Two Rod and Valve Gear Questions

[NW Mailing List]

On 8/6/2018 6:16 AM, NW Mailing List wrote:
>
> (1)  Is there always a mathematical ratio of 2:1 between (a) the 
> distance from center of axle to center of main driving crank pin, on 
> the one hand,  and (b) the length of the stroke of the piston, on the 
> other hand?  (Prima facie, this sounds like a really, really dumb 
> question... sorry.)
>
> *Yes, it can't be any other way.*
>
> (2)  In quartering drivers on axles, how far in degrees is one driver 
> advanced beyond perfect quarter, to insure that the engine will never 
> be caught on dead-center?  (And I believe N&W used right-hand lead, 
> contrary to most American practice, did they not?  If so, I wonder 
> where that practice came from?)
>
> *Quartering took care of the dead center issue on two cylinder locos. 
> Since this is something that cannot be changed while running, any 
> advance would cause uneven power pulses. I think you might be 
> confusing any "degrees of advance" with where counterweights were 
> placed to achieve cross-counterbalance.*
>

*Jimmy Lisle*

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