The Stovebolt Site Forums The Shop Area The Electrical Bay Remote Alternator location!

Adding air to my 235 and not 100% happy with options for mounting the alternator. Thinking about mounting my alternator off the frame next to trans with a pulley at the 'U' joint. vs cluttering up the inline 235 motor. Compressor can mount where the generator would be. I've seen this in a rod magazine some time back and thought it was very trick. Any input would be appreciated either way, pro or con on this idea.

The alternator would only run when the truck is moving, so whan you're sitting at a stop light, you will be draining the battery.

Look at the size difference between the alternator pulley and the crankshaft. The alternator needs to turn several times engine speed, so unless you're running interstate speed all the time, powering the alternator off the driveshaft isn't an option. I have run small alternators mounted on the transmission tailshaft, turned by a big pulley welded to the slip yoke, but that was on a dirt track race car, just to keep the battery charged during the race. We started out every night with a fully-charged battery, and probably didn't run 20 miles all night.
Jerry

I think you would be better leaving the alternator where GM put it and if you want a compressor, put it on the other side like GM did on their trucks with air brakes.

All good points, I was planning to run a larger pulley on the yoke and smaller on the alt. spinning it faster. I realize that stop and go traffic would be a killer but my drives are mainly at highway speeds. Just think it would be something to try and very easy to undo.
Thanks

I don't see it as a bad idea at all. They switched from generators to alternators because the gen didn't charge as much at idle. Alternators do. Alternators were not designed to run primarily at high rpm's.

I've been giving some thought to doing the opposite approach, on a none stovebolt application. CCOT AC systems cycle the compressor off and on periodically. How inconvenient would it be with the AC pump driven off the driveshaft? In light traffic the pump wouldn't be off that long at most lights.
This has got to be crazier than the alternator.

Does anyone have factory specs. for this GM alternator, ie. output at various rpms?????

Mad electrical offers these numbers for the internal regulated 63 Amp 10SI.

The available output at a 680 rpm idle is 35 - 40 Amps

rpm required for maximum output is 1275 - 1325 rpm

Remember that alternator output current is determined by the needs of the battery. Voltage is controlled at a constant level by the voltage regulator.
They consider the typical alternator output to be about 3-5 Amps while driving down the road with no lights or AC. It doesn't matter if you have a 30Amp or a 130 Amp alternator. That's all the battery needs.

You could switch to an electric AC compressor, and run a bigger alternator.

Richard, Your idea of the remote AC compressor vs alternator may be a better solution. I'm just thinking easier to run longer wires vs. ac hoses. Would there be any problems with the longer hoses required for such a system or the frame mount in general? There appears to be a good mounting location at the frame.
Thanks
Jim

Jim -

Check my alternator location:

http://www.joefuchs.net/gallery/gallery.php?eventid=5

Go thru the pictures until you get to the underhood shots of the alternator. It works great in that spot and the A/C compresor is in the generator spot.

Joe

Where do you find the electric AC compressors. I've googled them but can't seem to find anything.