Well in 1961 Fox produced the Fox .40 Rat Race engine. I assume people used it way back then. Fox had anodized it with a gold like yellow color sheen. But I think they quit doing it later though. Fox used the Fox .35 Rocket crankcase and stroked the engine with a longer stroke than the .35's. That resulted in there being a larger gap between the head and the top of the engine crankcase. Later Fox released the RC version of the engine too. Fox used a sticker on the side of the engine to denote its model, but the sticker would quickly disappear when in use.
