In the article "Electric Volvo Amazon combiI described the exploration and feasibility of converting my Volvo Amazon combi to fully electric. In this article in the series the first conversion steps are discussed.
De-ICE ing and weighing
After weighing the car as a whole, the stripping could begin. First of all, I have expanded the engine and gearbox. Or the ICE-ing as it is called in electrical conversion terms. ICE stands for Internal Combustion Engine.
After that, the car was back on the weighing setup. The car weighed 1219 kg in advance. Now I arrived at 333 kg for the front, 585 kg at the rear and therefore a total of 918 kg. At the front it has become 244 kg lighter and at the rear 58 kg, a total of 300 kg lighter.
The increase for the electrical components is around the 420 kg
- Siemens AC motor = 86 kg
- DMOC 645 controller = 27,5 kg
- 90 CALB LiFePO4 batteries = 306 kg
Then the gearbox is added again, so the total expected weight increase was approximately 450 kg. This brings the total to around 1370 kg. The curb weight is originally 1174 kg, so the increase is 196 kg. Even if that were to be 250 kg, 500 kg of the 250 kg payload remains. I planned to put 65 batteries in the back and 25 in the front. Considering I lost more weight in the front than I thought, 60-30 seemed a better distribution. Then the front remains about the same weight and the increase is behind.
Puzzling and fitting
Now that the car was empty, the big puzzle could begin where which electrical components should be placed. Based on the weighting, I came to the conclusion that it was better to place 30 instead of 25 cells in the front. The question is, does that fit? To get an idea of the dimensions of the motor and controller I made dummies from cardboard. The Siemens AC motor is more or less in the same place as the old B20 motor. The biggest issue was where I could put the relatively large controller (DMOC).
Cardboard is nice for a first indication, but little shape exactly and shape fixed. That's why I was the first to get started with the powertrain.
Upgrade gearbox and engine modification
The Siemens AC motor that I am going to use has a torque of 300 Nm peak in the range of 0 to 3000 revolutions.
A standard M40 gearbox cannot handle this (long) and the bearings will wear out quickly as a result. That's why I'm going to use an M400 gearbox. This comes from a Volvo 164 and is one of the strongest gearboxes that Volvo used for the rear-wheel drive cars at that time. Moreover, by using this tank I can keep the long gear lever characteristic of the Amazon.
A special adapter is made to attach the electric motor to the original clutch housing. Not only the gearbox gets an upgrade, the engine is also modified. The Siemens AC motor is equipped with a shaft with splines from the factory.
However, this has been redesigned and further developed by Garage 71. The shaft is removed from the motor for this purpose, turned and provided with a keyway and a puck. An important advantage is that you now have less height. On the one hand, this is beneficial for the transmission of the forces and at the same time the adapter between the motor and the box becomes thinner and therefore cheaper. In addition, the overall installation length decreases. The end result will then look like this.
Continue fitting and measuring
Then the whole of the engine and box could be hung in the car.
The good news was that the motor and controller were a lot more compact than my cardboard molds. The cables on the controller turned out to be quite short and the bonnet, despite its convex shape, quite low. This made the controller fit more or less in the front of the original radiator.
Re-using the original Volvo B20 engine mounts was not an option because the Siemens AC engine is slightly wider. That is why I started making a prototype with some corner pieces.
The engine is very slightly under an angle. However, this should be able to compensate for the universal joints of the drive shaft. Using the prototype, Garage71 drew the support and had the parts for this laser cut from 4 mm stainless steel.
In the end we welded the support 'in the work'. This puts the engine in place.
After these first steps of the conversion to electric I started with the restoration of the car. More about that in a next episode of this Electric Volvo Amazon combi conversion series (tag # old volvo-electric) on AM Classic. Want to see a preview or more details in advance? The project can be found at www.oudevolvo.nl/ev-combi.