1932 to 1936 Flathead Distributors

[Mark Slight]

I'm trying to find information about the 12175 shaft the runs thru the center of the distributor. I have a 1936 Distributor the number on the shaft that you can see from the back is 40B.

I was told there is a diference between shafts? the 40B is for engines with aluminum heads, 40A is for engines with cast heads. None of the Ford books or the Ford V-8 Club of America books mentions that.

Can anyone out there help with information? Thanks, Mark

 

[FlatheadTed]

Quote, A type 40 A distributor should be used with a Aluminium Cylinder head of 6.3to 1.
A type 40B is used with iron 5.5to1 often not marked

 

[Kahuna]

I wonder what the difference is?

 

[Mark Slight]

Thank you for the information; Like the Kahuna wonder what the difference is in the distributor? Started with my first Flathead Ford engine in 1953. I can't remember ever being asked what cylinder heads I had when I visited the parts stores for a rebuilt distributor, I can see the copression is different.
Does anyone know of a place where this is written, such as from Ford or Motor Books?
Thanks to all, Mark

 

[38 coupe]

The 40A, sometimes marked simply 40, has 22 degrees total advance. The 40B, and all other front mount flathead distributors, have 18 degrees total advance. The 40A was only used on 1933 aluminium head passenger cars. This information can be found in the 32 to 36 tech bulletins.

If someone has a 40A shaft I would be interested in it.

 

[BUBBAS IGNITION]

I have that bulletin set , will try to scan and post tomorrow.......

 

[keith oh]

Information can also be found on page 205 of Victor Page's "Early V/8 Ford Service Manual"

 

[Mark Slight]

Thanks to all who responded! Mark

 

[Dave D]

Quote, A type 40 A distributor should be used with a Aluminium Cylinder head of 6.3to 1.
A type 40B is used with iron 5.5to1 often not marked

According to the Aug 1934 Ford Service Bulletin the 40-B distributor should be use with dual carburetors (Stromberg 48/97) and aluminum heads. The 40 or 40-A should be used with single carburetors and aluminum heads and the 40-B with cast iron heads.

 

[Mick/mo]

Why not use either one and just advance the dist. untill it pings a bit on full acceleration. ,and it will be right on.

 

[Mick/mo]

Forgot to add. Back it off untill it stops pinging.

 

[BUBBAS IGNITION]

Heres the actual service bulletin...

 

[BUBBAS IGNITION]

Heres the Ford actual spark advance bulletin. I noticed the " hot dogs" at Newport always ran the 40A distributors.
Looks like 8 more degrees of timing , as Smokey would say " cheatin bastards"

 

[Mark Slight]

Bubba, you get a A+ for your efforts and attachments!
Thanks, Mark