Part 4
Perhaps at this point I should mention that the Stuart 600 was not
supplied as a finished engine, only as a set of castings, for the
enthusiast to machine and assemble, Stuart's offered to machine
certain items ,at some cost, which were too large for the builders
lathe, also optional were a second flywheel, a cast sub base, ignition
was by wipe contact and trembler coil ,they did offer a magneto kit,
with mag, mag bracket, chain and sprockets though the cost was over
half the cost of the engine casting set ! The engine would run on gas
or petrol and again a Stuart
carb was an extra. I do not know when the engine was introduced but I
have a page from a catalogue that builders had completed engines
before 1923 and its generally thought that it was taken off the market
around 1940 . Why build your own engine? well prosperous amateurs at
the time usually had to treadle their lathes, building an engine meant
youcould stop tredalling, mains
electricity was not generally available and electric motors were very
cumbersome and expensive ,mains coal gas as a fuel was available, plus
if you could obtain a small dynamo it was possible to charge the lead
acid glass cased accumulators to power your new radio, other wise it
was a trip to the local radio shop to get the accumulator charged. I
have seen a set of 600 drawings, so cannot comment if our engine is
built exactly to drawing though it does appear to be similar to other
Stuarts I have seen, screw threads are BSF with a few BA threaded
screws. I spoke to Charles about this engine many years ago, he told
me that when running on gas the hit and miss governor did not work
that well and was not suited to evenly drive a dynamo, so he had about
three experiments with petrol carbs regulated by the fly ball governor
and eventually succeeded in getting an even running engine, he said to
me that his work was a little Heath Robinson but it works very well, I
did try it on propane gas but as Charles found it is not ideal.
So I
decided to continue with the reliable late 1930s Amal
carb, after all it did run for a very long time with this arrangement.
I was also very lucky in finding a fellow enthusiast who had a Stuart
sub base and got me a new casting using his base as a pattern, the sub
base certainly improves the appearance of the engine by raising the
bottom of the flywheels above the base level.
Nigel Mcburney
