I've heard (no 1st person knowledge here) that the Chevy and GMC 6 cylinder water pumps of our era do not interchange. Question: Do the water pump pulleys interchange? Specifically, could I put a late 40s/early 50s Chevy water pump pulley on my '52 GMC pump and expect proper alignment of the bolts and the belt?
Bill, I know the water pumps are different but not about the pulleys. If you get the pilot hole size, bolt pattern, and depth I probably have a pulley I could make up for you. If you have the old pulley that is even better. I measure depth by laying pulley on a flat surface and put a straight edge across the fan mount surface then measure from bottom of straight edge to bench surface. Just made up an unobtainium dual groove w/p pulley for a 351 Cleveland.
Thanks guys, but there is a method to my madness. My '52 GMC with its original 228" six cylinder came to me with a 5/8" pulley on the crankshaft, a 5/8" pulley on the water pump and a dual 3/8" pulley on the Sanden A/C compressor. It has a 3/8" belt that rides on the bottom of the groove of the two 5/8" pulley, which causes slight squealing (more just a single loud chirp) when I first turn on the A/C or when started with the A/C on after sitting overnight. A micrometer measures the top of the belt at 0.39", just a smidge over 3/8". I ordered belts from two different manufacturers that were supposedly 13 mm belts. When they arrived both measured 0.47" (just under 12mm) instead of the expected 0.51" (13 mm) which still appear to ride on the bottom of the pulley, not in the "V". I sent the belts back. The 12 mm belt rode about 1/8" out of the 3/8" pulley on the A/C compressor, which I think would be OK even if it were the expected wider 13 mm. Anyway, now I'm thinking about changing all my pulleys to 3/8". A/C is already there. I'll scour eBay, etc. for a 3/8" crank pulley. I can find 3/8" GMC water pump pulleys, but only attached to rebuilt water pumps that require turning in a like part for future rebuilding. The GMC water pumps sell for around $200. Or I can buy rebuild Chevy water pumps with 3/8" pulleys for way under $100. If the pulley is the same I could put the Chevy pulley on my GMC water pump and be done for less dinero.
OK, Bill, understand now. The easiest way would be to use a Sanden 508 with a single wide groove pulley. By far the best price I have found is from Lucky's Rod and Kustom in Ennis, Texas. I don't know on the special pulley unit but on 508 regular compressors he's half the price of others.
If only it were that easy Evan. The crankshaft pulley on my 228 drives a belt that Drives the water pump and the outer sheave of the double sheave pulley on the Sanden compressor. The inner sheave of the compressor has a short belt on it that drives the alternator, so I do need the dual pulley compressor pulley.
Another thought Bill Is it possible to find a dual pully to fit the alternator (not unobtainium?) and re route the belts so the alternator drives the compressor instead of vice versa? Just a thought. Jim
Drive Pullies I had to subscribe to this as I'll be adding a Sanden AC compressor to my '69 C/10 one of these decades . My '49 Chevy 3100's 1957 235 , I used a brand 'F' 390 CID V-8 water pump pulley . When I go to the local Hot Rod Auto Jumbles these days , there's always one seller who only sells used pullies .
