Need pulley for A/C

[DDeFreece]

I need options for a pulley for my A/C. I have a 1978 Blazer with a v-belt pulley compressor. It's the long style. I'll have absolutely no problems mounting the compressor, if I can get a pulley on the engine. I want to stay with v-belt because I have a York for onboard air with v-belt. Preferably 3 groove. The compressor will go on drivers side.



Is it best for the engine to install a second pulley on the fan pulley or the crank pulley? I thought crank, but would like to hear opinions. I don't want to have slipping problems.



I have a Chevy crank pulley but the center hole is large enough that the 4 bolts in the 4bt crank pulley will be on the edge of the hole in the chevy pulley if not in the hole a little. Also, the base of the chevy pulley is of a bigger dia (4"+) than will fit in the cummins pulley (3. 5"), so I would need a spacer to set it further out to clear - about 0. 6" thick



So I need a source for a pulley that has a small hole like the cummins (. 750") and has a smaller base. I thought the late 70's chevy pulleys had a smaller base, but I'm sure the center hole is still bigger (1. 120").



So, what are ya'll using for a pulley?

 

[Steve Graham]

My 4BT was manufactured in 1988 and has the multirib v belt (8). Come to think if it I have never seen a B series with a single V belt. Now they have used them for accessory drives, but the main belt has always been a multirib belt. I would suggest building an adaptor to fit the crankshaft front end or making the pully you have fit. Shoulden't cost to much and you only have to make it once.



Steve

 

[Scot]

There are atleast 2 pulleys available from Cummins that bolt to the harmonic ballancer. I found mine using Cummins technical service. It bolts on and gives one V-groove outside the serpentine pulley. If you can't come up with a number, I think I can.

 

[smoke_em_out]

There is a company name starts with a K (sorry cant remeber name) that sells a kit. They use a special pully on the alternater. Then the York mounts on top of the alternater. I've also seen a v pully mounted behind the fan on a first gen. The name may be Kilby not sure. Hope that helps

 

[Scot]

part number is 3903826. I couldn't find the number for the first one I got but it was more shallow.

 

[DDeFreece]

You wouldn't happen to know the dia of the v-belt pulley? I found a chevy fan pulley that I modified to fit the crank pulley of the cummins but I would rather a larger dia to get the speed of the compressor up.

 

[Scot]

The actual OD of the pulley is 7 1/4" The belt is stepped down a bit inside and shows about 6 1/4" on the OD of the belt.