Mark Maras

So, is the cover being held for ransom?

Welcome and congratulations on your find. Does it have much rust? I have some parts from a late 71. What part of the world are you in?

I'm not familiar with the term (part) called a throttle switch. What type of fuel delivery system does the car have? Fuel injection (factory?), or carburetor(s), description and quantity. I'm curious what color the plugs were before the improvement.

Yup. I experienced the loose pan bolts multiple times on my first Z. I just got in the habit of checking them when I was under the car.

@Blue

Thanks for sharing. I enjoyed the sound track as much as the video.

Part of me is sad that I missed seeing it. The other part is glad I didn't see it. It must have been good!

IMO, you can safely bypass the main filter temporarily, there are the "last chance" filters inside the banjo fittings on top of each float bowl that should catch any major debris. That said, it would be worth checking them when the experiment is completed to make sure they didn't pick up any crud from the tank.

I agree. The pic of the plugs in post #181 were run three turns down. In my experience, three turns down should leave the plugs with a light to medium tan color. I'd check the float and the needle height first. Jalex. Back in post 181 when the car lacked power, did you try gradually adding more choke to see if performance improved? It's a great way to check for a lean mixture.

Attention!!! 10/31 16, 10:30 AM PST. Garage Squad, XFinity, Velocity Channel 711. "Disheveled Datsun" A motorcycle mechanic has a 70 240Z that has problems under the hood and the body too.

As an experiment, I'd re-direct the fuel lines with a temporary fuel rated hose bypassing the original steel fuel rail. Do it cheap and easy. Leave the old fuel rail in place until you decide if it was part of the problem. If the experiment works, replace the temp line with a permanent line.

I've considered this possibility too. Makes sense, but, the early set-up with 4 screw Hitachis and two steel fuel lines (one return) didn't have the problem. I'm still curious if the big difference is in the two vs. the three steel fuel line set-up.

Maybe an infra-red thermometer would help find the hot spots in the fuel system.

The latest member that I remember to do the carb switch was @rossiz. He went to SUs though. Also don't remember what year his 280 is but there may be some electrical info he can share. I have to ask, why not SUs?

Just because you can, doesn't mean you should.

Spring #2, Is the tang on the upper end broken off or is the end a clean cut?

Beautiful parts. The craftsmanship shows. Have you considered a garage business manufacturing and selling proper fitting parts? Black Dragon won't be an option in the future.

That first spring looks more like a thread insert from the side view.

That's what I would do. I think it will have the greatest impact on the problem. Let us know how well it works if you go that route.

Development of the Datsun 240Z. Hitoshi Uemura says that after the initial heat resistance tests at 104`F, "The ambient temperature in the engine room did not become a major problem. All the temperatures for the battery fluid, the electrical, and the rubber parts were within the normal ranges. The fuel temperature was also normal and we saw no hesitation during sudden acceleration. However, the NEXT MODEL, to which the more stringent emission control in North America was applied, would cause a problem in this area later."

So, It's looking like (at least to me) the three line set-up might be the place to look first to cure heat soak problems. @Jeff G 78, Did you ever try a two line set-up with the manifold water blocked? @jalexquijano, Refresh my memory about your set-up. Number of fuel lines by the valve cover? Carbs-3 or 4 screw and are they heated? Anyone else have an opinion about the two line versus three line set-up and heat soak?

Jeff G 78, What year were your round tops? I'm trying to figure out which changes Datsun made in 73(?) that caused the problem. Heated carbs certainly added to it. Considering fuel lines, I have a couple of sets of the factory engine bay fuel lines. One set is two lines the other is three lines. I think the three line set-up is newer. Is it possible the three line set-up was part of the problem? I don't remember any heat soak problems on my 71 which had two lines and the early 4 screw round tops.

I found a lot of holes in that story too. No percolation or rich mixture issues mentioned?, heat shields added later on? I'm with Patcon about the rapid turning under EXTREME heat conditions although I've never heard of it. I'm surprised they didn't find the problem before going to that extreme. I get the feeling that Nissan never considered it that big of a problem and just tinkered with it rather than an all out attempt to fix it. To cure the problem, one may need to refit the engine with early carbs. and intake components (didn't seem to be a problem early on) or move the fuel line from the wrap-around stock fuel lines to a line that comes from behind the engine to the carbs. Probably a little easier if you don't run a mechanical pump. @Bruce Palmer, got any thoughts about this subject?

Nice, Thanks