Lars
Having taught engine theory at the Provincial Trade School Level for 7
years what exactly do you want to know.
To figure piston travel in feet per min (normal) you need to know the
stroke of the engine.
Piston travel in feet per minute= stroke in inches X 2 X RPM/12
IE for a 318 at 3000rpm it would be: 3.31 x 2 x 3000/12=1655ft per min
4600 rpm would give 2537 ft per min
Max safe rpm for general use would be 6340 rpm which would give a piston
speed of 3497 fpm with 3500 being considered the safe max for normal
design although some like it to be 3300fpm which would lower the rpm
to approx 6000.
To find mph take rpm divided by gear ratio which gives the number of
axle revolutions per min times the diameter of the wheel in inches times
3.14 divided by 12 which gives the number of feet traveled per min
Multiply that times 60 which will give the number of feet traveled per
hour. Divide that by 5280 gives the MPH
IE 3000rpm/3.23(gear ratio)=928.79 axle rpm
TD of 24" X 3.14=75.36" traveled per axle rpm
So an axle rpm of 928.79 X 75.36"=69993.614" per min
69993.614"/12=5832.80 feet travelled per min
5832.80 fpm X 60= 349968.06 feet traveled per hour
349968.06 fph/5280=66.28 miles per hour
There are shorter ways but this is the best way to understand it.
DOn DulmaGE
Lars Larson 56 Plymouth wrote:
>
> Cant find info on calculating the following-
> piston travel, ft/mile
> engine rpm at 2500 fpm
> engine revs/mile
> anyone have an automotive engineering book with em in?
> too lazy to try to figger em out!
> thanx
> L.
|
|
Back to the Home of the Forward Look Network