12v Alternator on an 8v71

[Ryan B]

Hey folks,

I've got a tiny little bank of batteries (just one right now actually) and I wanted to throw on an old car alternator to keep it charged. I'm just not sure where to mount it. I haven't picked up the alternator yet because I want to find out if the size will matter or if there's any type I could get that might fit right in already. Has anyone done this? I was also looking for the original 24v alternator to see if I might tack onto the same belt but I'm starting to think it might not be belt driven because I can't find it anywhere...

Thanks!

[Timkar]

My 24V gear driven alternator is on drivers side at "rear" of engine (towards front of bus)

[bevans6]

Your MC-9 will have a gear driven alternator hung off the back of the engine on the driver's side.  There is an accessory pulley on the front of the engine that you could use.  It's about 7" in diameter and it rotates at engine crank speed.  You will need to figure out how to get the alternator to run at a speed that it can use, which is about three times engine speed.  I would look in the engine bays of your bus for a Vanner battery equalizer, if you have one of those you can use it to charge your small 12V batteries.  The Vanner is a box about a foot high, six inches wide, two inches deep and has three terminal posts on one end.  Mine was mounted to the luggage bay wall beside the battery cut-off switch.

Brian

[rgrauto]

Rydrman, on my 5a mci I used the empty ac mount on the right rear to place a 1968 ford diesel alt.(the reason I used this type was it was new and I already had it),It is 120 amp, heavy duty but it requires an external regulator with switch wire to turn it on or off.  To turn the regulator on/off I used a Gm two wire oil pressure switch/ sensor hooked to the 8v oil supply to activate a cube relay,fog light relay, to  activate regulator.  And yes I know I could have used a Alt. with a built in regulator and saved a lot of time and trouble but I the parts I had was almost free so why not use them.

[rgrauto]

Rydrman  The alternator I used was a 1986 ford diesel not a 1968 ,sorry not enough coffee ,yet !

[luvrbus]

A 1 wire Delco 105 amp driven from the camshaft pulley on the front engine will handle your needs in the future as the bank grows

[TomC]

I know at our dealership, we have new alternators for about a buck an amp. Generally there are two styles-J that uses a swivel mount to tighten the belt. And the other is a pad 4 bolt mount to be used with a serpentine belt that has an idler pulley to tighten the belt. One wire with built in regulator and some have a second wire for voltage sensing at the battery for more accurate charging.
You could remove the giant Delco DN50 and replace with two belt driven alternators. Good Luck, TomC

[bevans6]

If I had a gear driven alt, I sure would think hard on replacing it with a belt driven something.

Brian

[Ryan B]

Thanks everyone,

So it sounds like my best bet will be the accessory pulley at the front of the engine... Does anyone know what kind of mounting I will need, or do they make some kind of universal one?

[bevans6]

You have to design and fabricate it yourself, there is nothing off-the-shelf that can be bought.

Brian

[TomC]

A J mount will work better since then you can use the alternator to tighten the belt with the mount. Good Luck, TomC