Dual pulley progress report

[Olddaddy]

I've been working on a dual pulley setup to be able to run an alternator and ac pump on the later style narrow belts. I made up a dual row pulley using an original flathead harmonic balance and welding a second row pulley onto it. It will work and with some effort would do a nice job.

I also learned that late model slant/6 and small block mopar crank pulleys have the same bore as the flathead pulley. The keyways are smaller, but a stepped key, or enlarging the keyway would make them fit perfectly. This would make it possible to run two, three or even four belts since those pulley can be expanded to that many rows. It might create some difficulty in terms of space between engine and radiator, but might work. I considered running three rows, one for water pump and alternator, and two for AC pump.

Then I learned that even later mopar serpentine pulleys will also fit the flathead crank. Same issue as above, keyway needs to be enlarged, or a stepped key used. This would make it possible to use a serpentine belt and have all the accessories on one belt, and most importantly held close to the original belt line of the engine. That should eliminate the clearnce issues between the engine and radiator. It also allows use of the newer magnum style alternators, (high output) and the much smaller R-134 AC compressor.

I am posting a pic of the modified original flathead pulley (on the right) and a slant/6 two row pulley with the optional third row pulley in the background. Pending storms prevented pics of the serpentine pulley, but I will post them later.

[Tony_Urwin]

Charlie, how did you modify the original crank pulley? Did you simply remove the outer flange of the pulley with a grinder or cut-off tool and then weld another pulley on the front? Am I right in thinking that this setup is 2 of the wide-type pulleys?

The pulleys for the slant/6 obviously pose a problem: The hub is a different depth, so the pulleys sit back inside the engine mount, right? Maybe a stock 4 pulley setup for the slant/6 would yield 2 pulleys in proper position? And are the slant/6 pulleys the wide-type?

When you talk of the smaller R-134 A/C compressors...smaller than the Sanden 508? Or are you talking about a Mopar OEM compressor?

Thanks for sharing!

[Plymouthy Adams]

I believe when Charlie and I last spoke he was thinking of the C171 small rotary Chrysler compressor. I also used this compressor and adapter my bracket to fit the Chrysler big block 383. This compressor was not in use at the time the 383 was in production...worked out real well...

added note....I also used small block pulleys on the crank hub/balancer along with a Ford water pump pulley for proper alignment...

[Tony_Urwin]

What pulley is on that compressor? Wouldn't it use the newer narrower belts?

Is it possible to mix the two types of pulleys on the same belt?

[Olddaddy]

Tim was right on the compressor, it's an oem Mopar and pretty small. It has a serpentine belt, but I suppose a v-belt clutch could be installed on it. I made up my dual row pulley with a pair of narrow belts, but I could make up wide ones also. I would not cut them on anything but a lathe to assure concentric centers. I planned to cut the hub off a flathead pulley to use as a spacer behind the slant/6 hub to allow me to "bush" it out to correct position. However, at this point in time I am in love with the possibilities of serpentine belts. That's where my efforts are at the moment.

[billwillard]

Does thay sound cooool or what. I love the serpentine belt idea. Please keep us informand.