Accuracy of timber measurements in TC's Forever

[robj]

After days of measuring and leveling, finally getting to fitting timber pieces to my existing partial tub as in the "Through the Timber Portal" thread on "The MG Experience"

I have both TC's Forever and the second book, Forever More. My question is in regard to the accuracy of the measurements in the book, [mostly the first one]. I had some discrepancies in the tank board but nothing I couldn't adjust. [ie. in TCF there are 2 differing measurements for the height of the back board]

I started fitting the side screen box sides, and comparing the 2 sides I got from Abingdon Spares with the drawings in TCF and they, either the drawing in TCF, or the parts from Abingdon were more than a bit, off.
I first figured it was the parts but now it looks like it was the measurements in the book.

I ran into the issue where the box side fits into the sheet metal box pan. I'm 99.99% sure my sheet metal is original. When I measure the space at the bottom between the tank back board and the front inside of the metal pan I have a space /opening of about 1/64 less than 2 3/4". The replacement from Abingdon Spares measures exactly the same.

However, the drawing in TCF shows the bottom of the box side as 3". So who do I believe? At first I was thinking that as Sherrell seems to assume everyone is making everything from scratch and as I remembered a drawing for the metal pan I thought maybe he made the pan larger to more easily fit the curtains [as it seems they are a tight fit].

I checked the pan drawing and that measurement is 3 1/4" at the bottom. which makes sense as the ply is 1/2" which would leave 2 3/4" room for the side piece.

But if the side piece was made to the dimension in TCF it would total 3 1/2".

Has anyone else found issues with the dimensions in TCF? And if so do remember where they were?

Does anyone know of a source of measurements other than TCF? At least for comparison? I was looking at TCF as the "last word" but now with 2 different issues identified my faith is wavering.
Or is it me?

Thanks,
robj

[Steve Simmons]

Hi Rob, I think the first issue is that everyone has used a different car for their initial measurements. I would definitely expect some variation from one car to another, although the numbers you quote seem a bit too much. If it were me, and I were confident the metal was original and/or correct, then I would fit the wood to the metal. That said, after so many years you could be looking at the second or third metal box the car has worn. So long as the rest of the tub lines up, I wouldn't worry too much about the box.

Unfortunately I've moved both of my project cars off, so I have no more disassembled bodies to measure for you. Maybe someone else has one handy.

You could also check with Tom Wilson of this forum, and Doug Pelton of From The Frame Up. Perhaps also Hutson Motor Company Ltd. in England. They build a lot of bodies for our cars.

[robj]

Thanks Steve,
I've had quite a few discussions about this with my garage buddies, especially one cabinet maker friend that's nearing the end of a 10 year restoration of a '32 Cadillac . This is not the first barbecue for any of us. I'm sure the restorations done today are with much greater care than was ever taken on the assembly line.
I realized from the start a TC is pretty much a hand build vehicle. I guess my goal is to proceed as accurately as possible as a 1/16 error at the start can end up a 1/4" difference [or more] at the finish as one error compounds the next.
I think there are a few basic dimensions that are most critical , the level and squareness of the tub, the angle of the tank board and the correct alignment of the hinge pillar. And the door and fender fit.
I'm positive my tin for the storage compartment is original. [and the parts from Abingdon Spares fit].
I guess my concern was that any of the measurements in what is considered the "bible" [TC's Forever] has incorrect information.
I've discovered 2 instances and I was just wondering if folks had discovered others. And also, if there are any other dimensioned drawings out the for comparison.
Part of the issue I'm facing is the rear of my tub seemed pretty decent, [other than the tank board] but the hinge pillars and the latch pillars had so many holes drilled they were beyond repair. The tank board was 2 pieces joined with straps, so, I'm really working on it with what is an out of order sequence as opposed from starting from scratch. Possibly part of the issue.

robj

[Rob Reilly]

Well, the original parts from my TA measure 2-3/4" at the bottom end of the side curtain box sides.
But the new parts from Hutson measure 3".

The old parts are solid wood boards, but the new ones are plywood.

20240312_140859.jpg (64.45 KiB) Viewed 635 times

Mine is one of the first of the "narrow late" TA bodies, after they changed from the "wide early" TA body.
I have found other instances where measurements on my TA are different from TC, and also from later TA bodies.
I think Hutson used measurements from a later TA body to make their TA parts.
Making the invalid assumption that all narrow late TA bodies would be identical.
I suspect these are examples of how the details were changed throughout the production run, and simply not recorded or not perceived as important enough to be concerned about.
Especially 85 years down the road.

I have stopped using MG Experience.

[robj]

Rob,

"But the new parts from Hutson measure 3"."
That's interesting, maybe they used the TC drawing in TC's Forever?

The side panels I received from Abingdon spares were solid wood, ash I believe. And as I said they did measure correctly.
The panels I removed were plywood but no markings, so no clue if they were bought or owner made.
I'm pretty sure my TC is on its second or maybe even third restoration. It's at least on its third paint job.

I did find that my existing Rear Top Side Rail was mahogany and I thought this was homemade, but I mentioned this on the MG Experience forum and one of the guys that seems quite knowledgable said his TC was original when he got it and also had a mahogany top rail. so there's that.

I guess I was a little dismayed as by all reports TC's Forever is/was the "last word" and the first 2 things I'm working on had measurement errors. The first book, TCF called the backboard height 23 1/2" and TC Forever More calls it 24 1/2", then the issue with the side panel width.

It seems things such as basic measurements should be settled by now.

robj