The Stovebolt Site Forums The Shop Area Driveline 1954 Engine Fan Clearance

The previous owner of my 1954 Chevy pickup did not do much mechanic work in the past 25 years. So as I am fiddling around, I end up finding issues.
During the process of cleaning out the radiator fluid and engine cooling system, I found the thermostat completely shot. So it was equivalent to not having one.
Since I got that deep into it, I assumed the waterpump might never have been replaced or rebuilt so this would be a good time for a new water pump.

That is not a simple option. I looked at multiple sources which all say that they carry the waterpump that is for my model year and engine.
They all fit the engine, but the issue is really about the pulley size, so that my fan belt will work. And yes, based on some other forums here at Stovebolt, you do have to pull the radiator to get the fan off. But it is just 6 bolts so not a big deal.

The second waterpump I purchased has the correct pulley, but I realized the pulley sits a tad farther away from the engine block (toward the radiator).

A fit check was in order, and that is when I realized that the gap between the fan and the radiator reduced from ¼” to about .1”. maybe will be 1/8” when I tighten everything up.
That seems awfully close for the fan blade clearance. Therefore I think my solution is to just put the old pump back on. The bearings feel really good, the same firmness in rotating as the bran new one.
I thought I should check with all you smart people out here to get your opinion on the fan clearance to the radiator. Is .10" too close for a reasonably conservative comfort level?

New Old Truck Owner

Does the water pump impeller fit into a single large hole in the block, or does it have two holes in the front of the block that the pump bolts onto? The correct engine for a 54 truck will have a high mounted pump that aligns the fan with the center of the radiator, a cast iron pulley that is pressed onto the pump shaft, and a fan that bolts directly to the pump without a removable pulley. 2nd.-series 1955 and later engines have a lower mounting position for the pump, a bolt-on pulley, and about 2" or more of shaft between the pump body and the pulley flange. There is an adapter plate available that makes the early style water pump fit the later engine, sold by a member here on the Stovebolt forum.

The fan should not run nearly that close to the radiator- - - -there should be at least 1/2" or more of clearance.
Jerry

Thank you Jerry,
Mine is the earlier model. You are exactly correct in that it has 2 holes for fluid flow, the fan is aligned with the center of the radiator, with the pulley pressed onto the shaft and the fan is bolted on the pulley with 4 X 1/4" bolts. The newer one I bought clearly fits exactly the same in every way, except the cast iron body is just a little thicker.
I think the only other method I can figure out, if I want to use the newer pump, is to also buy a new radiator that is thinner. But I'm not there yet.

Thank you for your support. It is so great to get second opinions.

Keith

A simpler approach would be to machine the face of the pump pulley back a little, or press it back toward the housing if there's room to do that. When I converted one of those pumps to a double belt arrangement, I machined the cast iron sheave away altogether, leaving just the hub with the 4 bolt holes, and used a sheet metal 2-groove pulley for a Ford 302 V8. I used a 2-groove balancer for a 250 Chevy six to run the second belt for an air conditioner compressor and an alternator. Worked great!

It would also be a good idea to check on the condition of the motor mounts- - -two back at the bell housing, and one under the middle of the timing gear plate at the front. It's possible that the engine has shifted forward due to worn or broken mounts.
Jerry