GMCforum
For enthusiast of the Classic GMC Motorhome built from 1973 to 1978. A web-based mirror of the GMCnet mailing list.

Home » Public Forums » GMCnet » Driving in the heat - different this year - a trip report (radiators need air flow)
Driving in the heat - different this year - a trip report [message #137918] Sun, 07 August 2011 17:41 Go to next message
armandminnie is currently offline  armandminnie   United States
Messages: 864
Registered: May 2009
Location: Marana, AZ
Karma: 2
Senior Member
We are on our way to Montana and points beyond and we had to drive from Marana, AZ to Lakeside, AZ in the past two days. This is about a 5000 foot climb. The air temperatures ranged from the low 90's to low 100's and the engine temps ranged from 205 to 230. I am towing a 2000 4WD Tracker that weights about 3000 pounds. Most of the time I ran the chassis A/C but did shut it off on some of the longer hills. My fan clutch is a medium duty AutoZone 922747. The engine temperatures were very steady and could be easily attributed to the current conditions - grade and air temperature. There were no sudden changes in anything - fan noise or engine temperature. On level ground the engine ran at 205 which is normal for my engine.


The aspect of this that I think is worth reporting is that last year, under the same circumstances but with one notable exception, my engine temperatures were oscillating between 190 and 225 degrees at a pretty rapid pace. On level roads, never mind any climbing, the fan would come on at about 225 or so and cool the engine down to about 190 and then turn off. As soon as it turned off the temp gauge (a calibrated mechanical gauge) would show it climbing again and the fan would be on again very quickly. The fan, as measured with a stop watch, was on 70 to 90 percent of the time and making a racket.

The main difference between these two scenarios is that this year I have air deflectors on each side of the radiator and an air dam under the radiator. This has made a world of difference in driving in the heat for me. I'd bet that those of us who have pre-77 coaches would see benefits from installing those items too.


Armand Minnie
Marana, AZ
'76 Eleganza II TZE166V103202
visit my gmc blog
click here to visit gmcws.org
Re: [GMCnet] Driving in the heat - different this year - a trip report [message #137920 is a reply to message #137918] Sun, 07 August 2011 17:47 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
> My fan clutch is a medium duty AutoZone 922747. The engine temperatures
> were very steady and could be easily attributed to the current conditions -
> grade and air temperature. There were no sudden changes in anything - fan
> noise or engine temperature. On level ground the engine ran at 205 which is
> normal for my engine.
>
> I don't understand, are you saying the fan does not come on now ??

and

how is your starter doing

have a great trip

gene


--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Re: [GMCnet] Driving in the heat - different this year - a trip report [message #137921 is a reply to message #137920] Sun, 07 August 2011 17:55 Go to previous messageGo to next message
armandminnie is currently offline  armandminnie   United States
Messages: 864
Registered: May 2009
Location: Marana, AZ
Karma: 2
Senior Member
Gene, thanks to you and your suggestion to wire directly from the battery positive to the starter I have no more starter issues. I still have the PNSS jumpered too.

Armand Minnie
Marana, AZ
'76 Eleganza II TZE166V103202
visit my gmc blog
click here to visit gmcws.org
Re: [GMCnet] Driving in the heat - different this year - a trip report [message #137922 is a reply to message #137920] Sun, 07 August 2011 17:58 Go to previous messageGo to next message
armandminnie is currently offline  armandminnie   United States
Messages: 864
Registered: May 2009
Location: Marana, AZ
Karma: 2
Senior Member
Didn't see the question about whether or not the fan is turning on now. Yes, the fan turns on at low speeds when it should. It does not turn on at highway speeds - also like it should. Last year the fan was what was keeping the engine running by pulling air through the radiator - this year the air is being pushed through the radiator and the fan is not needed at highway speeds.

Armand Minnie
Marana, AZ
'76 Eleganza II TZE166V103202
visit my gmc blog
click here to visit gmcws.org
Re: [GMCnet] Driving in the heat - different this year - a trip report [message #137925 is a reply to message #137922] Sun, 07 August 2011 18:14 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
REALLY GOOD DATA

on my list to do

did you post pictures of the deflectors?

gene



On Sun, Aug 7, 2011 at 3:58 PM, Armand Minnie <armand@minniebiz.com> wrote:

>
>
> Didn't see the question about whether or not the fan is turning on now.
> Yes, the fan turns on at low speeds when it should. It does not turn on at
> highway speeds - also like it should. Last year the fan was what was
> keeping the engine running by pulling air through the radiator - this year
> the air is being pushed through the radiator and the fan is not needed at
> highway speeds.
> --
> Armand Minnie
> Marana, AZ
> '76 Eleganza II
> TZE166V103202
> http://www.minniebiz.com
> use the forum - it's easy
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Re: [GMCnet] Driving in the heat - different this year - a trip report [message #137927 is a reply to message #137925] Sun, 07 August 2011 18:27 Go to previous messageGo to next message
armandminnie is currently offline  armandminnie   United States
Messages: 864
Registered: May 2009
Location: Marana, AZ
Karma: 2
Senior Member
Yes, my air flow mods posted at http://www.gmcmhphotos.com/photos/showgallery.php?cat=5787 and lots of discussion on my blog too. There are also ready-made items available at the GMC vendors.

Armand Minnie
Marana, AZ
'76 Eleganza II TZE166V103202
visit my gmc blog
click here to visit gmcws.org
Re: [GMCnet] Driving in the heat - different this year - a trip report [message #137930 is a reply to message #137927] Sun, 07 August 2011 18:33 Go to previous messageGo to next message
Mr ERFisher is currently offline  Mr ERFisher   United States
Messages: 7117
Registered: August 2005
Karma: 2
Senior Member
I wanted all to know ;>)
cool so-to-speak

nice job on the blog also

gene



On Sun, Aug 7, 2011 at 4:27 PM, Armand Minnie <armand@minniebiz.com> wrote:

>
>
> Yes, my air flow mods posted at
> http://www.gmcmhphotos.com/photos/showgallery.php?cat=5787 and lots of
> discussion on my blog too. There are also ready-made items available at the
> GMC vendors.
> --
> Armand Minnie
> Marana, AZ
> '76 Eleganza II
> TZE166V103202
> http://www.minniebiz.com/gmcmotorhome
> use the forum - it's easy
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>



--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist

Re: [GMCnet] Driving in the heat - different this year - a trip report [message #137941 is a reply to message #137927] Sun, 07 August 2011 19:56 Go to previous messageGo to next message
C Boyd is currently offline  C Boyd   United States
Messages: 2629
Registered: April 2006
Karma: 18
Senior Member
armandminnie wrote on Sun, 07 August 2011 19:27

Yes, my air flow mods posted at http://www.gmcmhphotos.com/photos/showgallery.php?cat=5787 and lots of discussion on my blog too. There are also ready-made items available at the GMC vendors.






Sir: it has been said that imitation is the highest form of flattery. Tomorrow I plan on flattering you. I knew I was saving them mud flaps for something. Thanks..


C. Boyd
76 Crestmont
East Tennessee
Re: [GMCnet] Driving in the heat - different this year - a trip report [message #137951 is a reply to message #137941] Sun, 07 August 2011 20:55 Go to previous messageGo to next message
armandminnie is currently offline  armandminnie   United States
Messages: 864
Registered: May 2009
Location: Marana, AZ
Karma: 2
Senior Member
I must confess that Steve Ferguson was the one who suggested using 18-wheeler mud flaps. Great idea Steve. I used them on the air dam too because I broke the rigid one I made at first by hitting it on a driveway.

Armand Minnie
Marana, AZ
'76 Eleganza II TZE166V103202
visit my gmc blog
click here to visit gmcws.org
Re: Driving in the heat - different this year - a trip report [message #137955 is a reply to message #137918] Sun, 07 August 2011 21:16 Go to previous messageGo to next message
WD0AFQ is currently offline  WD0AFQ   United States
Messages: 7111
Registered: November 2004
Location: Dexter, Mo.
Karma: 207
Senior Member
Hey Armand, glad all is good on your trip with the new mods. How u liking those brakes?
Dan,
fro Peru, Il.


3 In Stainless Exhaust Headers One Ton All Discs/Reaction Arm 355 FD/Quad Bag/Alum Radiator Manny Tran/New eng. Holley EFI/10 Tire Air Monitoring System Solarized Coach/Upgraded Windows Satelite TV/On Demand Hot Water/3Way Refer
Re: Driving in the heat - different this year - a trip report [message #137960 is a reply to message #137955] Sun, 07 August 2011 22:02 Go to previous messageGo to next message
armandminnie is currently offline  armandminnie   United States
Messages: 864
Registered: May 2009
Location: Marana, AZ
Karma: 2
Senior Member
It was good to have those new disc brakes and reaction arm system on the way down some of those big hills. I am trying to take it easy on them because I am supposed to for the first 500 miles with the EBC pads but it is nice to know that they are there if I have to jump on them.

Armand Minnie
Marana, AZ
'76 Eleganza II TZE166V103202
visit my gmc blog
click here to visit gmcws.org
Re: [GMCnet] Driving in the heat - different this year - a tripreport [message #137974 is a reply to message #137951] Mon, 08 August 2011 02:54 Go to previous message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Hey Chuck,

Make the lower air dam out of mud flaps too, that way you won't plow up the
grass next to the barn like I did! ;-)

Regards,
Rob M.
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426


-----Original Message-----
From: Armand Minnie

I must confess that Steve Ferguson was the one who suggested using
18-wheeler mud flaps. Great idea Steve. I used them on the air dam too
because I broke the rigid one I made at first by hitting it on a driveway.
--
Armand

_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist



Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Previous Topic: Re: [GMCnet] Are windows for 73 model and 77 model GMC'sinterchangeable?
Next Topic: Re: [GMCnet] Isolator/combiner
Goto Forum:
  


Current Time: Tue Oct 01 00:00:15 CDT 2024

Total time taken to generate the page: 0.02926 seconds