wrong for this manifold anyway) and gasket both do a piss poor job of accommodating the smooth flow of air/fuel into this expansion chamber. So I made my own adapter plate which is chamfered appropriately on the underside to allow the mixture to flow in unimpeded. This goes double for the base gasket, which has a really nasty flap extending into the airflow in the base. As a former hydroplane racer, I just can‘t have that. So I traced the outline off the manifold and made an accurate gasket to go with my home made adapter plate. Now the air/fuel mixture flows smoothly down the throat of the carb and expands as intended in the expansion chamber. 

 

I am not trying to be a show off or a hot rodder here. From racing experience, I have learned how much the intake flow effects the transition from low to high RPMs. Ron Brown, the greatest crew chief in hydroplane racing history once told me “Every little bit helps“.   And I believe it. 

 

We have all seen gillion Webers installed on Z motors. Well, here is another...

 

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Anyone living in Washington state knows that today was a really weird day. It was foggy this morning, then sunny and hot, then dark and stormy, then the sky fell, with sheet rain and lightning like we never seen here. Before the deluge, I nicked off to the Pick “N Pull and nabbed a new coil mounting strap for this truck. Once I got home, I mounted it and the coils, cleaned and mounted the spark plug wires and began replacing the vacuum lines. Pretty productive, considering we skirted armageddon today.

 

As night began to fall, I put in the anti-freeze and oil. Cleaned the plug wires and remounted them, replaced some of the vacuum hoses and began plugging unused ports. And that will just about do it for today... except...to...say...

 

I NEED A CLOCK FOR THIS TRUCK! anyone want to sell or trade for a round 720 clock?  

 

I will post in classifieds as well.  Thanks!

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Boom- got me one!

 

Now, all three will have the tach and clock. The 4x4 has the voltage and oil pressure and so does my 2wd, but it isn't hooked up yet. That happens this summer, when I pull the dashboard. Few things are more satisfying to me than sitting in the truck in the evening after a grocery store run, listening to the quartz clock ticking away quietly.

 

Meanwhile, once I get this new truck running okay and sorted out a bit, I will attack the interior as the last frontier. Having done it before, I know that rehabbing a dash cluster and adding the clock and tach is just a real fun little afternoon project.

 

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I have been putting off the chore of draining the gas tank for fear of what i might discover. But today, my anxieties were set to rest as I hooked up  piece of tubing and hit the ignition key and woke up the fuel pump for the first time since 2008. Fuel pump works fine! I pumped a quart of gas from the tank into a jar and took a look. There was about 20 drops of watering were, which would be normal condensation, I suppose. the rest was clean gas- not even shellacky smelling! No rusty goo, nothing weird at all. so it looks like I may have gotten lucky with the fuel tank as well. 

 

I will drain the fuel tank here soon, but first I have to address a really nagging problem- hooking up the fuel line. Does anyone know what the best, most elegant way of connecting the fuel line to the carb without having a dumb looking loop of fuel tubing? Id sure like to see how you guys did it...

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Well, the fuel manifold is attached to the intake manifold, so there isn‘t a lot of shaking going on there. But a little flex somewhere would‘t hurt anything. I found a 90 degree fitting and I played around with that for a while, but it does‘t make the connection look any less rube tan the ‘goofy loop‘ fuel tubing route.

 

So I dug around in my tools and found an old tubing bender, designed to bend brake tubing, I reckon. If I can bend a smooth loop of soft steel tubing, I can probably fabricate something I would like a whole lot better than the goofy loop. A chunk of rubber fuel tubing at each end will give it enough flex. So I am off to the hardware store for soft steel tubing!

 

Something else interesting happened today. Overnight, I charged up a good battery. When I put it in this morning, I turned the key to ON position for the first time. The fuel pump came on, and I told you about that already. But it also had the nicest little door ajar chime that came on too. Neither of my other 720s have a door ajar chime, and this is the oldest of the lot.  

 

Does anybody know anything about this piece of trivia? Is it just broken in my other two 720s?

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Does anybody know anything about this piece of trivia? Is it just broken in my other two 720s?

It might just be broken in your other 720s. My 86 has it so I don't think it's due to age. I know some other Datsuns/Nissans have the same chime; I want to say that the 240sx had the same chime, but I haven't actually been inside a bone stock one. 

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It very well could be a blown fuse!

 

I think the chime is located in the driver's side footwell; it is a black box. It may even be located directly next to the fuse box; I do not remember. 

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Oh, thanks for the info. It pays to dig into that factory service manual, huh?... I should have looked there before I asked here. Today, I bent a piece of 7mm lumen bendable brake line into a pretzel, to hook up the fuel line. This is by no means a final solution, but it is an improvement over the goofy loop in tat it will be largely out of sight.

 

Once things settle down, I have a mind to silver solder up an entirely new fuel manifold that does not rout to the interior of the intake manifold, but rather routes straight up from the outside attiach point to a hookup on the outside side of the carb. KnowwhatImean? I think I do. I have a vision....

 

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Please let me know if you can download the pdfs in the link above.  That is why I put them on Google Drive.  I am not familiar with Google Drive.

 My guy! You did a hell of a job scanning. All you (the downloadee) have to do is request permission to access the document from the link, and it can be downloaded from Drive as is. 

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You should be able to move the fuel inlet fitting from left to right. Then delete that whole hard line piece under the manifold and run your return to the normal return port at the frame. Tidy up with zip ties as you please. Here's how mine ran for years until I went sidedraft. I think I got that old piece for under the manifold somewhere too....

 

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(Almost) exactly what I was thinking. My version will be (bendable) hard lines, bent to shape and sleeved onto sections of the original manifold and retaining the end fitting of the original fuel manifold but routing it to the outside, like you did.

 

I ran out of excuses and started the engine today. I can tell it is going to be great, but I had to retard it to get it to run and never did get the timing mark to show up, so something aint right. I will bring it back to TDC and look everything over again. (Maybe I am 180 out?). Maybe the distributor isn't advancing right. I dunno. I do know that I was leaking gas at the carb- the result of not having the fitting nut tight enough. That was exciting for a moment.

 

 

All and all, a promising beginning. Whatever the problem is, I will track it down in short order...

 

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Here is the ‘before‘ photo again, from the CraigsList ad. Making progress, bit by bit...

 

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