EVO All Evo Model Discussion

Evo Clutch.....

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Old Mar 15, 2018 | 08:24 PM
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Default Evo Clutch.....

I posted this in the Trans/primary drive section with no response and was wondering what you guys might think of this attempt to more clutch disengagement...

On my 98 Evo clutch I never could get more than .068" travel as measured at the release plate in the clutch basket with a dial indicator. I believe the FSM calls for .080".

The total movement allowable at the ramp is .122" which is limited by the amount the clutch lever action. So with that in mind I am trying to figure a way to get more ramp expansion with the limited amount of clutch lever travel that cannot be changed. I tried a 21* ramp as compared to the stock 18* ramp and there was no significant change. So I disassembled the ramp and took a look at the design and to me the ball bearings look small for the size of the notches in the ramps.

So I'm thinking if I increase the diameter of the ball bearing this would aide in increasing the amount of ramping with the same about of clutch lever travel.... The stock ball bearing measure .375". A larger bearing of 10mm or .394" would have a larger circumference which should make the ramp move the same distance with less pull...

I ordered them yesterday and hopefully I'll be able to get it all together on Sunday and make the same measurement with my dial indicator... Me goal is reaching .080" travel at the clutch release plate... What do you guys think....? thanx all......
 
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Old Mar 15, 2018 | 08:37 PM
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I think it's worth a try. You have the slack out of the system? The hinge pin in the lever is in good shape and not adding slack? Pulling the lever results in the clutch action starting without undo slack anywhere? No one has put one of those EZ clutch things in, right?
 
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Old Mar 15, 2018 | 10:47 PM
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How much are you backing out your adjustment screw when you lock it down?
 
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Old Mar 15, 2018 | 11:00 PM
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Might make the clutch pull harder. .068" separation should be enough, as long as there's nothing warped within the basket.
What is your "target" measurement? .080"? That's only 12 thousandths more. About 5 human hairs. (6 if she's a real redhead.)
Are you experiencing clutch drag now?
Got full lockup?
No slippage at WFO?

Just trying to see what your priorities are with this.
 
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Old Mar 16, 2018 | 05:42 AM
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Originally Posted by Dr.Hess
I think it's worth a try. You have the slack out of the system? The hinge pin in the lever is in good shape and not adding slack? Pulling the lever results in the clutch action starting without undo slack anywhere? No one has put one of those EZ clutch things in, right?
The hinge pin has no play and I installed new a new pin for the cable and no, no one installed an EZ setup..
 
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Old Mar 16, 2018 | 05:48 AM
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Originally Posted by texashillcountry
How much are you backing out your adjustment screw when you lock it down?
If it's an 1/8 turn, it's a lot. Can't back it off too far cause then not enough to disengage...

Originally Posted by NORTY FLATZ
Might make the clutch pull harder. .068" separation should be enough, as long as there's nothing warped within the basket.
What is your "target" measurement? .080"? That's only 12 thousandths more. About 5 human hairs. (6 if she's a real redhead.)
Are you experiencing clutch drag now?
Got full lockup?
No slippage at WFO?

Just trying to see what your priorities are with this.
Yes...
yes...
No.....
012" is a lot. It would be all the difference in smoother shifts without drag....
 
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Old Mar 16, 2018 | 06:37 AM
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Originally Posted by 98hotrodfatboy
If it's an 1/8 turn, it's a lot. Can't back it off too far cause then not enough to disengage...
I'm guessing you replaced the OEM clutch parts to match up with your bigger motor.

How old is your clutch cable?
Could it have stretched a bit?

Not entirely sure bigger ball bearings will help as they still need to be small enough for the snap ring to be installed over the ramp plates.

FWIW I just bought a scorpion low profile lock up clutch set up for my 111" motor.
 
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Old Mar 16, 2018 | 09:05 AM
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Originally Posted by texashillcountry
I'm guessing you replaced the OEM clutch parts to match up with your bigger motor.

How old is your clutch cable?
Could it have stretched a bit?

Not entirely sure bigger ball bearings will help as they still need to be small enough for the snap ring to be installed over the ramp plates.

FWIW I just bought a scorpion low profile lock up clutch set up for my 111" motor.
I have a completely new primary drive from Baker.

The cable is only a few years old and any stretching would have been adjusted out if any...

Correct on the bigger ball bearings. That's why I measured everything. They will only be .022" larger in circumference which will actually fit the ramps better. The OEM seem very small as compared to the ramps.

Theoretically because of the larger circumference it will change the position of the ball in the ramp and should have more movement in the ramps with the same amount of clutch lever movement. So with that creating a little more lever travel I'm thinking I might be able to maximize the ramp separation to it designed potential... I'll know this weekend...
 
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Old Mar 16, 2018 | 09:06 AM
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Having an older Evo which has always had marginal clutch-plate clearance I shall watch with interest. I adjust mine at the clutch by the book, but take out most of the cable slack. Makes me feel better, as if I've achieved a little improvement!
 
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Old Mar 16, 2018 | 09:38 AM
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Originally Posted by grbrown
Having an older Evo which has always had marginal clutch-plate clearance I shall watch with interest. I adjust mine at the clutch by the book, but take out most of the cable slack. Makes me feel better, as if I've achieved a little improvement!
Same here....
 
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