Proper Alternator??

[GlenCoombe]

I've read the thread a few weeks back about pully alignment re alternator eating belts. Now I'm of the opinion that the alternator installed on my rig is not the correct one. I don't see any amount of "shimming" would correct the amount of difflection. Is their a proper housing that is correct or is it just a matter of the right length shaft on the armature?
Also while preparing for replacement next week what's the highest amp rating I could put to use.
Hope you all can walk me through it.
We are actually on the road doing the shake down cruise this week in Myrtle Beach SC. It was a scramble to actually get it all done, and it's a long way from what it will be but "Airstream One" is on the road finally.

I love my bus...

[ALANSD]

I installed a 135 amp on mine, and upgraded the battery isolator to handle the capacity.
It mounted with little hassle, and had no pulley alignment issues.

[john hd]

G.M. does make a 160 amp alternator, i have one in my silverado.

it came with the snowplow prep package. perhaps a little creative time spent with a G.M. parts guy could yield some results.

pulleys can be swapped if needed, most newer ones will be set up for serpintine belts.

john

[GlenCoombe]

Alan, did you specify your year and Airstream or just P30 chassis? Is 135 the highest amp rating?

[wb13798]

i upgraded my altenator and as i was doing the work i noticed the wiring was not heavy enough to take the full out put of the altenator or the isolator. i did as alan did, i replaced the isolator with a larger unit . having seen an alt and isolator that had fried plus the wiring for unknown reasons. that got my attention. i havent replaced my wiring but i see no need to as i have not increased the load on the system.
three batteries are not a lot to maintain. increase the battery bank and install a large inverter , different story.

[74Argosy24MH]

10si 12si alternators, you probably have a 12si, check the fans.

Cases and shaft lengths are the same on all I have ever seen, even the newer CS alternators have the same case mount surface to pulley centerline (with a v belt pulley) distance, but the diameter is larger than the si.

What I would really look for are belts running on the wrong sets of pulleys. The crank probably has 3 grooves, the water pump at least 2. A lot of times belts break and people have no idea how they were routed, they get everything turning again but not aligned correctly. It might mean moving all/most of them to get it right, don't let any combination go unchecked.

[ALANSD]

Glen - I used the web site for my alt and starter. www.4alterstart.com

They are good folks on the phone as well. I got the isolator off Ebay, then sold my old one the same way, ended up minimal net cost.

[ALANSD]

73-86 CHEVY HIGH OUTPUT ALTERNATOR 135 AMPS
No problem installation and no modification to bracket system or wiring is required. Alterstart uses only the best new heavy duty component parts. $79.
also the cable---
Lifetime Warranty! Stronger is Better!100% New alternator power cable. This new four gauge commercial quality cable is 6 ft long and comes with crimped 5/16" copper terminals enclosed in heat shrink tubing. The entire cable is also …

[overlander63]

Glen , there are two different hub lengths on 454 water pumps. You may have the wrong one from a previous repair. Make sure the water pump pulley is aligned with the other pulleys.

[AYRSTRM2]

Man, I thought you guys were talking about "propellor" alternators. I was dying to see how this worked. Oh, well, maybe next time.

John

[GlenCoombe]

Well some situations work themselves out.... with little bloodshed. I paid a "free" visit to my local starter/alternator shop and was advised to replace the belt with a wider one. Shop owner said the alternator was about a 150 amp in his opinion. He thought the noise was coming from either the water pump or air pump. Suggested that when I changed the belt that I give them all a spin to check. Found the air pump rather tight as it would not complete a single turn on it's own. So.... after much up and down on Thursday trying to remove said air pump without success I resigned to just put up with the noise for this week in the western NC mountains. Upon finally getting everything lined up... giving only a modest amount of blood...but lots of sweat, I get it all back together and low and behold the noise is gone!! Go figure, something worked out and it only took the better part of four hours to do it!!

from Wal-Mart somewhere just outside of Waynesville NC....

[TheGanzman]

Originally Posted by ALANSD

Glen - I used the web site for my alt and starter. www.4alterstart.com

They are good folks on the phone as well. I got the isolator off Ebay, then sold my old one the same way, ended up minimal net cost.

Great link! They even have a 275 amp offering - WOW!

[ALANSD]

Originally Posted by TheGanzman

Great link! They even have a 275 amp offering - WOW!

Check out their starters, that's what brought me to them the first time. Its been very reliable and eliminated all heat related start problems for me.

[GlenCoombe]

So at 275 amps how many horse power would that actually take to turn the alternator?? Bigger sometimes can be overkill. Just my two cents.

[TheGanzman]

Originally Posted by GlenCoombe

So at 275 amps how many horse power would that actually take to turn the alternator?? Bigger sometimes can be overkill. Just my two cents.

How many horsepower? Probably ALL of it!

[overlander63]

Originally Posted by GlenCoombe

So at 275 amps how many horse power would that actually take to turn the alternator?? Bigger sometimes can be overkill. Just my two cents.

Not as much as you would think. Maybe 35 horsepower at maximum output. I just ran the figures, and it comes out to 33 horsepower, add a couple for mechanical loss.

[mcneon]

275 amps x 12 volts = 3,300 watts; at 746 watts/HP (yes, this number is correct), this equals 4.42 HP. Figure 60% efficiency, and you're looking at 7.37 HP to run the 275 amp alternator at full output.

Bob