RESTORING a 50s Seven 750 SPECIAL

[JonE]

OK, I'm onto waterpump necessity and researching! It does have a fan, Howard and the remains of a heat sensor (lying on the head) which I imagine goes off to the temp gauge on the dash. The engine must have been swapped at some stage. What I need to understand is the relationship between the fan (haven't worked out how that is controlled, but there isn't an obvious switch for it), an electric pump and a sensor which I imagine is some housing in the middle of a bit of main hose at the top of the engine? And whether all this can interact with the in-hose thermostat mod? Will a wiring diagram from a 40s of 50s car, say, help?

I've also seen a picture of Ian Clayton's former 750's interior, where the cabin floor is below the chassis members. After getting the transmission tunnel out yesterday and also finding the date stamp on the rear axle is 2/34, I find a serviceable fabric/carden prop and a messy space underneath with amongst other things, a heavy 18" square of 60's carpet! I'm intending to drill the rivets from the floor and lift the panels to get a better idea of how I wcould attend to the springs in future. And seeing if the seats could go lower in the car by eliminating this upper layer. It seems artificially high, but I don't think it can be.

[Chris KC]

Don't know Jon, I think it looks rather nice on wire wheels.

I would be wondering how old those tyres are though...

[JonE]

Starting to uncover how to get to the oily bits which need maintenance. Pop rivets everywhere and I now find that the floor is riveted from the underside, upwards, to the frame for the rear suspension, which in inconveniently just where I'd like to get the seat lower.
I'm wondering about cutting the floor from above to expose the spring to see if replacement/taking out is possible with access entirely from above. Ian Clayton's former car just had the undertray as its floor, with the chassis exposed in the cabin.
Some of the frame which is bolted to the floor is welded into the roll bar structure. but could some of it go, perhaps? 

The rear axle is dated 2.34 but NO marks below the date signifying ratio or serial number. Has anyone come across this on a D Axle before? There is also a '2' stamp on the top of the connection to the pinion/TTube section. Wondering if the chassis could have Nippy routes but haven't got to the crossmember ends yet.

           

[Ivor Hawkins]

  DXX 401web.jpg (Size: 66.15 KB / Downloads: 245) Great car Jon, I think that could be lots of fun with very little work...Not wishing to go against everyone’s recommendations, but I ran a Super Sportsman for a number of years, which had an HC motor and twin 1 inch SUs a cross flow radiator, which was very small and an aluminium header tank mounted just ahead of the bulkhead and had no issues with overheating despite not having a water pump...I would say go for it and watch the temperature...you won’t need a temp gauge, you’ll be able to feel if it’s getting hot through your plimsolls!

[Renaud]

I suppose a crossflow rad is one where water runs from one side to the other?

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Hi jon,
"I'm wondering about cutting the floor from above to expose the spring to see if replacement/taking out is possible with access entirely from above. Ian Clayton's former car just had the undertray as its floor, with the chassis exposed in the cabin."
You most probably know that that is how all the Lotus 7 were made too. Other Lotus also.

[Ian Williams]

Jon, it is hard to tell from the pictures, but I am thinking the roll cage and subframe we can see bolted to the floor are owner additions rather than part of the original Speedex frame structure. Not sure that roll cage would do much and it would probably not comply with any current regulations, you are also not going to be racing it, so perhaps remove the whole thing and then rethink the floor and seat back area.

[Nick Lettington]

Jon already knows this, but the frame was available to bolt on to the chassis and supports the top of the telescopic shock absorbers. The Roll bar can definitely go!



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[JonE]

Ian - here is a Speedex pre-Ruby rear suspension frame on the right hand wall... (courtesy of Speedex Info Exchange)
Mine could just "look a bit like that" though... but presumably the floor bit must have some function in bracing the bit with shockers on.
I'm just surprised that it was designed precisely where you might want to get a seat base lower into the floor.

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[Ian Williams]

Okay thanks for that information, I have never studied a Speedex in detail before but do wonder why the sub frame is braced across floor in such a way, I would have thought it better to tie it into the chassis. I think I would be looking at a way to alter this but Jon I do understand if you wish to keep things as per Speedex supplied parts. The big failing as I see it of many of these 60's body's is that in some cases drivers wear them like a skirt rather than sit down in them, I would be looking at ways to improve the driving position by lowering and reclining the seat.

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it would be easy to drop the section that is currently above the floor down to crossmember height and tie it into the side of the chassis and crossmember.

[JonE]

The subframe is definitely shaped so it could tie to a side of the chassis member. But if it were, the suspension mounts would be lower than the upper deck height...
My personal lockdown is being lightened up by my new weight-saving list.
front and rear plates 400g
bolts found in undertray 10g
unused brackets 40g
paint scraped off two panels (say 10g)
I do also keep eyeing up the (heavy) 6V battery and thinking that I could construct a small room for overnight stays in its present space....

Was amused on hearing a story about Colin Chapman making cost savings for the Seven s2, Renaud. Apparently he just kept chopping frame elements out a sturdy S1 until it eventually collapsed... and then added the previous one back in. I presume that's probably an urban myth.