Strokin' and engines

Posted by Mike West

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

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