Our family shop installed hundreds of top oiler systems in the early 1950's, and there was a need for them back then. During the Korean war, the quality of gasoline available for civilian use was extremely poor, and "top oilers" were sold to combat carbon deposits that led to sticky valves, detonation, and other driveability problems. By 1955 or so, the gasoline quality improved and we removed a lot of the systems we had installed just 2-3 years earlier. "Aviex" brand tune-up oil was one of the best, better than Marvel Mystery Oil, Casite, Bardhal, and Wynn's Friction Proofing.
Pre-1955 Pontiacs, pre-1949 Oldsmobiles, and 1932-53 Fords ran flathead engines. So did all the MOPAR 6-cylinders up to 1959. Chevy NEVER ran a flathead- - - -even the 1920's 4-cylinders were OHV engines.
Jerry
