Fabian
Well-Known Member
Headsmess you are impressively good at prolixity.
The crowded roller bearing seems to handle higher stress levels than the caged roller bearing, at the expense of higher safe rpm, which explains why Japanese and European bikes use a well designed caged big end in their 2-stroke engines.
With respect to the Chinese 2-stroke engine, the crowded bearing gives significantly greater bearing life, going from my experience; covering a heck of a lot of miles.
I am entirely consistent in saying that (for long term reliability) the Chinese centre mount 2-stroke engine lives a happy life under 4,800 rpm. Once you go over that figure, even with short bursts it compromises connecting rod bearing life, and if you beat on the engine with excessive rpm, the case hardening on the needle rollers fail; resulting in either seizure or simply ejecting the needle rollers out of the big end and tearing up the piston and cylinder.
This concept is anathema to those seeking maximum power; where they have no requirement for long term reliability, nor engage in long distance touring at relaxed rpm and relaxed speeds.
Why though would you waste your time beating on a Chinese engine when you could install a Morini engine into your bike and properly take advantage of the much improved engineering specification, if high rpm and high power is the desired outcome?
The crowded roller bearing seems to handle higher stress levels than the caged roller bearing, at the expense of higher safe rpm, which explains why Japanese and European bikes use a well designed caged big end in their 2-stroke engines.
With respect to the Chinese 2-stroke engine, the crowded bearing gives significantly greater bearing life, going from my experience; covering a heck of a lot of miles.
I am entirely consistent in saying that (for long term reliability) the Chinese centre mount 2-stroke engine lives a happy life under 4,800 rpm. Once you go over that figure, even with short bursts it compromises connecting rod bearing life, and if you beat on the engine with excessive rpm, the case hardening on the needle rollers fail; resulting in either seizure or simply ejecting the needle rollers out of the big end and tearing up the piston and cylinder.
This concept is anathema to those seeking maximum power; where they have no requirement for long term reliability, nor engage in long distance touring at relaxed rpm and relaxed speeds.
Why though would you waste your time beating on a Chinese engine when you could install a Morini engine into your bike and properly take advantage of the much improved engineering specification, if high rpm and high power is the desired outcome?