cockpit heat

[ALANSD]

now that it is over 90 degrees here I can report on the state of the heat in my drivers area. Last year it got quite warm with the roof air on and no dash air.
This year I have bypassed the heater core, flushed and refilled the cooling system with 50% distilled water 50% antifreeze and a can of CRC (napa) Coolant additive.
In 90 degree plus heat at 60-65mph , the driver and passenger areas were comfortable with little or no heat felt coming thru the floor, and the 454 ran at 160-170 all day. Never got over 180 in standing traffic jams for 30-40 minutes.
Good news for us southerners.

[74Argosy24MH]

Awesome!! No Cool & Quiet or other big $$ insulation? Maybe there is hope for mine after all. I finished my front inner roof today, did insulate the top of it with a ceramic insulation. Now to see how well it works.

John

[ALANSD]

I have to say even the co-pilot was happy with the temp in her area. Last summer temps outside hit hight 90's while we were in Shenandoah Valley, and it got uncomfortable up front.
I am hoping that is over as we head to Charleston,SC in a few weeks.
The engine temps stayed really close to 160. I had looked for Purple Ice or some other aditives locally, but found only the NAPA- CRC stuff, which was 5 bucks a can. One can to 20 quarts of coolant, which is close to what I now have with the heater core out.
I also have two ceiling mounted fans up front that help move the rear a/c air around us.

[Silvertwinkie]

Hey Alan,

I have been considering those coolant additives like water wetter, etc... do they really make the temp a bit lower? Also do you know if they are compatible with the dex-cool extended life coolants?

Eric

[ALANSD]

the CRC stuff came from NAPA and it said as i recall that it was compatible with alltypes of coolant. I couldn't find watter wetter or purple ice locally although Jeg's had it in the catalogue. I was ready then and did not want to wait for the mail order.
The combo of flushing ,new coolant, and the CRC did drop my temps to a niv ce low level considering the 90 degree weather, no heater core, and highway driving at 60+.
I was especially nervous in the one hour long to go one mile --traffic jam but I never hit above 180.
I am a cool happy dude.

[wb13798]

alan
went to nashville this weekend the coach water temp going up was running from 190 to 200. coming back was a different story and i dont know why. the temp was at 210 to 225 . no heavy traffis, no stops , steady moving at 65mph. last ten miles the temp dropped to 200. what is your secret????
lol
al

[ALANSD]

well other than the above mentioned chemical, when mine hits 180 the fan starts up and it drops it right back to 160. I have never hit over 190-200 even last summer in the VA mountains at 98 degrees outside.
I also don't use the a.c . up front just the roof air.

[wb13798]

when you say fan comes on what does that mean what fan?? i had a extra fan (electric) that had a thermostat and it went south and i gave up on the made in china tack ons. i do give some thought to putting a flex fan like ford engines have. and remove the fan clutch. i dont think my clutch kicked in the entire trip sunday. aND THIS IS PROBABLY THE FIFTH OR SIXTH CLUTCH I HAVE PUT ON . LOL
AL

[ALANSD]

yes fan clutch- mine is accurate to kick in at 180 degrees, and you can hear the roar at that point. Temps drops quickly to 160 after that. Often it never reaches 180 to begin with, staying at 160-170 most days no matter how hot out.

[PeterH-350LE]

Alan, I think we have another thing in common, besides our passions for classic MH:
bad Temp gauges!!
Mine also runs at 160-180 max, but a few tests with one of those laser heat sensors. the truth is 180-200. Makes sense anyways, because of the thermostat.
The last fan clutch I put in was a heavy duty one. It works like a clock. Rarely engages at Hwy speeds, but as soon as I drop down to 50-55 it engages. Roar..., back up to 60-65 it goes away. In my case it seems that it has more to do with airflow than noticable increase in water temp.

[thenewkid64]

My "new" 78 works just like your Peter, Roars up to 50-55 or so and then is quiet until I get back under 50. I think is has to to more with RPM's and the air temp than any thing else. Cooler outside temps and it would spin up for a short period and then quiet down. Even under 50 MPH.

I know the temp gauge in the 78 is wrong. The highest temp it registered on the trip was 155, and that was climbing a 7000 ft pass outside Salt lake city.

[mcneon]

I thought those fan clutches were viscous and just varied their degree of slip based on temperature. Is there another type I'm not aware of that's either on or off?

I have the original type of fan clutch on my Argosy 24'. Today was around 90 degrees, and I towed my 6000# race trailer at my usual 70 mph. Engine temp sat at around 190, oil and transmission fluids both right around 215.

Bob McKeown

[wb13798]

havent fixed the silver weenie yet. i installed a flex fan and it did stabalize the temp some but still at 220 . was to much noise the fan sound like my old pick up with the buck shot tires . she was really houling at 3000 rpm. took that fan off and returned to auto zone. did some research in their books and as it turns out auto zone has two fan clutches one is temp sensitive and one is not. i have the one that is not temp sensitive. going to switch that out and i hope that fixes the problem. i also took the thermostat out and ran it up the mountain to see what the temp would do and it did get hot but not to bad. 230
mr good wrench recommended i check for blown head gasket . they would do the test for $90 . checked with auto zone and they loan a test set that will pressure test the cooling system for leaks and bad head gasket. for free. well the silver weenie came thru with flying colors no blown head gasket. didnt think i had a blown head gasket as it wasnt losing any water. just getting hotter than i like to see. my guages are correct or very close. had the infared test done to verify the pick up and guage was accurate.

[ALANSD]

who did the infrared test? Might be worth checking my gauge also. The temp in mine has been consisitent over the two years I have had it, with the slight lowering of op temp after my recent cooling sys. service.. The additive water wetting agent might be worth a look for yours---whatever brand is available.

[wb13798]

the infared test was done at a muffler shop here in huntsville.
just finished installing the new clutch (thermal clutch) and i cant get the temp over 180. i havent put a thermostat in yet. and the water has the watter wetter stuff in it. before the trip to nashville i dumped a can in the system and it dropped the temp 20 degrees, i was impressed . now that i look back im lucky to have done same as i probably would have had to fix the weenie for over heating last week end.
the non-thermal clutch looks like the thermal but it is a rpm sensitive clutch. more rpm less friction and fan turns less rpms. it is supposed to turm one for one at low less than 1000 rpm .
we all have a problem with the 454s running hot and when you pull a toad you have more heat to worry about.
your sencet in the block might need replacing . they are not that expensive . i replaced mine before i had the temp checked at the muffler shop. also on my engine the right side exhaust manifold runs hotter than the left side. im going to put a 180 thermostat tomorrow, and hopefully that will be the end of this effort.lol
al

[masseyfarm]

I know its an old thread, but it describes what this fellow tried to solve here.
gmcmotorhome.com - Fresh Air Vents

This alteration leaves no visible outside alteration on your Classic Motorhome, such as a manual reversible vent would.

Fresh air is always better for cooling the body if you can get enough air movement, and this would allow you to keep that noisy window closed. His and hers could be installed as each is controlled individually.

Dave