Introduction to Engines

Whether it is a tethered car or hydroplane, the one essential ingredient for a successful run is an appropriately powerful engine. The design of hull or chassis must not be underestimated and the ability of the builder to establish a set up which has all the elements working together perfectly is vitally important. However, it will ultimately be the performance of the engine which determines the success or otherwise of the boat or car.

From the beginning of both sports, the building and development of engines was down to enthusiastic amateurs who had the facilities and knowledge to build suitable motors. Often the success of an engine would create a demand and the builder would either end up as commercial producers themselves, or pass on the design to an established manufacturer. The availability of powerful motors 'off the shelf’ involved many who would otherwise have passed the sports by, yet there were still those who either through shear determination, cussedness, or being unable to obtain the very best motors continued to build and develop their own.

The 30cc A and 15cc B class hydroplanes continue to be the province of the ‘home built’ engines as there are few commercial motors which would be suitable. The airscrew hydro’s and smaller conventional classes use highly developed versions of aero engines while flash steam is very definitely down to the very competent and highly innovative enthusiast.

The motors used in cars today present an interesting contrast. Because of the very specialised nature of the sport, most of the engines are ‘volume home produced’, which does sound a trifle strange. Several of the international competitors design and build their own engines, but have either sufficient manufacturing capacity at ‘home’ or as part of an existing company that allows them to build batches of engines for their own use and for limited sale to others. Stelling in Lithuania and Karpusikov in Russia both use and sell their own engines. The current European Champion, Mats Bohlin of Sweden uses an engine that he designed and built, whilst Gualtiero Picco owns the famous Picco engine factory, which produces almost half the engines in use at any competition. Only the 3.5cc ‘novice’ class uses a commercially mass produced motor.

Rowell 60. MK II. This 10cc engines was the most competitive engine produced in the UK. In 1952 Joe Riding recorded a speed of 115.83 mph using one of these engines. This still remains to this day the fastest speed ever attained by a car with a British engine.

10cc Hydroplane Engine.
A home built engine based on the George Lines ‘Sparky’ design. This engine is typical of the many excellent home built engines that were used for competition in the late 40s and early 50s.

Ten-Sixty-Six Hawk. A 5cc engine with a centrifugal clutch . A commercial engine using pre war design principles for those who did not require out and out performance. Could not compete against the Dooling and McCoy 29s being imported.

It is not the intention of these pages to provide an in depth history of the commercial development of model engines. That subject has been covered extensively in numerous books and periodical over the years. This page will provide links to a growing number of articles, which will look at some of the more notable, influential, successful, and mechanically beautiful engines used in tethered cars and hydroplanes.