Date: Sun, 8 Dec 1996 19:56:35 -0800 (PST)
From: Mike West <mwest@cdsnet.net>
Subject: Strokin' and engines

 I will tell you what I've turned and it fits Bobs description of
2 stroke 4 cycle. He can nod or ignore us as he is wont to do. :-)

 The only place in engine calcs that "stroke" is a value is in 
"Indicated Horsepower". ihp = PLAN/33,000.

 Where "P" = mean effective pressure of exploded gases in psi

       "L" = length of STROKE in feet

       "A" = area of cylinder in square inches

       "N" = number of POWER STROKES per minute.

 
 It goes on to say: In a four cycle engine an explosion takes place
on alternate down strokes of each piston. 

 This means the crankshaft makes 2 revolutions for each power stroke.

 Then if we are considering a four cylinder, four cycle engine,there
will be 4 times 1/2 = 2 power strokes per revolution.

 In an eight cylinder engine there will be 4 power strokes per rev.
 (end quote)

 Nowhere else will a definition of "stroke" mean squat.

 I know I have been in error, one that carries over from the 8 cylinder
cars. They are truly "4 stroke".

 Our favorite beastie is a 2 stroke 4 cycle in the engineering sense
of the word. Knowing that I can calculate a value.

 OTOH many of you will prefer to keep your definitions and that's 
OK by me.

 west