LP-Gas Fuel Systems Affect Engine Performance

Laboratory dynamometer studies indicate that some, if not most, commercially available carburetors and related fuel systems offered for large automotive LP-gas fueled engines do not provide optimum air-fuel ratios throughout their normal range of operating speeds and loads. Such deficiencies in carburetion have an unfavorable effect on the apparent performance of LP-gas as a motor fuel, especially with respect to relative fuel economies when compared to those experienced with liquid fuels.

Data are presented comparing engine performance obtained with four carburetor/regulator systems offered by as many different equipment manufacturers for the particular automotive truck engine employed in this study. Power output, and part and full throttle fuel economy data are included, as well as data to illustrate the detrimental effects of high carburetor air temperatures. Some results drawn from other engine studies on the use of an air type LP-gas converter and the benefits of liquid LP-gas injection which utilize the latent heat of vaporization of the LP-gas in reducing mixture temperatures are also presented.