EV Motor Adaptor Plates

The adaptor plate mounts the electric motor to the original manual transmission and clutch of a converted EV Car. The ShockEV adaptors are precision machined on order from our library of patterns. The adaptor comes in four parts. The transmission profile plate is machined from aluminum, and mimics the original engine mounting surface. The motor spacer ring is also aluminum. It mounts to the profile plate, and recreates the original spacing between the flywheel and transmission.

Taperlock Hub
The crucial hub is machined from steel. This is a taperlock fit, the industrial standard for high rpm, high torque applications. The hub mounts to the flywheel. Its inner surface is tapered, cone-shaped. This slides over a matching tapered bushing around the motor shaft. The bushing has a split in it, and is slightly larger diameter than the inside of the hub. As the bushing is drawn into the hub by six bolts, it is compressed around the motor shaft, squeezing closed the split. Once in place, it can be removed only with a proper pulling tool.

We do not use setscrews. Setscrews hubs will fail catastrophically, regardless of Loctite. Heatshrink fit hubs are nearly impossible to position with the necessary accuracy, and nearly impossible to remove once in place.

Our adaptors DO use the clutch. We do not make clutchless adaptors. A clutchless car requires learning a special touch to drive it smoothly, and not everyone can do it. Also, it requires a lag of a couple seconds between gears, which is a safety hazard. A clutchless system is also hard on the transmission. Finally, the clutch acts as an emergency disconnect between the motor and the wheels if something should go wrong at speed.

Custom Design

We do not recommend having your adaptor built by a local machinist. While he may be an excellent machinist, he does not have background in designing adaptors. We have a selection of custom-designed, custom-fabricated tools for precision measuring of critical points on the transmission. We have also developed custom software tools to aid with the CADD design. Your local machinist will not have these.

If we do not have a pattern for your transmission, we can make one easily. We will need from you:

• the transmission
• the flywheel
• one of the flywheel bolts
• any locating dowels
• the "magic number" (This is the measurement from the rearmost surface of the engine, where it mates to the transmission, to the rearmost flat surface of the flywheel. This may or may not be the actual friction surface of the flywheel. The measurement should be accurate to three decimal places in inches.)