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 » [GMCnet] Must have been a nightmare cooling these FMCs
[GMCnet] Must have been a nightmare cooling these FMCs [message #283199] Sun, 26 July 2015 10:35 Go to next message
glwgmc is currently offline  glwgmc   United States
Messages: 1014
Registered: June 2004
Karma: 10
Senior Member
I stumbled on this about trying to cool the FMC motorhomes. They were contemporary to our GMCs but used a rear mounted, rear facing Chrysler 440 with a rear mounted radiator. From the sound of it whether trying to pull air in through the radiator with a fan or trying to push air out through the radiator with a fan was at best a difficult proposition! Makes our discussions about cooling our GMCs sound easy….

From a FMC chat group posting:

"If you want to stay with a "push" into the shroud setup (tries to cool 230 deg radiator water with 300 deg + air heated by the exhaust manifolds) then you want what is called a "reverse rotation fan".

Fan blades are curved or cupped (just like a "spoon") that "scoops" the air across the blade. That curve or cup has to be in the direction of rotation. Just as you can't scoop a spoonful of water with the back side of a spoon, a fan blade curved away from the direction of rotation does not move much air and just makes a lot of noise. This blade curvature, direction of rotation, and which way it is mounted are important. There has been more than one FMC reverse rotation pusher fan installed BACKWARDS.

When doing anything with the FMC fan . . . remember . . . looking in the street side engine bay door, the top fan blade rotates TOWARD YOU. If you HAVE A PUSHER FAN, that top fan blade "scoop" should be rotating toward you as a cup or curve. Look at it and study which way the blade is curved and convince yourself that the "scoop" is facing the right way toward the radiator (for a PUSHER) on that top blade that will rotate toward you. Of course, if you have a SUCK fan (takes in ambient temp outside air that flows thru the radiator, then shroud, then thru the fan that BLOWS the air ON the exhaust manifolds, then out the sides and bottom) the blade curve is reversed. Rotation is the same, but the blade curvature is the other way. Fans are made one or the other, and are not reversible by just turning the whole thing around.The fan blade should be ABOUT half in and half out."




Jerry
Jerry & Sharon Work
Kerby, OR
glwork@mac.com
http://jerrywork.com

78 Royale with most everything done to modernize a GMC mechanically
77/94 Clasco bone stock and looks like it just left the Clasco facility
Both drive equally as well.


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


Jerry & Sharon Work
78 Royale
Kerby, OR
Re: [GMCnet] Must have been a nightmare cooling these FMCs [message #283200 is a reply to message #283199] Sun, 26 July 2015 11:00 Go to previous messageGo to next message
Chr$ is currently offline  Chr$   United States
Messages: 2690
Registered: January 2004
Location: Scottsdale, AZ
Karma: 1
Senior Member
My brain hurts after reading that.

-Chr$: Perpetual SmartAss
Scottsdale, AZ

77 Ex-Kingsley 455 SOLD!
2010 Nomad 24 Ft TT 390W PV W/MPPT, EV4010 and custom cargo door.
Photosite: Chrisc GMC:"It has Begun" TT: "The Other Woman"
Re: [GMCnet] Must have been a nightmare cooling these FMCs [message #283211 is a reply to message #283200] Sun, 26 July 2015 14:26 Go to previous messageGo to next message
ljdavick is currently offline  ljdavick   United States
Messages: 3548
Registered: March 2007
Location: Fremont, CA
Karma: -3
Senior Member
One of the motorhomes Charles Kuralt had was an FMC for his “On the Road” series. I believe they were made here in San Jose and were premium coaches for their time.

I suspect they’ve found an effective way to cool the things as so many diesel pushers use rear or side radiators. And - yes it makes our GMC cooling system seem like childs play!

Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, CA


_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


Larry Davick
A Mystery Machine
1976(ish) Palm Beach
Fremont, Ca
Howell EFI + EBL + Electronic Dizzy
Re: [GMCnet] Must have been a nightmare cooling these FMCs [message #283900 is a reply to message #283211] Tue, 04 August 2015 06:27 Go to previous message
Ronald Pottol is currently offline  Ronald Pottol   United States
Messages: 505
Registered: September 2012
Location: Redwood City, California
Karma: -2
Senior Member
Their next product was the Bradley armored fighting vehicle.

And now, all those facilities are gone, including the test track.
On Jul 26, 2015 12:26 PM, "Larry Davick" wrote:

> One of the motorhomes Charles Kuralt had was an FMC for his “On the Road”
> series. I believe they were made here in San Jose and were premium coaches
> for their time.
>
> I suspect they’ve found an effective way to cool the things as so many
> diesel pushers use rear or side radiators. And - yes it makes our GMC
> cooling system seem like childs play!
>
> Larry Davick
> A Mystery Machine
> 1976(ish) Palm Beach
> Fremont, CA
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


1973 26' GM outfitted
Previous Topic: [GMCnet] What is holding up the cupboards?
Next Topic: [GMCnet] VSS
Goto Forum:
  


Current Time: Sun Sep 29 05:26:36 CDT 2024

Total time taken to generate the page: 0.01040 seconds