Stewart Warner RPM id
 

Hi all , need to id a couple of tachos i picked up recently , made by Stewart Warner 3 to 2500 rpm , from 21 to 2500 rpm is marked in red , has the number 424 CH N6 stamped onto case in ink and the number 63900 cast in the rpm cable drive stem , olive drab rim with a u clamp and 2 wing nuts to lock into dash.

cheers dave

Hmm
 

I remember the 2100 red line area would be typical for something like a Diamond T, which ad a plate warning of engine damage if that limit was exceeded for any length of time.

Does it have a resettable warning pointer on it?

Hi Gordon , yes it does.

cheers dave

Probably a standard fit then
 

From memory, I've seen it on the Diamond T 4 ton 6 x 6, the Mack NM series, and the DUKW - not sure where the red line was on the DUKW though.

DUKW red line is 2750 RPM.

David

Hi Dave,

Can't help ID it, but thought you might find this site interesting regarding the numbers you posted.

The N6 is the date code, N:1945, 6:june

http://www.ruiter.ca/mc/info/SWSpeedoDating.html

Cheers,
Ian.