Unusual rear frame structure

[jabingb]

I recently borrowed a frame to better understand how a potential electric conversion might be laid out, putting on fire suit. But this question is about said frame and what is usually a tubular connection from the bottom of the rear towers to the rear of the bottom frame channel, take a look.

This is so reminiscent of bulkheads on 18/21/23s, etc. Surely this was someone's idea to either strengthen or repair the existing tube but it's so well done I wonder if anyone has seen this before, just curious.

[baileyman]

And a curious cross brace up front?

John

[nmauduit]

I would bet this frame has been welded so these mods would be non original, even from the photo several welds look obvious so direct scrutiny should confirm you that. You may wan to take measurements to check if that frame is square and close enough to the dimensions provided in the manual if you plan to use it a an accurate pattern...

[Donels]

I wonder if it's an early prototype subframe. Might be worth an email to Classic Team Lotus.

[vstibbard]

I’ve seen various mods like this on Elans that have been used in competition, typical one is gusset between the top joint to chassis and same between bottom of tubes.
Vaughan

[MACCA.GLM]

Never seen anything like that on a lotus or spider chassis.
I think a home made modification to give better access to the diff

[bitsobrits]

Is there a chassis number visible that might give some insight into the age? That bracket looks to be very well made, and indeed very much like a Lotus factory piece, so I'm in the 'prototype chassis' camp.

[Mike Ostrov]

Hi, guys. I too would like to understand the source of the chassis, as it is one of my three spares of which I have many suspension (3 sets of rear arms, for example) and Twin Cam spares for anyone having a need. Just please send me your wanted list to: mikeostrov "at" webtv.net or give a call: 510-232-7764

I had a S2 and S4 FHC complete, in pieces and purchased a few rolling chassis to use for the creation of my two Elite/Elans. The Elite/Elan MK I has a Coventry Climax FWB (1460 cc) with a Datsun 280 X 5 speed and fully adjustable Elan suspension on our 15 inch wire wheels. The Elite/Elan MK II has a 1725 cc Stromberg Twin Cam in front of a C-4 Ford automatic with a 3.54:1 differential ratio. Same suspension and wheels. Just a nice cruiser. I painted them both the same color. The C-4 is vacuum operated, hence the use of the Stromberg head with European high balance tube to supply the vacuum source. My Weber TC which is reserved for installation into one of my last Elite restorations. I used only the early chassis or frames with the 7 degrees of castor, which is the same as on our Type 14 Climax Elites.

So, wish I could offer any background on this unusual chassis. The mystery continues.

Cheers. Mike, enjoying some cherry pie and chocolate milk at 03:08 before breakfast. PS: just found in the shop corner an old Mac Tilton alloy Twin Cam flywheel. Weighted in at 7.2 pounds or so. It was stacked next to a Tilton alloy flywheel for my Coventry Climax engines. Must be a hundred yeas old!