zKars

Don’t forget good old powder coating. Lots of shiny, chrome, aluminum and silver options out there. What I like best is the toughness of the coating to resist the inevitable foot and boot rubbing abuse these things take.

Here is one picture I took back in April when I saw it.

The only “thing” I spotted, and he does mention it in his ad, is that it was repainted, “A decade” ago, but it was repainted without removing glass/weatherstrip etc which is easy to spot. The repaint is one of the best I’ve seen in terms of color match and correct sheen/finish/look/feel. You’d swear it was original paint in outstanding condition. Everywhere I looked on the car, (over a relatively short period of time, I did not study every inch), everything looked correct for the VIN. I was there trying to sell him a Z, which, after I saw what he had (and picked my jaw up from the ground after seeing this Z), we spent of our time on, shall we say, “sales craft”.... Turns out he was looking to replace this one with more of a driver quality car. And here we are with this one for sale. I will gladly go and look at it for anyone who wants to get more detail or my opinion, and give it more careful look over. I’m sure the owner will have no problem with this.

i've seen it. It is amazing.

That door is definitely for 77-78 280, 2 seater. Definitely not 2+2, which is MUCH longer overall. The earlier doors are totally different internally, latches etc, as is the window frame, there is no way this door could have an earlier window frame, they don’t mount the same way. This door appears correct for your 78. This does not help you much as to why this door does not fit your car. Perhaps we need to see the door on, so we can see exactly how far out it is, how and where.

I’ve seen too many glass fuses that look great, even test great, but if can twist either end cap even a little bit then it’s got a crappy internal connection that is about to fail.

In the 2 or 3 I've done so far, the amount of suction is spectabulus (yes I invented a word, no beer involved) so there is no problem with getting fuel from tank with an air filled line. Only time will tell about real world performance and life. The only thing I screwed up was getting the check valves in the right way the first time. And maybe the second....

The last "gotcha" is the tiny thin seal washer between the check valve and its seat in the housing. I was able to remove virtually NONE of the OEM ones. They were hard and stiff and stuck in real well. They were easy to scrap out, but were always destroyed in the process. So you may need to source or make some new ones. 3/4 OD (19mm) and about 18mm ID. Only about 0.05 thickness. A tiny ring of RTV would do as well.... You want that check valve sealed to the housings. NO LEAKS ALLOWED around the check valves.

First thing to say about the "details" is that all the OEM pumps I took apart and scavenged parts from are identical as far as the location and size of the bolt circle that bolts the main body halves together and the top cap in place. So you can interchange just about any part with any part from any brand. The GMB and Spectra ALSO use the same bolt patterns. So you can interchange their bits with the OEM bits. There are small gotcha's here. Some of the upper caps are not interchangeable across all brands as the divider wall in the center is not in the same clocking with the bolt pattern. All you have to do is use a matching cover and middle housing from any one brand. Next is a small annoyance that the way the check valves are held into the middle housings is VERY different with the GMB/Spectra. Cheaper and crappier of course. They use a 4 point punch around the perimiter to trap the check valves into the housing. Hard to get them out, and if you did, you couldn't get your OEM check valves to stay in as you'd have a heck of a time re-punching around the edge to keep them tight and in place. Pictures coming. SO,. It actually makes sense to use the check valve housing and its matching cap from your old OEM pump and bolt it to the GMB/Spectra base housing. Keep all the good bits together. It does mean you have to do so sort of clean up of your OEM castings to match the new GMB castings if you care about that stuff

What you do, is go buy the $19 GMB, replace its check valves with your old perfectly good OEM ones, and put that hybrid baby back in the car for millions of additional miles and smiles. (Please put the GMB check valves on the cement floor and crush them into dust with a large hammer, lest you get tempted to use them at a later date. Don't) You get a new diaphragm, new lower seal, your perfectly good check valves, and the new GMB upper diaphragm that all make up a nearly new unit, and should run for a few years pump. Ok, all is not perfect here, there are a couple of details you need to deal with, but its all manageable. I'll explain in a but once I take some pictures. I guess the risk is that the GMB diaphragm material will fail faster than the OEM (or the new Nikki ones you get with Nikki pumps for non Z's to steal their internals from, remember that thread?) that is still to be seen, but all in all, maybe we have a cheaper route to rebuilt pumps here.

I've recently been through the wringer on mechanical fuel pumps. I LOVE the stock mechanical pumps and dearly wish to be able to use them more. Silent, plenty of volume to run triples etc up to 250 hp (my educated guess). Stock new pumps put out a CRAP load of volume even at cranking speeds. The cheap "offshore" GMB and Spectra fuel pumps that are out there that look like the stock Nikki/Ampco/Kyosan Densi pumps have been reported here and elsewhere are a ticket to very early failure. I can further attest to this experience. Had a fresh GMB make it about 10 km before leaving a customer/friend stranded. So after much investigation of the issue, I have good news. 1. The GMB and more expensive Spectra are identical inside. The diaphragm and check valves are visually and texturally identical. Might as well buy the GMB ($18.72 CAD on Rock Auto) 2. The problem is with the check valves. The design of the flapper is weak and shitty. The OEM diaphragms are thick and strong and seem fine. The failure is that they stop (or barely start ) being able to pull fuel from the tank. Any air gets in there and they loose prime. If you actuate the pump by hand on the bench in a vise with your finger over the intake, you can barely feel any suction. Do that with OEM pump and it will suck the skin off your finger tip. (Air intake only, no liquid). Now the really good news happens when you want to rebuild your old OEM Pump. Up till now it's been tough to find rebuild parts. I took apart about 20 OEM pumps (all three brands, 14 Z and 6 510 ) and noticed the following. 1. Diaphragms; Depending on age and use, some were fine, some were hard and/or cracked. No surprise. About 40/60 good/bad. 2. Upper diaphragm. Not even sure what the function is of the upper rubber diaphragm, but 100% were soft and reusable. Don't think they endure much hardship. Maybe one was a little stiffer than the others. I'm sure we could fill an long thread discussing what its for.... Please don't here. 3. Check Valves. The real surprise. 100% of them were 100% perfect and appeared nearly brand new. All were clean, no sign of crud buildup or damage or erosion/corrosion. These things are indestructible apparently and totally un-affected by fuel or time. 4. Lower seals. Where the rod passes through to the actuator. About 4 out of the 20 were still soft and usable. Lots of splits and hardness. Ok, knowing what we know about the new copies (GMB and Spectra) and the old faithfuls, and what's wrong and right about both species, is anyone seeing the possibilities here? OEM Body, check valves removed OEM check valves, front and back. Thick solid valve body. GMB check valves, front and back. Thin rubbery floppy material. GMB check valves are held in place with punched nibbins. Very hard to replace the valves. Well, easy to get out, but how do you keep new ones in? You'd have to drill and tap a pair of center holes to use the stock center hold down bracket thingy. Do-able, but.... Are these held in tightly against the gasket? Is there a gasket? Do they come loose with use and abuse? Inquiring minds need to know! GMB mid case with their check valves in place, top view back side of GMB upper hosing. Note different shape of center beam. Top of GMB pump housing. Fuzzy picture like the whole situation.

Pertronix is famous for burning up if you leave the Key in the ON position with the car not running for more than 15 minutes or so. Pertronix II is supposed to be more tolerant of that but I’ve seen failures.

Interesting. Perhaps the root misconception is that the needle is actually more of a continuously tapered shape, it is NOT a series of 1/8” Long tubular sections. Thus you ARE changing the Needle OD continuously as you raise and lower it by small amounts. Even though I can find drawings with both concepts, the first one here is more the correct representation of the actual shape More like this; Not like this:

You can tell I’ve been drinking and thinking again... If the SU needles have richness “stations” (Progressive diameter changes) every 1/8th of an inch, why does moving the richness adjusting knob by as little as 1/4 turn make a significant and measurable change in AFR? The thread Pitch on that adjuster is 1.0 mm, so it should take 3.5 turns to make a one station shift..... Just saying, what the heck is going REALLY going on that no one wants to talk about... Is there more to the amount of fuel that is allowed to leave the jet tube than the simple needle OD/tube ID difference right at the top of the bridge or top of the jet below the bridge? Or a complex function of the various ID/OD changes throughout the jet tube? Does this revelation also lead one to addition tuning engineering? Or just more reasons to drink? Let’s see whatcha’ all come up with on this one...

I could not imagine that the factory would expect the valve cover appearance to remain even remotely “in good condition” if it were shipped as pure bare un-treated alloy. Aluminum was not a “new” material in the late 60’s. It is no surprise they would apply some sort of preservative. Paint however is a surprise to me. Mostly its fun to realize that the bare aluminum assumption is likely wrong after all this time. Another day, another day of learning. Now we can all go off and try to produce a paint formulation/process that reproduces the factory appearance.... I have to go out and touch just a corner of the back of my NOS cover with a dab of acetone and see what happens...

Sherlock Holmes here. Since changing the sender and the dash gauge produces the same result, there is only one thing in common with both scenarios. The tank itself. (other than the wiring) There is therefore, something in the tank that is touching/interfering with float movement at that 1/3 position. Big dent in the bottom? About the only other thing about the tank is the rotational orientation of how you are inserting the sender into the tank. There is a little tab on the tank, and small gap in the sender ring that line up? Really scrapping the bottom of the tank/barrel here... Another test, If you move the sender arm in free air with it out of the tank, does the gauge respond in the same way? (have to connect a ground wire between the sender body and the tank).

M8 bolts have a 12mm head (JIS bolts anyway), M10 bolts have a 14mm head. Same for the nuts that would fit M8 or M10 studs. The four TOP bolts on an EFI intake manifold are M10 bolts, the studs on all the shared thick washer locations are M8.. Only the EFI heads have these M10 intake manifold bolt holes in between the M8 holes that are used on the carb intakes.

Hard to see without disassembling a few, but most of the ones I see do NOT appear to have a flat washer between the spring and the big hex nut #28, unless its much smaller and thinner than I can see. Other than increasing the spring pressure or giving the spring a kind of base, I don’t see that spacer washers are needed for anything in particular. There isn’t anything in the drawing, #29 is just a spring

Here is one example I have.

They are in very nice condition. I would ask that you measure the distance from the lock button hole to the end of the door card. If they are nearly 9 inches, they are not suitable for a North American 75 280z. The lock button position needs to be at 6”. From my research these appear equivalent to the 77-78 280 door cards here. The other thing that I observe is the location of the two large holes where the arm rest mount through. On the 74.5-76, the holes are lower and slightly back compared the later ones. You can compare them to the embossed lines as well. 74.5-76 the holes are on top of the pair of horizontal lines, while the later ones; the holes are above/touch the upper horizontal line and don’t touch the lower one. You can use this to year ID any door cards when you can’t see the location of the lock button in any pictures you might see. Here are two door cards with a ruler to show the lock button location. 77-78 on top.

I've had bearing come with those seals. Absolutely remove the seal. Just pick them out, they are not held in tightly at all.

Yup, that’s new one I haven’t ever seen before. I can see how it could happen. i do have to note that no matter which way you put that bolt in, there is a large cross groove in the splines that the M10 bolt has to pass through, that locks the splines from slipping out of the yoke. Yes, if its in the wrong way, or is loose, the splines can come loose and there could be play, but I don’t see how that joint could come apart as long as the bolt is still in place through the groove. If the bolt falls out, then yes, it can come apart. If the splines were not inserted far enough so that the lock bolt can pass IN FRONT of the entire shaft, than that is a real problem, but I think the over all length constraints would make it hard to assemble all the components without realizing something was wrong. Wish I’d made a list of all the critically wrong stuff I’ve seen on the Datsun’s I’ve touched. Everything from rusted out seat belt mounting points to seats barely bolted down. Trust nothing unless you’ve checked it yourself.

I added some text to the topic Mike started . Worked just fine

I know, any title will do, this one just resonates with me. It should be something more descriptive for sure. "Illustrated S30 Parts History". "Parts History Illustrated" "Parts Progression History, Illustrated" Anyone else?