I'm looking at 12 degrees in Oregon on Tuesday, and my truck hasn't been getting up to operating temperature like it normally does on my 15min commute. Will blocking the grill get my temps up faster? Also, is there any aero advantage to doing this?

Another thing I have noticed is that my fan always runs on my truck from the moment I start it 'till I shut it down. Is this normal?

 

The fan running is normal as its a friction coupler for the clutch. It should however, be not fully engaged until it gets hot. With the engine OFF, the fan should be able to be turned by hand.

Getting grill covers or making your own is a very good idea. Better engine temps will make everyone happy. You getting heat and the engine burning all that fuel.

 

i remove my fan in the winter and replace it in the spring. i also block the rad (behind intercooler) with plasticized cardboard (politician yard sign).

i have had zero issues with this in the couple years i have been doing so.

if you slide cardboard in front of the rad without removing the fan, be sure to cut a hole large enough allow cooling for the fan clutch. also a piece without holes could potentially flex the fan blades towards the rad while it spins . . . i doubt it would make contact, but the potential is certainly there . . .

 

I'm doing the same this winter(remove fan)...I'm still testing mine...I haven't put carboard back in yet...I had the rad all blocked up and it got warm quick...But that was at 10C..

 

I been experimenting for 15 years for more heat and have come to the conclusion there is only one thing you can do for more heat and faster warm up in the cold, use the recirculate position on your vent control.

In cold weather without a load the Cummins doesn't even need a radiator, the heater core is enough to cool it. Covering the radiator makes little difference if the thermostat rarely opens. Recirculate position recycles warmer interior air rather than running cold outside air though the heater core.
Unfortunately the 24 valve vent control only has one recirculate setting, max A/C. It will work though.

Minus 22F here this morning and I had heat right away in recirc, truck had been plugged in all night. Five miles down the road and I was cooking.
I haven't used my winter front in ten years, it's worthless.

 

Good point Infidel. I hadn't even thought of that, but blocking the radiator should make almost no difference if the thermostat is functioning properly. If I understand things correctly, a closed thermostat should just recirculate the fluid that is already in the block and not send any of it to the radiator.

My second question is if blocking the grill would make the truck more aerodynamic and get better fuel economy. In nascar, blocking a larger portion of the grill allows for faster speed on the track. I don't know if this would make a significant difference though.

My third question is about the fan. Flexalite claims a 27hp gain by using their product. I highly doubt that removing the entire fan assembly would even give half that hp back. 27hp is equal to 20,142 watts! Has anyone tested the claim Flexalite makes, or even notice a difference running with the fan removed? 27hp would be easily noticeable. The Flexalite fans themselves have a max draw of 500 watts. They are claiming you can replace a 27hp fan with a 0.6HP one. That is 1/40 of the air moving power. Something doesn't add up.

 

Redpoint5, you are correct, something does not add up. I've done the research and here is what I found, the stock fan, when locked up will move 8,800 cfm. The flex-a-lite fan will move 5,500 cfm. That is a 37.5% decrease in cfm. People have used them with success, but I tow heavy and when I had my 2000, I did not want heating issues so I left the stock fan on and blocked the front of the truck off and 1/2 the rad and took off the fan.

When I took the fan off, I noticed ZERO difference in fuel economy or power. It was just quiter on startup and it seemed to warm up faster.

 

same here, much quicker warm-up times when the fan is removed and rad covered (not much of a difference in cab, but the temp gauge sure climbs a lot quicker when the two are used in combination)

and yes, i also notice a warmer airflow when in re-circ as it uses cab air instead of the cold outside air . . .

 

I do notice a difference with the winter front on, namely it keeps my temps up when driving. Without it I notice that the temps are low enough that the thermostat keeps opening and closing, that is just me though. I have been running them for 5 yrs now, and think they make a difference.

 

Cummins says a locked up stock fan pulls 23 hp.
Sort of doubt Flexalite could pull 4 hp out of nowhere.

 

Those of you who remove your fan in the winter, be careful if you set the fan settings on something that engages the A/C. The front/floor setting in particular engages the A/C, but isn't marked with the little A/C symbol. When the A/C engages with no airflow through the condenser, pressure in the system can get dangerously high.

As long as you're aware of this and set it on full front, or full floor then it's no big deal.

Just fyi...
Mike

 

I would also like to remind everyone to watch the temps!!!

I installed a board to block the radiator..worked great when it was cold..but today the temps hit 70F..oops I forgot to remove my board..the radiator temp hit 210+...didn't boil over but I would guess it wasn't far..no damage

-dkenny

 

also a reminder - i remove my fan, then pull the boat out of the backyard in early spring to swap locations with a 5th wheel. well the boat trailer tires were stuck in ice - th truck was working pretty hard and not moving an inch - so no airflow at all resulted in coolant overflow!! oh well, i was due for a coolant change anyway . ..

 

i love my winter front. i can deffently tell a temp difference in the truck with the front on. the best fix though has been adding a pac brake. warms the truck right up

 

I bought the set of plastic inserts for my grill, and I can def. notice quicker warm-up.

Does anyone have the cloth one that goes over the whole grille? i was lookin for one right when I bought my truck 2 1/2 yrs ago. the dealer and accessory places said they quit makin em like 6 months before I bought my truck.