Engine/Transmission (1994 - 1998) fan clutch question

[Mhannink]

Except for the differences in temp and air density, you could probably control the others. If your amient conditions did not change with the seasons then you could eliminate more variables and get close.



Pretty sure the 20, 25, and 27 HP were developed on a dyno but thats again at the top of the rpm range and likely the fan 100% locked. How much at 2000 rpms on 70 degree day? Not sure it can be claculated with an efficacy.



Trying measure mileage difference in th winter fan on\off is hit or miss too because the ambient has so much to do with the efficiency. Likely, without the fan the engine gets warmer and more efficiency because it is not loosing as much heat thru the cooling system. Can't attribute that directly to the fan.



As far as SOP, I have not been able to tell the difference in power. Have not run it long enough in enough different conditions to tell if there is a benefit either. Others claim differently but without some solid facts and controlled test, its still just an opinion.



Up to you want you want to believe and figure is the best.

i know around here i dont notice much between winter and summer mileage. thats me being the only driver, and no changes to the engine. i have noticed looking at my records that sept and oct seem to be my best months for fuel mileage. i think its because the ambient temps and conditions are the closest to prime in those months.



im asking people to get an idea. the more responses i get the more acurate the info. it helps elimenate the variables.

 

[Mhannink]

Maybe I can get some good data for you the very first few tankfuls after removing the fan and clutch.





I will tell you that up here in the Great White North any fuel mileage gains from the fan removal will be negated almost immediately as the fuel is cut in stages depending on the predicted temperatures to improve cold weather flow, that of course lowers the Cetane rating, which results in decreased power and fuel mileage.



Mike.

yeah the fuel is another variable that doesnt help. i know how they cut the fuel and its affects on the engine. however if the fan being removed and the fuel is thinned for the cold and mileage stays the same its a good sign that the fan affects it. its a negitive positive and far from conclusive but its still a result the lends to my theory.

Sounded like they keep them all the time, said that they still have some demand for them.



I have just been out pestering my Snap-On guy to see if he could find any M-12 shrader test tees,,,,nothing yet.

I suspect that if I bite on the $300. 00 hammer and the "every punch ever made" kit that he is trying to sell me he might be more helpful... ... ... ... :-laf



Mike.

thats a good idea they might have something. snap on will not be cheap though. its funny my experience with several snap on dealers, they really are more helpful when you spend good money with them. other tool dealers just seem to be very helpful no matter the money spent with them. just my experience.

 

[HEMI®Dart]

Fanless..

Hands down one of the best mods I have done. Engine noise is cut by 20%, faster warm-ups, improved throttle response, idle speed increases by ½ a needle width, mileage improves about 1, 1. 5 MPG so I don't see the winter fuel blend mileage decrease as much. This will be about my 14th winter fanless during the cooler months. Highest I have ever got the temp up to is about 200° during bumper-to-bumper traffic. The heater core will work wonders if you start to warm up. 5 Speed.

 

[Mhannink]

Hands down one of the best mods I have done. Engine noise is cut by 20%, faster warm-ups, improved throttle response, idle speed increases by ½ a needle width, mileage improves about 1, 1. 5 MPG so I don't see the winter fuel blend mileage decrease as much. This will be about my 14th winter fanless during the cooler months. Highest I have ever got the temp up to is about 200° during bumper-to-bumper traffic. The heater core will work wonders if you start to warm up. 5 Speed.

thats about what i was thinking.

 

[mwilson]

Hands down one of the best mods I have done. Engine noise is cut by 20%, faster warm-ups, improved throttle response, idle speed increases by ½ a needle width, mileage improves about 1, 1. 5 MPG so I don't see the winter fuel blend mileage decrease as much. This will be about my 14th winter fanless during the cooler months. Highest I have ever got the temp up to is about 200° during bumper-to-bumper traffic. The heater core will work wonders if you start to warm up. 5 Speed.

Mark, if you want to try the fanless winter thing don't forget you need to pull the relay for the A/C clutch so it can't come on while in defrost. There is a mod that can be done to remove the contact in the heater control panel if you preferred that solution. It's in the DodgeRam.org website.



Also where you have a 5-speed you wont have any transmission heat issues while sitting at a stop light on a 40 degree day.



I have learned to pop the autos into neutral if stopped at a light on a sunny spring afternoon.



That's my sign to get the fan back on the truck, winter is over..... :-laf



Mike.

 

[Mhannink]

i am contemplating the idea. the problem here in cali is we can be low 30's upper 20's in the early morning and 50's 60's sometimes itll touch 70 in the afternoon. thats too warm for no fan i think, but it is an interesting idea.



on another note. ran over highway 4 from modesto to reno and then back 88 through valley springs. all narrow winding mtn road with grades up to 24%. modesto to reno leg temps where 60 and lower never heard or felt the fan. even at 8700ft the engine had tons of power and drove really really nice. from reno to modesto though temps started in the 70's and slowly rose to 90+, never really heard the fan but could feel a big difference in the way it drove. thankfully i was going down hill over all. fuel mileage hasnt been this good in a long time from the looks of it. i dont have any numbers yet though to support that. i think the fan clutch needs to be replaced. high 70's low 80's should not bring the fan on real hard when cruising down hill at 60mph.

 

[HEMI®Dart]

Mark, if you want to try the fanless winter thing don't forget you need to pull the relay for the A/C clutch so it can't come on while in defrost. There is a mod that can be done to remove the contact in the heater control panel if you preferred that solution. It's in the DodgeRam.org website.

Forgot to mention that. Pull the A/C clutch relay too.