Tuesday, March 8, 2016

EV Conversion - Electric Karmann Ghia: Car, Chevy Volt batteries, engine removal, shaft coupler preparation

Electric Karmann Ghia - EV Conversion 

Now that I have perfected the electric go cart I would like to move on to something bigger and more fun. I decided to do an electric vehicle conversion of a classic convertible that I can use for cruising in the summer with my family.The idea is to find a cheap, light, old car that has alot of style. Doing an EV conversion would improve performance and reliability and make the car easier to drive. It also reduces emissions.

Please note that this blog is for information only. These are not directions or instructions. Working on cars and especially electric cars can get you injured or killed.

The Car

 I was looking for a lightweight, four seater convertible and manual that could be had for less than $8,000.  I found a 1971 Carmen Ghia on Craigslist.org that fit the bill nicely.

Once I had the car, the next step was picking a configuration and then making a parts list.
I decided on a DC motor because they are cheaper and easier to work with. I decided to use a used battery pack from a Chevy Volt or Nissan Leaf because they are the cheapest way to get a high capacity battery. I ended up finding a Chevy Volt battery in a salvage yard for an amazingly low price. I used the website car-part.com to find the battery.

The Batteries

The Chevy Volt battery pack (13 14 15 CHEVROLET VOLT LITHIUM-ION VOLTAGE BATTERY 16 KWH PACKAGE OEM J from eBay)comes in a T configuration. It is encased in a steel frame on the bottom and a fiberglass top. The top is removed by taking out all of the bolts. Once I did that, it was still tethered by the service disconnect wires.

The service disconnect port. T40 screwdriver was needed to remove.

Here is the battery pack exposed without the top cover. I always wear insulating gloves when working near the batteries.

The batteries are covered by plastic protectors with all of the battery management system wires and connections. This view shows the battery terminals exposed by removing the plastic cover and connectors. Extreme caution must be used when coming near the exposed contacts.

The modules are all connected with hydraulic tubing. The hose clamps were loosened before removing the batteries. There were thru bolts on each side of the battery holding them together as well. This image shows the black bolt pulled out.

There were also straps holding the cells together. On the bottom, there is a metal strip holding the batteries in place. After removing the nuts, the metal can be lifted up to allow the batteries to be removed.

This shows a battery section removed.

Here is the battery pack with one section removed. You can see the hydraulic cooling connectors.

I connected the modules in a parallel configuration using the oem connectors and measured 169.6 volts. That works out 3.53 volts per cell. My plan is to have the battery split into 4 sections of 96 volts and run them in parallel to achieve 192 volts. I figure I can fit 3 sections in the rear, were the engine is and the fourth in the front trunk where the spare tire is.

Removal of Engine and Gas Tank

Now that the batteries have been extracted and set up, next item is to remove the internal combustion engine and gas tank from the Karmann Ghia. This is a view of the engine with the battery and air handler removed.

Here is a views of the car with the gas tank removed from the front.

We lifted the car and rested it on cinder blocks with 2x6 lumber on top. We then used a floor jack to lower theengine after disconnecting the four 17mm bolts. It took a while to locate the bolts and get them removed. Once they were out, the engine came off the trans-axle easily.

View from underneath. The car has to be pretty high up to get the engine out. You will notice we had ramps and a 2nd jack set up for safety since the car was not that stable on the concrete blocks alone.

Engine lowered down to the ground with the jack. Job well done. We had enough clearance to roll it out from under the car without hitting anything.

Preparation of Shaft Coupler and Adapter Plate

Now that the car is ready for the electric motor, I had to get the shaft coupler and motor mounting adapter plate ready for installation. I went with a set from Wilderness E.V. The adapter is set up for the Warp 9 or ADC 9 motor and configured for air cooled VW mounting. The coupler uses the existing clutch which is bolted to a plate and then mounted on the transmission along with the motor.

This shows me drilling holes in the shaft coupler plate to match the holes in the clutch disk. I used spray paint to trace the hole location on the disk. I used a drill press because it was impossible to do it by hand.

 Clutch disk with spray paint around the rivet holes.It was really annoying to get the rivets out so that the bolts could be placed.
 This shows the dowel alignment tool that was used to center the clutch disk on the shaft coupler plate. This was given to me by Advance Auto Parts. If the disk is not centered, the plate will wobble and vibrate as the engine speeds up. The dowel tool was wrapped in plastic and tape to snug up the connection.

Supplied bolts are used to attach the shaft coupler plate and clutch. I added washers so that the nuts don't compress into the clutch material.
 I bought new bolts for the motor mounting adapter plate.
 This shows the dowel tool resting on top of the motor mounting plate with the shaft coupler on edge.
 Dowel tool inserted into shaft coupler
 Dowel tool coming through shaft coupler into clutch disk
 Final result, clutch disk mounted to shaft coupler plate, hopefully perfectly centered.

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