Additional electric cooling fan in front of rad?
#31
11-29-2011 | 10:34 AM
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Joined: Jan 2011
Posts: 16,322
Likes: 84
From: Savannah Georgia
#32
11-29-2011 | 07:48 PM
#33
12-08-2011 | 02:30 AM
#34
12-08-2011 | 02:50 AM
All good guys so how do you square this then i run a mk1 disco with no cooling fan yes you heard it no cooling fan i took the viscus coupled unit of to replace it with an electric which i have a temporary/manual switch on it and used once to date when idling in traffic for ten minuets and no it warmes up more or less the same i was hoping for faster but MPG is a little better
#35
12-08-2011 | 04:07 AM
Three Wheeling
Joined: Nov 2010
Posts: 66
Likes: 1
From: Las Vegas, NV
All good guys so how do you square this then i run a mk1 disco with no cooling fan yes you heard it no cooling fan i took the viscus coupled unit of to replace it with an electric which i have a temporary/manual switch on it and used once to date when idling in traffic for ten minuets and no it warmes up more or less the same i was hoping for faster but MPG is a little better
#36
12-08-2011 | 04:52 AM
Super Moderator
Joined: Jan 2011
Posts: 16,322
Likes: 84
From: Savannah Georgia
WBB:
What kind of MPG change did you find, and what are your conditions (flat, hilly, mountains, short, long trips, etc.)?
If you are driving at roadway speeds, no fan needed. At 60 mph air is moving thru radiator at 5280 feet per minute.
If your cooling system is in good condition, takes a while to warm up to where you would "need" a fan when idling. Depending on your driving habits, outdoor temp. Spike said his fan was on the bench for the winter, but no mpg change noted so far.
Electric fans work, and virtually every car and van with a transverse mounted engine uses only electric fan(s).
Electric fans have an advantage that when at idle, when engine speed is lower, their air cubic feet per minutes is the same, not reduced.
Electric fans have a disadvantage, when used in a slow moving - high rpm driving situation, like rock climbing. There, the higher rpm mechanical fan, and more so when hot, will move more air.
The viscous drive decouples to about a 20% ratio when spun up and warmed to normal temp. So that saves gas, compared to a direct mount fan. Your savings could be realized vs the 20% load of the few HP used by the viscous fan, vs increased load on alternator by electric fan.
The electric fan has a disadvantage in the small alternator of the D1 (100 amp) and the almost undersized (130 amp) for the D2. The D2 is packed with so many electronic things it needs plenty of power. If you have a weak battery, an extra electric fan load at idle, when alternator is already struggling, might not be a help.
Electric or viscous drive can certainly work in routine driving. Cooling system needs to be in good condition either way. If viscous drive is working properly it does the "thinking" for you, rather than an on/off switch. IMHO you might want to add a thermostat, so the fan operates when you want it to, and you have manual over ride if needed on long hills, trailering, etc.
If you are depending on the temp gauge to move and tell you when to switch on the fan, that could be a problem in models where the gauge is slow to operate, or as in the D2, ECU controlled to never show overheat - until you are way up in the heat zone.
One of the reasons peole put in an electric is cost of repair of the viscous system. But since it shares a common size (6 inch) and reverse rotation, with millions of Chevy and GMC vehicles, the junk yard can provide some cheap ($20) substitutes. Pix attached, and with the deeper fan I run 6 degrees cooler over the same little flat road test drive I use driving to Egypt (Egypt, Georgia) in 100 plus summer weather at about 100 feet above sea level and 95% humidity.
While some owners may be offended by cross breeding used parts, I can assure you the dead Blazer I removed these from felt no pain. It is an option for those on extreme budgets, and those travelling, in a place where few Rover parts are to be found. The Chevy and GMC fans are frequently a wimpy black plastic or hard white plastic, boh can be trimmed to fit if needed with shears. Can be used without trim if you remove the fan shroud for "get back home" operation. Trimmed plastic subject to splitting, can damage radiator.
And I must admit that the 18 inch electric fan on a Ford Taurus looks like it could be a source of experimenting as well.
What kind of MPG change did you find, and what are your conditions (flat, hilly, mountains, short, long trips, etc.)?
If you are driving at roadway speeds, no fan needed. At 60 mph air is moving thru radiator at 5280 feet per minute.
If your cooling system is in good condition, takes a while to warm up to where you would "need" a fan when idling. Depending on your driving habits, outdoor temp. Spike said his fan was on the bench for the winter, but no mpg change noted so far.
Electric fans work, and virtually every car and van with a transverse mounted engine uses only electric fan(s).
Electric fans have an advantage that when at idle, when engine speed is lower, their air cubic feet per minutes is the same, not reduced.
Electric fans have a disadvantage, when used in a slow moving - high rpm driving situation, like rock climbing. There, the higher rpm mechanical fan, and more so when hot, will move more air.
The viscous drive decouples to about a 20% ratio when spun up and warmed to normal temp. So that saves gas, compared to a direct mount fan. Your savings could be realized vs the 20% load of the few HP used by the viscous fan, vs increased load on alternator by electric fan.
The electric fan has a disadvantage in the small alternator of the D1 (100 amp) and the almost undersized (130 amp) for the D2. The D2 is packed with so many electronic things it needs plenty of power. If you have a weak battery, an extra electric fan load at idle, when alternator is already struggling, might not be a help.
Electric or viscous drive can certainly work in routine driving. Cooling system needs to be in good condition either way. If viscous drive is working properly it does the "thinking" for you, rather than an on/off switch. IMHO you might want to add a thermostat, so the fan operates when you want it to, and you have manual over ride if needed on long hills, trailering, etc.
If you are depending on the temp gauge to move and tell you when to switch on the fan, that could be a problem in models where the gauge is slow to operate, or as in the D2, ECU controlled to never show overheat - until you are way up in the heat zone.
One of the reasons peole put in an electric is cost of repair of the viscous system. But since it shares a common size (6 inch) and reverse rotation, with millions of Chevy and GMC vehicles, the junk yard can provide some cheap ($20) substitutes. Pix attached, and with the deeper fan I run 6 degrees cooler over the same little flat road test drive I use driving to Egypt (Egypt, Georgia) in 100 plus summer weather at about 100 feet above sea level and 95% humidity.
While some owners may be offended by cross breeding used parts, I can assure you the dead Blazer I removed these from felt no pain. It is an option for those on extreme budgets, and those travelling, in a place where few Rover parts are to be found. The Chevy and GMC fans are frequently a wimpy black plastic or hard white plastic, boh can be trimmed to fit if needed with shears. Can be used without trim if you remove the fan shroud for "get back home" operation. Trimmed plastic subject to splitting, can damage radiator.
And I must admit that the 18 inch electric fan on a Ford Taurus looks like it could be a source of experimenting as well.
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