Zed Head

Take some measurements. Measure the opening of the rim. Maybe it's not meant for a Nissan. Measure the stud lengths. Use the method I described and be sure that the studs are pulled all the way in. Besides the problems you've had there's a lot more wrong with what you're doing. Those hubs are flithy. The area where the rim contacts the hub should be clean, on both the hub and the rim. No offense intended, but there are more people than you and your wife/girl friend at risk here. Get some help from somebody who knows cars. People get killed by wheels that fall off of vehicles at speed. Not the ones in the three-wheeled car, the people that get hit by the 50 mph wheel. Besides the guilt, you'd be financially liable. Sorry to be a downer, but there's quite a bit wrong in this thread.

It's the hose connected to part # 7, the PCV valve, in the drawing on Page EC-2. The Emissions chapter. I'd post a picture but the function is broke. It's underneath the intake manifold.

That's the thread I was thinking of but I couldn't find it. Unless the comments are in the one I linked. My general impression has been that the vapor lock problems caused people to make changes. And swapping to round tops from flat tops was a common change. Going back to what was known. Kind of like removing "emmissions junk", or going back to carbs from EFI. The past always seems more comfortable.

It might be in this thread somehwere.

I think that there's a long discussion on the forum somewhere about switching to round tops, and when it often happens. Not sure. I'm definitely not a carb guy. The text says that they were rebuilt. "Service in 2023 is said to have included rebuilding the carburetors, replacing the ignition switch and spark plug wires, flushing the fuel and cooling systems, and performing a valve adjustment and an oil change."

Another 73 is up for sale, but with very low miles. Looks garage kept. I wonder if the hoses, hydraulics, booster, and other parts will hold up long if somebody starts driving it again. An odd dilemma - keep the original parts but don't drive it, or replace the parts and enjoy it. https://bringatrailer.com/listing/1973-datsun-240z-254/#comments

A 280ZX at PicknPull in Lynnwood WA. With the rare 2.7 liter engine. Looks like it still has the engine. Might be worth a look for a parts picker. https://row52.com/Vehicle/Index/JN1HZ06S7CX430334

He didn't do a very good job, obviously. You can stack a bigger nut or washers or a socket over the lug/stud and pull the lug all the way in using the lug nut. It should square up as the bottom of the lug seats. Do each one separately. Those aluminum wheels don't like high torque, it will deform the metal around the hole.

I used heater hose and it worked fine. I think it was 5/8". There is a metal screen-like thing in the factory hose used for flame arresting if there's a backfire in the intake system. Dig it out and put it in the new hose. Since the top hose was cracked you should check the bottom hose also.

I'm saying that when the engine is idling high after it's been warmed up, and you think that it should be idling at a lower RPM, open the hood, and press the linkage toward the closed position. If the blade is fully closed and the idle stays high then it's not a linkage problem. If the idle drops, it is a linkage problem.. Just trying to use the process of elimiination. Yo have to do it when the problem is happening though, not when it's not.

Try closing the throttle blade by hand from the engine bay. The throotle bore can get gummed up causing the blade to stick. If you can close it by hand then you can focus on getting it to close by itself, like it should. Check that the throttle return spring is intact and connected. It's not uncommon for them to rust and break, invisibly. It's knd of buried behind and under the linkage at the throttle body. There's a weak spring on the blade itself and a strong one on the linkage. A real pain to get connected if it's off. . . .

Another mid-20's Z sale. https://bringatrailer.com/listing/1973-datsun-240z-252/

You've been lucky. Your wheel is probably wobbling and that can cause the nuts to loosen. Once they get loose they spin off pretty fast. I lost two lug nuts on about a 1/2 mile drive because I forgot to torque them down after putting a wheel back on. The remaining two were trying to be free also. Stick the lug nut in the holes before installing the wheels. If the nut sticks all the way through the hole it's too long.

I got hung-up on the computer file in your first post and completely misunderstood what you were doing. Thought you were sending them the computer file only. I see now. Can you post a picture of the part after you "print/manufacture (additively)" it? There's powdered metal additive manufacturing now. You end up with a real metal part, direct from a computer file. Pretty amazing.

The $40 seems really low if they're building a hard mold. Hard to believe. I'd guess that they could 3D print the part and cast plaster around it. Then they'd have to worry about draft. It does seem an interesting place. https://lancasteronline.com/opinion/editorials/atf-investigation-of-lancaster-county-amish-farmer-highlights-the-importance-of-gun-regulation-editorial/article_b519cf3e-8096-11ec-ae18-b7900627a47f.html

I'd check the air supplier tube and/or the gas cap. And the breather tube. (Edit - actually all of the ventilation tubes. There seem to be many. Must be important.) I see that siteunseen has just replied. Same thought... . . .

I wonder how much heat is transmitted to the mustache bar? A thought. Also, what is air flow like around the diff? Nissan's finned diffs put the fins on the bottom where the air flow is. I wonder if anyone ducts air to the diff, like they do for brakes. It's an interesting topic to think about, especially with a low budget. Have fun.

Have you thought about gluing cooling fins on to the cover you have? Today's adhesives are very strong and can be conductive. https://www.3m.com/3M/en_US/p/d/b00006335/

How about remote cooling? Like they use in laptops to cool the main processor. Borrowed this from a Youtube video.

You are right. https://en.wikipedia.org/wiki/Delco_ignition_system

Looks like you added fins inside the cover. Here's an interesting video from a guy who has a bunch more on the topic on his Youtube channel. He's selling parts of course, but he does raise some interesting points.

Once an insult shows up the rest doesn't matter. That's what it boils down to, for me. Maybe it's a cultural thing. We have different values. You seem to be saying that a person who contributes to a discussion gains the right to insult other people in a discussion. The more they contribute, the more insults they're allowed. That's just not how I work. You're focused on the punch. I'm saying that the turd is still right there where everybody can see it. The punch is ruined. Stop defecating in the punch bowl please. It's pretty simple. It just takes a small amount of self-control. Read your post before clicking "Submit Reply". Remove the insults. I have written whole paragraphs myself but not posted them. I knew that they would not advance the discussion, or add to the forum, whichever one I was participating in. It takes some objectivity though. It can be difficult. Good luck. There's really not much more to say on this matter.

In sand-casting the sand is the mold. It just brushes off. The core, or form, is what might be molded, for high production parts, but they're not building a mold for $40. Almost has to be 3D printed. Interesting project, but getting all the way to a usable part will take many steps. Good luck.