Zed Head

Your diode wire would be the upright part of the "T". This a 78 drawing so wire colors are wrong, but the T and S orientation is common across the alternators.

The Dave Irwin adapter converts one of the 71 wires to an "L" wire. Here's a schematic from the 1978 FSM. 1978 was the first year of the internally regulated alternator. Interesting (to me), I just noticed that there is a resistor inline with the charge lamp. In the past I think I've seen discussions about what happens to charging if the lamp burns out. Apparently, nothing. Charging still happens. In your case, when the diode opened, there was no current through the stator coil. No magnetic field was produced so no charging happened.

The other components, the rest of the system overall, could be tested by bypassing the diode. A simple jumper wire or alligator clip could do it. Probably have to kil the engine by pulling the coil wire. Then - how to fix it. What type of diode, how to solder or crimp? Or just buy another from MSA.

https://bringatrailer.com/listing/1972-datsun-240z-358/

So this is not the factory setup for a 71? Does it have Dave Irwin's internal regulator modification?

I don't know 1971 but on a 1976 the charge lamp lights when the key is turned on aa a circuit and bulb check. It grounds through the alternator edit- external regulator then turns off when charging exceeds battery voltage. It should be battery voltage with the key on and the plug unplugged.

Thanks, and that is interesting. Google Translate serves its purpose well. Is there a Japanese Wikipedia? Any thoughts on where that "new" N42 casting comes/came from? There is a disconnect between ATK Vege (which seems to be a combined company, looking at the logos and the descriptions) and the KSS that comes up through that Japanese ATK link. 1936 versus 2003. North America versus Japan. From the web pages - https://atkvege.com/about-atkvege/ About ATKVegeATK North America is the largest private label Crate Engine Remanufacturer in North America. Partnered with our sister company, VEGE de Mexico, ATK VEGE has a history of Remanufacturing that dates back to 1936. https://atk.co.jp/company/ name KSS Co., Ltd. Representative President and CEO Keiji Okawa Established August 2003 Capital 3 million yen

Don't overlook the winding wire. At the T plug on the back of the alt. One Sense wire, One Lamp wire. The Lamp wire needs good connection. I've had the spade connector get loose and lose conneciton. No charging.

I think that the poor painting is probably becuase they are rebuilt engines. It's interesting that there is so little on the WORLD WIDE WEB OF DATA about ATK. Not even a Wikipedia blurb. https://atkvege.com/about-atkvege/ https://www.lkqcorp.com/?s=atk https://www.lkqcorp.com/blog/2011/12/14/atk-vege-engines-yamato/

That's good info. The OP was in Lithuania. I wonder if Tony D's explanation was half right except that maybe Nissan produced modified castings for sale to rebuilders or for their own rebuilds. Tony D suggested that the ports were welded and machined but the casting sprue suggests that they were cast that way. I'm no expert but I don't think that you could cast molten aluminum over old castings and get a good bond, besides trying to match properties and the post-machining involved.

Since you're in experimentation mode and you have fabricating skills, you might remove the factory mount and fab up a new mount that gives the desired angle. It wouldn't need to be super strong or made for permanence if you're only evaluating cruising speed. Keep the strap in place in case of breakage. It could be a solid mount. If the angle is perfect but the vibration is the same, then you can start looking elsewhere. The RTz mount either gives a certain angle with the GM mount, or it gives a range of angles in use with the snubber, as the diff nose moves up and down. The GM version is an actual mount, the snubber version is essentially a solid strap. p.s. have you considered mounting a camera under the car to see what the diff nose is doing while driving? Maybe something is moving. Or, looking back at your pictures of the crossmembers, why don't you just shim the crossmember mount downward with some washers. Perfect the angle, take it for a drive. then you'll know if you should go further.

Somebody called datsunparts bid $2200. There's a business called datsunparts, looks Roadster focused. Might be worth more parted out. Those exhaust ports are weird. Maybe it's a "detuned" L28 for a different model. Maybe the Z's got the good stuff. https://datsunparts.com/

Found a picture on BaT. #138 shows a condenser on the back of an alternator. Bring a TrailerNo Reserve: 1972 Datsun 240Z 4-SpeedBid for the chance to own a No Reserve: 1972 Datsun 240Z 4-Speed at auction with Bring a Trailer, the home of the best vintage and classic cars online. Lot #181,834. Uploading Attachment...

Still in the crate. Has odd exhaust ports. Has anyone seen this before? Also has an odd "temperature sensor bung" that looks like it was welded on. Maybe for use in the 280ZX? N42 heads didn't use the cylinder head temperature sensor. Bring a TrailerNo Reserve: Datsun L28 Crate EngineBid for the chance to own a No Reserve: Datsun L28 Crate Engine at auction with Bring a Trailer, the home of the best vintage and classic cars online. Lot #190,091.

Do you have a Nissan factory transmission mount to try? Maybe you're fcoused on the wrong member. The T3 mount is the only "non-factory" part.