Picture Added 3/27/99 T. E. N.
Picture Added 3/27/99 T. E. N.
What to do about power brakes? I mentioned in one of my planning entrys that the power brakes depend on manifold vacuum from the gasoline engine. No gasoline engine, no manifold vacuum. The solution? An electric vacuum pump.
A common choice for a power brake vacuum pump are the pumps made by Gast or Thomas. I don't know what their original market was for, but it wasn't a car. They are noisy, and require an external switch to turn them on when vacuum drops.
The best solution for power brakes? Suprise! It comes from GM. Back in the early '80's when GM was using a 1.8 litre in their "J" body cars, the engine at times couldn't provide enough manifold vacuum to power the brakes. The result? GM built a nifty little vacuum pump to provide power for the brakes (GM part#2203-4995 if anyone is interested). You can get this from GM. You can also get it from Big A, NAPA, you might even try Pep Boys. The aftermarket suppliers cost less than GM, but there's a catch: there's a "core" charge. That means if you don't turn in an old unit when you buy one of their (remanufactured, I guess) units you have to pay something like $56.00 in addition to the cost of the pump.
I tried finding one of these vacuum pumps in a junk yard. The impression I get from talking to people over the web and what I saw in the junk yard, is that these pumps were only used on fully loaded 1.8 litres. The result? The average early 80's Cavailier with a 1.8 litre in a junk yard doesn't have the pump. Since this means I'm going to have to pony up the core charge, in addition to paying for the pump, I might as well spend a few dollars more and go to GM and get a new one. I plan to do this later in the summer when the car is closer to completion.
Do I need a reservoir? Some cars have a power brake reservoir to hold more vacuum for long braking, like going down a long hill. I'm not sure whether I will need one. Jerry Halstead used one of these pumps and found he needed one. Other people on the EV mailing list tell me I don't need a reservoir. I'll go by trial and error; I'll add one if I find I need one.
The Escort had power steering, which I didn't plan to support in the EV conversion. To replace it, I picked up a manual steering rack from a junk yard for $35.00. The junk yard I dealt with was on the web, so it was easy dealing with them. I Emailed them the parts I wanted, and they Emailed back whether they had the parts and how much they cost. I also looked for the vacuum pump at that point and couldn't find it.
The engine will be removed from the Escort tomorrow. I plan to pickup the engine's flywheel tomorrow afternoon and ship it to Texas where it will be trimmed and balanced. Once the flywheel is ready, they'll package it with the motor coupling and adapter plate and ship it back to me.
On the weekend of August 1, I travel to New Hampshire to pick up my electric motor, and get a first hand listening to of the Curtis controller. I also plan to visit my sister in Vermont. Anyone who reads this and subscribes to the EV mailing list knows that over the past two weeks (7/6/98 - 7/17/98) there's been a very heated discussion about the whine the Curtis 1221C and 1231C controllers make at low speeds. The discussion concerned me enough that I wanted to hear a Curtis controller before I spent the $1075.00 and bought one. Bob Batson at EVAmerica has a Curtis in his Bradly, and he offered to let me hear it when I come up to pick up the motor. You can find out a lot of things over the Internet, but some things you just have to find out first hand.
In an earlier entry, I detailed how the main power pack connected to the motor controller and other electrical devices. In the next entry, I detail how the 12 volt system works. In a gasoline car, there is a wire that runs from the ignition switch, to the coil in the primary ignition circuit. In an EV, that wire is used to provide power to the main contactors and other equipment that's powered up when the ignition switch is on. A full schematic and description follows in the next entry.
Engine Removal & Battery Racks
12 Volt Electrical System
Conversion Index
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