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Cooling

Spanky

Moderator
Staff member
When building my engine I knew I wanted to use an electric fan because of space limitations and also safety. I'm the guy that puts his fingers where they don't belong when the motor's running! :rolleyes:

That said, I know people who insist that a mechanical fan does a better job of cooling, especially when paired with a shroud. My 16", electric fan does an adequate job of cooling my mild 350 Chevy on those 90-degree days. What type of fan are you using and why?
 

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I use a mechanical Fan on the "Yelot" with no problems for the past 14 years but it does have a home built Shroud.

On the "Cedan" I use the same Electric Fan as you show on your car with no problems. It don't even run most of the time..... either or not........
 
I have an electric fan on mine for the 8 years that I have owned the T. Cools well. Only problem that I had, when a guy re-wired the entire T, he hooked up the fan to push air back thru the radiator, which resulted in an overheating. I fixed it in a Hardees parking lot.
 
Got 3 old cars. 32 ford mechanical fan 350 engine. 50 Studebaker mechanical fan and electric pusher for traffic 350. 29 Ford pickup electric fan iron duke 4 cylinder.
the 32 and 50 have shrouds. The 29 cools the best.
 
I'm using an electric fan too. With the slant six my fan wouldn't have been centered over the radiator to use a mechanical fan
 
Hey! I get your concerns about safety and space. Electric fans are great, especially in tight builds, but it’s true that mechanical fans with a shroud can cool better in extreme conditions. A buddy of mine uses a mechanical fan and noticed a performance difference. What’s your experience with the electric fan over time? :)
 
The radiator doesn't know if you have an electric or mechanical fan, it only cares about how much air is flowing through it. This discussion really should be about cubic feet of air flow, now about what powers the fan blades.
 
If you run an electric fan, be aware that your alternator could have a large influence on fan speed at idle. Image it's 98°F and your sitting in stop and go traffic. Just when you need the highest fan speed it's at the lowest speed..

If you are using the 10si alternator and you are idling at 700 rpm the alternator is putting out about 25 amps, assuming you have the 63 amp model. Note that the alternator turns about 2.5 times faster than the crank rpm. So in this example the alternator rpm is 1750.

The graph uses alternator rpm.

Delco_10SI_PerformanceCurve.png

It's for this reason that I run a CS-144 alternator. Assuming the same 1750 rpm and a 120 amp alternator. The output at idle will be about 50 amps.

Don't forget it's not just the fan you are running but the fuel pump, headlights ignition ..... etc.

Delco_CS144_PerformanceCurve.png

Measure your pulleys to determine your ratio, alternator to crank ratio. With a higher amp alternator I would recommend a DUAL belt pulley.
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My 2 cents on the pros and cons of a mechanical vs. electric fan.

Mechanical Fan - larger fan blades, it's always working and is the typical simple approach. Cons? Takes up a little more real estate and puts a little bit of drag on the engine.

Electric Fan - thinner design (more compact), only gets turned on when the temp sensor determines it's hot.
 

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