A great philanthropist for tethered car racing world wide over the years has been Paul-Otto Strobel. Through his long association with the late Gualtiero Picco he supplied Picco motors, not just for tethered cars but buggies and RC cars as well. The driving force behind the production of 10cc engines was of course multiple Champion Picco, but the market was limited as only tethered car racers wanted them, so restricting sales somewhat. Seeing a threat to the continued supply Paul-Otto announced several years ago that he was becoming financially involved with Picco so maintaining the supply of motors.

Following the death of Picco in 2011 the factory found production of the engines uneconomic so Paul-Otto started to commission runs of around 100 motors at a time, a not inconsiderable investment in itself. As far as I am aware, the first of these was the 8th Edition with the black enamelled head and unique, charcoal coloured, crankcases. There followed the red head Testa Rosso and finally the green head Passione, which is currently the motor most in use.

When the supply of Picco motors looked as if it would cease, Paul-Otto took the immense step of commissioning Profi to produce, not just 10cc, but 5cc and 3.5cc tethered car motors. Profi did produce an immensely successful 2.5cc engine, but as a front induction would require an extensive redesign and new dies, totally uneconomic for a very restricted market.

The 5cc and 3.5cc had rear Zimmerman valves, and as proved by the late Jan-Erik Falk and Michael Schmutz could be made to perform exceptionally well. The 10cc was a different beast with a double crank to drive the Zimmerman and a rotary, Yamaha style, exhaust valve. Exhaust valves are nothing new in tethered cars, but they were usually part of the external exhaust system. These though were incorporated in the castings, very close to the liner to give maximum effect. Unfortunately, a legal wrangle over the dies Profi used required the whole batch to be reduced to produce and the internals sold on, ouch. So the Photo this month shows the range of Strobel Profi motors, including the one that never made it.

All the Strobel motors produced by Profi had the POS rocking horse logo embossed on the transfer passage.

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