13. 1958 MGA Twin Cam
The original motor offered in the MGA was a fine engine, but someone at MG decided that the MGA needed more power and the company offered an optional high-performance engine with dual overhead cams. This motor was not the upgrade that MG wanted it to be. The engine leaked, burned pistons, fouled spark plugs, and caused all kinds of headaches for owners. Unless you were a gearhead and routinely checked timing, fuel octane, and made sure to stay within RPM limits the Twin Cam motor would break apart and puke oil all over the place. Long after the vehicle was retired, the problem was narrowed down to the carburetors. At certain RPMs the fuel would froth, causing a lean condition and burning the pistons.