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« on: March 15, 2021, 01:14:12 PM »
Topic as title, often comes into focus in different threads with detail embedded but a little difficult to find.
The primary drive chain of smaller Honda 4 cylinder engines appears to be one of the most frequently worn components, even if the other parts show very good lifing for the mileage they've completed. It may not show a good condition with even the most diligent of servicing, and so to consider some of the influences that could bring this about.
It's a Morse type chain design, developed into "Hi-Vo" as a defined product by Borg Warner transmission company. A combination that's split between very clever design and mechanical performance but opposed by very simple materials (could be considered crude) and construction that gives some fairly unique properties.
Essentially could be considered as a linear gear drive with soft engagement to rotating gear pairs, it can mask mechanical condition exceptionally well from new to old tolerances. High torque capacity but with the trade off being it's relatively heavy for given size that has an effect of centrifuge at high rotation speeds. This aspect of the design seems to be one of the contolling parameters in Honda using two small diameter gears, then changing ratio onwards to gearbox by using differential clutch drive gears to complete the primary route.
Still, it's capability has to be rotating at 10,000rpm crank speed and keep together with that attendant centrifugal force acting on it. This does in reality provide the "tensioning" with this type of drive, and why they are usually used without such devices.
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