The Ford Barn

JayJay · 11-13-2024, 10:21 AM

The aluminum 2-blade fans are notorious for not fitting on the water pumps because they rub on the snout of the water pumps. Snyder’s instructions (https://www.snydersantiqueauto.com/c...INUM%20FAN.pdf) talk about this, and Snyder’s should know, they manufacture these things for all the vendors. The solution is to turn or grind down the snout of the water pump housing. I’ve had to do this to four water pump housings in the last two years, and have built a jig to clamp an assembled pump in the lathe to make it quick and easy. I turn the nose to about 1.630" (1-5/8"+) from the nose to where the boss for the front grease fitting comes out.

If you don’t have the pump apart and can't chuck it up in a lathe, the way to do this is to put fresh paint on the snout, then slip the fan onto the shaft and turn it as you very lightly press on it. It will rub and leave a mark on the pump where it hits. File or grind that down, then continue. When you have it turning freely, take just a bit more off to allow for heat expansion. Repaint the snout and you’re ready to go.

The reason this happens, especially with “leakless” pumps, is that the bore (or overbores in the case of the “leakless” pumps with bearings) may be perpendicular to the mounting surface, but may not be exactly centered on the front of the nose. The cast aluminum fans, on the other hand, are a bit thicker than the original stamped fan, and interferences develop.

11-13-2024, 10:21 AM	#16
JayJay Senior Member Join Date: Jan 2020 Location: SF Bay Area Posts: 2,670	Re: Replacement 4-blade fan. What say you? The aluminum 2-blade fans are notorious for not fitting on the water pumps because they rub on the snout of the water pumps. Snyder’s instructions (https://www.snydersantiqueauto.com/c...INUM%20FAN.pdf) talk about this, and Snyder’s should know, they manufacture these things for all the vendors. The solution is to turn or grind down the snout of the water pump housing. I’ve had to do this to four water pump housings in the last two years, and have built a jig to clamp an assembled pump in the lathe to make it quick and easy. I turn the nose to about 1.630" (1-5/8"+) from the nose to where the boss for the front grease fitting comes out. If you don’t have the pump apart and can't chuck it up in a lathe, the way to do this is to put fresh paint on the snout, then slip the fan onto the shaft and turn it as you very lightly press on it. It will rub and leave a mark on the pump where it hits. File or grind that down, then continue. When you have it turning freely, take just a bit more off to allow for heat expansion. Repaint the snout and you’re ready to go. The reason this happens, especially with “leakless” pumps, is that the bore (or overbores in the case of the “leakless” pumps with bearings) may be perpendicular to the mounting surface, but may not be exactly centered on the front of the nose. The cast aluminum fans, on the other hand, are a bit thicker than the original stamped fan, and interferences develop. __________________ JayJay San Francisco Bay Area ------------------------ 1930 Murray Town Sedan (under reconstruction) 1931 Briggs S/W Town Sedan It isn't a defect, it's a feature! Last edited by JayJay; 11-16-2024 at 08:45 PM.