Captain Obvious

Keep in mind that not all of the manufacturers use the same shape for the rotating cam post that sticks out the back of the lock. This, of course, also means that there are more than one shape used for the corresponding hole in the actuation arm that clips onto the back of the lock. Point is, if your plan is to buy a new lock and move that arm over from the new one to the old one, it might not fit. To make matters worse, the factory locks seem to be unique in their shape... Granted, I'm no lock expert and I've surely not seen all the options available, but I can attest that the aftermarket Chinese locks on ebay use a different cam and hole design and their newer arms will not fit the post on the original locks.

Do you have the original flat top carbs on the car or have they been switched to the older round tops?

Ouch! Those sleeves must have really been rusted in place. Kinda makes me wonder if they were that stuck, then what is the condition of the rod portions that were under the sleeves? Are they so rusty that the diameter has been reduced?

So, you've got a 280 that came to you with an N-42 block and a N-47 head and you're wondering if you can replace your cracked N-47 head with a P-79 off a 280ZX? Is that right?

78sid, Are you using the original black plastic knob, or have you switched it to something else? I found the plastic knobs to be quieter than others because the softer rubbery plastic absorbs vibration. I switched to a wood knob and as goofy as it seems, it makes much more noise than my original faux leather plastic knob. Shifter bushings? I made some out of Delrin. Has some compliance like stock, but not as harsh as brass. They work great:

Yeah, but the reason it seemed like such a great place to tap off was that it was already self contained to the console. The point is that you could get your "hot in ACC" and your "hot at all times" without having to run another wire to the console. Unfortunately it's not as good as it sounds.

OK, Seems nobody else wants to play? Here's the issue: The 4-way hazard light system works at all times regardless of the key position, and because of that, there IS a wire going to the hazard switch that is hot even with the key in your pocket. So, it sounds like you could use that wire as a "Hot at all times" supply to a radio install, but you can't because that wire is hot at all times EXCEPT when you turn on the hazard switch. When the hazard lights blink OFF it's because the battery connection to that wire is broken by the hazard flasher module and if you use that wire to your radio, your memory supply will blink on and off with the lights. In other words, it works great until you use your hazard system. You might be able to construct a simple storage circuit to hold you through the times that the circuit is open, but it depends on the internal design of the radio you use. In my case, I unfortunately could not do that and had to find my hot at all times connection elsewhere.

Here's some pics of the connections to the mysterious sub-harness. These pics are from my 77: Still no ideas?

What did they call the heat soak reducing cooling fan that blew on the injectors on the 280ZX's? I'm wondering if maybe they realized as far back as 76 that they might want to include something like that and put provisions if for the fan, but never used it until some time after 78? That's all I got.

Hmmm. I'm not quite ready to give out any bonus points yet... My thinking when I made my original suggestion of tapping into the hazard circuit was that since the 4-ways work at all times regardless of the key position, then there must be a signal going to the hazard switch that is hot even with the key in your pocket. And that belief can be verified... If you probe the wires going to the hazard switch, there is in fact a wire that is hot regardless of the key position and has 12V on it even with the key in your pocket. Sounds like it would work great, right? Well, not so quick. There's a definite problem with using this wire and I'm only giving out bonus points if you can specifically identify what that problem would be. :bulb:

So what the heck is the "Cooling Fan Motor Sub-Harness? Nobody has ever noticed them before?

Haha! Your WAG is not correct. There is only one wire on the flasher switch that is normally hot. I'm saving the boobie prize for myself. I love those. :laugh:

This suggestion has a problem and won't work. Bonus points to the first person who can figure out what that problem is. :bulb:

So... I'm looking over the wiring diagram trying to figure out the cleanest way to get an always hot voltage line to my new radio install and I see these on the wiring diagram: Anyone know what these connections are all about? I went to the garage to see if they really exist, and they did (at least on my 77 they did). They are present but unused and are located above the passenger's right knee above the relay bracket. Lo-n-behold, one of them is hot at all times just like the diagram says it should be. So what's the deal? Was that some option that I don't have? Was there a factory electric fan installed in some cars? It's on the wiring diagrams for 76, 77 and 78. I don't have one for 75 so I don't know about that year.

That engine looks awesome. What did they offer that in?

I just measured my red 5-speed pattern to be 1.050 OD. I don't have one of the earlier plastic patterns here to measure, but I did measure the recessed hole in a wood knob to be 1.080. I don't know anything about the ones offered from ebay. So, it's be as much of a difference as I mentioned above, but it might be enough that you'll have to fill the gap to keep it from looking funny.

The later metal cloisonné style maps are slightly smaller in diameter than the earlier plastic ones. Maybe an eighth of an inch or so? If you try to use the cloisonné style on your wood knob, there will be a small ring gap around the outside edge. If you try to use a black-n-white plastic style in your black plastic faux leather knob, it might not fit into the hole. You might be able to force it in, but I've not tried.

It's not deadheaded. It's got a hole out to atmosphere at the end, right? That's the whole reason it leaks! With a small almost deadheaded leak like that, the "normal" flow direction doesn't really matter... Remember you've got both absolute and differential pressure in that system. Thermal expansion provides the absolute and the water pump provides the differential. Either one of those pressures is capable of forcing coolant out a leak hole. In your case, I suspect that the absolute is forcing water "backwards" up that tube and out the leak hole. And BTW, I found lots of gunk in those tubes when I was messing with that stuff on my 74.

First round's on me!! I'm buyin'!!

Haha! Yeah, I figured as much. I know you know your stuff and it had to be something simple like that.

I'm guessing that you're talking about the tension/compression rod bushings in the front suspension and the sleeve that fits over the threads on the T/C rod... If that's the case, you should be able to hold it in a vice while you twist the T/C rod out of the sleeve? Might not work because the sleeve is pretty thin and if you squeeze it, it might ovalize and clamp down on the threads. Other ideas? Hit the shoulder of the sleeve with a hammer and chisel or screwdriver? Drive it off a little at a time? Cut it off with a hacksaw? Be careful not to get into the threads on the rod. Try some heat on the sleeve in conjunction with the above?

Nope. The ground for the fuel pump relay is hard wired on connection #72. The ECU really has absolutely no direct link to the fuel pump operation at all. The only link between the ECU itself and the fuel pump operation is indirect. By that, I mean... The engine won't run without the ECU and the vane in the AFM won't close the fuel pump contacts unless the engine is running. But other than that, there's no link. In short, the only way the ECU controls the fuel pump is through the use of air. Remember, we're talking 77 (and prior) here, but I believe the above applies to 78 as well. You would just have to change references to AFM to oil pressure switch instead.

All of the bars I've refurbished started with the original tubes. I've not made replacement tubes to date. Sometimes I wonder if it would be easier to remake the tubes from scratch as well, but so far, I haven't done that. I'll dig out my notes tomorrow in the shop...

Yeah, interesting that the hole diameters are different. I have never messed with it, but I've heard there is a flow restrictor in the oil passage leading up from the block into the head. The prevalent theory being that you could completely open flow the oil in the head (like dumping all your oil out of a cracked spray bar) and you would still have enough pressure at the crank that you wouldn't waste your mains. You would ruin the upper end, but the crank should survive. If that's the case, then maybe they opened the holes in the cam so it wouldn't shoot so far? When it's not leaking all over the place, those spray bars really spray. Like... Multiple inches of spray. With the holes in the lobes, you only have to hit the follower. Anything sprayed on the underside of the valve cover really doesn't do you any good. Just thinking out loud...?

I'm sure it was a simple use of the wrong acronym, but for the sake of clarity and completeness, the above is incorrect. It's not the ECU that controls the fuel pump, it's the AFM and the fuel injection relay (above your left knee under the dash) that control the fuel pump. You could completely remove the ECU from the car and if you lift the AFM vane, the fuel pump will run. But back to the real point... Other than the fuel pump, I don't think there is anything else that you would have to spend any attention on when converting to carbs. The FI harness is it's own entity and separate from everything else. The only things it makes contact to are FI specific components and the battery.