Block the radiator: It really does work!

[David_VT]

OK OK, yes I did doubt the merit of this but I finally tried it and WOW what a change in warm up time!! I am man enough to admit when I am wrong, so here goes my tale...

I found an unused chunk of thin plywood.
I cut it just a bit wider and as tall as the radiator. I
I cut a 5" diamond pattern in the center (easy with the circular saw).
I wrapped the edges and any place I suspected might make contact with the radiator with duct tape.
I slid my newest $3 B. O. M. B. device in the space just in front of the radiator. (cost is duct tape)
I started my cold truck (15degreesF) and let it idle with the heater blower on low. Normally it would still be on 140 if I came back 20 minutes later.

Well, I was pleased to find the temp gauge well above 140 and almost touching the low end of the 'normal' sweep. The cab was warm!!

Next I took the truck out on the road and pushed it a bit. The highest I could get the temp was just over the centerline of the gauge. (yes, still 15degreesF on the outside).

Finally I went to lunch and allowed the truck to cool down (i. e. NO ESPAR). An hour later I started for home and was very pleased to see the temp leaving the 140 mark within minutes of starting out!!!!

Thanks to those who encouraged me to try this!!

PS: the board makes no contact with the radiator and actually leaves a small gap between the board and the fins since the outside edges are resting on the right and left radiator housings. The other coolers are still in the airstream, something a grill blocker (i. e. Lund Cold Front) would have prevented.


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99' SB 4x4 : DDI's, HOT PE, SPA dual gauge, ESPAR, Line-X OTR, Ladder bars, AMSOIL, etc (GPS,Cell,CB,... . )

 

[gitchesum]

I had to do something about mine. Even in 70 degree weather it stay on the low end of the gauge. I experimented with cardboard. I've got two pieces of cardboard with a 7 inch space open in the center of the radiator. I also slid it between the radiator and the other coolers. In 70 degree weather I can get it to 190. With the colder weather(45*, yeah, that's cold down here) I can get it up to about 170. I'm going to build a sset-up similar to what you have. I got a cool new tool to cut the hole with. Rotozip with the circle cutter. I guess a 6" hole should be good enough.

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Curtis Harris

"JAWS"(The Great White)
Updated 11/19/00
1997 Club Cab Dualie
correctly valved 5 speed. White, Brown Manf. brushguard and rear bumper,Sprayed in liner, Stock plate and AFC properly adjusted. That's all for now. More to come.

 

[David_VT]

OH, you are great! I finally found a good reason to buy a ROTOZIP!! Bravo

 

[drawson]

Dave, you really want to warm up fast remove your Rad fan altogether. I run a Lund weather front anytime it's below 40 deg, but this year I took the fan and clutch right off the truck has never been happier. Until doing this this truck never had steedy temp below 50 deg, even with the thermo that is suppost to stop the cycling it still cycled but now I have steed temp alot fast than before and there is a slight increase in the MPG also.

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EAT'M UP
97 2500 Club 4X4 3. 54, Forrest Green/Driftwood, LSD 5 speed, & Psychotty Air System, TST #11, 370 HP injectors, timing at 16 deg. , 16CM2 housing, AFC spring kit, Geno's Exhaust Blanket, TST EGT gauge & 0-60 boost gauge in A Pillar, Cat-be-gone, 4" Dynomax Bullet muffler, Crome 4" turn down, AmsOil Through out, Geno's trans filter kit, AmsOil Bypass system, Lund Winter front, Leer Cab Level Shell Driftwood , 255/85R16, Dyno'd 342 HP pre injectors & turbo housing *NRA/USPSA member and proud of it*

 

[JohnE]

Following the 1 ft² rule requires an 8¼ in diameter hole.

The rule of thumb my father taught me was to match the fan diameter. I never questioned the reasoning, but it seemed to work.

Wife just got me a hammer drill for Christmas. I don't know if the Roto-Zip® will be justified. I think the Father's Day Sawzall® may have to hack the hole... ... .

Cheers;

 

[David_VT]

My understanding is that the required hole is more for the OEM fan clutch than anything else.

Anyone think otherwise??
===============
This board I made is so simple, maybe I'll make a second with a 9" hole for any highway travel.....

 

[illflem]

If the hole isn't in the center the fan blades can become stressed and crack where they join the hub. No fun having a blade break lose at 2000 rpm,it can take the radiator with it.

 

[The patriot]

Drawson, you might want to disconnect your AC compressor clutch wire. When you put on the defroster, I believe it cycles on.
You wouldnt want this too much if youre not moving. You need the airflow across the condenser, otherwise it may blow out.
The voice of experience has spoken. #ad
#ad


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98 Quad cab 4X4 2500 12 valve,5 speed,3. 54 rears, 8' bed. Boost and egt gauges but basicly stock except for a "properly adjusted" AFC. Cat in the garage. Uniden HR 2510, Texas Star 1200 amp. 59,000 Mi as of 10/21/00.
NRA life member. High power/IDPA.

 

[drawson]

Thanks for the concern Patriot. When I removed my fan I also installed an electric 16" fan out side the A/C condenser on the right side. I have this fan set up to come on anytime the A/C clutch come on and also a manual over ride that I can turn it on any time. I was having problems on morning that I needed defrost with the engine actually cooling down too much, so I pulled my A/C clutch relay out until summer.

 

[Vaughn MacKenzie]

I removed my fan about a month ago and have the radiator 90% blocked, with temps staying in the 20s these days. The Cummins does warm up quite a bit faster. It did get up to 195-200F once when I let it idle 15 minutes once after it was good and warmed up (got stuck in a long line in the store). Other than that there has been no hint of overheating.

My EGTs run really low until the engine warms up, usually 350-400F cruising but drops to 225F the moment I let off the pedal. Even goes down to 200 going downhill. After warmup EGTs are still rather low.

Vaughn

 

[TORQUED]

I cut a piece of plastic to put in front of the trans cooler and airconditioning condenser. This works great. I also put a removable piece over that hole. I use that one when it's 5 degrees or less. I don't think I'd completely cover everthing unless you have a horton.

 

[jqram35]

I was just curious about EGT's and if anyone had taken a look at them with the blocker in place. I'm in Missisippi and want to be on the safe side. It does warm up during the day down here.

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2001/3500(ETC/DGP)6X6/4. 10 LSD//K&N/MUFFLER & RESONATOR MISSING

 

[Extreme1]

drawson and Vaughn, do you folks ever tow with no fan? How warm (air temp) can you? I've been thinking about doing this but usually only tow on long trips and I don't want problems.

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'94 3500 4x4, 205,000 miles, Never had a cat, Auto w/shift kit (thanks Dave G), 3. 54 Gears, TST #5 plate, 235-85-16s, Rancho 9000s w/remote, Isspro gauges inplace of cupholder & Amsoil Air Filter & Lubes, AWOL silencer ring & intake boot. NRA member. Blue Ribbon Coalition member.
"Warrantee? We don't need no stinking warrantee!"

 

[Steve]

EXTREME 1
I took mine off, worked fine,Tryed towing with it off. Temp got up to 70 deg (outside). It was ok until I stoped then the engine temp went to 200 deg. I would not tow with the fan off unless its Cold outside.

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95,2500,auto,410;2-WD
Gear Vender Overdrive
tst #5

 

[drawson]

I have towed a very heavy backhoe three or four time since taking my fan off. No problems at all but the temp hasn't been above 45 deg since then.

 

[David_VT]

Going for the fan removal this week. I have a 5 hr highway trip today and am too chicken to remove it before that. It will make a good baseline for blocked radiator with fan, prior to removing the fan unit.

 

[Big-D]

IllFlem... Understand the stress on the fan blades with the radiator totally covered, but what's wrong with the old trick of 1/2 covering the rad with cardboard? Remember the old "zipper" front covers on the big trucks? Open/Close as necessary. They worked like a charm with one eye on the temperature gauge.

 

[illflem]

Big D,the way it was explained to me was say if you cover just half the radiator there will be more airflow on the uncovered side. Every time the fan blades pass the uncovered side they work a little harder and flex,when they get to the covered side they flex back. I'm sure most everyone has broken a piece of metal or even a stick with back and forth bending,so you get the principle. If the uncovered hole is in the center the fan blades are under equal load,no back and forth flexing. This mainly applies when you cover the radiator right on the front of it by slipping a thin object in-between the intercooler and radiator. If you are covering just the front of the rig there are several inches of space for the air flow to equalize,then you have no problem.

 

[Greg_NH]

I just installed my Lund winter covers tonight. The ride home was noticably better. It warmed up quicker, and stayed warm(170 to 190 deg). The temperature on the ride home was ... OH ****, I just put a piece of plastic directly in front of my temperature probe!!! It doesn't seem to work so good any more. #ad
#ad
So what do I do now? I'm thinking about either drilling a 1 inch hole in the plastic directly in front of the temperature probe, or maybe relocating the probe. What do you guys think?

I didn't think having an OAT guage was a big deal, until I got one. Now I love it. It also doesn't work when I have my plow on (I see temps over 80 deg. ).

Thanks for any advice you can give

Greg



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2000 2500 Quad Cab, SLT, 4x4 Auto, 3. 54 LSD, Forest green two tone paint, all options except leather and CD player, Fisher 8 foot minute mount plow, Dodge Sill Guards, Dodge mud flaps, Dodge bug deflector, fog lights (installed myself), Line-X bedliner, Back-Rack ladder rack, Viper remote starter/alarm.

 

[JJW_ND]

To remove fan... . get a 1 and 7/16" combination wrench. Any cheap throw away will do ($15 - $20).

Wrench will fit over large fan hun nut. Standing in front of truck hammer wrench clockwise or to the right. If it does not want to break loose, jam a large flat bar/ screw driver between two of the four small bolt heads on the hub to hold the hub while hammering nut loose.

With current temps, could remove radiator. Doudt Tstat has opened in several weeks.

jjw
ND