Clutch selection for 68 L36

[Charles F.]

Last question: the car had a CenterForce clutch that was simply not satisfactory. The builder is suggesting a Hayes clutch. The engine is bored and stroked (to about 500); it makes significantly more than stock HP and torque.

What say you ?

Thanks

Chuck

[Dick W.]

Re: Clutch selection for 68 L36

LuK is a very good clutch. Not a lot of pedal pressure, but more than adequate for a street engine

[Larry M.]

Re: Clutch selection for 68 L36

Hays has always made a good clutch. The Street version is probably adequate, but the Street/Strip one should be more than enough. Not certain how strong your left leg is though??

Also the S/S may require beefing up the stock clutch linkage.

Many folks have been very happy with Centerforce II and with LUK Rep Set.

Larry

[Brandon T.]

Re: Clutch selection for 68 L36

I agree with the above go with LuK..went with a LuK in my 68 l36 and love it.

[Richard G.]

Re: Clutch selection for 68 L36

Remember their are two general categories of clutches.
1) Borg & Beck style;

Typically has three fingers. This style clutch has springs that act just like a normal spring. When you hold down the clutch it gets harder the further down it goes and is hardest to hold on the floor.

2) Diaphragm style;

This acts like a standard clutch in till it is almost all the way disengaged. Then it gets easier. This makes this style clutch much more street friendly. The disadvantage is this style clutch will sometime stay on the floor after the clutch is reengaged at high (sometimes very high) engine rpm. This very undesirable characteristic has been engineered out on the better clutches. I remember this unnerving experience when I put a 1969 302 in my Camaro years ago. The aftermarket diaphragm style is usually referred to as rev-lock or something similar. Addition weights that act centrifugally to increase the clutch pressure have been added.

The diaphragm style is a later design. I know GM used this style in 1971. Anyone else that could identify the exact year for us?
Rick

[Michael G.]

Re: Clutch selection for 68 L36

Chuck,

I've used some of the clutches mentioned. The Hayes S/S to my knowledge requires no additional fortification of the clutch assemblies and will handle the power. LUK replacment clutch has been mentioned and are a quality line of clutches.....futhermore LUK makes a line that is equivalent to the Haynes S/S. It's refered as their "heavy useage" line of clutches. Now here's where it gets interesting.....the so called 11" clutch disc that Hayes sells is around 10.75" but called an 11" clutch. The heavy useage LUK clutch disc is 11.25" and fits under their diaphragm clutch cover nicely on your original fly wheel. Currently have one installed on my '66 L-36 engine

[Joe L.]

Re: Clutch selection for 68 L36

Remember their are two general categories of clutches.
1) Borg & Beck style;

Typically has three fingers. This style clutch has springs that act just like a normal spring. When you hold down the clutch it gets harder the further down it goes and is hardest to hold on the floor.

2) Diaphragm style;

This acts like a standard clutch in till it is almost all the way disengaged. Then it gets easier. This makes this style clutch much more street friendly. The disadvantage is this style clutch will sometime stay on the floor after the clutch is reengaged at high (sometimes very high) engine rpm. This very undesirable characteristic has been engineered out on the better clutches. I remember this unnerving experience when I put a 1969 302 in my Camaro years ago. The aftermarket diaphragm style is usually referred to as rev-lock or something similar. Addition weights that act centrifugally to increase the clutch pressure have been added.

The diaphragm style is a later design. I know GM used this style in 1971. Anyone else that could identify the exact year for us?
Rick

Rick-------



The diaphragm type clutch was used for ALL 1963 and later Corvettes regardless of clutch size. The Borg & Beck coil spring ("3 finger") type clutch was used for all 1956-1962 Corvettes. I believe that 1955 used a diaphragm type, though.

[Duke W.]

Re: Clutch selection for 68 L36

Use of the diaphragm clutch design began in 1963, and it can be installed in most pre-'63 modlels.

Any current OE replacement clutch (Luk, Sachs, Borg Warner brands) should be quite satisfactory for normal road use, and I believe the three above brands are essentially the same parts.

You'll be better off to leave the hot rod clutches to hot rodders and let them deal with all the issues.

I've never had a OE diaphragm clutch hang up on me up to 7000 revs, but if you don't have enough freeplay, you can go too far overcenter on disenagagement, and this can cause high rev hangup, so keep freeplay near the high end of the spec in the CSM.

Duke