Zed Head

For what it's worth, I bought a junkyard flywheel and pressure plate with the intention of using them eventually. I didn't get the disc, it looked like it had grease on it. And I'm using a used flywheel now, that I sanded clean, from a parts car. With a new pressure plate and disc. If the ZX is a 2+2 it's probably a 240mm clutch and flywheel. The clutch discs will swap from 240 up through 280ZX but need to match the pressure plate and flywheel. Coupes use 225mm, 2+2 and Turbo use 240mm. If you decide to do it, get the throwout bearing collar also. It matches the pressure plate height. That would be a complete set, ready to go.

To Blue's point - it's hard to tell if the diff mount is really in good shape, when it's on the car. The loose rubber is not obvious. I think that the "clunk" is actually the sound of the diff dropping back down on to the crossmember and mount after the loose rubber lets it lift. It doesn't have to lift far to make a noise when it drops back down. The strap doesn't really come in to play. I thought mine was fine, but once I replaced it, I stuck it in a vise and could pry the two pieces apart easily with a big screwdriver. And there's actually a measurement you can make, shown in the Rear Suspension chapter, to help determine if the rubber is worn. Also hard to tell if the u-joints are good without sticking a screwdriver in to the joint and reefing ti around while watching the seams of the seal with a strong light. Twisting the half-shaft by hand won't really do it. They see a lot more when in action.

It's been posted occasionally that one-wheel burnouts are the death of a diff. The hole for the spider gear pinion shafts wallows out. I've seen pictures where the hole is so worn that you can see the ovality and the looseness of the shafts. You might see something if you pop the cover. Kind of confusing that the deeper you go in the diff, the more "pinions" there are...

Does that part show up on the Arizona Z Car web site or do you have to call them? I tried to find it but the AZC site is kind of a mess. There's someone on another forum looking for one.

I think that the differences between the two engines might be very small. The change in HP calculation methods really confused any comparisons. But if you look at the specs, it seems like the old style engines should actually have the power edge. The cam specs are a hair better for the N42/N42 engines. The CR is a hair higher for the later ZX engines. 8.8 vs. 83. The intake manifold is smaller on the ZX engines, and so is the throttle body. The cam specs for the old engine should produce more power. Really hard to tell, but it's probably just a few HP either way, with maybe a different shape to the power curves. I have a spare 1981 ZX engine in my garage myself. I bought it because it was in good shape, the price was right, and I thought that it might be a little "better", But after digging in to the details I can't find the better part. Seems a wash. On the other hand, the later ZX's ECU and EFI system could offer potential for a small investment of time. Probably has a more developed fueling algorithm, and it has an O2 sensor feedback for efficiency. Tried to cobble/copy the specs in for 76 v 82. Intake open duration is 8 degrees longer, and stays open 8 degrees later for 1976. Which should allow more charge to enter. But the lifts are the same, I believe, although I can't find the numbers in the 1982 manual. 76 on the bottom. There might be other changes in the F54 block it self that make it more desirable.

I can't find the man reference usually used but the one I found says that 19 tooth is the white gear for a 3.9. A lot closer to a 4.38 than a yellow, for a Z. 510's and Z's both use the same size tire, I believe http://community.ratsun.net/topic/26704-matching-speedo-gears-after-rear-end-swap/ Post #7 A similar question came up on another forum and someone posted the link below. It will give you an idea of the difference you'll see between the two. It really depends on how you intend to use the car. Nissan designed the systems to allow starting from a stop easily, including hills, and cruise at freeway speeds. Race cars need to accelerate from corners and go fast on the straights. Drag cars need to accelerate and top out in a gear as they hit the lights. Auto-cross: in the powerband with throttle control. Stuff like that. http://webspace.webring.com/people/cz/z_design_studio/

Don't forget tire size. With a bigger tire the diff will spin slower. A big tire and a 4.38 might spin the propeller shaft at the same speed as a small tire and a 3.36. Yellow is way down at the other end though. Count the teeth to be sure what you have. Maybe it's old white.

If you do a Google search on the part numbers, you'll get several options here. http://www.carpartsmanual.com/datsuns30/DatsunZIndex/Engine280Z/FuelPumpHose/FromAug-76/tabid/1619/Default.aspx Also look at the post Aug 76 parts, menu on the left. Looks like the same pump but different hose and tube setup. More metal, less rubber. You might also try your local dealer. Surprising what parts they can still get. Also, if you decide to go cheaper and use an aftermarket pump, you can make a loop in the hose to get it to curl around from port to port without kinking.

We've had some good discussions about the "vapor lock". The info gathered suggests that the simplest way to cure it is to convert to an aluminum fuel rail. The larger bore of the rail holds enough fuel to cool the injectors via boiling and condensation, with the heat conducted and radiated away by the aluminum. http://www.classiczcars.com/topic/48810-hot-start-issue-with-efi-who-has-it-who-doesnt/ Assuming that you're talking about a 280Z. The 240Z's with carbs and mechanical pump can have a real vapor lock problem.

I was replying to what you said in Post #3. If it is a ZX control, then it won't fit the Z distributors is what I was saying. If my memory is right. I have both styles in the garage and remember noticing that they were different. I could be off but I think I'm not. I'm sure I'll check soon, just to be super-sure. Nissan changed a lot on the ZX distributors, from the Z's. Edit - Hey. I had a bad memory. I was positive that there's one vacuum canister that won't fit another type of distributor. But, I did go out and swap the 280Z and 280ZX vacuum canisters and they fit fine. I feel better now, sorry for the confusion. Carry on... Edit 2 - Must have been the points distributors I was thinking of. For those swapping to electronic, they can't swap the vacuum canister. So 240Z distributors would be off the list.

I don't think that the test I described is written up in the usual places. And what you're writing doesn't tell much, but does fit a dirty AFM switch. The 10 volts is normal. The starter drops the voltage as it uses amps. You can test the AFM contact switch at the AFM, or at the EFI relay with an ohm-meter, but the easiest most direct test is to take the black cover off of the side of the AFM, or take the inlet hose off, turn the key to On/Run, then move the AFM vane. If you have the cover off and there is power to the AFM contacts you might actually see a tiny spark. The contacts look like a tiny set of distributor points and are actuated by a bent rod when the AFM vane moves. It's very simple. All it takes is a piece of hair or dust to hold the contacts open. Probably why Nissan changed the system. I would do that test. You'll know more than you do now. Forgot to say - I have cleaned the contacts in an AFM with the striking pad from a book of matches. Never did figure out what exactly was blocking it.

I think that the ZX uses a different form. The Z advance control won't fit on the ZX distributor. That's a nice item though. Is there similar for the ZX distributors?

If you run a torch over the outside metal around the bushing rubber it will get hot enough to degrade and soften. It can then be pushed out, leaving a few pieces of rubber to scrape away. No need for the smoky fire, although it does look like fun. Much cleaner too.

I was wondering about the TSB also. It would be cool to see some official Nissan communications on the subject. It seems odd to use the standard tip on the dished piston and the projected on the flat. Just initial gut feel. They are different heads though, N42 and N47 vs. P79. But if Nissan realized a problem later on, that would be interesting.

Kind of sounds more like the AFM contacts, if he's only losing power to the pump. If it was the ignition switch he'd lose all power. Details on the "checks" and whether or not this is a new problem on a car that was running or a problem that came with the car would help. The easy way to check the AFM contacts is to turn the key on and move the AFM vane. The pump should get power. If it's quiet, you'll hear it running. I've had my AFM contracts get dirty and kill power to the pump. The engine would only start, run for a few seconds, then die.

Looks like Nissan Parts Zone sells bonafide Nissan parts, so I would assume that you're okay. Your other post looked like maybe you just used them for parts numbers. Wasn't clear (to me) where you actually bought them. I posted "just in case". Good luck with it.

I thought you might have a comment. I remember you rebuilt yours a year or two ago. How is it working for you?

Not to be a downer but the synchros that are commonly available seem to be of questionable quality. Didn't know you were doing a full rebuild or I would have posted the link below. There's a guy on Hybridz who did extensive work on these transmissions, for racing, and destroyed many synchros in the process. I think that he ended up using Nissan factory synchros. I can post the link if you'd like, it's multiple pages. May not change anything but worth reading - http://www.datsunstore.com/transmission-manual-shift-c-202_216_243_271.html?page=2&sort=2a http://www.datsunstore.com/syncro-ring-through-7083-p-1458.html

You'll probably want to gap the plugs wider to take advantage of the high energy ignition module. So the -11 is the way to go since it's prebent to .040" gap. P is for projected tip and it's not really clear why Nissan jumped around on that specification. People have their theories but the shape of the combustion chamber is probably what matters most. Can't really go wrong using the factory spec. If your engine used a P tip, use a P tip. New wires are a good idea since you'll have more voltage with the wider plug gap. It's the -11 that's probably giving you problems on the fitment. -11 is prebent for the .040" gap. These would not work with points well but you don't have points any more. I'd use the BPR6ES-11.

These two sites should get you there. The transmissions used the same seals for the 280ZX's for sure, even up in to the 1990's cars (71C transmissions) I believe. Might have to buy a few and read the fine print though to make sure you get made in "not China or Mexico". http://www.showmetheparts.com/timken/ http://www.carpartsmanual.com/datsuns30/DatsunFairladyZIndex/PowerTrain/TransmissionCase/5Speed/tabid/1702/Default.aspx

You might jack the car up and see how far the wheel drops. The wheel will drop to the bottom of the shock's travel. If the shock is topped out the wheel won't drop much at all, just any compression of the insulator. I think that's right...

If you click through to the original listing it says $15,600 does not meet the reserve. Watch for future relisting. 1971 Datsun Z-Series AMAZING FULLY RESOTRED AND UPGRADED DATSUN 240 Z Current bid:US $15,600.00Reserve not met[ 14 bids ]

If you browse around the site you'll see that many Z's that are sold to new owners have not been well-maintained. I would drive my 76 280Z in the cold winter of Chicago, but I've got it back in to good shape. There's no way to know what you're dealing with until you have it in your possession. The EFI systems are definitely designed to handle cold weather though, with cold start enrichment and temperature compensation from the computer and the extra gas from the CSV during starting. Handling is a different issue. If you've only driven front wheel-drive cars, rear wheel-drive can surprise you and get you sideways, especially quickly with a small car like the Z. Besides the fact that it only takes a small bump from one of today's common SUV's to do significant damage to a Z. You might drive fine but the other guy is going to crush your car.

Take a magnet to the body. That looks like a thick body filler layer, that came loose for some reason. Might be signs of damage on or under the headliner, inside, also. If they put body filler there, it could be anywhere. Also, if it's as thick as it looks, that gives a sign about the quality of the work overall. Thick is not good.

There was a thread on Hybridz a year or so ago about the high "American" dyno numbers, started by some Australian guys, I believe. Rebello was the subject. PMC Racing had some comments. Interesting. Did you measure cylinder pressure? It's an indirect look at compression ratio. Detonation is essentially a cylinder pressure issue. Just curious.