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Jim I was wondering what type of balancing you use with your engines, static or dynamic. I am sure at 30000+ rpm balance is a major factor and some what of a black art.
If anyone is interested, I would take the time to explain in detail, with photos, about the automatic fuel metering carburetors used on these engines. The carburetors are 100% maintenance free & have been thoroughly tested & used for more than 23 years.Jim Allen
As for the dyno, I think a fairly simple and accurate instrument could be constructed using a set of reduction or speed increasing belts and pulleys, connected to a generator (such as a 2 HP treadmill motor) and a variable resistance load. The RPM can be read by a simple tachometer and the power can be determined by the actual DC current and voltage along with the previously measured (or estimated) efficiency of the generator.
Quote from: strictlybusiness1 on July 22, 2014, 03:28:40 AMIf anyone is interested, I would take the time to explain in detail, with photos, about the automatic fuel metering carburetors used on these engines. The carburetors are 100% maintenance free & have been thoroughly tested & used for more than 23 years.Jim AllenJim more information for the info hungry newbies like me would be much appreciated!
Jim,I've been following your thread and your work is first rate. I appreciate your photos and explanations. Having built miniature I.C. engines for a good number of years I have played with many types of carbs. I do have a very sophisticated O.S. carb that has a similar setup of which you describe. It has a small tapered slot around which the barrel rotates to control fuel flow through the idle and mid range. It also has needles to help assist in low, medium and high fine tuning. For my type of work the biggest problem I see is trying to calculate the required slot taper and the amount that the barrel has to rotate to uncover a given area of fuel flow. It's a very simple setup for your purposes using the 2 stroke pulses to pressurize the fuel system which is common to RC engines but I'm afraid trying to adapt this to my small 4 cycle engines would actually involve more complexity than what I currently use. It does give me more insight into other systems being used, thanks. gbritnell