Period Upgrades?

[simon1966]

So I am heavy into the rebuild of my MGB engine. Big brother is in the background so this has some AH content Meanwhile my mind is full of those delicious thoughts concerning the work that I want to do to the 100.

I am curious as to the view of the cognoscenti with regards to period upgrades. It is very clear from several previous threads that simply bolting on M upgrades to a BN2 does not a 100-M make. It does not matter if these upgrades were made by dealers back-in-the-day, or just last week at a restoration shop.

I know now for a fact that my car had a 4 speed BN2 box installed by a PO back in the 60's. I also know that the mechanical clutch linkage was replaced by a hydraulic system at the same time. I have written documentation from the PO to support this. As a result, the tunnel over the gear box is not original, but something fabricated from fiberglass.

My inclination is this, to keep the box as the 4 speed. Probably go back to the mechanical linkage for the clutch and to try and find a replacement for the fiberglass tunnel cover.

The other glaring part that is wrong on my car is the steering wheel. Looks like the modern repros are actually quite good, so this I think is easily solved.

The gear box cover looks to be harder to resolve. Any thoughts on this? I assume that the sideshift 4 speed cover was different to the BN1 cover, or maybe it was not? Some direction here would be really helpful.

Thanks for your input.

 

[AH100M]

Both BN1 and BN2 gearbox covers come up on Ebay periodically and yes, there is a big difference between the two which also affects the trimming (carpet, vinyl).

The lower five in this photo are BN2 tunnels.



This is a trimmed BN1 tunnel.



This is a trimmed BN2 tunnel.

 

[DerekJ]

Bolting on M upgrades doesn't make a factory M, but that is not a reason not to do it. Lets remember that M modified !00 BN1s were around before there were any 100Ms. In that sense you could say they are more original. As long as you don't call it a factory 100M there is no problem.

Regarding the Steering wheel I would fit a Moto Lita Derrington. I would also keep the four speed box and the hydraulic clutch.

 

[British_Recovery]

You can probably use the trans cover from any four speed, side shift gearbox. There is also a vertical panel that goes between the tunnel cover and the firewall bulkhead. So BN2, BN4, BN6, BT7 before center shift, BN7 before center shift.
Check to see what gearbox you actually have.
Bob

 

[simon1966]

Bill thanks for the clarification. My, where did you find that cache of gear box covers? Are any of them for sale still?

Derek, thanks for the comments. I have no interest in making my car an M. I was using that as an illustration of the kinds of things that have been done to cars in the past. I rather like the idea that my car has some "history" to it.

 

[pan]

G'day Simon,
You say your 100 has been modified with a hydraulic clutch operation. Is that because the four speed is from a 100-6 (BN4) or later model?
If so there would be no point in reverting to the mechanical operation. In fact it would be difficult to do.
The BN2, which retained the mechanical clutch of the BN1, has a different bell housing from the BN4, which is when the hydraulic operation was introduced.

 

[simon1966]

I am going to take some photos of this conversion. According to the PO the box is a BN2 and others have confirmed this from visual inspection. The hydraulic conversion was a PO modification, rather than a dealer or official modification. I have a lovely passage in a letter he sent me where he describes the moment he made the decision to do this modification. The linkage broke with the clutch depressed and the car in gear, sitting at traffic light in Manchester.

 

[stuntflyr]

Would love to read that story!
Chris...

 

[simon1966]

Here are 2 not especially good shots of the master and slave end for the clutch. You can see how the PO mounted the master inside the brake bracket and then mounted a reservoir close by. It looks to me as if the slave was then mounted to the bell housing and used the last mechanical link to the clutch.

 

[AH100M]

That looks like a BN2 gearbox.

The gearbox cover cache is not mine. I found the photo on the web last year when I was researching the positions of the carpet snaps - mine had holes all over the place.

There is a rod in the mechanical clutch linkage that is prone to breaking. In fact the PO of my BN2 broke it and welded it back together. 'been fine for over thirty years. (I know, it'll break the next time I drive the car now). So your story is likely true.

You can get a Moto-lita steering wheel hub that with just a little tweaking will accept the original horn/trafficator assembly.

 

[pan]

Yep! That's a BN2 transmission. Looks to be a clever conversion but the original is so simple. I'd go back to mechanical. Kilmartin Automotive Sheetmetal can supply every thing that you need.
All 100 owners have a story about the mechanical linkage, including me. But I have retained the mechanical and have had no trouble since I sorted out the problems. This consisted of restoring the set up to original. Believe it or not, when he designed the linkage, Geoff Healey knew what he was doing!
At a recent club 'garage day' I had an opportunity to inspect another club members 100. This car had the most awful modifications to the mechanical clutch release system. I am going to recommend to the car's owner that he fit a KAS linkage.

 

[glemon]

Yep!
All 100 owners have a story about the mechanical linkage, including me. But I have retained the mechanical and have had no trouble since I sorted out the problems. This consisted of restoring the set up to original. Believe it or not, when he designed the linkage, Geoff Healey knew what he was doing!

I would agree, in the ten years I owned my 100 one of the few things I did NOT have to rebuild, fix, or fiddle with at all was the mechanical clutch linkage, it was greasy as heck and the rod was bent, but the only time I ever messed with it was when I took the tranny out. Also very smooth clutch, would have guessed it was hydraulic if I didn't know better, that being said if the hydraulic set up appears to be a well engineered conversion, and you are goal is not 100% originality I don't think I would go through the trouble of converting back.

 

[simon1966]

This is all very helpful, thanks everyone. It is good to be solidifying my thinking. I really don't know what the future will bring, and how active I will become in the AH community. For now, work makes this rather difficult, but this won't go on forever, and I look forward to a day when I can bring my car to the meets and conclaves. I am not sure if I want to go down the 100% authentic, accuracy route for judging purposes. Or if I want to respect the history of the car and keep these features that were added in the past. I do know that I want the car to be done well, and that I want to use the car and enjoy it. For now, I would say I am leaning towards keeping the 4 speed and the clutch control and seeking out a better tunnel that the home made one. I am undecided about the steering wheel. But that decision can be made a long time in the future.