Re: Fan Shroud Question
[Re: CraigS]
#1661258
08/20/14 12:39 AM
08/20/14 12:39 AM
|
Joined: Dec 2003
Posts: 22,717 Bitopia
jcc
If you can't dazzle em with diamonds..
|
If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,717
Bitopia
|
I have an opinion, and its predictably not shared by many I would guess. A shrouds main purpose is to provide a venturi for a rotary fan to improve its pumping effiency. The closer the venturi tube, the better, of course in a car in can never touch. The next purpose is to channel the inlet air thru the item being cooled, the radiator. Many think that the entire amount of air the fan is moving must be moved thru the entire radiator. This is where I disagree. I believe only enough air needs to be drawn thru the radiator to provide enough engine cooling under the worst conditions, ie high ambient temps, no car movement, without too much temp rise before car is likely to move, that's a time factor, and every car/situation is different of course. The problem I see with over shrouding, which I think is the point of your question, is at speeds over say 60mph?, your fan becomes pretty much an obstruction to air flow and is almost useless and a hindrance. If the restricted air can find a new less restrictive path around the fan, but still thru the radiator, you have a good compromise solution. Others may differ. https://board.moparts.org/ubbthreads/show...e=1#Post7973457Pic #43 shows a simplistic workable solution
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
|
|
|
Re: Fan Shroud Question
[Re: jcc]
#1661259
08/20/14 01:33 AM
08/20/14 01:33 AM
|
Joined: Jun 2005
Posts: 310 western Ky
CraigS
OP
enthusiast
|
OP
enthusiast
Joined: Jun 2005
Posts: 310
western Ky
|
JCC ,I should say that this is the second radiator,as the first was destroyed by the fan digging into it in a "panic" stop situation,where I stopped very hard at a yellow/red light and the engine rocked forward in the mounts and damaged the core.I had the fan 1/2 inch from the radiator,and no shroud.This setup cooled adequately,except in stop and go traffic the temps would rise pretty quick (200- 210 degrees) until I got moving again,then never above 185 .Down the road it was good.This is in my 78 dually,tow rig,440 d300.I was thinking the shroud would help that low speed issue,especially since I am taking out the 1/2 inch spacer to give the radiator some more clearance to the fan.I have changed the mounts,so that should not be a problem again,but wondering if this shroud will restrict airflow going down the road.I am thinking withso little area behind the shroud it probably wont hurt.
|
|
|
Re: Fan Shroud Question
[Re: CraigS]
#1661262
08/20/14 11:43 AM
08/20/14 11:43 AM
|
Joined: Dec 2003
Posts: 22,717 Bitopia
jcc
If you can't dazzle em with diamonds..
|
If you can't dazzle em with diamonds..
Joined: Dec 2003
Posts: 22,717
Bitopia
|
For another source of info, might want to read this link, especially paragraphs 4 & 5 on "Airflow". http://www.hotrod.com/techarticles/engine/cooling_system_tech/
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.
|
|
|
Re: Fan Shroud Question
[Re: CraigS]
#1661263
08/20/14 03:14 PM
08/20/14 03:14 PM
|
Joined: Jan 2003
Posts: 27,478 So Cal
autoxcuda
Too Many Posts
|
Too Many Posts
Joined: Jan 2003
Posts: 27,478
So Cal
|
Quote:
I definitely have those criteria met. I just wonder if there is enuff shroud left to make much difference?
The factory 67-72 A-bodies V-8 shrouds have similiar clearences you list in you 1st post. About 1"-2" on sides and nothing on very top and bottom. People have added just this shroud and it makes a helpful difference.
|
|
|
|
|