Yeah the properly lapped and mated joint faces is THE business... sorry forgot to mention that - Twas 3am-ish.
Lapped and ground with a No 10. Cornish winding engine balance beam bearing OLD beach pumice lapping compound - that is the gear...... I have cans of it at $11.99 per 250 grams.
Ummmmm the 3 millimeters BTDC timing point..
I'd say given the machinations of a nice hot engine, running at say 2/3 maximum RPM, the bore diameter and stroke, the mixture turbulence, the flame speed, and my general knowledge of the timing of mixture ignition of infernal combustion engines etc., etc., etc.. I'd say that it refers to the piston location BTDC and not the crankshaft position.
Ignition timing for optimum power - well 3mm before TDC, on the piston, that I think would relate to about 10 or 12mm on the flywheel radius - which also sounds about right.
Tho I do not know if the 3mm BTDC is right either.
Basically the suck it and see approach is to fit a water brake to your engine such as a part submerged marine propellor in water or a generator with load, or spray a fixed solid stream of of water into the rotating mower blades at a shallow angle etc., and to run the motor at say 2/3 maximum speed and find the point by adjustment of the points - where the motor pulls it's hardest and does not slow appreciably.
This simple test is "the way" to figure out the most efficient settings for the engine.
Kind of like running a lathe - it all comes down to the amount of metal you can removed in Kg per hour. It is calculated by the amount of electricity going in and the amount of metal going in the waste. The complex algorithm is all the things like feed rate, depth of cut, surface speed / RPM, cutting tool materials, coolants and surface finish etc..
The issue with motor mowers is how much physical material can be sheared off and driven through the output chute, at a specific blade speed, at a given feed rate, for a specific quantity of fuel, in a specific time interval.
This is it in a nutshell.
Although the standard 2 stroke engine really is a piece of.... has much room for improvement; a properly set up engine will cut more grass for less fuel, in less time, than a clapped out engine running worn down blades, with worn engine seals, bearings, rings and piston, a far too rich mixture, and with incorrect timing.
(toss in oil viscosity - deposits in the cylinder, head and exhaust ports etc.)
It's not ONE specific item, it's the combination of all the events that determine the most efficient conversion of chemical energy into kinetic energy.
I did not write the article - the main issue in (lifting) re-posting that Victor Specifications information, is that it has the drive side shaft taper listed on it - whichI am interested in.
And given the transitory nature of life and the web, thought it best to "copy and past it" here - before the webpage submerges never to be seen again.
Other than that - I have NO idea about the validity or otherwise of any of it.
Not like I am a fool - but I have not cross checked any of it, I don't have the factory blueprints and engineering specifications....
The only Victor manual I have - is a few pages of a shitty Haymes (?) manual photocopied from a pubic library.
BUT - in an overall sense; most of that information
APPEARS to be correct - though a touch limited for my liking.
Speaking of grumpy old men.....
Someone was selling 49cc engines online - cheap.
So I thought I'd ask a former buyer IF he thought the engine was a decent product - like so; and have a LONG slow think about the answer:
With the little 49cc engines, I gather that it may have a centrifugal clutch and a single speed reduction gear box.
What is it's peak power output, and what is your impression of it?
Does it appear to be a quality product or just chinese junk?
Would you buy a second one?The answer:
(Note: the motors do come with a manual)
It does have a single speed reduction gearbox and a centrifical clutch it is not a piece of Chinese junk. And i most certainly would buy another one because it also looks BEAUTIFUL! and i havent put it on my gokart yet so i dont know the power! Hope that answered your questions.
OH good.....
