I have a issue with my build where i did not have the room for a (ulgy, m***ive, ruin the look, GM style alternator, and did not want it side mounted and hanging out in the wind like dog balls. I looked at rearend mounting it, but figured that might be a pain. So, here is what i came up with. I went to my local Starter/Alternator repair shop and told them I needed a small alternator, that was not a million dollars. They hooked me up with a "Denso 30 amp Alternator" model # 121902. Out the door it was $130.00. You can see how much smaller this alternator is. First problems I found... the pully on the new alternator uses a 3/8 belt...the flathead needs a 5/8. Second issue, the GM alternator uses a 17mm shaft, the new alternator has a 13 mm. I dont know if any pulley over the counter that has a 13mm ID and a 5/8 belt....so we are gonna make one out of a GM/Flathead conversion Pulley (Speedway #91016250) We need to make a "press in" sleeve to bring the conversion pulley from 17mm to 13 mm....but wait! The folks who made the alternator were kind enough to include one! This was the shim that was behind the origional pulley. Using that shim as a guide I machined a pocket into the Conversion pulley so I could then press the shim into it. I also relieved the back side of the pulley to clear the nose of the alternator. We now have a pulley that will fit our new alternator perfect! I did have to put a shim behind the spacer to lift the pulley off fo the face of the alternator a bit more, (i hate when the measuring device gives you bad information!)....no problem though, easy fix. The mount is going to be a regular flathead slingshot mount, When cut down it lines up almost perfect. Start by cuting the legs off as close to the mount as possible. Put the alternator into its new position over the bracket Determine how much needs to be removed from the leg, i took off almost an inch. You can see here it is almost a direct fit after the leg is cut. These brackets are steel, so some quick welding and grinding will give you a bracket perfect for the job. I put everything back together, and check it out!...it fits with 1" of belt adjustment. I still need to make what looks to be about a 1/2" tube shim to align the pulley with the water pump pulleys. from what i can see it may fit with a 2X3 set-up also...maybe. Hope this helps!
Nice tech! I run one of those on my truck too you can also run them without the back cover (I think they look better that way)
Great tech man! Here's a link to a '60 amp' one wire Denso I'm using. http://cgi.ebay.com/ebaymotors/CHEV...ies?hash=item5d252790cd&_trksid=p4506.c0.m245 Rich
I could have saved you a lot of work. A had a bunch of brackets CNC for the small alternator. One for the 1948 and earlier and one for the 1949 and later. The alternators on EPay are rated at 45 amps, chrome or natural aluminum.
Yea, I have seen the alternator for less money since i bought it, but I know the local guy and didnt mind supporting him a bit. I went with the natural so i could take it apart later and Iron Phos. and powdercoat it. (i am a powder engineer....I powder coat everything)....fun...we do exisist. Looks like I coulda bought a bracket too...O' well...I cant see where I would ever get an award for my thorough research. I am more of a look around the shop and figure it out kinda guy. However that is a nice bracket there "designs that work....looks like a winner
It might, not counting the tabs you could get it in a 4 to 4.5 inch hole. What is a gen. housing ID measurement?
Covered here, but I hear it can cause them to overheat. http://www.flatheadv8.org/Generator to Alternator.pdf Bob
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