Bored, so I nerded out on rad/stroke ratio

[rapieper at yahoo.com (Ron Pieper)]

Momma wanted to watch her Thursday night TV, and the kids were in bed, and it was too cold to work
in the garage, so with nothing else to do, I figured I'd see what the the scoop was behind varying
the con rod/stroke ratio.

Gotta DIY, being me, so I did some trig in Excel and a little (very crude) derivation, I came up
with this:

http://scirocco.dhs.org/cheapassron/misc/rodratio.jpg

No units (AFA ft/s/s, etc.) but I do believe it works as a visual aid.  The center of the graph is
TDC.  Obviously something is wrong with the Y axis offset, but I think the shape is right.  

This is not new news, but from what I see, it tells me that longer rod/stroke ratios lead to
overall lower piston acceleration rates (meaning less stress and higher revability?) and later
peak accleration (meaning compensations in cam (less overlap required?), intake, and exhaust
design, but what exactly I don't know).  Anyhow, some of you MatLab gurus may want to pick up on
this and discuss what positive impacts one could make on a NA engine.  Oh, and fix my spreadsheet
(verrrry crude) http://scirocco.dhs.org/cheapassron/misc/piston_speed.xls

Now, back to your normally scheduled discussions...

=====
Cheapass Ron
'81 Scirocco S - "Victor Jr."  7SM
(2.0L 16V, GL 4-speed w/ Quaife installed, Megasquirt coming...)

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