Zed Head

Do you know what vehicle it came from? There are truck transmissions with similar features. It definitely looks from the 280ZX time frame. The only words you've supplied are "82 71C" though. What is the full description?

I'd watch the wrecking yards and/or look for a damaged 5 speed 71B. Like EuroDat said, the failure modes are fairly common. You could probably get an undamaged main shaft and that coupler from any "blown up" 280Z or 280ZX 71B 5 speed. Or, buy a whole junk car with transmission. People often just sell compete cars for not much more than a transmission costs. I got a complete engine and many extra parts when I did that, plus made some cash back when I junked the remains to the salvage yard.

I screwed up. Seems like the 4 and 5 speed should be the same, they have the same first 4 gear ratios, but, apparently, they are not. Make sure that that 1982 5 speed is not a Borg Warner 5 speed. The turbo 5 speed. It is very different and requires a different mounting, propeller shaft, and shift lever. Plus the ratios might not be what you want. If the guy doesn't know it's a "B" he might be confusing it with the BW. Did he supply a picture? They look very different.,

It's a collection of parts. The fact that you had a very odd failure actually works in your favor.

Not really clear what cgsheen1 meant. The cam towers have to have the ports for the spray bar. If you run spray bar cam towers and a spray bar then oil will flow to the spray bar. The cam towers have the passages. As I understand things, but I haven't actually seen it, only read about it, the cam will accept oil from the cam towers if it is drilled for it. So if you put a drilled camshaft in a spray bar head you'll get oil traveling both ways. Can't find anything on carpartsmanual because Nissan considers the cam towers as part of the head. You can't buy them separately.

carpartsmanual says they are. EuroDat's list probably also. Edit - I screwed up here and missed a "4". Sorry about that. They are not the same. http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/transmission-gears/4-speed/from-sep-71/25 http://www.carpartsmanual.com/datsun/Z-1969-1978/power-train/transmission-gears/5-speed/41

How did the focus shift from a battery drain through the starter solenoid wire (apparently a short circuit through the solenoid windings to ground) to the fusible links? I don't see a connection.

You could reuse the nut if you didn't destroy it when removing it. Just peen over a different spot or use red Loctite. You said that you have the early 5 speed, so a 4 speed should have most of the parts that you need to combine with what you have to make one good 5 speed, as suggested earlier. People have 4 speeds sitting in their garage as spares after a 5 speed swap.

People strap cameras under their cars and have good results in seeing what's happening. And if you posted a video of the noise somebody might recognize it. It's weird how the ear and brain can work together. "Banging noise" covers a lot of spectrum.

You never really know what you're getting at the typical pump. Today's cars are designed to adjust to the variation. https://www.fueleconomy.gov/feg/factors.shtml "Some fuels contain less energy than others. Using oxygenated fuels or reformulated gasoline (RFG), for example, can cause a small decrease (1%–3%) in fuel economy. Most of the gasoline now sold has a small amount of ethanol in it—up to 10% by volume depending upon the region. Using gasoline with 10% ethanol decreases fuel economy by 3%–4%. The energy content of gasoline varies seasonally. Typical summer conventional gasoline contains about 1.7% more energy than typical winter conventional gasoline."

Here's a new to market low number 1970 car. A bit crusty. Oklahoma. https://bringatrailer.com/listing/1970-datsun-240z-81/

The 78 sold for about what it did the first time. https://bringatrailer.com/listing/1978-datsun-280z-117-2/

Did you remove the snap ring?

The first one looks like a heat shield. Engine bay, exhaust area most likely. Looks like it has nuts attached so it would match clear holes. The round cutout probably fits around something round.

https://www.merriam-webster.com/dictionary/hydroscope#:~:text=Definition of hydroscope,steel tube — compare water glass

The wiring diagram shows a seat belt timer for the Manual and a seat belt relay for the Automatic. Possibilities. If you can find a really quiet place you might hear something click as you connect and disconnect the solenoid wire.

If you look at the list of things done before he calls it "rebuilt" you can see that it's not even up to the level of a remanufactured alternator. He just cleans and polishes the parts, skims the head, and puts it back together with new seals, apparently. The guy has been doing the same thing for many years. He even has newer complaints on the various review sites. I saw a few for late 2021. But, he's got a good web page and knows how to promote. Doesn't care about reputation, apparently, just making the sale. From his N42 head web page, below. The only new part is the valve seals. The heads only have a 30 day warranty. So, anyone who buys one better work fast. "REBUILD PROCESS INCLUDES: Complete disassembly, Inspection and Pressure test Deck Re-Surfaced Reconditioned Polished Rocker Arms Cleaned and Installed OEM stock Springs, Retainers and Lash Pads Full Set of new Valve Seals Stock Polished Camshaft. (Performance Cam Kits available, discount offered. call for details) All threads cleaned and repaired as needed Full Reassembly and Valve Adjustment (Re-Adjustment Required Prior to start up) 30-day warranty Trust your Datsun to a professional licensed Datsun Restoration business with over 15 years experience."

Tetraethyl lead's original purpose was as an anti-knock additive. The protective properties on the valve seats were an unexpected benefit, I think. It has an interesting history. The petroleum industry realized early on that the lead emissions were poisonous but pushed it in to the market anyway. $$$ https://www.britannica.com/science/tetraethyl-lead

Anyway, leaded gasoline and ethanol containing gasoline are two different things. Different issues.

You're also confusing ethanol with lead. Two different things. The good old days of leaded gasoline, and the corn lobby. Here's a pretty good summary of what's going on that covers many of the elements. The AP is, according to previous discussions, a middle of the road news outlet. One of the most objective. It's about the corn. https://apnews.com/article/biden-business-iowa-campaigns-elections-227e09a39aed1680e1f4813334aeae64 Members of Congress from both parties also had urged Biden to grant the E15 waiver. “Homegrown Iowa biofuels provide a quick and clean solution for lowering prices at the pump, and bolstering production would help us become energy independent once again,″ said Iowa Republican Sen. Chuck Grassley. He was among nine Republican and seven Democratic senators from Midwestern states who sent Biden a letter last month urging him to allow year-round E15 sales.

This looks like political commentary. If you want to talk about fuel, that's cool, but 10% ethanol has been around over many administrations, red and blue. The guy before didn't roll back the ethanol mandate. Biden has nothing to do it with it, really. The supposed reason for ethanol is to create a measure of independence from petroleum suppliers. A source of non-petro energy. There is debate about that. But it's not a red-blue debate.

If you're having cooling problems, a fan shroud is a good place to start.

Looks like the picture is as it was de-boxed. If you look at the coolant passages it looks pretty corroded. Also interesting that if "polished" means the rocker arm pads, that that is different than reground. I wonder how the wipe pattern looks.

Looks that way. It's described in the listing. The guy had actually bid and paid for a different car in the past, a Porsche for $50,500. Who knows, he might have got COVID-19. "This is a re-list after the vehicle was previously sold on BaT in March 2022 and the winning bidder failed to follow through with their commitment to purchase. This was not due to any fault with the vehicle. The winner has been banned from future participation on BaT and their buyer’s fee was not refunded." https://bringatrailer.com/member/rlife/

Just kind of funny. Nice looking car though. "rebuilt cylinder head with polished rocker arms sourced from California Datsun Inc." And blue combustion chambers. https://bringatrailer.com/listing/1978-datsun-280z-117-2/