A single cylinder engine, elseplace than lawn-mowers, can be found in motorcyles called “Bullet” in India, or “Le Enfield” in the UK.
These motorcycles, are pre-WW bikes, having an original displacement of 350cc., and now available in 500cc too.
In India these are the most common of bikes, till now and have been used for various puposes, from delivering milk, policing, or or even for border control by the army, as ronnie would tell you.(incidentally ronnie biswas 4m juhu in '82-84?)
In fact bikes as old as 1952 are still maintained in mint condition, and that is regarded as somewhat as a world record.(check guiness? mebbe?)
These engines do not have a fly-wheel but incorporate the magneto and the clutch assembly to compensate for that. In fact they have a completely detachable gear-box, which can be taken off one bike and put on another in 20 minutes.
Low end torque is substantial, and they, even with the lack of mid-range HP, have a sweet high end ride with speeds (when tuned) 110 mph, which is more than adequate on Indian roads.
Balancing the engine is not so much about weights etc, what my bretheren here talk about, being all into hi-tech vehicles.
Balancing the engine on a 4 stroke, single cylinder bike is all about alignment, because what are you gonna balance it against?
It is about all the angle being either 90 degrees or in a straight line.
When you are balancing a single cylinder engine, all you gotta do is make sure that the crank is absolutely true, the bearing seats are true, (because if they are not, you would have an anomalous wear of the bearings) and the final drive sending the power to the gear-box is perfectly aligned.
Then, instead of timing belts in this particular engine we have tappets, which work to open and close the valves.
So instead of cast iron rocker housings, we can install alloy housings, to reduce the noise, and instead of the regular high-tensile timing gears we can install fiber wheels.
These, along with a few other changes from the original manufacturers spares, will give you an engine which is vibration free, and the only sound you hear in idling, would be a “boob!” at every other rotation.
Incidentally these engines can idle at 350rpm comfortably.
My knowledge come from the fact that I was rebuilding carburetors of these bikes at the age of 7, when I was 1/6 the weight of the bike itself(and earning money for my labors.
I could even set the timing of these bikes with touch, in pitch dark, with just a screw-driver and a 10mm spanner, and touch.
And while we are at it, lemme tell you that the ¼” spanner would work on most parts of the bike. You have 2 of them n u r set……
So lets not all get “techhy” about it, 'coz such engines do exist. And anyone who needs more info can feel free to contact me if he/she pleases.
In fact, if anyone of the members wants to come down to India n ride one of these bikes lemme know, I have not done a tour in some while and would love to take them along ths spring.
Excuse the tone, but this is something I hold dear to me heart.
And don't get me started on 2-stroke engines, please………….