Thread: 2000 rpm View Single Post
 02-27-2009, 04:52 PM #27 (permalink) superchow Master of 140 hamsters     Join Date: May 2008 Location: Lacey, WA Posts: 183 Hamster - '07 Honda Civic EX 90 day: 29.41 mpg (US) Whooshy Wagon - '04 Volvo V40 90 day: 23.33 mpg (US) Minotaur - '09 Ford Taurus X SEL 90 day: 19.05 mpg (US) Thanks: 1 Thanked 8 Times in 7 Posts Rearanging that formula to output RPM... (720 * Piston speed) / 2 * Stroke in inches = RPM Honda Civic 1.8L stroke = 87.3mm = 3.437 Ideal piston speed (for most engines) = 16.4 to 19.8 ft/s Solving... @ 16.4 ft/s, RPM = 1718 = 39.3 mph @ 19.8 ft/s, RPM = 2074 = 47.4 mph These numbers coincide with my high (successful) FE attempts. Now I just need to find that darn BSFC chart for the R18A... *sigh* p.s.: Someone with a diesel engine shout out their speeds at a given RPM - then we can figure out why diesels can run so slow and still get their awesome FE. Logic would dictate a longer stroke than gasoline engines to stay within the "best" piston speed range. __________________