The Stovebolt Site Forums The Shop Area Engine Shop Position of fan vs. rad

Hi, all!
My twuck is a '55 First Series 5-window with a 235 1957 engine. The radiator is the high brass tank 4# original(I think)but the core leaks through all the mashing it's taken over the years. I was tootling around looking at getting the rad out and into a rad shop when I remembered that the rad is a tad higher than the engine fan blade. The blades actually extend (spins) 1/3 below the rad! The rad is fully seated in its mounting frame.
I have no history details on the years-ago engine swap (to the '57/235) or any other mods done to the rad, etc. So my quest now is to determine whether fan/rad position is normal for the year and model(3100).
It would be handy if I could compare some pics of other similar engine bay front ends.
Appreciate any help, guys. Wayne

Welcome to the board. The situation you describe is par for the course when a later 235 is put in an AD truck. If it cools OK I wouldn't worry about it.

Thanks for the welcome!

Yer probably right but it must be the old techie in me, as it still bugs me. How could a '57 be any different than a '54? Wouldn't the engine mounts be the same ..or.. hmmm.. I wonder if, when the last owner retro'd to a 4 speed (on the floor) Borg he had to (somehow) drop the engine to make the tranny fit?

The '55 first and older 235s are a different animal from the '55 second and newer 235. The waterpump sits higher on the older engines. It also has a shorter shaft. The water pump shaft on your engine has been shortened to make it clear the radiator. There is an adapter available to use the early engine water pump on the late engines and someone will soon chime in saying you need one. I still say if it doesn't overheat, you're OK with what you have. I ran one for years in a '55 first I had in the '80s.

dont know if this helps,,can almost seee it... heres mine http://good-times.webshots.com/photo/2566939310052422310LLSWkx
and here
http://good-times.webshots.com/photo/2738314610052422310MBAPcb

To properly position the fan, you need to purchase an adaptor plate (pre68 Dave, on this site) that uses the old style waterpump. Both 3/8 and 5/8" pulley width pumps are available from NAPA. The plate requires drilling and tapping a couple holes but you use the adaptor plate as a guide and for the most part it is not that complicated. This moves the fan up about 4" and gives you additional fan/radiator clearance.

I tried a "short pump" in my 56 engine in a 54 truck and found that the $40. adaptor plate and earlier pump (41-54) was "the" solution to my cooling and clearance problems. This also allows you to use a stock water pump that is readily available over-the-counter.

The instruction sheet he provides is detailed and warns that you should avoid using a 55-62 passenger car balancer as it will overspin the pump.

I have a couple pictures of the early pump and the adaptor plate on pg 3 of my webshots "shoebox". I hope this helps.

Fatweed I bet ole' Pluto makes anyone driving anything smaller that a Cadillac tuck their tails and get out of the way.

" The '55 first and older 235s are a different animal from the '55 second and newer 235. The waterpump sits higher on the older engines. It also has a shorter shaft. The water pump shaft on your engine has been shortened to make it clear the radiator. There is an adapter available to use the early engine water pump on the late engines and someone will soon chime in saying you need one. I still say if it doesn't overheat, you're OK with what you have. I ran one for years in a '55 first I had in the '80s. "


Ah.. ok. That makes sense now that it's been explained. I won't go and recheck as it's sitting outside in the dark and rain, but I do recall that the shaft seemed awfully close to the rad. Does that adapter actually reposition the shaft (& fan) higher or does it just provide a shorter shaft? And nah, it seems to cool fine in the summer ..well it did until the rad problem er-occurred after I kept sticking BarsLeak in it to help it along. The guage is now starting to creep upwards - - good thing it's getting into winter - - and the rad is starting to leak again.
So far as the rad goes, my hunch is that with one of the newer cores installed (and engine cooling flushed), I may be able to either run the rad at higher pressure(?) or it will just cool better with the newer technology. So yes, the new rad will probably negate any need for repositioning the pump or fan ..just a hunch ;^)

Thanks, David (Fla54Chevy3100). What a great series of pics you have on your site. I will bookmark it for project reference later. I see what you mean by the adapter. I helps explain the description left by "cletis". If it means I have to screw around with a drill and tap routine then I may forget the idea until there's more incentive on my part ..it's coming on winter and the garage is full of other plans. David, did you also have your rad re-cored? If so, do you keep it at the same 4 lbs. pressure?

There is one other choice - add an electric fan on the outside of the radiator up high on the radiator. That can also fix the problem. You can use a thermal self activated switch set to come on at a certain temp or you can have a switch in the cab you can turn on when you need it. Works good!

Joe

Good suggestion. However, I would think the fan would have to be at least 12vdc to be efficient.
My truck's still in the dark ages with 6 vdc.

I went through similar problems with my 1940 when I put in a '55 235. Check out the lessons learned I wrote up here:
http://oldgmctrucks.infopop.cc/eve/forums/a/tpc/f/462107036/m/4471020781

After trying the short shaft water pump, I went to the adapter plate and 53-54 216 water pump and everything worked fine.

Here is a pic with the short shaft pump that was too low:

http://rides.webshots.com/photo/1479818654067858381yEqjEk

Here is a shot of the motor installed with the adapter plate and '53-'54 pump.
http://rides.webshots.com/photo/1506214624067858381lUqIIS

Steve