A lot of Engineering
We are great admirers of the huge amounts of quite complex designing and engineering that went into building motors for boat and cars. The equipment available in most cases was basic compared with what we have now, the true 'home workshop', with the domestic grate being pressed into service for castings. Whether the aim was to produce a motor that was quicker than others, or an engineering exercise because the builder wanted to we do not know. What we do know is that although most of them did run they were a bit like the infamous V16 BRM, engineering masterpieces but far from successful.
As with the BRM in the immediate post-war period, we start off with supercharging. The performance of racing cars and aero engines had clearly illustrated the advantages to be gained by forced induction, but getting it working in model sizes proved exceedingly difficult as induction problems plagued all the builders
|Basil Miles supercharged OHC twin from 'Barracuda'||Bert Stalham Supercharged OHV V twin from 'Tha'|
Basil Miles' motor was sold
through Gildings in 2003, current whereabouts now unknown. The Stalham V twin is still in existence and resides with the family of
George Chapman who kindly loaned it to the Model Hydroplane Club for
display at Alexandra Palace some sixty years after it gained a medal
at the London ME Exhibition.
|Experimental unit by Andrew Rankine with a pumping cylinder||Dr Hewlett's supercharged split single|
Most of the 30cc motors being used in tethered hydros were single cylinder, overhead valve, either with camshafts at the back or front of the motor, or motorcycle style, alongside. Numerous variations on this basic layout were tried, based on full size practice, single overhead cam, twin overhead cams, gear or chain driven, radial heads and the even more exotic rotary valves. There were even examples of sleeve valve motors, a most odd choice for a high speed racing engine.
|Aspin type rotary valve||Superbly engineered OHC single|
If there was a theory, then inevitable someone would try it, and sometimes try it without there being any evidence in the first place. Full sized practice established that more cylinders produced more power for a given capacity, but again this did not translate well into models. Similarly open exhausts, megaphones, multiple exhausts were all tried to little effect.
|Eight exhausts for four cylinders||Four exhausts for one cylinder|
Twinshaft and combined engine/gear units were popular in tethered cars from the word go, especially with the smaller diesel units in the late 40s and into the 50s. Here we have two examples from the drawing board of Edgar Westbury. The Cadet based unit with the integral gearbox was described in a long series in Model Car News and the dies for the gearbox were in existence until a few years ago. The Craftsman Twin based twinshaft was built by Harry Rae but was not direct drive as it had a starting pulley on one end of the crank and a centrifugal clutch on the other, both disguised as brake drums on the 1066 wheels. We suspect the Cadet unit was also built by Harry as it has the same style of clutch. With the discovery of these photos it has enabled us to complete another (very) long term project with a profile of Harry Rae and his involvement with tethered cars.
|Westbury Cadet with integral gearcase||Direct drive Craftsman twin unit|
No connection with either cars or boats, but we include these motors as a matter of interest from one of the great 'pioneers', David Stanger. Although there are various single cylinder motors to his credit here we have a V twin, a unit built three, an inline three and a V four. These may be considered crude by modern standards but remarkable as they were built in the first decade of the 20th Century to power flying model aircraft.
|Three two stroke singles on a common crankcase||V four four stroke|
|Very early V twin fours troke, atmospheric induction||Three cylinder, twin overhead valve four stroke|
Thanks to the Westbury family for this latest selection of images, part of a far larger archive recently passed to us.