110-555 or this ...

[Henry W]

As soon as I find out I'll let you know.

[mobile_bob]

the thing about the 3 step programmable regulator/controllers such as the balmar is they are in effect an electronic transmission
and you can program them to work with about any sort of mechanical pulley ratio.

balmar calls it their small engine mode, wherein the controller is programmed to allow the alternator to work with the available power.

so you could use any pulley ratio you like, and have the ability for the limited power available to still work well.

i have a r175 i built up several years ago, i use a single multigroove belt (6 groove iirc) and it runs over the flywheel making contact with the back of the belt, then over a lift gate motor which i modified with an A/C clutch to be a starter motor, then up and over the top via an idler and then down over a pulley driving an alternator. the alternator pulley i am using is 2.4" so the alternator is spinning its butt off.

the hehr controller i used to set it up allowed me to adjust the output of the alternator to use the available power, and it works fine.

while i have never used the sterling regulator/controller, my bet is it too can be programmed to allow you to drive the alternator with the available power from the engine of choice.

i didn't have a larger pulley, i had 6 or 8 of the 2.4" pulley's so i used what i had on hand knowing that the drive ratio was much faster than i would have liked.

i don't recall the output numbers i was able to achieve with this setup, but i do remember this much, it must have been acceptable to me or i would have taken it apart and done something else and would not have proceeded with designing and building an exhaust heat exchanger and done testing to develop it as the alternator would have been the only thing i had to drive to provide loading on the engine to test the heat exchanger.

knowing me, i would have ran the engine at an rpm sufficient to have the alternator running at or near 6k rpm maximum, as the 555 has a max rpm of 8k rpm.

i would also expect that the 170 and the 175 would be similar in drive capabilities, however i would have to go out and measure the flywheel diameter and get back to the forum with that information.  i might be able to get the shop cleared enough to get a picture of the r175 unit and post it as well.

bob g

[Henry W]

Ok, this is probably the largest 8 groove pulley that should mount directly to your alternator.

Neihoff pulley: part #A3-229


https://enginepartssuperstore.com/Category/A3-229/C-E--Niehoff-Alternator-Pulley


These guys are almost in your back yard. They are the ones that found the pulley. Give them a call, they do pick up.
https://prestolitesuperstore.com/

Its 99mm (3.898") in diameter. I was told it's a direct bolt on.

[Henry W]

These numbers represent rpm's. The numbers will give a fairly close idea what a drive pulley ratio of 2.437 could be at certain engine speeds. The engine flywheel is not grooved so there will be an error on the alternator numbers. The alternator numbers will be higher than posted.

Engine 1000---Alternator 2437

Engine 1200---Alternator 2924

Engine 1400---Alternator 3412

Engine 1600---Alternator 3899

Engine 1800---Alternator 4387

Engine 2000---Alternator 4874

Engine 2200---Alternator 5361

Engine 2400---Alternator 5849

Engine 2600---Alternator 6336

[Henry W]

Keith, it's been a while. Did you get a pulley?