C1 practical difference between 10" and 10.5" clutch?

[Ian G.]

Hi guys,

I plan to get a three finger clutch for originality of feel in my 59 and to avoid having to hassle with adjusting it for the hangup problem on diaphragm clutches. Can someone tell me the practical difference in feel/performance in installing a 10" clutch (as original) or the 10.5" clutch that will fit the standard 9004 14" flywheel?

[Tom P.]

Re: C1 practical difference between 10" and 10.5" clutch?

Back in the 50s, in both pass cars and Vettes, the V8 clutches were 10in. Today, AS FAR AS I KNOW, all the replacement clutches for a flywheel that ORIGINALLY had a 10in clutch, are now 10.5 (or maybe more precisely 10.4in).
Now, regarding hangups with a diaphragm clutch. That only happens with the lighter duty FLAT finger diaphragm style. The diaphragm clutches with the cone shaped fingers don't have the problem of hanging up in the 4500-5000rpm range. For those of you who have experienced this phenomenon will understand what I'm talking about.
Yes, I realize the 3 finger pressure plate is the original style, but for all around use, I would sure recommend the diaphragm style pressure plate with the cone shaped fingers and the short throwout bearing.

[John H.]

Re: C1 practical difference between 10" and 10.5" clutch?

What Tom said. Forget the dinosaur-technology 3-finger Borg & Beck clutch; use a current cone-finger diaphragm clutch and don't look back.

[Ian G.]

Re: C1 practical difference between 10" and 10.5" clutch?

FYI: I see Brute Power selling a 10" inch (90109) and a 10.4" (90105) in three finger style.

I'm weird in that being too young to have never driven the cars back in the 50's or 60's, so I kinda want the old experience, warts and all :P Also, wouldn't I have to disengage the gorilla spring when using the cone diaphragm clutch?

Can you guys tell me what effect a 10" vs 10.5" might have theoretically?

[Stuart F.]

Re: C1 practical difference between 10" and 10.5" clutch?

I am with Tom and John, and any other of us old farts that chime in. I changed to diaphragm clutches back in 1961 while racing every weekend at Great Lakes dragway - and never looked back! Of course I was a glutton for punishment too; I used to use white springs in my 11" B & B and watch the dashboard torque each time I stood up in the seat to push in the clutch. I had to braze two clutch rods together too. Finally I got wise and went with an 11" truck disc and pressure plate and learned the art of power shifting (low 13's w/a B/S 57 post Chevy w/street tires wasn't too bad back then).

Now granted, you don't need the 11", but find the best 10" or 10.4" (whatever) diaphragm clutch fits your flywheel, etc., and do your excercise in a gym.

Stu Fox

[Domenic T.]

Re: C1 practical difference between 10" and 10.5" clutch?

I was a victim of the diaphram hang up in the early 60's and never new why till now.

In the 80's a company in Huntington Beach Ca (Hays) gave my shop 2 diaphram clutches they were making to try. They had weights on the fingers to stop the hang up.

I ended up removing the weights because they started making noise and the pressure plate had WAY to much spring pressure ( my floor board flexed) for street driving.

The point I am making is, get the stock pressure unless you plan to use 11" slicks.

You can only shift as fast as you release the clutch and I found that the heavy springs were actually adding to the 1/4 mile time because of the extra time it took to push against the heavy springs.

Every one loves a power shift, and with stock tires, stock pressure is all you need.

DOM

[Rod K.]

Re: C1 practical difference between 10" and 10.5" clutch?

Any recommendations for brand?

Am I correct in recalling from earlier threads the "gorilla spring" would not be used??

Thanks.

[Tom P.]

Re: C1 practical difference between 10" and 10.5" clutch?

Any recommendations for brand?

Am I correct in recalling from earlier threads the "gorilla spring" would not be used??

Thanks.

If you're referring to the spring between the frame bracket and the lever on the clutch cross shaft------------NOOOOOOOOOOOOOOO, DO NOT GET RID OF IT!!!!!!!!!! Keep it for proper clutch linkage operation.

[John H.]

Re: C1 practical difference between 10" and 10.5" clutch?

Any recommendations for brand? Thanks.

Paragon carries an excellent 10.5" LuK RepSet diaphragm replacement for all C1's - I've used several of them; smooth engagement, low pedal pressure, no problems.

[Bruce B.]

Re: C1 practical difference between 10" and 10.5" clutch?

The LUK setup John H. mentions works great and is easy on you leg muscles.