XK120 OTS Centre of Gravity / Rotisserie construction

Has any one thoughts on using a rotisserie on a FHC ? It will be a bit more tricky than an open top as I doubt it could be skewered down the tunnel. I wonder if I could adapt this to work ?

Well Jim, here is one similar with a MK 1 mounted so a little FHC
E will present no problem.
Peter B.

Thanks Peter
I was thinking it would mount without the chassis
but perhaps would work better left on .

The frame weighs more than the body shell so you would need a more robust rotisserie than the one I fabbed. The frame would get in the way of working in some areas though the advantage would be superior support for the body and you wouldn’t necessarily need to have the bodywork mostly completed to provide sufficient rigidity to suspend it. You could also go with a full 360 degree rotisserie by tying in your mounts to the frame itself rather than additional supports for the body shell.

I opted not to go with a full 360 degree rotisserie as it would have taken additional bracing fore and aft to minimise the unsupported length of the shaft and to reduce the moment loading where it attaches to the cockpit bracing. I see no reason the FHC couldn’t be mounted in the same way I mounted the OTS, though. You’d be a little top heavy with the fixed roof but the weight distribution can be balanced with counterweights lower down.

Hello Nick,
I’ve been following your progress on your XK120 with much interest and envy. I’m almost ready to start on mine and am really keen to get on with it.
It’s a pretty good driver so mechanically it will be fairly straightforward - no need for an engine rebuild, just stop as many oil leaks as possible, renew welsh plugs, repaint etc.
But it will be a full body off resto otherwise.
I’m thinking I will strip the paint/filler and fix the door hinges, get body gaps reasonably close before removing the body from the chassis and placing it on some sort of rotisserie.
And there’s the rub. Rather than reinvent the wheel, I was wondering whether you might post your photos of the bracing you built?
Any tips regarding order of things would also be greatly appreciated.
Thanks in advance for any help you can give and for your time.
Good luck with yours.
Garry

Here is my version


Jim

Hey there, Gary. I took several videos of the cockpit bracing and rotisserie construction last year but haven’t got around to sorting them out for posting. Other priorities. I’ll be reuniting the engine/gearbox and frame this week followed shortly thereafter by dismounting the body from the rotisserie for placement on the rolling chassis and will thereafter have some free time. Thanks for the prod.

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Thanks Jim
I hadn’t thought of doing it that way. That would do away with the need for bracihg the cabin internally. Which would make access to that area a lot better.
Thanks for the idea.
Cheers
Garry

If I’m remembering it right, Garry, yours is an OTS which has, needless to say, a not entirely rigid body structure. If you were to draw sections across the body, where the profile features the least amount of steel is where it is structurally weakest, in this case the point at which the sills meet the door shut panels (red circles in the pic below). If you lift the body off the frame without first stabilising it the weight of the rear clip will bear down on those two weak points and the body will flex and twist. You might afterward be able to get things back into precise alignment but it would be much, much better to solidly brace up the cockpit while the body is still mounted to the frame with the doors fitted so that all ten body-frame mounting points stay in their relative positions. As it is, the cockpit bracing isn’t quite enough.

The cockpit bracing stabilises the body from the very rigid dash structure back but the forward part of the body comprising the large expanse of the front wings and their valences is largely unsupported and will also flex with the effect of gravity bearing down on it. This causes the flat wing quarter panels to splay out slightly and go concave, at the same time affecting the shape of the bonnet opening. This happens when you lift the braced body off the frame and is addressed by incorporating an adjustable support that’s tied into the rotisserie shaft for positioning the two triangular front wing brackets (red arrow).

Likely clear as mud.

Another reason I haven’t put together a how-to is figuring out a clear way to describe the process from beginning to end, but if you’re shooting for precise panel gaps and contours I strongly advise you not to lift the body off without bracing it securely.

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As in, never lift a car body, of almost any stripe, off its frame w/o rigidly bracing it.

The couple I am familiar with–and make the 120/140/150 seem like the Brooklyn Bridge, in comparison–are MG-As, TRs 2/3/4/5, and big Healeys.

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