5-7Heaven,
Do you think a high horsepower 2-stroke (3-4 hp) works well on friction drive or is better suited to 'non-tire chewing' methods of drive?
-Lowracer-
I have run modified 460 engines on friction drive. Although many MBers haven't had tire-chewing issues, I believe I've worn through more tires than anyone on both forums, especially on high-hp engines. Another problem with friction drive and the 460 is its lack of torque at low rpm, ESPECIALLY climbing moderate hills.
I believe that the shift kit and extremely low gear ratios are key to keeping high hp/rpm engines within their narrow power bands. My 460 and Tanaka 47R engines work exceedingly well with shift kits,especially with 37.09:1 first gear. Steep ramps and gridlock traffic on moderate hills are easily handled. The 37.09 gearing is akin to Happy Time setup with an 89-tooth sprocket. Believe it or not, with 34.91:1 gears(like an 84-tooth sprocket), I have difficulty climbing the same ramp and hill.
On one particular hill near home, I always needed a good running star with the 460 engine and friction drive. It did not matter if I used 1.25", 1.375" or 1.50" rollers. Once the rpms dropped below its power band, it was like running a 1 hp engine. Also, there was no way of regaining low rpm while on a decline. I would have to reach the hilltop before the 460 would begin to increase its rpm.
Surprisingly, you don't need a super HD rear wheel to handle high hp with the shift kit. I've been using SS 14-gauge 32-spokes on double-wall Alex rims for a year. I've had one loose spoke, that's it, no other issues. My Armadillo tires have lasted a year with no appreciable wear. They should last for a few more years. When the rear tire wears out, I'll rotate the front tire to the rear and install a new front tire.
Hope this helps.
