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was done on a Volkswagen bus. I don't have a link, sorry.
Here's the basic stuff he did...
1. He started with a regular Volkswagen Bus that had a regular but seized Volkswagen engine in it. Out came the engine, the transmission, the gas tank, all the fuel-system components...
2. He then bought a 150-hp industrial electric motor. You want one that runs on three-phase AC power--DC motors are less efficient. You can get these in all sorts of voltage ratings; if you can find a 72-volt motor, great. Fortunately for you, VW Buses are capable of being pushed around pretty easily with a 75-hp motor, and they'd be easier to find. I was going to suggest a reach-truck motor, but they're probably too small. (I can't say for certain, because no one who makes reach trucks tells you how big the motors are.)
3. Battery time. Forget car batteries; what you want are forklift batteries, specifically Exide Workhogs. (An aside: We run Exide Workhogs on all our lifts. There is a cute little cartoonish drawing of a razorback boar on the batteries. I don't think there's been a day gone by when some little kid will point at the machine and go, "there's a pig on that machine!") With a 72-volt motor you will need two batteries because these are 36-volt batteries. You also need a DC-AC converter that puts out three-phase power.
4. Now is the time to beef up the suspension. The battery on my forklift weighs 1200 pounds. You will have two batteries, the motor and the variable-frequency drive, so you're looking at about a ton and a half of power system weight. A VW Bus engine weighs around 300 lbs.
5. At this time you need a machinist. Pick one who really likes to experiment and show up with lots of money in your checking account. He is going to do two things. The first is to modify the end of the armature on the motor so you can bolt a VW flywheel to it. He will then convert part of the VW engine case into a mount for the motor.
6. Next, you need a variable-frequency drive. This is the Modern Electronic Equivalent of a gas pedal. The VFD makes sure the motor is running at the same RPM no matter what load you put on it, which means it's a fairly complex computer. I would mount this somewhere it can get a lot of cooling air; they get very hot. This device is why you must have a three-phase motor; VFDs don't work on DC or single-phase power.
7. A trip to a steelyard will gain you some channel iron, which you use to beef up the floor where the batteries are. Bus floors will not support those huge batteries otherwise.
8. An industrial electrical supplier will furnish 25 feet of copper wire that has conductors about as big around as your thumb. I don't know the gauge, but it is probably something like octuple-zero gauge. Alternately, my electrical department sells half-inch solid copper ground rods, which could be run through half-inch PVC pipe. Raymond's electric forklifts run the power from the VFD to the drive motor over solid copper bar stock, and it works for them so it should for you too.
9. Now start bolting everything together. You'll need the flywheel out of the Bus and a clutch kit. You could modify the armature so you wouldn't need a clutch, but the Bus I remember had a clutch in it--it was cheaper to go with the clutch than to screw with making an internally-fluted hole in the armature. I guess you could weld the centerpiece out of a clutch disc to the armature after boring the armature to accept the pilot shaft end...but that would have required tearing down the motor.
10. If you want a slick finishing touch, run the charger cables up to the fuel filler door.
Alternate plan: buy a used reach truck, tear it apart and use the drive system in a car. Then learn how to write software to allow the EV to go faster than 8 MPH.
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