Captain Obvious

Simple... I wouldn't have to create anything. I'd use a boring head who's purpose in life is to do exactly what you described. And if your mill is R8 native spindle, you can skip the collet as well. Use a small one (like 2 inch) and dial it in. Easy-peasy. And as for the centering, I wouldn't mess around with that either. I'd whip out the Blake co-ax and indicate it in-situ. Blake is expensive, but there are far-east options that won't blake the bank. If you don't have a boring head, or a co-ax, you could resort to a fly-cutter and an edge finder.

I got this available:

I took a look at the FSM to refresh my memory, and the ring gap should be measured at the bottom of the bore where the wear is the least (77 manual EM-15 bottom left). Makes sense since what you really don't want to have happen is for that gap to close up to zero when things heat up. You're a couple thousandths smaller gap at the bottom of the bores, right? I'm no engine rebuild expert, but I think you're fine.

Wait... The earth is a toroid?

I just looked up the SDS for Purple Power, and the main cleaning agent is sodium hydroxide (lye) which can be an issue for damaging aluminum. Looks like a quick ten minute spray and rinse is OK, but I wouldn't dunk the pistons in it and leave them overnight. 1. Sodium Hydroxide 25% Concentration 3 - 4 % (weight) CAS no. 1310-73-2 2. Chelating Agent Concentration 1 - 2 % (weight) CAS no. 67401-50-7 3. Diethylene Glycol Monobutyl ether Concentration 1 - 2 % (weight) CAS no. 112-34-5 Notes - I looked up the chelating agent and it's Ethylenediaminetetraacetic acid (EDTA) and the last item is an organic solvent (2-(2-Butoxyethoxy)ethanol. Reference - https://f405ae25-bd48-4e9f-92a9-0f03256f19bb.filesusr.com/ugd/14ad0e_342940d078d94505b11d1358c997718c.pdf

Clean enough to eat off of!!

I pulled my ultrasonic off the shelf a couple days ago to see if it was large enough to fit the piston top inside to clean the ring grooves, and it's not only large enough for that, but it's actually large enough to accept an entire piston AND rod. Sounds like I should get myself a bottle of Purple Power as my cleaner liquid for the US!

Question for the collective... So what was the deal with this car? He bought it at Mecum for 12.5K (plus buyers premium) in April and everyone went nuts for the car saying "He stole it at that price" and he could instantly flip it and make $$thousands$$: https://www.classiczcars.com/forums/topic/62036-my-mecum-purchase-1972-240z/ He put about $4K into it: https://www.classiczcars.com/forums/topic/62036-my-mecum-purchase-1972-240z/?do=findComment&comment=577203 And then started trying to sell it in July. Didn't sell for 25.5K: https://www.classiczcars.com/forums/topic/62553-saturday-houston-auction-of-my-1972-240z/ Didn't sell for 23.9K and didn't sell for 19.9K: https://www.classiczcars.com/forums/topic/62704-for-sale-1972-datsun-240z-23900-or-best-offer/ And then in the end, it finally sold for 15K plus commission: https://www.classiczcars.com/forums/topic/63201-auction-for-my-72-240z/?do=findComment&comment=588925 So I've passed on a couple 240's because I wasn't sure I could get my money back and ended up kicking myself a little later because they sold later for a good profit. But then this example comes along and that does not happen. Anyone have any insights as to why? Is it just a fickle market?

I think that comment is simply a reflection of the available ranges for current measurement. Those reviews look to me like they were written by "electricians" who spend their days working on 120-240 AC circuits. House wiring and appliances. They are making a distinction between that type of work, and the "electronics tech" sitting at his workbench troubleshooting a radio. They're implying that the guy working on radios might need something better for measuring low currents in the milliamp or microamp range. My thought is that even though there are some "really small current" devices on the Z cars, I don't think most people would need a meter to mess with them. Things like fixing a radio, or the clock. And that other stuff about spurious "ghost" voltages and stuff? Scares me more than it seems like a feature. Best I can tell is they're saying that "ghost voltages" are sources of voltages that have a high source impedance. Goes like this... Your normal voltmeter draws very little current in order to make it's measurement. In fact, the lower the better. You want to draw very little current, because any current you draw with meter will affect the reading. But they're saying that in "electrician" work, you can run into the situation where you might read a voltage on something (their video measured 4V between H and G on a power strip), but they're saying that if you switch over to their "LoZ" range, it will show you zero volts. The implication is that when you apply a load to that voltage, it drags it down to zero because the source impedance is so high. Frankly, I'd want to know where the high impedance bleed over is in my circuit that is allowing me to read 4V where I should be reading 0. What's the threshold for ground fault interrupters anyway? The 117 also has a non-contact voltage alert range, but I'm sure you've already got a pocket sized non-contact indicator you've been using for years and already trust. I'd just stick with that. Personally, I'd always measure it before I go sticking my hand in there, regardless of what a non-contact indicator says. My bottom line? I don't think there's anything on the 117 that you would need over the 115 unless you want to toss out your old non-contact indicator and want to start taking the 117 to the job site.

I'm thinking our introduction to tranny wrestling occurred at about the same time and on the same vein of cars. Ahhhhhh... the smell of gear oil in your hair. Good times... Good times!

I'm not sure what they mean by "consistent spurious currents". Have you got a link to the discussion?

You've got a lathe, right? That bushing should be easy-peasy!

Perfect!

Haha!! I've always done the same thing. For years, aligned clutch disks by calibrated eye and fingers without an alignment tool. Lost track of how many. Then once I actually had an alignment tool for whatever I was working on at the time and felt like I was cheating. And your note about turning the output shaft was exactly what I was getting at about the futility of trying to align the rotation of the input shaft to hit the splines perfectly. I've always used the "put it in gear and rock the output shaft around" method. The worst you can be off is half a spline width. I've had trannys go straight in without a fight, and I've had them where I had to wrestle them for a frustrating amount of time before getting things to mesh.

Couple questions and suggestions. It's been many moons since I've pulled the tranny out while leaving the block in the car... Once the tranny cross member has been removed, isn't it necessary to support the rear of the engine to keep it from rocking on the two side engine moutns? Block of wood on a jack under the oil pan or something? Or is a support under the front pulley? I don't remember which direction the engine wants to tip. Other things? You don't need an alignment tool to remove the clutch plate. It'll drop a little bit once you remove the pressure plate, but no big deal. No need to mess with the alignment tool there though. You got two hands. And when putting the new clutch plate into place, I'm not sure the clutch alignment tool fits through the spring fingers of the pressure plate. The reason that 's important is that I think you might have to put the pressure plate on first. Loosely into place before you reach in and lift up the clutch disk to slip the tool into place. But again, been many moons. This step "Turn clutch tool to match trans input shaft as best as possible." I think is an exercise in futility and optimism. I don't think you can align the splines rotationally by eye before trying to fit the tranny into place. And even if you can, wouldn't it be a lot easier to turn the transmission input shaft to match? Haha! Lastly, You used the word "hammer" a bunch of times. I would prefer the word "tap". It's semantics, but if other people are thinking of using this procedure, I think it conveys a better mental image.

Looks pretty! I would clean the paint off the oil washed surfaces though. Especially the pressure relief valve. I worry that the paint will come off that ball once bathed in hot oil. Probably not enough paint to really matter, but just for the insurance, a little carb cleaner on a rag should wipe it off. That's just me. :)

Wow. That's quite the failure. So on a good selector fork, the only thing that contacts the synchronizer slider sleeve is those two little plastic pads on the tips? Woof. Is there a thinner grooved channel worn into the side of the slider where the rivet heads were located? Or are the rivets so loose that they just slide back forth inside the fork? And on the steel forks... It looks like they don't use plastic pads at all? Seems like a much better (albeit more expensive) design. Wonder if they changed it to make it cheaper or quieter (or something else).

Is the cheapo HF scale good enough to do the weight matching? Mine has resolution down to 1g (in theory). I have no idea how accurate it is on an absolute reading, but it ought to be reasonably good at relative (comparative) measurements. You don't care much about the absolute number... You just want to see if they're all the same.

Agreed. Those pistons look fine to me.

LOL. Yeah, there is that. There are lots of relays in the world, including plenty that pull in at an appropriate voltage. But you won't find them at the local parts counter where everything is expected to work off 12V. You'll have to go somewhere like Digikey as SteveJ suggested. Or, as suggested, change the actuation source to somewhere else that would work easier with a 12V relay.

The reason you aren't getting enough voltage to consistently trigger FPR1 is because of the way the "N" terminal works. Clearly academic, but just in case anyone wants to know... That "400 RPM" cutout is a bit of a misnomer. They use the "N" output from the alternator to pull in the fuel cut relay #1, and that "N" output from the alternator is actually the "Neutral" connection of a three phase "Y" connected generator. The voltage on this neutral output is the normal alternator output voltage divided by the square root of three (about 1.73). So for example, when the alternator output is twelve Volts, the neutral wire should have about seven Volts on it: Datsun assumes that by the time the engine is spinning at 400 RPM or higher, the alternator is up and operating, and the voltage on the neutral output is high enough to pull in the fuel cut relay. So you need a relay with a pull-in lower than 8 Volts in order to be guaranteed to pull in with the L-N (Line to Neutral) voltage from the three phase alternator.

I got nothing technical to add, but wanted to say this thread is awesome.

LOL. Well it sounds like Anthony is making progress regardless, so whatever works!! Maybe we are helping?

I feel like we're coming in at the middle of a story... What's "the yellow". Is there a yellow wire going to your relay? What relay? @SteveJ, You're already on top of this one?

The pull-in voltage is the voltage at which the relay will be guaranteed to pull-in. So a relay with a pull in spec of 8v means the relay is guaranteed to actuate if you put 8 Volts across the coil. Less voltage might not pull in, but eight volts is guaranteed to pull in.