Roger,
I have to admit I had to read that passage in the Yowl twice; ‘did he just say what I thought he did?!’ I was going to write a response, but figure, naw, it just had to be an oversight. But if you have not already done so, you should send in a clarification identifying (most important) and correcting (less important) the wrong bit, as there probably are a lot of folk that do not know any different and are going to accept the whole as gospel based on your excellent reputation with Scotts. To err is human, but to ‘fess-up is manly (an point fingers is politic!) You have sort of hinted about it here, but for those reading this that are wondering what bit is the fuss about, specifically it has to do with the rollers needing to skid to equalize the difference in circumference between the inner and outer race of the big end. At first this may seem like an profound anomaly, but in reality the rollers can maintain contact without sliding by the effect called precession. The difference between the distance traveled by the roller, rolling against the outer race compared to the inner race is made up by the rollers advancing – or proceeding – around the crank pin. This can be easily be demonstrated to non-believers with a caged ball bearing (before seals hid the action.) Holding the outer race and rotating the inner the cage rotates with, but at about half the speed, as the inner. For those that still insist some small amount of skidding must be going on, silence them by give the analogy of a planetary gear train. The teeth do not allow any slippage. There is a lot of thought provoking ideas in what you contribute, so I would hate to see the less technical folk left to wonder what was the wheat and what was the chaff. Though they do say a little bran is good for the diet!
Of course rollers can skid under certain circumstances. Snapping the throttle open in neutral or ‘blipping’ was always said to be unkind to the rollers.
I do have some other thoughts to toss into the fray on the subject of eccentric crank oil grooves, but there is another post specifically on that subject so I will place them there for debate. I would be interested to see if anyone thinks they have any merit.
Best regards,
-Doug
