Captain Obvious

My pleasure! That adapter should work fine. Or (if you haven't ordered it yet), I could send you my 1/2 NPT tap and you could just run that into the hole. The trick for me was that I wanted my ninety degree fitting pointing in the correct direction (down) when I was done. So I chased the threads in stages until I was convinced the fitting would get tight at the right location. For you, if you're just running a straight axial adapter, you wouldn't even have to worry about that. Been a while since I looked into it, but I think the only difference between the NPT and BSPT is a small change in the thread form. NPT uses 60 degree threads with a flat at the tips of the threads, and BSPT uses a 55 degree form with rounded roots and crests. Going from BSPT to NPT is easy... Just removes a small amount of metal here and there. Going the other way (from NPT to BSPT) requires more metal removal. Let me know if you would like to do that. So what CHTS did you pick up? Stock Nissan, or something aftermarket?

Oh, and you're killing me with that. We just got four inches of heavy wet slush.

I'm not sure that filter is going to work, but it's worth a try. The original filter is designed just a little bit too long on purpose so it is crushed some when you screw the plug home. That's what seals the ends. You can see that injector filter is significantly longer than the flat top filter, and I worry that the plastic carrier on that injector filter will just shatter when it's crushed to length. I betcha with a custom cap it could be made to work though... Custom machined brass plug/cap with a small recess in the center that accepts the blind sealed end of that injector filter. In other words, change the cap to be an innie instead of an outie. With an innie that's a snug fit around the outside of the blind end of that injector filter? I bet they're pretty consistent. Just thinking out loud.

OK. I got sizes. FIrst, the large hole in the 260 housing is 1/2 -14 BSPT. I re-tapped that BSPT hole to 1/2-14 NPT which was really easy since the thread pitch is the same between the two. After I did that, I was able to use a common US NPT fitting to duct hot water to my throttle body. Here's the pipe tap I used: And here's the fitting I used when I put the 260 thermostat housing on my 280. It's a 90-degree PEX fitting. 1/2 NPT on one end, and the ability to use rubber hose on the other: In-situ, it looks like this. The other side of the throttle body goes to the metal hardline around the front of the engine and ties into the water pump inlet: And here's a pic of the 280 EFI temperature sensor. Now hopefully I'll remember off the top of my head what threads it uses:

No, unfortunately the 280 temp sensor did not fit correctly into that hole.. And that's one of the things I did to the 260 housing was to figure out a way to make that sensor fit. The temp sensor is straight threads and seals with a washer, so not only is the thread pitch wrong, but the sealing style is wrong too. I wasn't thinking this at first, but my project is actually relatively applicable to what you want to do, isn't it? So here's what I did to get that sensor to fit... First, I drilled out the original hole some: Tapped it to a straight thread. 5/8-18 I believe: And them made a brass adapter to bring the hole size back to what is necessary for the temp sensor: A little blue threadlock so the sensor will turn before the adapter will, and glue the adapter into the housing. Then thread the sensor into the adapter: All that said... That's why I think it would be easier to just use an adapter to the other larger hole. That option was not available to me because I had plans for that other hole. I use the larger hole to supply water to my throttle body. I'll check all the sizes when I get a couple moments in the shop.

Don't think so. Last I looked, there were a couple people out there in the ether that make aftermarket replacements, but I think the design of the factory parts (the newer version at least) are better. There were two revisions from the factory... The early ones (like what you have on your car) sucked because they fell apart (like what yours is ready to do). The later version (like the one on the far right in that pic) were put into service to replace the early ones and do not suffer the same fate. I actually don't know if they are still available at Nissan new. I think you should check and report back.

"It's a COOKBOOK!!" Fantastic. I was also trying to make a reference to Soylent Green, but it got kinda lost in the wash.

@z8987 if it's still available, you should buy the (newer design) oil spray bar all the way on the right in this pic: Parts for sale by @madkaw in this thread: https://www.classiczcars.com/forums/topic/60915-various-datsun-engine-parts/

The only hole on the 260 thermostat housing that is NOT tapered threads is the one closest to the head where the temp gauge sender unit goes. Everything else is BSPT. Now as for the sizes... I don't remember offhand. I did a whole bunch of modification to a 260 housing and adapted it to use on my 280, but like many of my projects (when I don't think anyone else could possibly benefit from the details), I didn't keep good notes. The project is done and it worked out great, but I don't have the sizes documented. I can tell you, however, that there is nothing 5/8 BSPT in the 260 housing. That's too big. I believe he largest hole in the 260 housing is 1/2 BSPT which is great because it's the same thread pitch (14 threads / inch) as 1/2 NPT. So I just ran a 1/2-14 NPT tap into the original BSP hole and converted mine from BSPT to NPT. Then you can use easy to find adapters to change from there if necessary. At least that's what I think I did... I'll double check the sizes and let you know for sure.

Haha!!! I'm not posting any pics of me from 1980.

I've been asked what I look like. My answer is Captain Obvious. I bet he makes more than me...

That's Logan 5. It's a cheesy movie considering today's special effects, but it's a classic sci-fi story. How do you maintain utopia? Step one: Don't have any old people. At least they didn't eat them. You know... To serve man. (how many other references can I stuff into a few short sentences? )

I'm no expert, but... 1. No. You need the engine turning faster than can be accomplished by hand in order to get good compression test results. 2. I've dissected several brands of oil filters in the past and have been dissatisfied with the internals. As a result, I've now switched all my vehicles over to Denso filters that I get from Rock-Auto. It's a pain because you have to plan ahead and can't just run down to the local parts store, but IMHO they're really better. 3, Not Champion. Use Japanese plugs in a Japanese engine. Denso or NGK. 4. If the points aren't all burned up, cratered or have a lump of material migrated from one side to the other, then you can probably save the replacement for later. You should replace them once you get out of the "just trying to get the engine running" stage though. 5. Ask Wheee! 6. "Did I forget anything?" Yes. Of course you did.

Awesome! My kind of problem!! A non-problem! So either it was just the wiener in the warp drive from taking off the AAR and starving the engine for air, or there's an electrical intermittent connection in your wiring tangles. You'll find out at the most in-opportune time. But even if it isn't keeping you from passing smog, you might want to take some time off from other projects on the car and clean that stuff up. I've found a great sense of peace knowing that all my EFI connections are new, clean, and tight.

The oil spray bar is there, but it's not to be trusted. The tell-tale angle of the tips says it's at high risk of coming apart soon. Especially at the rear. I'd get a replacement in there before you put any significant time on the motor.

Yup. that's the exact situation where the BCDD is supposed to help, not steady state on a dyno. The BCDD will also help reduce the amount of oil pulled past the rings and valve seals when the cylinder vacuum goes up when you let off the gas and the intake manifold vacuum spikes. Especially on a worn engine. On my first Z with it's worn out engine, I used to get a terrible eye-burning blast when I completely let off the gas at very high RPMs. I believe I have a much better understanding of the system now, and looking back, I don't think my BCDD was doing anything. That extra rich mixture (too rich to burn), combined with a whole bunch of oil getting pulled past worn surfaces produced a bird dropping cloud of unburned HC's. I was a new work force entrant then just trying to get to work. Now I'm a tree hugger.

POR-15 is a moisture cure polyurethane coating. It doesn't "dry" in the common sense, It "cures" with combination from humidity moisture in the air. If it's cold and very low humidity (like it may be in Canada at this time), it would certainly slow the cure. It'll be ready by spring.

It's been longer than 30 years. They should send that car to Carrousel. That's about the worst I think I've seen. Woof!

The only time the BCDD does anything to decrease emissions (reduce HC) is when you are coasting and have a high intake manifold vacuum. So unless they measure the HC while they are decelerating driving the car, or blipping the throttle and seeing what the HC's do while the RPM's are coming back down to idle, then the BCDD won't make any difference to your emissions test. Under steady state conditions like idle or 30mph steady cruise, the BCDD doesn't do anything and has absolutely no effect on performance or emissions or anything at all. Under steady state conditions, it's just a closed valve. However... Don't get me wrong. I'm a tree hugger at heart and am glad to hear that you are proceeding with a plan that keeps your BCDD intact. Just clearing up some of the technicalities about the operation. Oh, and Wayne is the man.

Hmmm. Other things to consider... In the later (latest?) years, 78 I think, they stopped putting the altitude correction nubbin at the bottom of the BCDD. Probably except for CA. So I don't know how detailed your visual inspection is, but you might need one from 77 or one from a CA 78 car. The final version still has an adjustment screw underneath, but doesn't have the bellows inside for altitude correction. Seems like the kind of thing that every state except CA would not have let them get rid of. There's one of those stubbier BCDD throttle bodies sans altitude correction for sale right now in this thread: https://www.classiczcars.com/forums/topic/61556-280z-oem-parts-fuel-ignition-door-stuff-grill-etc/ Other thoughts? Again, not knowing how rigorous your CA inspection is, but the energetic Z owner could be able to disable the BCDD internally and prevent any leaks while still having it appear externally as though it's fully functioning. Not that I would encourage such behavior, but if it's a trade off of selling the car out of state or driving it...

Cool tool. It's not a direct measurement of airflow (like the flowmeters are), but it's better than nothing. I assume set them to zero (or at least the same between the two) to match them before starting the engine? There's no guarantee that the distance from the top of the carb dome to the piston inside is the same between carbs. I would also be a little tentative about driving around with those on the car. You won't have any suction piston damping and will lean burst when you press the gas pedal. One backfire (front fire?) and your dial indicators will likely be slammed to the limit and probably damaged.

Pretty much every Z I've messed with is in this category. AFM's adjusted to account for vacuum leaks. Idle speeds adjusted to account for BCDD leaks. Etc...

Well don't get all hopeful yet guys. It's just a theory. The simple (the Obvious) one to look into. Hopefully it's that easy, but it's still a potentially failed avenue. However, in the end of all this, I do hope you completely clean up all the wiring going to the sensors in the throttle body. Clean, shiny, well packaged.

Well to me, that's a tiny bit of "consolation". Consolation that your car isn't absolutely perfect and incredibly cheap. I was starting to get sore from kicking myself.

Glad to help in my own little way!