Heat Pipe Early Fuel Evaporation

Heat pipes for providing early fuel evaporation (EFE) are evaluated. Two design concepts for using heat pipes in the EFE application are described. It was found that a heat pipe can be used as a self-regulating EFE system without direct coupling of intake and exhaust manifolds, at some sacrifice in warm-up rate from that of direct exhaust heat. A 1360 kg car equipped with an emission control system composed of lean mixture carburetion, heat pipe EFE and exhaust gas recirculation achieved emission levels of 0.7 gpm HC, 5.8 gpm CO, 1.7 gpm NOx on 1975 FTP with good cold start driveability.