The Stovebolt Site Forums The Shop Area The Electrical Bay generator/alternator pulley conversion????

I have a 216 engine and water pump with the wider older style belt pulley on them. The new alternator I purchased has the more modern narrow belt pulley. I need to change out the alternator pulley to match the waterpump and harmonic balancer belt widths. What do I do to find a pulley that will match this set-up. The alternator pulley is 2.5 in diameter and the old generator has a 3.5 pulley. I am told that the pulley I need to use has to be 2.5 in order to allow the charging system to effectively stay charged by spinning the pulley quick enough. What are you guys using??? Thanks in advance for the help, Joe

I used the original generator pulley on my 2 ton with a 270 and it seems to charge just fine.

Is the pulley your using from your generator the 3.5 size like mine? And did you have to make any modifications to the generator pulley or the alternator shaft when matting them up together? Thanks for your input!!!

I was able to replace my alternator (GM 10si) with a generator pulley when I was using it on my 216. The oly disadvantage was that it ran slightly too slow, so it didn't charge quickly at idle. I still have it sitting around on a fried alternator and you can have it if you can't get yours to work, just shoot me an email.

Thanks 4onthefloor! I will try working with what I have already and let you know what I come up with in a few days. Joe

50 Chevy - Take your alternator to a local Generator/Alt/Starter place with your old wide belt. They either have the wider pulley in stock or can order it for you. I've done two of them, the pullies are about $20.00 retail.

Speedway Motors has them. They have online ordering.

I have the 3.5" pulley and I did have to very carefully grind down the height of the pulley center to be able to put the nut back on. The larger pulleys are available from Napa, etc but I was in a cheap mood that day and it didn't take long to trim down. Mounting brackets are also available or you can look at the catalogs and figure out what to build

Hey guys thanks for all the input. I truly feel that this is the best forum on the net. I never feel let down or feel like I am asking something dumb that I am already suppose to know. I consider myself a learning novice.

I actually took the suggestion of 52pu and struck gold with his suggestion. It cost me 15.00 + tax for the conversion. Thanks again for all that responded!!! Joe 50chevy

I have the wide pulleys available and you can order online from the website and see what i have been doing in my absence. The address is fifthaveinternetgarage.com
Go to the parts counter and you will find what you need.

The pulley diameter is important. the 2.5 diameter helps increase the alternator output at idle and low speeds. Our engines do not idle near as fast as the modern engines...
It often makes the difference between bright headlights and dim headlights....
Thanks Randy

Randy, thanks for the info and the web address. I will take a look there. Joe