Just saw this on egay. A flathead with the alternator driven of the drive shaft?? Is this a common thing? First time Ive seen this. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=4546694810&category=6235
. I had a friend who did that on his SBC powered fiberglass 34 3W. He had a LOT of trouble with it........ Under the car is a hostile place for a alternator, AND it is not turning when the car is sitting at a light or at idle. The RPMS are not as high on the driveshaft as the RPMS on a engine either I would NOT do it.....just my 2 cents .......
This has been around for a long time and I've always wondered how well it worked. I could see it being OK on a primarily highway driven car but stop and go traffic could result in a dying battery, especially at night. As Deuce said the driveshaft RPM's are less than engine RPM's until you reach high gear, then they are the same in a 1:1 high gear transmission. With an overdrive trans the driveshaft speed is actually faster than engine speed, so in that scenerario it might be a slight advantage. Weighing all factors I wouldn't do it. Frank
race cars like porsch and other gtp, gtr gt1 racers usde it all the time but on any street driven car there are lots of problems. that car looks like the belt is just looped around the drive shaft.
i did it once on a Model A roasdster , never had any problems...but it was never driven in any heavy trafffic/stop and go...plus there wasn't a heavy current draw like electirc fan/air it had an amp gauge and would show a slight dischage at idle , and would go to charge as soon as it started moving i don't think i'd do it again , there wasn't any advantage to it
I've seen this a few times, but mostly on "show cars'. The main reason seems to be because it's different & therefore a talking point. From a practibility stand it's not worth the effort (my viewpoint) & as has been mentioned by others cops heaps of water & mud if you choose to drive your on anything other than a "perfect" day. Cheers.
Tucked up by the axle isnt as hostle as you'd think. The new Mustangs mount the alternator down in teh lower left corner of the engine, level with teh crankshaft pully. It gets nearly as much road spray in teh rain as a rear alternator would, and it's made to last at least 100,000 miles driven year round.
Been discussed here a few times: http://www.jalopyjournal.com/forum/showthread.php?t=122753&highlight=driveshaft+alternator http://www.jalopyjournal.com/forum/showthread.php?t=89519&&showall=1 http://www.jalopyjournal.com/forum/showthread.php?t=69754&&showall=1 http://www.jalopyjournal.com/forum/showthread.php?t=42898&highlight=driveshaft+alternator
About 20 years ago a friend mounted an AC compressor in his A coupe and ran it off the driveshaft. Worked ok till he got in slow traffic or had to stop.
My two cents worth from building both race cars and hot rods: Driving the alternator from the prop shaft is very common on road race or circle track cars , because there is so much more competing for front-of-engine space (dry sump pump,structural engine mounting plates,etc.). Since a race car starts once (hopefully) and then runs at high speed the rest of the time , this works quite well. But I would never do it on a street car for all of the reasons mentioned already.
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