What size clutch ‘41 sedan coupe

[AnthonyG]

I went w a 10” in my ‘35 Tudor & have enjoyed it for years! The pressure to push is almost not noticeable! Some advise, I experience a situation that stumped me & others. I requested a 10” assy on my ‘49 8ba engine I was having built. Obviously the builder didn’t notice the vibration during the bench test stand. I installed it n my ‘35 w a rebuilt ‘39 tranny & over 1000 rpm the vibration was terrible. Long story short, it was the 10” clutch flywheel. It was n 11” flywheel redrilled as a 10” & was out of concentric .075”. After months of trying to find the problem I finally had an experienced Early Ford mechanic discover it. He installed a correct 10” flywheel in & it purred with no vibration! He said it was pretty common w guys wanting to replace the 9” assy w a 10” so they’d get a junked 11” & use the 9” as a drill fixture instead of having it done on a boring mill or Bridgeport mill.
Best of Luck on your project!
Tony

[Kube]

Originally Posted by AnthonyG

I went w a 10” in my ‘35 Tudor & have enjoyed it for years! The pressure to push is almost not noticeable! Some advise, I experience a situation that stumped me & others. I requested a 10” asst on my ‘49 8ba engine I was having built. Obviously the builder didn’t notice the vibration during the bench test stand.i installed it n my ‘35 w a rebuilt ‘39 tranny & over 1000 rpm the vibration was terrible. Long story short, it was the 10” clutch flywheel. It was n 11” flywheel redrilled as a 10”& was out of concentric .075”. I finally had an experienced Early Ford mechanic discover it. He installed a correct 10” flywheel in & it purred with no vibration!

I have drilled and tapped flywheels for different clutches. However, all of this was done utilizing precise coordinates.
To think as some do, they can simply "get it close enough" by marking the holes in a clutch plate is laughable.