The Stovebolt Site Forums The Shop Area Engine Shop Water Pumps and Pulleys

Here we go. I need information about water pumps, pulleys and fans used on the 216 and 235 chevy engines. Which fans go with which pulleys and on what size of engine?

I have a 1950 Chevy Pickup with a 1956 235 engine. I know I need the short shaft water pump, but I don't know what size pulley or fan. I have seen them in almost every combination. (Probably not a good thing). I have also heard the term cavitate or cavitation...I need to be straightened out on the subject.

If someone could explain all this to me that would be awesome.

I just went through that. I used the 3" pulley first and my engine would not cool. I switched to a 5" and got it cooling. The original for the '56 engine was 6" so if you could find one that size it would probably be better. (All sizes are approximate.)

Here's a link to the discussion we had.

You can get a low dish 7" pulley off a Ford truck in a junkyard which is the perfect size for the stock water pump, just with less dish. Then you use a press to shorten the shaft. However, this leaves the water pump low on the block and the stock fan might hit the harmonic balancer. You can either go electric, or get a fan that fits.

However, the best option is to get an adaptor plate that lets you run the 216 pump on the 235, which puts it up high where it belongs.

Thanks from your help,
I will give it a shot

I just went through this same situation. I have a 55' 235 and a 53' pick up so identical problem. I relocated the radiator flanges to the rear of the radaitor so it was moved all the way forward in the surround. Got a short pump and pulley from Patricks and then went through about 4 fans and spacer setups before I got the clearance on the crank by tweaking the blade from a 56' Chevy car. It just does clear and looks like it should work. There may be a better setup but this is what I did.

Here is a deep question

Instead of buying the special water pump from Patrick's, I bought one from Car Quest, pressed the mounting plate down and cut the shaft. It fits great.

When I look in the radiator, it doesn't seem like the coolant is moving like it should. My thermostat (180) works, and it was hot when I checked it.

I am wondering if the impellers could be different on these two different pumps. The "right" one from Patrick's, or mine from Car Quest.

I have the 6" pulley

What do you think, Patrick grows them? I don't know what he charges but I'll bet he makes a healthy profit doing the same thing you did.

I might be wrong in making this remark, but I don't think you will see a whole lot of movement when looking into the opening of a full radiator.