Stock Flywheel Thickness
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Stock Flywheel Thickness
Hi again guys . .
What is the stock thickness of a SBC 153 tooth flywheel? I started mocking up the install of the hydraulics and i'm noticing I need a whole crap load of fork travel just to get the TO bearing to sit flush on the clutch fingers. Its a Mcleod clutch by the way. Mine is 0.915-0.925 and I've read some saying its 0.960 and some saying its about 1.20. I measured mine with machined face down on a flat surface then measured inside the mounting bolt hole to the surface that mounts to the crank.
Chris
What is the stock thickness of a SBC 153 tooth flywheel? I started mocking up the install of the hydraulics and i'm noticing I need a whole crap load of fork travel just to get the TO bearing to sit flush on the clutch fingers. Its a Mcleod clutch by the way. Mine is 0.915-0.925 and I've read some saying its 0.960 and some saying its about 1.20. I measured mine with machined face down on a flat surface then measured inside the mounting bolt hole to the surface that mounts to the crank.
Chris
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Joined: Apr 2009
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From: Charlotte NC
Call the major companies that make them.,,,,unless someone as the EXACT figure.
Are you sure that your pivot ball stud is at the correct length????
AS I wrote in another POST...and as I have been told and I still sue today. The main thing is to make sure that when the clutch fork is making contact with the pressure plate fingers....that the clutch fork is in the center of the cut-out in the bellhousing. That way...when you engage the clutch...they clutch fork still has room to move and not bottom out an contact with the bellhousing.
I believe the pivot ball stud needs to be set at 4.75" measuring from the TOP of the pivot ball stud...to the surface of the bellhousing that CONTACTS the engine block....and if you are using a 'block saver plate' you have to take that into consideration also.
AND I am sure that you checked your bore concentricity and parallelism also.
DUB
Are you sure that your pivot ball stud is at the correct length????
AS I wrote in another POST...and as I have been told and I still sue today. The main thing is to make sure that when the clutch fork is making contact with the pressure plate fingers....that the clutch fork is in the center of the cut-out in the bellhousing. That way...when you engage the clutch...they clutch fork still has room to move and not bottom out an contact with the bellhousing.
I believe the pivot ball stud needs to be set at 4.75" measuring from the TOP of the pivot ball stud...to the surface of the bellhousing that CONTACTS the engine block....and if you are using a 'block saver plate' you have to take that into consideration also.
AND I am sure that you checked your bore concentricity and parallelism also.
DUB
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Instructor
Joined: Jul 2010
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Yes, yes and yes . . . I had a nice long explanation typed but my browser for some reason froze. I have a stock GM flywheel and I cant find anything on min and max thickness.
I'm trying to figure out if I need a taller bearing or taller pivot ball.
I've read many places to minus your flywheel thickness from 0.96 and adjust your ball stud accordingly. My flywheel is 0.92 . . so that says adjust my 4.75 pivot ball height 0.04 towards the motor.
I checked the following per Novak Conversion website for how to check bearing length.
Rear of block face to clutch fingers is 3.75. Rear of block face to rear face of TO bearing on input shaft at its most rearward spot is 5.5 so that makes it 1.75 then minus 1.2 for clearance and 1.2 for wear and that gives me 1.25 bearing height which is what came with my McLeod clutch. I was able to measure all these because the trans is out and everything is easily accessible.
There is many opinions and posts on this and I'm not sure what is right or what is wrong. Does all of this sound right to everyone???
I'm trying to figure out if I need a taller bearing or taller pivot ball.
I've read many places to minus your flywheel thickness from 0.96 and adjust your ball stud accordingly. My flywheel is 0.92 . . so that says adjust my 4.75 pivot ball height 0.04 towards the motor.
I checked the following per Novak Conversion website for how to check bearing length.
Rear of block face to clutch fingers is 3.75. Rear of block face to rear face of TO bearing on input shaft at its most rearward spot is 5.5 so that makes it 1.75 then minus 1.2 for clearance and 1.2 for wear and that gives me 1.25 bearing height which is what came with my McLeod clutch. I was able to measure all these because the trans is out and everything is easily accessible.
There is many opinions and posts on this and I'm not sure what is right or what is wrong. Does all of this sound right to everyone???
Race Director
Joined: Apr 2009
Posts: 19,294
Likes: 2,753
From: Charlotte NC
I myself go for as much thickness in the flywheel for heat dissipation. Doing these for customers...getting the flywheel resurfaced is fine...but if it is in question....I replace it so I do not have to do it again due to improper clutch break-in by the owner.
Even though I APPLAUD you getting so technical in the measurements. I have never run into this being an issue causing such precise measurements to the thousandths. All I need to know if the amount of 'throw' that is needed for the throw-out bearing to press on the fingers of the pressure plate and get it to release. Because what are you going to do when the clutch disc begins to wear....thus the measurements are different from an original disc. You make sure you clutch fork will not bind.
Then needing know the amount of 'throw' of my slave cylinder when it has been set-up and determined that ( in most cases) the clutch pedal needs to stop when 1 inch of clutch master cylinder plunger movement has been achieved.
Then I apply what I wrote before to make sure the clutch fork will not hit or bind....and is in the center of you cut-out in the bell-housing. I shoot for the clutch fork coming out and angling a very little bit towards the front when the throw-out bearing makes contact withe the pressure plate....if not perpendicular....BUT not past perpendicular if I can help it.
I know ..and not sure if they are still out there because I have not looked for them...but 'back in the day'...they sold shims that you could put between the crankshaft and the flywheel and space the flywheel back out after it was re-surfaced....due to not using an adjustable clutch fork pivot ball stud.
DUB
Even though I APPLAUD you getting so technical in the measurements. I have never run into this being an issue causing such precise measurements to the thousandths. All I need to know if the amount of 'throw' that is needed for the throw-out bearing to press on the fingers of the pressure plate and get it to release. Because what are you going to do when the clutch disc begins to wear....thus the measurements are different from an original disc. You make sure you clutch fork will not bind.
Then needing know the amount of 'throw' of my slave cylinder when it has been set-up and determined that ( in most cases) the clutch pedal needs to stop when 1 inch of clutch master cylinder plunger movement has been achieved.
Then I apply what I wrote before to make sure the clutch fork will not hit or bind....and is in the center of you cut-out in the bell-housing. I shoot for the clutch fork coming out and angling a very little bit towards the front when the throw-out bearing makes contact withe the pressure plate....if not perpendicular....BUT not past perpendicular if I can help it.
I know ..and not sure if they are still out there because I have not looked for them...but 'back in the day'...they sold shims that you could put between the crankshaft and the flywheel and space the flywheel back out after it was re-surfaced....due to not using an adjustable clutch fork pivot ball stud.
DUB
