| [GMCnet] Air flow and fan clutch [message #95810] |
Fri, 13 August 2010 20:04  |
Gerald Work
Messages: 102
Registered: June 2010
Karma: 0
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Senior Member |
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I agree, Gene. The air temp hitting the clutching fluid in the fan clutch and measured water temp from the engine/radiator are two very different things. Trans fluid external coolers, engine oil external coolers, ac loads all add to the air temp passing through the radiator. From my experience your aluminum radiator has so much more cooling capacity than the stock radiator that the water temp stays nearly at the thermostat open temp independent of these other loads or the physical load on the coach. The air temp, however, does go up and down as a result of passing through these external coolers before passing through the radiator itself and that is what seems to me to cause the fan clutch to cycle even while the water temp remains flat. If you take that great big fan out of the system as some appear to want to do then I don't see who those varying air temp loads could be accommodate, which sooner or later would have to start impacting the water to air heat transfer throu
gh the radiator.
While not an expert on fluid dynamics, my knowledge of the field suggests electric fans might do far more good if installed to evacuate hot, stale air from the back of the engine compartment rather than installed in front of the radiator where they might well act more as a block to air flow than as a promoter of air flow. A radiator with nothing in front of it tends to act as a major air flow barrier, let alone what it becomes when fronted by all these external oil coolers. The one thing I have not heard described is mounting the external oil coolers outboard of the radiator, each with their own small electric fan, in the air flow that now bypasses the radiator when the finder liners are removed. Just a thought......
Jerry Work
78 Royale, 455
Kerby, OR
Sent from my iPad
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| Re: [GMCnet] Air flow and fan clutch [message #95867 is a reply to message #95810] |
Sat, 14 August 2010 19:58  |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
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Senior Member |
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| Gerald Work wrote on Fri, 13 August 2010 18:04 |
... The one thing I have not heard described is mounting the external oil coolers outboard of the radiator, each with their own small electric fan, in the air flow that now bypasses the radiator when the finder liners are removed. Just a thought......
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I saw a coach that had something like that on the driver's side, (not a very good picture): <http://www.gmcmhphotos.com/photos/showphoto.php?photo=32424>
It had ductwork behind the cooler with a "pull" fan inside the driver's wheel-well in front of the tire.
The coach had so many unexplainable modifications it scared me. By the time I figured that it would be fun to figure it out, the coach had been sold.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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