HS30-H

Ben, did you put your hand underneath the bonnet extension panel, ahead of the bonnet? That's where the strengthening ribs are on the original factory panel. Some of the photos of this car showed that panel to be slightly ill fitting/distorted. If there were no ribs it could indicate a later replacement. Great story by the way. Believe. You'll get there.

Evidently.

I think you should try to properly diagnose the problem, and fully understand what exactly is wrong, before writing off the strut and searching for a replacement. Take it off, take it apart, use Mk.I eyeball and whatever measuring equipment you have to hand. Get to the bottom of the issue. I'd treat them as a matched pair and do them both, in fact. Devil's Advocate:

Those are cobwebs, not cracks. My money's on this being something less dramatic, and fairly easily cured.

Kats, I have a 1968 factory manual for the (pre-'A') L20 six which has a nice layout drawing for the H130 Cedric's engine. It shows our early-type 'reservoir bottle' plumbed into the top hose area, a long way from the radiator cap. Clearly any pressure-relief type radiator cap that might be fitted on that particular model did not affect the function of the reservoir bottle system:

It's more likely to be something else entirely. A bent spindle would possibly cause all sorts of other problems, not least of which would be hub bearing trouble. I don't see it as the likeliest scenario here yet, so don't do anything rash. You need to fully understand the problem before you make any attempt at rectification.

The strut tubes are indeed welded to the spindle casting/forging. If you invert a strut and look at the end where the knuckle is bolted onto it, you can clearly see the welded joint. I can't imagine a tube being welded on at the wrong angle and passing quality control.

This statement would benefit from having a little bit of sunlight shone on it...

I think we are on the same page there. But for Kats' installation on his blue HLS30U, he is using the later type reservoir bottle and that means an unpressurised bottle, one-way system. It looks to me as though Kats is getting quite a lot of coolant in the reservoir bottle. More than I would have expected. Japan has been pretty hot (to say the least!) lately, so maybe the cooling system is struggling to keep up? Kats, is the pressure rating on your 240Z's radiator cap quite low?

My (early) version of the bottle - which came with a radiator-type pressure cap - would theoretically be suitable for that type of setup, but I just can't see a scenario where the pressure in the 'reservoir tank' is higher than that in the engine/radiator - allowing coolant to flow back? Here's the factory parts list showing the 432/432-R system: If you look at the radiator cap, it seems to be a simple sealing cap with no pressure relief valve. In this setup, the pressure relief cap is on the 'reservoir' tank. I think this would allow overflow/cavitated coolant to pass from the radiator into the reservoir tank, with excess pressure and/or coolant to be vented via the drain tube. The pipe connecting the radiator and the reservoir is radiator hose type quality, pressure resistant and with proper clips. Nissan clearly did away with this system later, using a simple cap on the 'reservoir' (it has a small hole in the top to vent air) and a normal pressure relief type radiator cap. The later GT-Rs were like this too. My KPGC10 has a slim, unpressurised overflow catcher tank next to the radiator.

Kats, the S20-engined cars had the tank/bottle acting merely as an 'overflow' catcher. There is no return path to the radiator as the coolant/air can only move in one direction so it's not the same as a 'header tank'. Generally speaking, it was a characteristic of high rpm/high performance engines of the period for them to cavitate their coolant somewhat, and the tank is simply a way of avoiding the slightly embarrassing scenario of, er, uncontrolled spillage... Nissan called it a "reservoir", but as far as I can see the only way that it can be used as such is if you manually pour the coolant caught by the "reservoir" bottle back into the radiator when it has cooled down.

Kats, The good news is that you don't have to drill any holes in your HLS30U for the mounting bracket. Nissan very kindly put them there for you...! I was lucky to pick up an 'early' type overflow bottle for my 432-R replica project car. Actually, I rather like that yellowed age to the nylon part. I prefer to keep it like that. I tried to put as many genuine 432/432-R parts on the car as I could, but it's a very long list.

McDonalds, Kentucky Fried Chicken, Starbucks, Universal Studios Japan and Tokyo Disneyland. Apart from that, you're pretty safe.

The 432 does not have a mechanical fuel pump. It has only the electric pump. How would it "run fine" without the electric fuel pump - its only fuel pump - running?

The 432's exhaust manifold is stainless steel. It is not ceramic coated. You may have missed the point that the inlet side of the S20 engine - being a twin cam 'crossflow' design - is on the opposite side of the cylinder head to the exhaust side, so the exhaust manifold dos not heat up the carburettors or the rest of the fuel system in the way that it does on the L-gata engined versions.

Tried for some better shots:

Full ignition system illustration from 1969 Nissan 'Service Shuho' publication No.184:

The original plug HT leads were individual part numbers 22451-A0203 (plug no.1) through 22456-A0203 (plug no.6) and they came ready to fit with both ends complete and including the boots for the distributor end, the long plug connectors and the rubber seals that go into the cam cover. They were individually numbered for each plug, also dated, and with makers name SUMITOMO, all printed in yellow on black wires. The long HT lead from the coil to the distributor cap was part number 22450-E4200. Here are some (not very good...) photos which might give you an inkling of what they looked like: If you're chasing factory period-correct original you've got your work cut out. The ignition system is a recent (Ultra?) system, you need a cloth-covered top hose and the Tsuchiya service sticker for the air filter should be on the top of the air filter box itself (in front of the radiator) not on the duct. Couple or three non-factory drilled holes there too (annoying, isn't it!?). All an easy fix, apart from the holes - and I'd just stick grommets in them and not worry. You might be able to get the correct leads from REVIVE JALOPY or RUBBER SOUL in Japan. If they can't supply the correct, Sumitomo printed, version they should be able to supply a decent replica in black, which will certainly be far more pleasing to the eye than blue or red.

There were four in the header rail adjacent to the interior light recess too. And then there's the captive nuts pre-installed in the radiator support for the factory oil cooler brackets and the holes in the radiator support crossmember for its 'feet'. There are also holes in the radiator support crossmember for the 432's air filter box and radiator overflow bottle. Lots of - shall we call them 'hermaphroditic'? - details to accommodate both LHD and RHD configurations too...

From the yellow 1970 Nissan Sports 'Race & Rally Manual':

It was a nice article for the time, and a valiant effort to get into the details of the car, but lots of little 'secrets' went over their heads. These cars were far from standard, and what they were actually looking at was effectively a super lightweight 432-R type bodyshell with an L24 installed. That L24 was far, far from standard (not surprising that the Works team played their cards close to their chest) as it had a different crank, rods, pistons, oil pan, flywheel, clutch, cam, modified E31 head and all sort of other little tricks. Very deep subject.

You might want to check the bag on that Hoover. It sucked up a picture of a different car on a different event. As you can see on the door, this is from the 1972 RAC Rally and it is a different car.

The man with the clout was Mr Ewold van Bergen of Nissan-Datsun South Africa. Very influential and much respected in Japan.

In a nutshell, yes. I believe that's the most simple and logical explanation, and all the evidence - including that for other Nissan products - points that way.