Quote:
Originally Posted by Stan Weiss
First let me correct myself that should be 139.5% VE
Exactly, if we look at a 572 ci engine, bore = 4.375", stroke = 4.75" at 8400 it will have the same mass air flow at 124.8 % VE.
Stan
|
Stan as the stroke gets longer, the valve lift
rate "wants" to be greater due to piston speed. Two motors same displacement with heads of same flow capabilities but different bore and stroke... the longer stroke motor isnt likely to acheive as high a VE as the shorter stroke motor... it certainly WONT if you use the same cam and rocker ratio... and making rod length ratio equal or different wont make much if any difference.
Keep in mind bigger bore motor could run bigger valves and be made to flow more than the smaller bore could... again same displacement, the bigger bore motor now has the potential for even greater VE.
VE is king in making power per cubic inch.