Motor Mounts: Serving the FE3 on Adapter Plates

Mounting the FE3 to the Miata using the stock motor mounts.

The original FE3 Miata used stock Miata mounts (bushing and cup) bolted to a 1/4″ steel plate which was bolted to the FE3 block’s bosses. This is a simple solution that avoids extensive fabricating and puts the transmission shifter in the center of it’s “pass through” hole in the tunnel.

The disadvantage is that it moves the engine forward in order to position the stock Miata mounts behind the forward bosses so the steel adapter plate can bolt up. This position also required moving the stock sway bar mounts forward to avoid contact with the A/C compressor. It’s less than ideal for overall weight distribution in the car, but didn’t have any long term negatives nor impact handling in a street environment. Nuts for the Miata mount to bolt too are tack welded to the back of the steel “adapter plate.”

Below are some templates that can be scaled to reproduce adapter plates for both sides.