Keith,
You are correct in that weight of the car affects the clutch life. It
is equal with that of the torque of the engine. The coeifficent of friction,
caused by the springs in the clutch and the "stickiness" of the disc, resist
either the torque of the engine, or the weight of the car, which acts as
torque through the drive line.
The series 5 style clutch will slip when there is a great deal of
torque from the engine. This slip translates into reduced performance, and
increased wear. This has been proven by many people who race Alpines in the
USA.
It might also be noted that Rootes went to a different clutch for the
H120 and Holbay upgrades.
I will use the series 5 style clutch when I can because I have lots
(Lots!) of them. I wouldn't consider them for any performance application.
Lou
----- Original Message -----
From: "Alkon" <alkon@bigpond.com.au>
To: "Alpine list" <alpines@autox.team.net>
Sent: Monday, January 27, 2003 3:17 AM
Subject: Re: VOLVO Clutch
> The load on the clutch is not only a factor of horsepower.
> The weight of the vehicle has a large effect on clutch life.
> We used a small Ford zephyr clutch behind a high performance 283 Chev in a
> Mk 3 Zephyr driving through the original Ford four speed gearbox. This set
> up worked ok in the lightweight Zephyr but the same clutch and gearbox
would
> not have survived if installed behind the same engine in a full size Chev.
> The Alpine is a small lightweight vehicle so I would expect clutch life to
> be sufficient to last untill the engine needed attention.
> I drove a 3.4 Jaguar with manual box and quickly learned that slipping the
> clutch was a big "NO NO". The magic smoke escaped as quickly as foward
> propulsion ceased :-). Jag drivers manual says " for best acceleration off
> the line use about 2000rpm, allow cluch to fully engage before flooring
it"
> Slipping the clutch on normal changes is clutch abuse and does not improve
> performance.
> In fact driving the Jag taught me to allow all the bits of clutch/gearbox
> etc to work at their own pace. Fast gear changes never happened with the
Jag
> (Moss) gearbox. A pause in neutral between gears always helped. The same
> technique in my 55 Californian means silent gearchanges occur, and gearbox
> bits don't fall in the bottom of the box :-))
> Australian car racing involves great races like Bathurst where "hard"
> drivers go quickly but often never finish because they break something.
> Rootes Australia entered the Humble Minx (badged as Sunbeam ) in the great
> race. It finished and put up lap times that I feel were nothing short of
> amazing considering that this was a stock unmodified sedan.
> I personally have learned the hard way about vehicle abuse. If it is
broken
> I get to walk :-) so coaxing maximum performance without breaking anything
> has become second nature to me.
>
> The point that these Volvo parts are more readily available is a good one
> and adaptation of these parts should not be difficult, but to say that the
> substitution is needed because the original parts cannot take the power is
> not suffucient reason for me to make this change. In Australia I would
> simply adapt Holdem ( GM) parts as they are cheaply available where Volvo
> parts cost a premium in Australia.
>
> If the Rootes engine drivetrain is not holding together then it was not
> assembled correctly. I have rebuilt motors in my previous Hillmans and
> pushed them full throttle for up to 100miles without failures. We are
> talking about sitting on 6 -7000rpm for 20 miles at a stretch. To the
extent
> the exhaust piping becomes more than red hot.
>
> I have gone on a bit here but the point I am trying to make is that the
> Standard Alpine drive train is more than capable of handling any amount of
> enthusiastic street use and a fair amount of classic racing use as well.
>
> Keith
> 55 Californian
> 56 Minx
> 68 Hunter
>
> >---- Original Message -----
> From: <ellis838@concentric.net>
> To: <alpines@autox.team.net>
> Sent: Monday, January 27, 2003 2:28 AM
> Subject: Re: VOLVO Clutch
>
>
> > The MGB cover and Volvo plate works well is cheaper and easier to get,
> > I also think the quality of the MG/Volvo parts is better. Sorting the
> > combination of pivot block and release arm is the only difficult part.
> > The 7 inch Rootes plate seems to like to spit the springs out and the
> > plates I have bought look like they were rebuilt in the back yard in
> > grandpas spare time. I figure my 1725 is good for 130+hp and with the
> > 205 tires I am not sure the stock 7 inch clutch could take the strain...
> > Jim E
> >
> > Alkon wrote:
> >
> > >The Volvo clutch throwout bearing is a ball race and runs on a guide
tube
> > >around the gearbox input shaft. This type of clutch is totally
> incompatable
> > >with the Rootes carbon throwout bearing. If you want to use the Volvo
> clutch
> > >pressure plate then a guide tube and the correct type of throwout
bearing
> > >must be used. This work is really fairly simple to do and made easier
if
> you
> > >can steal the right parts off a Volvo. I have done this adaptation to
> couple
> > >a Jag box to a Chrysler Hemi V8.
> > >
> > >Unless you use dragracer clutch techniques. (7000rpm and step off the
> > >clutch.) then the Rootes supplied item will handle anything that your
> 1600
> > >or 1725 engine can deliver.
> > >
> > >Keith
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