Zed Head

Does anything pass through at all? You might use a high pressure EFI pump or even just a low pressure pump and set up a loop, with a small tank of carb cleaner or similar. An EFI pump will have pressure and volume. Let it run and purge it. Run it backward also.

I thought that you had a picture of your mustache bar end bushings somewhere, but I can't find it (edit - found it, #10 here http://www.classiczcars.com/topic/58053-worn-transmission-mount-best-replacement-video-inside/ ) They looked kind of loose. They can move many different ways. (Had a different description here but the forum ate it). Buy you can't swap n the urethane without destroying the rubber. So that's a big decision. I tested mine by getting some big washers at the hardware store and inserting them between the rubber stopper and the bar, to clamp the bar ends down. It stops the up and down but the sideways motion is still possible. But it did reduce the thump. U-joints are really hard to diagnose. You need to stick a large screwdriver in to the joint and reef it around. Moving a wheel by hand or twisting the propeller shaft and looking for movement at the u-joint doesn't really cut it. The joints are under very high loads in-use so you're not going to break them with a screwdriver. Look for gaps at the seal, red rust dust, or just wiggliness.

Here's an 81. It looks just like a 78 that I also have. carpartsmanual shows a change in the L24 engines but doesn't give a year. Sorry to get the thread all oily. It's just a spare engine.

One improvement I could see from reversing flow would be the ability to clean the "steel net", that you would be adding if you matched the system design, in reverse. I think I've mentioned this in other threads but we used to build mufflers for our vacuum pumps in chemistry lab so that the exhaust vents wouldn't blow oil vapor. We packed a piece of pipe with steel wool, just like you show in your post, and attached it to the vent. Without it, there would be a steady oil mist whenever we pumped a vessel down. But in order to match what Nissan has you'd need a very large filter/separation chamber on the valve cover side. More than just a flame arrestor sized piece. Might be bale to build one inside the valve cover. To take the geekiness in another direction, it would be nice if the steel net in the block had easy access so that it could be removed and cleaned. I imagine that as it gets gunked up over the years, it loses surface area and becomes less effective, letting oil vapor pass through. Could be why some old engines end up with a lot of oil in the intake manifold. My old 76 engine was wet with oil in the intake. You'd have to cut a whole in the side of the block though, or add a filter box to the end of the pipe that goes to the PCV valve.

The reverse flow is described in the text, but that would have been a really big image (like your steel wool image). It's also illustrated in later FSM's with arrows. Funny how Nissan seems to expect a lot of blowby, sooner or later. I'll take a picture of the inside of the ZX cover and post it, just for fun. They were fine-tuning things in the ZX cars, like using a slightly smaller throttle body. Counter-intuitive, why bother kind of things.

Didn't you just finish all of the work to put that in your car? What happened? Did you ever get to try it out? Just curious.

Also notice that 1972 doesn't show the flame arrestor. Maybe it's an EFI thing only. Edit - it's added in 1973. Maybe they had a few problems in 72... Oddly, they moved the PCV description to Engine Tuneup. Sorry for the distraction. Seems to fit the geek factor though. No offense.

Might be interesting to compare a 240Z baffle to a 280ZX baffle. See if Nissan did any tinkering over the years. I have an 81 ZX engine in the garage.

There's a measurement shown n the Rear Axle chapter. 9 mm and 2 mm. The instructions are kind of odd. I think that they're trying to describe a range. Once you get past the diff mount and the u-joints then every other rubber part is suspect, along with bearings and nuts and bolts. Somebody recently described how their sway bar bushings were causing a clunk. Loose strut inserts are fairly common. Maybe your diff is worn out, they're durable but it happens. Someone described the small bushing in the hub casting being completely disintegrated, causing a clunk. Many possibilities.

I have an easily accessible valve cover and a camera if difficulties are encountered. I was part of the dialog in that other thread. Interesting topic. I hate changing my oil.

No offense intended. Better to hear it early than late. Looking forward to watching the build. Carry on.

Now I feel bad. Until I think back to all of the unsafe things I did at 16. Besides that, the bling factor is strong for that tank. Seems way early in the game to be buying and installing a fuel cell. The path of bling is fraught with peril and expense. You'll need Triple A, for instance. Or friends with a Z car bolt pattern, close by.

Ouch. We do sound kind of harsh. But, he says he's planning to be an engineer, and this is the kind of stuff engineers do. The fabrication and installation aren't too bad, but the engineering is poor. Those six clamps on the strap steel will let go in a second, I'll bet you can pull them loose with your finger tips right now. Then the strap bends will open up and the cell will rise up and is flopping around on the ends of the braided hose. Engineering is a state of mind. Critical thinking. Digging in to the fine details. https://en.wikipedia.org/wiki/Bulkhead

Besides that, if you ever plan to race it, it won't pass inspection - 9.3.26. https://dk1xgl0d43mu1.cloudfront.net/user_files/scca/downloads/000/022/824/GCR-_Updated_July_2017.pdf?1498667032

You avoided the question about if it moves,and ignored the issue of lines getting pulled. I went to school with two sisters that had been in a house fire. All you could see of their faces was lips and eyes. The rest was covered with a protective mask. Seriously, your installation is terrible. Your friends and your mom might have been doing it that way for years but when the gasoline is leaking after an accident you'll wish you'd done it differently.

That makes sense then. Good luck. On that note - just curious - but if you reach in to the car and push forward, backward, or sideways on your fuel cell, will it move? The two strap system looks like it could use a bit more engineering. And, safety-wise, the tank is inside the cabin of the car, which is generally a bad thing. Leaks, hoses torn loose (they're exposed on the outside), and accidents can all expose everyone inside to raw gasoline. Sorry to pick, but it is what it is.

I thought the car already had an RB25 installed. You might rethink the RB part. It's an exotic engine from an exotic land and costs exotic money to get it done and maintained. Lots of extra work just for "RB". No offense to any RB guys that have already done it. It's a challenge, but not a good one for someone who doesn't have a load of cash to spend on it.

My theory about the diff clunk has been that it's the diff mount metal dropping down and contacting the crossmember metal. So, even though the snubber might stop the lift, it might not stop the compression downward. I ran some tests when I had clunking, by stuffing pieces of rubber inner tube in to various areas. One was to jam it in to the gap inside the mount, which will lift it and stop it from dropping. If it works, you need a new mount, like the transmission mount. The other cause of clunking is bad u-joints.

That was prime time for California Datsun. Is it one of his? Known for sandy parts. Part of the shining process.

Might be a 280ZX L28. They run much higher advance and that timing tab has an extra 10-15 degrees over my 76, with AC, pulley. The pulley diameters are different than mine also. What are the block and head numbers? F54 and P79 (or P90) are ZX. Edit - except 79 and early 80, which are still N42 and N47.

Everything looks right. Sounds like your old coil just went bad. Your MasterPro coil is right on spec., should work fine and last long. 246Blue won't like it, but it's the world we live in. Google says lots of good things about that coil. Here's the 1972 specs. which should be common across all of the points ignition systems.

If I recall the 240Z circuit right they have the a resistor before the tach and the coil is after the tach. Seems a weird way to lock the tach and coil together in to one circuit. If I had a 240Z and had this problem I think that I'd run a separate power wire to the coil, in parallel with the tach, and then add a potentiometer (rheostat, whatever) to the tach circuit. Use a resistor or the coil itself to determine overall coil circuit resistance, and the potentiometer to control the current through the tach. Seems like the main problem is getting the right amount of current through the tach. I don't know if the problems described are too much or too little. If it's too little then this wouldn't work. SteveJ, or CO, or Mark M or Dave WM or one of the other guys that thinks about electrons alot might have some thoughts on it.

Mike LOVES these kinds of problems. @Mike

It's called a "float" bowl because there's a float inside that moves up and down to seal the fuel inlet and maintain a certain fuel level. A floater in a bowl is a whole different thing. Your fuel direct from the tank doesn't look terrible. There shouldn't be crud in the float bowl though. A simple filter before the carbs should keep the fuel clean to the carbs. Silicone on a carb float bowl is almost always bad. It means somebody did a half-job. You don't want any broken gaskets on the carbs either. I'd get some new gaskets and clean and reset those carbs to spec. myself. then reinstall them with a good fuel filter to keep things clean. Just for starters.

To Detroit or England (shipping docks)? Thought your brother was going to hoon around Michigan for a while. Interested in what it takes to get it to England. Could be educational. That floorboard rust is still wet. Leaks! Common.