Zed Head

Just for learning, I pointed out the contact points. That lever in the middle bounces back and forth between them.

The diffs are probably all the same if they are as they left the factory. But the mounting hardware could be different. The very early 240Z's had the differential mounted forward by a small amount, about an inch and a half I think. It caused vibration so they moved it back. So the mustache bar and the differential mount are different along with a shorter propeller shaft.

What's the casting number on the head? I circled where it should be. Post a picture of it, it will show if the head has been shaved by its distance from the surface. It kind of looks like it has been. Also, take a picture of the back of the cam shaft. There should be a letter stamped in to it. And take a picture of a cam lobe or two. You can tell if it's been ground by the size of the lobe.

The pistons combine with the head's combustion chamber volumes to determine compression ratio. The F54 used the P79 or P90 head. It has a larger volume than the N42 and N47 heads. The F54 and the N42 L28 engines have similar CR's. 8.8 and 8.3. The engine in this thread looks interesting, probably has more interesting parts. Probably should be rebuilt but if it ran okay before it could just be reassembled with a new head gasket. All from a tiny leak...

What is the engine supposed to be? You just kind of appeared from nowhere. There are some not-so-good things in the pictures but it's hard to tell what they are. You might clean up the piston tops and post another. Detonation can cause damage that looks like foreign object damage. It can also break rings.

p.s. does anybody know why I can click on the first picture and have the ability to magnify immensely (just keep clicking and it keeps growing) but cannot do the same on the second picture?

What do you know about the engine? It has studs and non-stock pistons and a mish-mash of valves. It looks like somebody ran straight water for a while the passages are full of rust. Did you jam the timing chain? If not you'll probably need to reset timing anyway. Could be that your damper is broken or the wrong one also. You should probably get Monroe's book. https://www.amazon.com/Rebuild-Your-Nissan-Datsun-Engine-ebook/dp/B006VUICHG

That's Datsun Spirit. https://www.datsunspirit.com/ They do have headers but they look different. The welds. https://www.datsunspirit.com/product-page/6-1-stainless-steel-true-equal-length-header-with-merge-collector

I see now. Spirit Garage is a Japanese company. Funny, if you google Spirit Garage you'll get a whole different thing. https://www.spiritgarage.com/product-group/1 Return shipping would be expensive. Another option is to have somebody modify the headers. Your problem is just a normal part of building your own car.

Here's a link to the company. Never heard of them before now. Don't know how it works, there's no parts shown. He looks more like a representative for other companies. https://jessestreeter.com/

It's been discussed before, but the coolant might actually be for heating, as I recall. There's a thermostatic valve in the line. Some people don't run coolant through them, they block them off, I think. So, maybe major modification is possible. On the other hand though, cooling would probably be good, because the header pipes are so close. Angling the mounting surface is a good idea except the the carbs will then be angled also. You'd have to bring them back in to line by angle the mount from the manifold to the carb. Surprised actually, that they don't fit right. I wonder if the guy would take them back and remake you a set. They look custom built. He might appreciate the feedback too. If you're having problems other people are too. SU's are common. You'd be doing him a big favor by letting him know. Be nice and you might get a good result. Hopefully he didn't order a big batch from some offshore company. Good luck.

A spacer would probably work but it would need to be designed to work with the yokes. The intake and exhaust surfaces need to be at about the same level for the yokes to clamp properly.

There was somebody recently (maybe Dolfinz?, who knows) who had a NOS VR, if I recall right, that did not work. They opened it up and found that one of the set of contacts was stuck shut (I think). Cleaned it up and it started working.

Are they hitting the tubes of the headers? Headers can release a lot of heat. Used to be fun to take a high speed run at night then open the hood and look at the glowing red metal. Not a Datsun but all headers are about the same. Heat management is a problem with carbs. Can't remember how you're fueling your engine.

Does it have the original voltage regulator?

When the idle is hanging high, leave it alone, open the hood, and press on the throttle body linkage to see if the blade is hanging in the TB. I had that problem on mine and it was just a gummed up throttle body bore. Not uncommon, Nissan rerouted the PCV hoses to reduce the problem. The other possibility is the BCDD.

After you figure out the meter problem you might want to put a handheld meter on your charging system. 15 is too high.

You probably have a Russian account. You just don't know about it.

It's on the front page of the site. They're probably getting hacked and spammed. My email account is getting a ton of spam, much more over the last few months, especially the last two days. Just got one that looked like an official Microsoft "unusual activity" email. The link to do something about it had "unusuaaly" in the link. Reported it as phishing.

Maybe your password is already strong.

Just remove it and see if the system can cool things down. The engine should never get up to operating temperature without a thermostat. If it can't keep things cool then it won't matter what thermostat you have in there. p.s. the thermostat is actually a heating device. It blocks coolant flow until the coolant reaches desired temperature.

The Pertronix II is current-limiting. Maximum spark energy. The ballast resistor takes it back down close to Pertronix I level. Probably between I and II. Just saying. Let it ride as-is and if you ever get the tach out think about trying the modification. Can't blame you for not being eager to take the tach out. It's a PITA. If it was mine I'd probably reach up under the dash and just pull that wire a little farther away and see what happens. I think that the point of the adjustment is to reduce the magnetic field. Might be enough to just bend the wire.

Who is this Guild person? I've seen comments but it seems to be a "secret" among the investors and collectors.

Chocolate Thunder never got another bid. "TheBo" bumped it $5,000 in one shot and nobody followed. Interesting. They've bought other cars. https://bringatrailer.com/member/thebo/

Interesting question. The 76 wiring diagram shows it as close to the license plate light. Rear of the car somewhere. Many other things branched in to it. I have a vague memory of something behind the plastic panel that covers the rear inside of the car, over the tail lights. I'll bet it's there somewhere. Easy to check, a few Phillips head screws. Nice and dry there, a good place for a ground connection. But if you think you have a bad fuel pump ground you might check the connector by the tank first. If everything else works.