32 replies to this topic

[Tim Wilkins]

What year would this motor have been produced?  https://www.ebay.com...IAAAOSwC5NfAmEX

[zipper]

After 1969 -1970 I'd say, don't know when that Gr 15 incarnation came out.

[Bill from NH]

Tim, I ran those pink Mura motors in Phaze III chassis from 1970-75.in weekly racing at Modelville Hobby. So they would have been produced in 1970 or before.

[TSR]

Yes, end of 1969 through 1972, and they are  "B"  "stock" motors with armatures left unbalanced, and while their can is painted pink, they have nothing  to do with Cukras. The asking price on that motor is a bit over the top for a "Group 15"... but hey, if you need it... 
Whatever.

[Bill from NH]

You didn't need to buy a multiple of these motors to find one that ran decent. These pink B-cans ran faster than Mura's Green C-can equivalent on the Modelville Orange. Racers who tried the C-cans, quickly switched back to the pink cans. I still have my motors from the 70's. The one I cleaned up, now is wrinkle black w/ a blue endbell & added buss bars. 

[TSR]

Bill, it is strictly due to what's inside the cans. The Mura C-can was subjected to cheap Group 12 arms and cheap magnets, all the way to power monsters with Champion mags and S23 arms... BUT... the Mura C motors being smaller and lighter,it is possible that the "B" motors, far heavier, applied more down force on the rear tires and thus, made the cars faster for another reason than raw power, especially on a tight "road course".
Speculation of course since I do not know what the track and what was inside those "C-can" motors compared to what was in the pink "B".

[Bill from NH]

I never bought any of those C-can motors, but someone gave me one of their rejects. I took it at the time because it represented a free new can & endbell for my use. I might still have it around. If I do & can find it, I'll check the mags & arm. We were told these motors had the same short-stack arm as the pink B-cans, but maybe that was just a distributor's poetic licensing. The Modelville Orange was the same track we ran NCC 20's. The humps had been removed, the racing surface was epoxy paint, & the track had plenty of power. The winter of '73, I race-directed the weekly races on this track.

[TSR]

 

We were told these motors had the same short-stack arm as the pink B-cans, but maybe that was just a distributor's poetic licensing.

Bill,
very unlikely since the Mura "C" requires a shorter armature than the "B". The "B" arms are almost 1/8" longer...