A part of the large Mura chapter in the new soon to be published “Electric Dreams” book addresses the success and failures of one of the most controversial slot car motors ever, the infamous B-can motor.
Devised by Ron Mura, Bob Lenz, and with input from John Cukras, the “B” was not what one would call a success (except maybe in the UK where it was widely used in the 1/32 scale racing classes) but today still fascinates the enthusiast.
I am not going to tell you the whole story recorded from the actual actors (that will be for you to read later) but I thought I would post a few of the many variants of this motor, manufactured or at least sold all the way through… 1975, something few really know.
So, in no particular order, here are a few pictures of some of the motors gathered over the years by Scott Bader and Yours Truly and now at the LASCM.
An original late 1968 “B” Production with comm vent, the original 16D brush holders with slot in the lead-wire terminal, and Ceramacoat armature:
Here is a two-hole Group 12 dating from 1970:
Another NCC Group 12 from late 1969 with the rectangular
vent hole:
A 1969 “bubblegum” with the “Ceramacoat” Team Cukras
armature and rectangular hole:
A 1972 production “B” Production with axle clearance,
produced for the UK:
This one was sold by Cobra in 1969 as a Group 15:
Another B with the two-hole pattern, built for the UK market after 1972 as proven by the end bell design. This destroys the urban legend that “B” motors were no longer produced after the introduction of the C-can motor:
Yet another B with ball bearing sold in the UK in early 1969. Note the slot in the lead-wire terminal and compare to the later motors:
One of the most famous and interesting B motors was this Long John kit with new longer magnets and Bob Green-wound arm:
A 1969 B-Production sold by REHco:
Hi In my oppinion for UK 1/32nd racing the B can Group 20 motor seling then for £ 2.50 was a great motor that won me and countless others many races. Granted the C can was better but it was much more expensive. Our club Ecurie Spa Leamington and then Warwick slot racers members loved them.
yours in slot or our of it trevor
Just curious to know what became of Ron and George Mura? In the 60’s George and his brother Nick built a Willy’s gasser style pickup truck that competed in the Oakland Roadster show. In a recent article, it states that what became of George and his brother Nick after they sold the truck in the late 60’s is a mystery. So I was just curious to know if anyone knew the story of the brothers from say 1966-on. Thanks!
Thanks for the article. I agree with Trevor. The B can Group 20 was cracking value for the 1:32 club race here in the UK and I have many happy memories of racing them.
Remember why this motor was created. Mura needed magnets and Versitec provided the solution.
The magnets in the “B” motors were from the Versitec 101. Globe tried to build a can motor since the SS91’s were just not suited. The 101 was a failure due to the poor brush set up, sticking with the 1/8 shaft diameter, 5 poles and other reasons. They were stuck with hundreds of magnets, I heard almost 3 thousand pairs. In either case this is why the motor cans were so wide, this accommodated the thickness of the magnets. Also the radius was not quite right but it still functioned. It failed because the standard was created around Mabuchi sizes and the C & D cans won out since Mura was alone with this configuration. Mura ended up using Versitec’s source for the magnets for the later designs.
Peter Lentros