Build an Electric Car: Installing the Motor

Before putting the motor assembly together take the flywheel to the machine shop and have the flywheel balanced. This may be a good time to replace the pressure plate and clutch disk and start with new ones. Also inspect the throwout bearing on the transmission shaft.

The motor is mounted to the transmission with an aluminum adaptor plate and spacer ring. The adaptor plate is made of 1/2 inch thick adonized aluminum. Adaptor plates are available for a whole range of cars. The spacer ring ensures correct clearance between the motor shaft and the transmission shaft. The hub, which is attached to the motor shaft, is used to mate the flywheel to the electric motor. And the clutch assembly bolts to the flywheel as it did on the gas engine.

The first step of the motor assembly is attaching the hub to the motor. The hub in the kit is machined with a key way, two threaded holes for the set screws and a matching bolt pattern for the flywheel. Once the hub is on the shaft drill into the shaft through the set screws holes so the screws will seat properly. Blow out any metal shavings and screw the set screws in place. Two set screws are used for each hole, one on top of the other.

Position the motor so the terminals are easily accessible once the motor is mounted in the car. Next, position the spacer plate and adaptor plate to the face of the motor and bolt them into place. Bolt the flywheel to hub. Then bolt the clutch assembly to the flywheel. Make sure all the bolts are tightened to the correct specifications.

Once the motor assembly is complete, it is lowered into the engine bay and bolted to the transmission. It may take a few tries to align the shafts of both the motor and the transmission so an engine lift and an extra set of hands is real helpful. After the unit is bolted into place, with the drive wheels off the ground, put the car in gear and rotate the tire to make sure the motor shaft is also rotating. After this test hook up the motor to a 12-volt battery and briefly run through the gears to make sure everything is working and well balanced.

At this time the car’s new heating system is also installed. The new heater pumps hot Prestone solution through the existing heater core. The unit uses the existing heater controls and operates when the heater lever is moved to the hot position on the dash. The tank above the heater supplies Prestone to the heater. The heating element is powered by the propulsion batteries and the unit’s pump is powered by the 12 volt system.

There are other options for heaters as well. A popular heater being used today is a resistive heater that resides where the heater core is inside the heater plenum in the dash area. This heater requires no plumbing like the other heater described above. In some cars such as the Ford Escort the heater core can easily be removed from the heater plenum behind the glove box. The ceramic element of the heater is powered by the main battery pack. This unit also can use the same heater controls on the dash.

Getting back to the motor we need to securely bolt the motor to the frame of the car. One end of the motor is already anchored to the frame with the transmission so we need to secure the other end. The kit comes with a motor support that wraps around the motor and has a base to provide an area to mount a bracket to the car. You have several options here. Attaching a brace from the upper motor mount attachment points on the car to the motor support is a common option. For rear wheel drive cars the motor support can be attached to a brace that attaches to both frame rails. In rear wheel drive cars it may be also necessary to add a torque bar from the frame of the car to the motor to prevent the motor from twisting in the motor support when the motor is started.

For this conversion a rack system was designed to span the width of the engine compartment to support not only the motor but the controller, three batteries, and the battery charger as well. The rack is made of 3/16 inch thick angle iron. The rack rests on top of frame rails integrated into the unibody construction of the car. A smaller rack is located where the radiator used to be. This rack will support three batteries. It helps to build fomecore models of the racks for positioning purposes. You can also give the finished model to the welder. Below is a photo of the finished rack.

Get professional detailed electric car conversion Manual, click HERE

Next step is installing the components

 

January 10, 2009 · Filed Under Build an Electric Car

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