The Stovebolt Site Forums The Shop Area Engine Shop Fan hitting radiator-

hey gang I need help on figuring out why the fan is hitting in a 1954 -1/2 that I put a 1955 235 auto engine in bolted to a t-5.When I rebuilt the engine I finished with a short shaft water pump for some reason.I'm needing about 1/2 inch and I'm questioning myself now on having the correct radiator and or a combination of it and the changed out water pump.Do we have any articles or previous discussions on this.Help and THANKs

Although not the most professional approach--you may be able to tweak the fan blades back for enough clearance. And, possibbly put some spacers in also to move the radiator forward.

I take it this is a 2nd series '55 engine. If so, is this an o.e. (bolts into the block) pump with a short shaft or a plate to adapt the 55 1 series & eariler pump to the later engine?

Yes, there have probably been a few thousand discussions on this topic.

If you have a late 1955 engine (255 in the engine serial number), you need a special short-shaft water pump (a work-around), or you need the adapter plate to use an older style water pump (the better solution). Either of those adaptations will work with the original radiator placement.

Since the radiator mounts to the rear surface of the radiator frame/housing, spacers will only make your situation worse.

I have seen scores of cob-job adaptations to the radiator frame to allow for the needed clearance. The top piece of the frame gets removed/re-situated and the radiator frame gets turned around, front side to back side. What a mess.

Where did you buy your short-shaft water pump and what is the part number? Maybe they sold you the wrong pump?

Bend the fan blades?
I hope you're kidding.

To get additional clearance I removed the two thin angle brackets welded to the side of the radiator (Spot weld cutter). I bolted the brackets in place on the radiator frame and then placed the radiator in place with the fan installed and the tack welded the radiator to the angle brackets to allow propper clearance. I then removed the radiator and finished welding the brackets/ground welds flush and repainted.

My 55 engine in 52 truck with shortened water pump (I did it) had next to no clearance and only worked with the old 216 fan...
Had it been an option at the time I for sure would have used a water pump adapter kit. I recommend anyone in the same situation use one, sure seems like the perfect solution!

Grigg

New Guy{Coralhead} brought up a problem I had to deal with. The new LMC radiator for the '49 3/4 216 had the mounting brackets tacked in wrong position. Relocating the brackets / sending it back to LMC were two options. Repair of the OEM radiator won out. The space from fan to radiator should be approx 1/4. The new guy option brimgs up the questioning yourself on the rad / parts combo. Good luck with resolveing this .

I know Patricks sells a short water pump that works. If you are using a water pump from the late 235, then you want to use dhte 235 fan as the 216 fan runs about 190 percent with that set up. or so I've read...

Also, be careful tweeking the fan blades. As RPMs gain, the fan will move slightly toward the radiator.

My engine setup is a '59 235 in a '50 AD. Prior owner had already installed the new shorter water pump but after pulling the engine and overhaul the fan was just touching the radiator and I needed about 1/4" to make it work. I am labled as a "New Guy" on this website but I have pulled many a wrench. My dad was a mechanic and raised a family of 7 kids pulling wrenches. One can always learn new tricks to put these trucks back together.

He may sell a water pump but it wouldn't be any better than the one I shortened (just press the hub off or on further, shorten shaft, re-install hub, no trick to it).
I had barely enough clearance between the balancer and the fan and the fan and the radiator.

Again, I suggest folks use the water pump adapter plate and forget about these short shaft pumps. The short pumps barely fit (sometimes don't) and you can still have cooling issues because the fan's part way below the radiator.
If I ever run another Stovebolt in an AD the adapter plate is what I'll use.

Grigg

Just a question here........Exactly how do you push the fan adapter farther down the shaft? Do you use an arbour press and do yo need to get a solid backer against the back of the shaft? What if it goes just a little too far, it seems it'd be a bear to pull it back.

Just questions that come to mind when I see guys post that they shortened the pump themselves.

-Mike-

What about the pulley location once you move the mounting pad? Won't the belt be out of alignment?

Joe

When I shortened the shaft on a water pump I already had a different pulley that worked with the shorter shaft. The idea is to push the hub on the shaft so the shallow pulley lines up with the crank pulley.

As far as actually pressing the hub back, I remember using a hydraulic press and supporting the back end of the shaft, You don't want to stress the pump body or the bearings.
If you need to pull it off use a gear puller.

...... why am I telling y'all this???
[size:14pt] Here's the real solution!![/size]


Grigg

Grigg thanks for satisfiying my curiosity on modifing a water pump.

One more question, with the adapter plate what water pump or pumps will work? Would say my stock pump on my 261 work or will the adapter only accept the early style water pump?

The only pumps that work with my adapter are 1941-52 if you want to run the wide belt, and 1953-54 pump if you want to run a 3/8" belt.