The Stovebolt Site Forums The Shop Area Engine Shop Electric Fan Option

I have a 1956 235 inch in my 49 half ton. I did not install it. The fan is about a quarter inch at best from the radiator. Changing the fan belt would require removing the rad. I have driven it this way for about 20 years. I am still wary.
I thought of removing the fan and installing an electric fan outboard of the rad to solve the problem. I have no overheating issues with the truck and I know about the short shaft pumps but I believe installing one (drilling and tapping holes) is beyond my skill set.
Another option would be to get a 235 pump as I have now and shorten the shaft. The fan pulley in that case may rub against the block and of course I wood need to align the generator pulley with the shorter shaft.
I think an electric fan might be the easiest solution.

I think you might get a number of answers here. I also think the electric fan is best for a few reasons. I have a Spal 16 inch with a thermostat switch and really like it. In fact I wouldn't consider going back to a pump mounted fan. I expect the savings in worn out pumps from blades which were only sort of in balance will pay for it. One point I think is important enough to mention...these fans do draw more amps than you might think and the best and most efficient from a standpoint of moving air are sort of amp-greedy.

Electric fans are most efficient when pulling air as are the original belt driven fans. Food for thought.

If the fan is mounted ahead of the radiator pulling in air would that not be considered pulling air?

No...
Fan mounted in front of the radiator "pushes" the air through, fan mounted on engine side of radiator "pulls" the air through.

Puller fans are more efficient than pusher fans. Pusher fans also blocks off some of the natural air moving through the radiator at speeds above idle.
As an example, I'm running a 16" puller fan with shroud on a 350 mounted in a 49 GMC, the only time the fan comes on is at idle and at speeds above 60. The natural air flow is enough to keep the engine temp approx 100 degrees ABOVE the ambient temp.

All that said there are folks that claim no problems with pusher fans.

One thing you might consider is smaller dual puller fans that won't interfere with the water pump pulley. Many come with low profile shrouds that will improve their cooling efficiency.

Good luck
Dave

With the little room that I have between the existing fan and the radiator I cannot see how I could put an electric fan in there. I recently saw a 34 Ford with two smaller electric fans mounted in front of the rad. I think that would be the only place an electric fan would fit on the truck. Will have to do more research.
I understand that above 60 or thereabouts a fan is not necessary hence the thermostatic fan on my Caprice. But above 60 in my truck would be like being in the space shuttle. I never get that fast. Actually 54, not 55 is the sweet spot for cruising in the truck.

My 2 cents from personal reasoning. I could be wrong but haven't seen anything yet to convince me that I am. All electric radiator fans are "puller" when mounted on the engine side and "pusher" when mounted on the grill side. They turn the same direction either way AND the motor restricts air flow whether in front or in back of the radiator. A LOT of people say "puller" fans work better but I've never seen any empirical evidence to prove that. All I've seen is anecdotal evidence. Even googling it only returns personal opinions with no supporting evidence. IMHO put the fan where it works best for your application.

Assuming the fan doesn't have a full radiator shroud, as in most electric fans on the market, so that the only air passing through the area of the core where the fan is mounted, is what the fan itself moves, the advantage is???

The puller fan "may"restrict air flow but it's cool air flow that has already passed through the heat exchanger before it hits a possible restriction.... Hence it has already cooled the coolant...

The pusher fan restricts air flow before it enters the heat exchanger, just by it's physical size impeding said air flow, and again this restriction is before it has had a chance to enter the heat exchanger so theres less air flow to cool the coolant.

No comparison....

re. shroud, a properly installed shroud has the effect of creating a low pressure area within the space between the radiator and the fan/output. Air being air will rush to fill a low air pressure condition. The air entering the low pressure area will travel through every orifice contained within the radiator to fill the low pressure space. A shroud increases the overall heat exchanging efficiency more so than a similarly equipped vehicle without one.
Thermal dynamics at it's most basic.....

Puller be better than pusher.... LOL...
Dave

Ah, but there IS a comparison. Sedg, I apologize for hijacking your thread. I have counter points to make but won't further hinder the thread. Dave, if you want to debate the value of where a restriction in a system is placed relative to the effectiveness of the system we can continue via PM.

Wow, this is getting dicey. IMHO, and I speak from experience...(dual) pullers is the ONLY way to go...bar none. And yes the incoming air has already passed through the heat exchanger. With a pusher you might as well place a piece of cardboard is front of the rad. Same difference.


Go back and take another round of measurements...with dual fans most of the time you can achieve a tighter yet acceptable clearance.

I am currently running a 216 with an electric pusher fan in texas. I have driven in temps up to 113 degrees without overheating. I melted, but truck had no issues. Only time I hear my fan kick in is a idle and I assume it kicks on above 60-65. Even at 70mph (3.55 rearend gears) no issues. Just my experience with my truck.

Electric fan is a 1300 cfm fan from jegs and 1/2 inch from radiator.

Chris

I would say that the advantage for this scenario would be that the surface area not covered up by the electric fan would have unrestricted air flow through the radiator at higher speeds (40 MPH or higher).

PM? Matters not to me. This thread posed an interesting quandary and it seems good debate has ensued.

Food for thought, the new car/mall truck industry has gone nearly 100% to electric fans and with very few exceptions all are mounted as pullers with shrouding, seems an expensive manufacturing decision to make when a simple pusher fan in front sans any kind of shroud would be a cheaper option.

Dave

Sheesh. All he really wanted to do is change his fan belt!

And not have the fan blades chew up the radiator!.

Move the radiator forward 1/2"!
PROBLEM SOLVED!
Jerry

Yep, mine's a '40 but with manual fan bolted to the front of the support instead of behind. I've had it that way for several years. Also put an electric pusher for A/C recently. Haven't really tested that much yet. No issues so far, anyway.

Dennis

Can't move the radiator forward with out butchering the shroud and the cradle where it sits on the frame. Considered moving the flanges on the radiator to the front side of the frame but it would still interfere with the bottom. I have seen a few which have been moved a head and in some cases tilted but in each case the sheet metal in front of the rad is carved up.
Maybe I am missing something here but I have been staring at this problem for a long time.

How about an after market fan?

Flex-a-lite has steel fans that project 1 1/2" forward of the mounting surface. So, you need to measure from water pump to radiator to see if there's enough clearance.

I would assume it bolts up to the water pump flange and the bolt holes must be standard.
Being "flex-a-lite" I imagine the blades must twist like when feathering an airplane prop.

The steel fans don't flex. They call them "race" fans. If the flex-a-lite fan is narrower than the stock one, it might help to increase clearance. You have to get yout tape measure and see how much spce you have from the flange to the rad.

Not much space. From the hub flange to the rad is about 2". That's RGO

Another good idea ruined by data. Oh, well.

Sedgwick,

That is the same issue that I was having. I researched all of the electric fans and they were close, but wouldn't fit. I was forced to move to a pusher fan and connected it to the ”X” on the radiator supports. I used a 1300 CFM fan from jegs or summit racing because it was the thinnest I could find. 2.05” depth. I haven't had any issues in the heat of texas!

https://www.jegs.com/webapp/wcs/sto...=&Nrpp=&No=&persistYmm=false


I can take pictures of it once I return from vacation on the 15th if you wish.

Chris