don't like the look of my alt mounted up front and don't have the room for it anyhow. i could of course make a low-mount or drivers side bracket to solve the problem. i always had an image in my mind of a very clean look to the front of my motor. i'm thinking of running a 9 inch ford rearend alt mount. i will be running 2 group 27 batteries like i do on most of my rigs, and other than the fuel pump, it will have very little load most of the time. anyone have experiance with one of these set-ups?
I ran one on an IRS setup and it worked fine. Just keep in mind that many alternators have to hit a certain RPM before they begin charging (not sure why...). The alt will be turning much slower driven off the driveshaft until you get going fairly fast. Using a large pulley on the driveline and a very small one on the alt should fix this. You can get a 4 bolt flange yoke for the 9" and sandwich the pulley in between the driveline and the yoke.
It can be done, it has been done. Here is what you are in for: 1) The alternator has to spin about 3 times faster than engine rpm, so take that into account in terms of the pulley ratios. IOW if you are running an OD then you need to overdive the alt that much more at the rear. 2) The alt will be exposed to that much more water and dirt and rocks. 3) You need to mount it such that it does not hit your floor pan or interfere with your rear suspension or exhaust pipes. Other ways to accomplish the same thing: Run a flexible cable to drive an alternator hidden under the floorboards. Use Search, several examples of that here on prior threads. Incorporate a Harley alternator (rotor and stator) into your flywheel or the crank pulley. They have more poles than an automotove alternator, so they work fine at engine rpm with no overdrive.
Saw this setup at Hollywood Hot Rods when I stopped by there ...searched here and found some pics... Cable Driven Alternator... http://www.jalopyjournal.com/forum/showthread.php?t=337080&highlight=cable+drive+alternator
Q: how well does it charge when you're sitting in traffic? A: not at all Regardless of pulley ratio, blah you're running off your battery whenever the car stops, so be prepared.
Yeah i know I'm not going to have any charging at a stop, but with decent batteries i think i'll be ok. clearance isn't an issue, no exhaust running thru chassis. the radiator in the pics is just for initial fire-up. i will be running a rear mounted radiator when done. I'm really trying to highlight the look of the six. will have my triple weber intake and a large tube weedburner header with slip in baffles. one pic shows a chassis header i chopped up just to get the open flames away from the motor for test starting.
I can see the court case now "your Honor.. I had to do the burn out, my batteries were getting low!" it's been done, people have also used pto's to drive alt's in trucks/vans, not sure how big the unit was.
The driveshaft spins at the rpm dictated by road speed, tire diameter and diff ratio . . . regardless of OD - or not. OD only slows down the engine. Unless, the OD is on the rear end....
i've done a little research on a couple of the kits available. just to get an idea of how to put it together. thinking maybe a 60 amp alt with a 7 inch pully on yoke.
Mount the pulley at the transmission output yoke, not the rear end. Use the rear motor mount bracket bolts as an alternator support point. That way, there's no up and down pounding of the alternator every time the car hits a bump. Jerry
why the hell didn't i think of that! the idea sounds real interesting. i have to check for clearance issues, but it bears some investigation, thanks!
We run a Sprint car set up that mounts directly to the rear end housing. I believe it's made by PowerMaster. Shouldn't be too hard to find.
Also, if using an imported part doesn't give you a case of hemmohroids, try one of the small-diameter alternators off a rice rocket. That's what we do on the round track cars to save weight. Jerry
Serpentine belt laid on the driveshaft proper and retained from traveling via the alternator pulley with its built in guide pulley. Maybe adapt an idler arm as well? Up front near the trans.
On my SBC powered '32 roadster I ran the alternator off the rear of the drive-shaft with a drive pulley about 4" in diameter and some home brew brackets to hold it all together. It did look trick but I got tired of dead batteries and that maybe it will and maybe it WON"T start feeling I'd get. I rarely ever saw the volt meter charge enough to maintain the battery unless I traveled a long distance at 60mph plus. I ran a 4:10 gear and 31" rear tires in the rear. I always carried a spare jump box in the trunk. Used the jumper a lot in the 3500 miles I drove it. My advice............not worth doing.
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