07 - Attaching Motor to Transmission

This open-source kit uses a pre-fabricated adapter plate and coupling provided by Electro Automotive. You need to tell them that this is for an S20 transmission on a '92-'95 Honda Civic. They might ask you for a flywheel bolt pattern to confirm that the adapter plate is correct. Delivery time is between six and eight weeks, so be sure to order your adapter early. At this point, it's a good idea to replace the clutch pressure plate, throw-out bearing and friction disk because taking this system apart in the future will take a lot of work.

Setting the Advanced Timing on the Motor

Honda Civic's are different from other vehicles because their engine shaft turns in the clockwise direction instead of counter-clockwise. You'll have to make sure the brushes on your Warp9 motor are rotated in the proper direction (CW) to get the proper advanced timing. There are instructions on how to do this here:

http://civic-ev.blogspot.com/2008/08/rotating-brushes-on-warp9-motor.html

Mating the Motor to the Flywheel and Transmission

Directions for installation come with the adapter plate. You can see pictures at this blog entry:

http://civic-ev.blogspot.com/2008/09/attaching-flywheel-to-warp9-motor.html

http://civic-ev.blogspot.com/2008/09/attaching-motor-to-transmission.html

I've included the instructions that came with the adapter here:

1. Separate adapter ring and profile plate. They were bolted together for ease of shipping.

2. Bolt adapter ring to motor with 3/8"-16 allen capscrews provided to 35 ft-lb of torque. (I added blue threadlock too)

3. Bolt adapter profile plate to adapter ring with 1/2" - 13 bolts provided. Make sure to orient the motor so that the high-voltage terminals are on top and one of the 1/2" motor hoisting holes is straight up. Torque to 35 ft-lbs. I added blue thread-lock too.

4. Test-fit the key in the bushing (on left) before assembly. It should slide easily. If it does not, rotate it 90 degrees and try again, as one orientation might fit better than the other. If there is a difference, use the fit that slides easily. Insert key on motor shaft (picture above). My shaft key didn't fit in the motor shaft and I had to file down the sides a bit before it went in. Hopefully most folks won't have to do this...

5. Your hub may have an indexing dimple or scribed line on the inner edge, next to the bushing. If you have the indexing mark (mine did), be sure to align the slit in the bushing with the mark. Slide the hub/bushing assembly over the shaft and key. The assembly should move freely on the shaft.6. Gradually tighten the 10-24 allen-head screws in the hub/bushing assembly (see picture above) until the assembly will move on the shaft only with some slight effort. DO NOT USE ANY LOCTITE ON THESE SCREWS.

7. Mount the flywheel on the hub, using existing flywheel bolts. Tighten just enough to hold the flywheel firmly in place on the hub. (I used two bolts to ease the installation)

8. Move the flywheel/hub assembly until the distance from the face of the flywheel to the face of the adapter is .774" +/- .010" I used a straightedge to extend the face of the flywheel out to the face of the adapter plate to measure this distance with my calipers.

9. Once the spacing is correct, carefully remove the flywheel without disturbing the position of the hub. Tighten the 10-24 allen-head screws in a "star" pattern (criss-crossing to tighten bolts in opposing pairs instead of going from one to the next in a circle). Tighten firmly by hand, but without upper arm strength, as it is possible to snap off these screws. The necessary torque is less than 1 ft-lb.

10. Re-install the flywheel on the hub with red loctite and recheck the magic distance. If the distance is incorrect, determine the amount and direction of error. Remove the flywheel and loosen the allen-head screws about 1/2". Free the hub from the bushing with a sharp rap on the bolts using a brass hammer. Reposition bushing on shaft in the direction and amount to compensate for the distance error. Re-assemble as above.

11. Lock the flywheel from rotation and torque the bolts to the manufacturers specifications. This torque is 87 ft-lbs for the Honda Civic. Since I knocked off the starting teeth from the flywheel, I didn't have anything to hold it steady. Instead i used a piece of angle iron with a hole in one side to hold the flywheel still using two of the clutch plate alignment pins.

12. If your hub has a brass pilot bushing, lube it with a thin layer of molybdenum based grease. I don't believe the Civic has this pilot bushing.

I wanted to make sure the motor spun well with the flywheel installed, so I attached a local armature-to-stator wire (S2 to A1) before attaching a battery. I used Noalox anti-corrosion compound and heat-shrink tubing with integrated heat-glue to keep the connections tight.

After installing the clutch disk and pressure plate (using the centering tool for alignment), I spun up the motor with a the Civic's original 12V battery to make sure it ran in the proper direction. Since the voltage is so low, I didn't worry about over-reving the motor. If I had used 144V, over-revving the motor would be likely.

Preparing the Assembly for Installation

At this point you'll probably want to put masking tape over all the vent grilles on the Warp9 motor to prevent metal shavings and other dust from getting into the system.

You'll also need to cut part of the tail shaft of the Warp9 motor off to prevent interference with the Civic chassis. Cover the tailshaft bearing with masking tape to prevent metal shavings and other grit from entering the bearing. Cut most of the Warp9 tail shaft off, leaving 3/4" of shaft to bolt the RPM sensor to.

You can find more pictures at:

http://civic-ev.blogspot.com/2008/10/cutting-tail-shaft.html

Making the Rear Motor Mount

Acquire a piece of steel 1/4" thick and 8" x 12" in dimensions. Use the pattern provided in the files area with a ruler and compass to trace out the outline for the motor mount. Center punch all the holes, cut the outline and then drill the holes out with the large center hole last. After cutting out this pattern, bolt the pattern to the rear end of the Warp9 with 5/16"-18 bolts 3/4" long. These will have to be removed later for powdercoating, so you don't have to make them too tight.

Installing the Motor/Transmission Assembly

Reference pictures at:

http://civic-ev.blogspot.com/2008/09/blockages-from-motortransmission.html

Place the whole motor/transmission assembly on a heavy duty furniture dolly. Add a 1/2"x13 eye-bolt to the lifting hole on the top side of the Warp9. Attach one end of a length of 1/4" chain to a bolt on the transmission just aft of the shaft centerline. Use a bolt, two washers and a nut to attach the other end of the chain to the large 1/2" eye-bolt. Try hoisting this assembly a few times with the engine hoist to find the right length of chain to use and which link to attach the hook. You want the whole assembly to remain mostly level, both front-to-back and side-to-side.

The motor/transmission assembly is longer than the typical engine hoist is wide, so you'll have to rotate the assembly 90 degrees to slide it under the car and still fit between the hoist legs. Once in place, you can lower the engine hoist to attach the lifting hook to the chain. After lifting the assembly by 4-5 inches, you can carefully rotate the whole thing 90 degrees into the proper orientation. Slowly raise the assembly bit by bit, watching out for blockages as you raise. You should be able to raise the assembly enough to re-install all the bolts on the transmission end of things. Make sure you get all bolts for the left motor mount, the front transmission mount and the rear transmission mount.

Once the transmission is bolted in place, add a vertical 2x4 support under the Warp9 motor so that you can properly align the rear end of the motor with the driver-side engine mount.

Remove the driver-side motor mount from the original engine. You are going to have to cut away part of the underside of the mount in order to allow for clearance to the angle iron it will attach to. There is a clearer picture of this at:

http://civic-ev.blogspot.com/2008/10/bolting-together-rear-motor-mount.html

Next, acquire a 5" long piece of 2" angle iron 1/4" thick. We'll be using 3/8" bolts to attach this angle iron to the motor's tail-end mounting plate and 1/2" bolts to attach to the driver's side engine mount. Use clamps and two 1/2" nuts as spacers to properly hold the 5" piece of angle iron in place. The angle iron should be centered front-to back on the center 3/8" hole in the vertical plate. Adjust the height of the angle iron so that there is at least 3/16" of space between the top edge of the vertical plate and the underside of the angle iron. This is needed to allow the 1/2" bolts to fit since the clearance is very tight. When everything is in position, use a scratching awl to mark the 3/8" holes through the vertical plate and the 1/2" holes down through the engine mount.

Unclamp and remove the angle iron, then drill out the marked holes. I made the 3/8" holes 25/64" so that I'd have a little wiggle room in case all the holes didn't line up perfectly.

Re-install the angle iron by adding two 1/2"-13 x 1 3/4" bolts with nuts to the angle iron. Then bolt it to the backside of the vertical mounting plate with 3/8"-16 x 1 1/4" bolts and nylock nuts. The spacing between the angle iron and the engine mount is very tight, so you'll need to experiment possibly with different bolt lengths and spacer washers. Finally, flip the engine mount down onto the upright 1/2" bolts and add two 1/2"-13 nylock nuts to hold the mount together.

Licensed under the TAPR Open Hardware License (www.tapr.org/OHL)