Correct fillet radius for Model A crank journals ?

[Special Coupe Frank]

I seem to remember reading / hearing that when having a Model A crank re-ground, it is essential to maintain Ford's original spec for the fillet-radius on the rod and main bearing journals.

Can someone provide that specification ? ( I can't seem to find it... )

Thanks !

Frank

 

[Kurt in NJ]

from the print---5/64 -- 1/8

stroke and index within .005

the flywheel pilot(rim of flywheel flange) and timing gear shoulder must not runout more than .001, face of flywheel flange less than .0005

within .00025 round, .0005 taper

 

[George Miller]

I seem to remember reading / hearing that when having a Model A crank re-ground, it is essential to maintain Ford's original spec for the fillet-radius on the rod and main bearing journals.

Can someone provide that specification ? ( I can't seem to find it... )

Thanks !

Frank

It is very important, if you do not want to break cranks at the number 4 crank journal. Good luck finding some one that will put that radius on there wheel. Most do not want to do it because the grinder wheels cost to much.

In the old days when we ground cranks in my Dads garage we had wheels with differnt radius on them, we just changed wheels.

I could not find any one in our area than wanted to do it right, so I set up the portable grinder we had in my Dads garage to grind rod journals in the car. I put the crank in my engine lathe and used the portable grinder.

 

[hardtimes]

It is very important, if you do not want to break cranks at the number 4 crank journal. Good luck finding some one that will put that radius on there wheel. Most do not want to do it decause the grinder wheels cost to much.

In the old days when we ground cranks in my Dads garage we had wheels with differnt radius on them, we just changed wheels.

I could not find any one in our area than wanted to do it right, so I set up the portable grinder we had in my Dads garage to grind rod journals in the car. I put the crank in my engine lathe and used the portable grinder.

Pay close attention to George's words.
The machinist who put the 'correct' radii on my C crank, said the same words that George has warned about.
Remedy was expensive, IMO, but how much is your peace of mind worth
I had him prepare a 'stone' with the proper radius to do it 'right'.

 

[Mike V. Florida]

Here you go;