Fan Shroud helpful?

I found by accident when I covered the front of the radiator for a quick warm up air was flowing forward around the sides ?! Hood was off inside the garage, the cover wouldn’t stay in place . As for shrouds the fan needs to be properly installed ( the fan needs to be in the round opening, not in front or behind the round opening , most modern’s have a flange that the fan rotates in .
 
Aeronautical Engineering 101

Werner, Post #19, has the right answer. Just like an airplane wing, there are tip losses when the high pressure air at the back circulates around to the low pressure air at the front. The wing tips on commercial aircraft are designed as a fence to stop this circulation. The shroud does the same thing, it stops the air from circulating around the tips of the fan. You will see some fans for blowing air on people with a circular ring that surrounds the fan tips for the same reason.

However, then the air being forced through the radiator because of the forward movement of the car is greater than what the fan is pulling through, the shroud can get in the way, blocking some of the air flow.
 
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Is overheating a common problem with the A? Admittedly, living in Germany, I very rarely see 100F... I have, occasionally, driven in 100F temps without any overheating. I drove at a snail's pace through detours due to a bicycle race recently in 100F+ temps and the engine remained cool.
 
When I lived in riverside California I purposely drove my model A. an hundred and 10 ° temperatures several times including low speed stop and go driving to see if it would overheat and it never did!
 
nkaminar said:
I will second what Jim said. Good at idle and in parades but a detriment at speed.
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A Model a fan shroud is not a detriment at higher speed. There is ample space to evaculate air when the Model A is moving down the road. Go on ebay and you'll see scores of fan shrouds that trap air and cause heat soak.
 
my a has an original fan shroud on ,plus a brassworks radiator,i think its a good thing ,
yesterday it got up to 83c into a head wind all day 33c or so
topped up the coolant this arvo only took maybe 3/4 ltr
 
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The Brassworks said:
A Model a fan shroud is not a detriment at higher speed. There is ample space to evaculate air when the Model A is moving down the road. Go on ebay and you'll see scores of fan shrouds that trap air and cause heat soak.
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How can we identify the fan shrouds that trap air and cause heat soak and avoid them?
 
I don’t have any science to back this up , only life living in the sticky Midwest , wet humid air makes a/c work harder as I noticed when maintaining a 3 story office building . So if your driving your A in dry air it will cool the A’s cooling system better than driving in wet humid air ?!
 
Big hammer said:
I don’t have any science to back this up , only life living in the sticky Midwest , wet humid air makes a/c work harder as I noticed when maintaining a 3 story office building . So if your driving your A in dry air it will cool the A’s cooling system better than driving in wet humid air ?!
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Not a huge difference, but yes, dry air is denser and has higher thermal conductivity than humid air at the same temperature.
 
To answer the ?, Ford may have dropped the shrouds to save money. So little experience noted unless Murray Fahnstock wrote about it during the era.
The engine pans may be more benefit for air flow and grounding.
 
duke36 said:
To answer the ?, Ford may have dropped the shrouds to save money. So little experience noted unless Murray Fahnstock wrote about it during the era.
The engine pans may be more benefit for air flow and grounding.
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I agree. The engine pans were retained by Ford for all 4 years, but the fan shroud was not. Henry was fanatic about simplifying design and driving costs down in manufacturing and assembly.

For example, look at the evolution of the throttle assembly that bolts to the back of the A engine. Each iteration is simpler in design, cheaper to make, yet serves the same function.

I suspect Henry decided the shroud was not really needed for most drivers and dropped it. That saves on material cost and assembly line time/cost. It would be interesting to look through the Benson Ford Archives for the Engineering notes that let up to the decision to drop it.
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The reason I asked about a shroud was because I was in the process of ordering a new radiator from Brassworks and I was wondering should I get a shroud? Brassworks has excellent customer support but I completely forgot to ask them on two occasions (dumb azz). I ultimately went without a shroud for two reasons (1) there was virtually no support on this thread for having one and (2) I want to be able to remove the water pump without disturbing the radiator (yes, I have the bolts that look like studs with nuts).
 
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