The difference between the diaphragm spring clutch and the "long" type that
has not been mentioned is the operating pressues.
The diaphragm spring has more pressure on the driven plate but requires less
pedal pressure to disengage than the long type.
this translates into a nicer drive.
Mixing a better pressure plate with the original driven plate is the easy
way to keep compatability with the original gearbox.
A larger diameter clutch often creates problems at higher RPM while solving
grip or heat problems. Rootes went from the small early clutch to a larger
unit then reverted to a smaller diameter later in production for some
reason.
If it is desired to fit a larger clutch then remachining the flywheel to
suit a diaphragm style pressure plate and having the gearbox front bearing
retainer modified to the Volvo style throwout bearing is the best option.
Your clutch rebuilder can fit the Alpine driven plate splines into any size
driven plate you desire. This option is best coupled with an adjustable
clutch slave cylinder rod to optimise clutch operation.
I still have doubts that the cluch is at fault. But short of fitting pick
ups for data logging to the crank and gearbox input shaft and monitoring
the differences in rpm of each item as well as clutch pedal position I can't
conclusively prove anything.
One of my speedway racing friends was the biggest cluch destroyer, denied
any "bad habits".
I put a brake light switch on his clutch pedal that turned on a big red
light on the dash of his car every time he left his foot "resting" on the
clutch pedal. This "lie indicator" could be seen from outside the car as
well :-))
He soon modified his ingrained driving habit and we spent less time
replacing burned out clutches.
WE were racing Holden powered speedway cars. My car was a Torana XU1 with
tripple Dellorto carbs, yellow terra heads ect. etc.
Revved out to over 7000rpm never had a clutch failure using a standard
Holden heavy duty clutch as fitted to the 1 tonner Ute range.
Keith
55 Californian
----- Original Message -----
From: "Jarrid Gross" <JGross@econolite.com>
To: "Louis & Laila" <bwana@c2i2.com>; "Alkon" <alkon@bigpond.com.au>;
"Alpine list" <alpines@autox.team.net>
Sent: Tuesday, January 28, 2003 3:14 AM
Subject: RE: VOLVO Clutch
> Lou and piners,
>
> I had a 7.5 inch clutch (brand new) in a 1725 with stock mechanics, but
> running fuel injection. The added torque was all it needed to begin
> slipping the clutch at WOT. When the clutch begins to slip on its own,
the
> result is a snowball effect, where the clutch gets hotter, slips a tad
more,
> gets hotter slips a tad more, until you are puting all your engine power
> into smoke and heat.
>
> Why Rootes used that tiny clutch on the 1725 is beyond me.
> I use the 8 or 8 1/2 inch now, but it is soooo heavy.
>
> Jarrid
>
>
>
>
> -----Original Message-----
> From: owner-alpines@autox.team.net
> [mailto:owner-alpines@autox.team.net]On Behalf Of Louis & Laila
> Sent: Monday, January 27, 2003 8:34 AM
> To: Alkon; Alpine list
> Subject: Re: VOLVO Clutch
>
>
> 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
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