Ok! Stupid Math time. Here is the Process for the G's of acceleration at 4000 RPM
4000 RPM.
1000 firings per minute.
8000 Reversals ( Top and bottom. Actually, it would be 7998, but for ruond #'s it is close enough. )
Wouldn't that be 2,000 firings per minute, since four-cycle internal combustion engine ignites every two revs? 1/2 turn=intake, 1/2 turn=compress, 1/2 turn=power stroke, 1/2turn=exhaust
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Assume the engine has a 3.88 Stroke. ( That is for my V-10. chevy 350 is 3.48 )
Remember, that is average spped in the cyl. Here is a diagram of a cyl to help with the rest of my math.
stopped (Bottom dead center) -- Medium speed -- top speed -- Medium speed -- Stopped (top dead center)
So the average spped (medium) is exactly 1/2 of top speed, whcih means top speed of the piston at 4000 RPM is about 30MPH. Now remeber, the stroke is 3.88 inches, so that piston is accelerationg to 30 MPH in about 1.94 INCHES. That is about the distance from the #1 key to the #4 key on your keyboard. That is insane. A top fuel dragster might hit 30MPH in about 15 feet.
Speeds like this is generally expressed in m/s
Ok, now for the physics. we must Convert to Metrics ( how annoying ) So 1.33 inches = .033782 meters. 30 MPH = 48 KMH = 48000 Meters/minute = 48000/60/60 =
That means that the piston is accelerating to 13.3 meters per second in .033783 meters.
That will give you 393.7m/s^2, or in words, velocity increase by 393.7meters/second, every second.
how annoying? Start with meter to begin with and you'll be a happy camper. I was all confused with inches, meters and crap.
Well you got this wrong.
30mph=48.28km/h =48282meters/HOUR= 13.4meters/second
Plug that into our acceleration forumula. Acceleration = change in velocity / time taken for change.
change in velocity = 13.3 m/s
Time taken = 1/133 second
13.3 / (1/133) = 17728.9 m/s^2 acceleration.
one G is = to 9.81 m/s^2 17728.9 / 9.81 =
1807 G's of acceleration ( my last post was in error as you can see )
Um.. Thats screwed up completely as well.
393.7/9.806=40.14 note: 9.806m/s is gravitational acceleration is and this is referenced as 1G
and you have 40.14G
That means that the 2 lb piston has 3600 LB's of force on it when it is spinning at 4000 RPM. That is about the same as a Lincon town car.
Say .91kg piston has 1.6E04 N of force when it is spinning at 418.9 rad/second .
Not only can you see how much force is on that piston, but you can see how monumentily in-efficent the engine is. If 100% of the force was transfered to the wheels that 3600 LBs of force would be equal to about 1800 Horsepower. And that is only one cyl.
The other cylinder is always pulling in different direction and it smooths it out.
METRIC RULES!!!!
Edit: sorry.. I screwed up so many times on doing the quotes properly.. I'm using bold, cuz its easier to read than italic, but if there's error oh well.
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