Cooling the 454

[detectivedrew]

I am aware the Chevy 454 inherently runs hot.  It is even more difficult to get air flow back to the dog house; the engine sits a few feet back from the front grill. I have a tranny cooler and another cooler attached to the air intake side of the radiator. Aside from making sure the fluid is okay has anyone added additional electric fans to cool the engine under idle? Thanks

 

[mypursuit]

  Do you have an electric fan in front of the radiator and is it working?  Not sure of your 84 but my 96 Class A has an electric fan in front that comes on and off automatically at a preset temperature.  It helps but my gut still tightens when the Chevy starts getting hot.  Another thing to do to help is turn the heater on with fan.  You get hot but it helps.  Lastly, some winnebagos have a aux heater in the back of the coach that will help if turned on. 

 

[detectivedrew]

Hi,

Two problems. No electric fan attached to the radiator on this model, only a 7-fin fan that runs off the engine. Secondly to put on the heater in the summer would put me in a panic (I boil at room temperature). The engine does not get to the point where I feel it will overheat, I just want something to prevent the potential of overheating in hot summer weather. It was 102 last weekend and we postponed a trip due to the weather, but then again, any engine hates driving in that kind of extreme temperature.

 

[PJ Stough]

In my experience there are three things that should be checked on the 454.  One is make sure that your fan clutch is working as designed.  Second is to make sure that your water pump is working as designed.  The fins on the water pump can deteriorate over time, causing it not to pump as much water as needed.  The third is to make sure your radiator is not plugged, either internally or externally.

Paul

 

[detectivedrew]

Hi Paul,

Fan clutch? I have a belt driven fan, does it still have a fan clutch? I will check the water pump and radiator. Thanks

 

[PJ Stough]

Not sure yours has a fan clutch.  I know the 454 in our 88 Sportscoach did.  The fan clutch looks like this and is attached to the fan.  http://www.summitracing.com/parts/HDA-2784/?rtype=10

Paul

 

[detectivedrew]

Hi Paul,

I am no mechanic, it may be attached to my fan. I will check things out. Anything else (due to your 454 experience), I should check out engine wise in order to prevent a breakdown?  Thanks

 

[PJ Stough]

Hi Paul,

I am no mechanic, it may be attached to my fan. I will check things out. Anything else (due to your 454 experience), I should check out engine wise in order to prevent a breakdown?  Thanks

If you check and make sure those things mentioned are ok, hopefully, the engine will not over heat.  Other than that, the 454 we had worked well.

Paul

 

[mnmnutswer]

Paul & Ann hit it on the head...

My 454 got heated up a little over a 5,000 mile drive. After returning home I had a new fan clutch, thermostat and water pump installed. Also had a new twin elect cooling fans installed in front of the transmission cooler it works off the water temp and I also had a switch installed so I can turn it on if I know I am going to climb a long grade. This way I can cool the system down prior to starting the climb.....NO more ruining hot.

 

[detectivedrew]

Sounds like a sweet combo Paul. Did you do the twin fan installation yourself? Any pics? Thanks

 

[udidwht]

Old thread but useful info...

To verify good flow thru the radiator. When first (cold engine) do you see the auxiliary fan free wheeling on the front of the oil-cooler/ac condenser? That is a sure sign that neither the radiator or cooler/condenser are plugged with excess debris.

On mine I can use my finger to stop the auxiliary fan and when I let go it starts free wheeling again. It will do this until the mechanical clutch fan disengages after initial cold start.

 

[Utclmjmpr]

The 454 will run all day in a lower gear,,if that won,t do then go lower.. Most heating problems are folks in a hurry with "keep up with the Jones" syndrome....When geared down the engine is under less load and stress,, the fan is turning faster and oil is pumping faster also...Don't hesitate to use the trans for it's intended purpose..>>>Dan

 

[John Canfield]

I should have moved this thread from Winnebago to Motorhomes 10 years ago .

 

[JayArr]

Fan clutches are cheap compared to overheating damage.

Electric fans can help or not depending on the installation. Try taking two box fans and sit them on your kitchen table with one feeding into the second.

Run them both on high and you get a massive air flow.

Now set the first fan on high and the second fan on low (simulating idle) and put your hand in between holding a small piece of ribbon or string.

You'll see turbulance. You can't easily push air at 25mph into a fan running at 15mph.

Electric fans were meant to replace mechanical fans but sometimes people get the mistaken idea that they will supplement them and the will, sort-of, but no vehicle leaves the factory with such a degraded cooling system that it needs an extra fan so if you're thinking of adding electric fans consider solving the real problem instead.

As PJ said above - new radiator, new thermostat, new water pump, new fan clutch and I'll add - make sure all of the factory shrouding is still in place, it's there for a reason and it's important.

 

[Ex-Calif]

My 454 powered RV has about 65k miles on it. It appears the front mounted electric pusher fan is stock as well as a shrouded clutched engine driven fan. I drove it to Flagstaff and higher last summer and it pulled the hills without any cooling issues.

I did flush and fill and replaced all the hoses when I bought it. The pusher fan runs continuously with the engine.

The gauge read close to 220 but using my I/R gun I found the actual temps at 200. I highly recommend an I/R gun in your tool kit.

 

[JayArr]

Ex Cali

Is the fan clutch electric?

With an electric fan clutch it's possible for the computer to shut off the mechanical fan and let it freewheel while the electric does the work. That way they aren't fighting each other.

Or maybe I'm just wrong about the two fans opposing each other?

 

[Ex-Calif]

Ex Cali

Is the fan clutch electric?

With an electric fan clutch it's possible for the computer to shut off the mechanical fan and let it freewheel while the electric does the work. That way they aren't fighting each other.

Or maybe I'm just wrong about the two fans opposing each other?

No the mechanical fan is not electric. I have heard arguments both ways about both electric and mechanical "fighting" each other.

The way I view it is, at least on mine, the electric fan ensures a positive pressure through the radiator where the mechanical fan takes over. I do know with the engine cover open there is a lot of air being moved.

 

[Old_Crow]

My '89 P30 coach had both the engine mounted fan and the dual pusher electrics from the factory. The electric fans were wired to only cycle when the a/c was on AND the engine temp was above a certain point. In the 5 years and 15k miles I owned that coach, I only heard them cycle 5 or 6 times.
The engine driven fan, OTOH, cycled on and off every time that the coach was in a hard uphill pull.

The pusher fans would, indeed rotate with the air that the engine driven fan pulled through the radiator, but that was merely from airflow through the blades with no power applied.

 

[mnmnutswer]

Sounds like a sweet combo Paul. Did you do the twin fan installation yourself? Any pics? Thanks

Yes easy install