Pugnator нарыл:
The V/P Index number is the product of the effective volume times the effective compression ratio, times the number of cylinders, times a correction factor weighted to produce a number roughly proportionate to torque in ft./lbs. at low speed. Please note that this number is best used for comparison purposes (before & after changes in compression, &c.), not as an absolute prediction of engine torque.
V/P = VE Ч CP Ч N Ч .3%
Symbol Meaning Definition or Calculation
B Bore Piston diameter, in inches
S Stroke Full (nominal) crankshaft stroke; TDC to BDC measurement (180° rotation), in inches
SE Stroke, Effective Stroke measured from intake valve closing point (less than 180°) to TDC [always less than S”, supra]
VN Cylinder Volume, Nominal B2 Ч S Ч .7854 (1 cylinder)
VE Cylinder Volume, Effective B2 Ч SE Ч .7854 (1 cylinder) [always less than VN”, supra]
VC Chamber Volume VC = VN ч (CRN - 1). Total volume (1 chamber) above piston @ TDC, in inches.
N Number of cylinders (4, 6, 8, 10, &c.)
AP Atmospheric Pressure 14.7 psi @ sea level (zero elevation); use the correct lower figure for higher elevations
CRN Compression Ratio, Nominal CRN = (VN + VC) ч VC
CRE Compression Ratio, Effective CRE = (VE + VC) ч VC [always less than CRN”, supra]
CP Cranking Pressure (absolute) CP = (CRE1.2 Ч AP)
GP Gauge Pressure GP = (CRE1.2 Ч AP) - AP. To predict gauge pressure, subtract atmospheric pressure (14.7 psi @ sea level, &c.) from absolute pressure. See supra: .
V/P Volume/Pressure Index V/P = CP Ч VE Ч N Ч .3% (.3% or .003 is a correction factor to return a useful 2 digit number roughly proportionate to torque)
Note 1: Mark Juric, a reader & patron has generously supplied a Microsoft Office 2000 Excel spread-sheet for easily solving these equations. To download a copy, click here:
Note 2: RB Racing has a similar calculator (and many others) on-line, click here for a look:
В общем если выше читать то это просто индекс объема цилиндра/давлению в нем в ПСИ. Это лишь показывает оптимальное давление в цилиндре для достижения МКМ на малых скоростях.
В общем вот линка на полную статью:
http://victorylibrary.com/mopar/cam-tech-c.htm
