Re: Will Owen's Dream Car

[George Graves <gmgraves@xxxxxxxxxxx>]

While I certainly agree that torque-tube drive shafts are superior to 
the rubber couplings infesting the drive shafts in our 116 'Alfetta' 
based cars when it comes to frequency of maintenance, I have to 
disagree that it's an overall panacea for the ills of the 116 driveline 
design. Several front-engined Ferraris have torque-tubes, but of 
course, they differ from the Alfetta in that they have the clutch in 
the front, and therefore the drive shaft only turns when the clutch is 
engaged. Maintenance-wise, it's probably a wash. No, one doesn't have 
to replace "giubos" every 60K or so, and torque-tubes don't throw 
chunks of rubber which can break things (like engine 'bell housings' 
-which happened with my old 2.5 liter V-6) when they fail 
catastrophically. But on the other hand, when it comes to changing a 
clutch, I'll take the giubos ANY DAY over having to disassemble a 
torque tube by REMOVING THE ENTIRE TRANSMISSION OR ENGINE to get the 
torque-tube disconnected to get at the clutch. Torque-tubes work well 
because the front mounted engine and rear mounted transmission cannot 
move in relation to one another, thus the drive shaft is never required 
to flex in any direction as It is held rigid by the pipe enclosing it. 
In race cars, this arrangement can be (and was) used to stiffen the 
chassis, in road cars it just makes changing the clutch a costly 
maintenance nightmare.

What I don't understand about Alfa is why they didn't use the old 
tried-and-true Hotchkiss arrangement with a universal joint in the 
drive line and a sliding spline drive shaft instead of the giubos. This 
arrangement gives the drive shaft all the movement it needs between 
engine and rear-mounted clutch/tranny, and eliminates the Achilles heel 
of the rubber doughnuts. I can only guess that the reason has to do 
with absorbing the shock of take-up on the drive shaft  when the clutch 
is engaged. If this is indeed the reason, then I believe that I would 
have placed the clutch at the engine-end of the drive-line and avoided 
the whole mess.

George Graves
'86 GTV-6 3.0S





On Thursday, June 12, 2003, at 09:18 AM, alfa-digest wrote:


> Date: Thu, 12 Jun 2003 11:19:30 -0400
> From: "John Hertzman" <johnhertzman@domain.elided>
> Subject: Will Owen's Dream Car
>
> Will Owen, seconding my admiration for the 6C 3000 CM backbone 
> chassis, takes
> it a big step further, adding "I've said this before and I'll say it 
> again: if
> only, if only, if ONLY the connection between the engine and the 
> transaxle on
> the 116 cars had been a rigid one, what is merely a stunningly good 
> car to
> drive under most circumstances would have been just about the best 
> ever under
> any circumstances."
>
> That rigid connection between the engine and transaxle was at the core 
> of the
> stillborn tipo 160 Grand Prix car, the contemplated successor to the 
> 159. It
> had a short steel backbone connecting the flat twelve engine with the 
> rear
> transaxle gearbox ("tipo di telaio: tubo centrale in lamiera 
> collegante il
> motore e il cambio-ponte") and concentric driveshafts (if I am reading 
> the
> drawings correctly) with the outer (still with one giubo) enclosing an 
> inner
> one to the front differential of the four-wheel-drive system. No other 
> framing
> members; the front suspension mounted directly to the engine. Three
> leading-shoe drum brakes, twelve carburettors feeding the 
> naturally-aspirated
> 2.5 liter engine, 285 hp at 10,000 rpm, driver seated behind the 
> transaxle
> slingshot-dragster style, pretty heady stuff for the early fifties.
>
> Will was talking about a road-car, of course, and ended with "I'll 
> take mine
> with a copy of the plain-jane 3-liter coupe body, please. Contributions
> gratefully accepted." The logical model for an appropriate coupe 
> variant of a
> parallel road car design would have been something like the Sportiva. 
> Both the
> Sportiva and the 160 GP were aborted to concentrate the company 
> resources on
> the forthcoming Giulietta. Would have been nice if they could have 
> managed all
> three.
>
> John H.
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