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 » Trip Report (HOT,HOT,HOT)
Trip Report [message #92097] Thu, 15 July 2010 21:35 Go to next message
g.winger is currently offline  g.winger   United States
Messages: 792
Registered: February 2008
Location: Warrenton,Missouri
Karma: 0
Senior Member
Finally got a chance to do a test run, 95 degrees, about 200% humidity and alot hotter than I wanted for the first long run. Had driven up to get it inspected. Runnin a bit rich, went down one size on the mains. Cooled down the inside with the roof AC. Unplugged and drove to dinner at the wifes favorite Mex. resturant. 3 miles to the interstate, 7 miles on the service road and after dinner back on the interstate. AFR looked pretty good, little bit rich at WFO. Slight bog when the seconarys start to open, might be a bit loose on the air flap spring. BUT,,, notice the temp climbing, 210 on the elc. full sweep autometer gage. 200 on the new oil temp. Shut off the AC about 1.5 from the restraunt and it came down pretty quick to 195. On the way home I decided to let it ride. 215, almost 220 on the water, 205 on the oil. Oil is in one of the unused "IN" ports on the remote filter before the RAD cooler. Water is in the front of the block where the vac. thermo valve was. Original water temp gage looked normal. No coolant when I stopped either time. Strange,, the fan clutch never came on. Can't remember the fan clutch coming on at start up or when we got off the hiway. Still got alot to do. So, any Cad. conversions have yours run this hot??? Larry?? Ken?? What was the hottest air temp??? Dash AC on?? Oil temps?? Thanks,,,,Paul {runnin hot in the state of Misery(oops,,,missouri)} Leavitt
Re: Trip Report [message #92099 is a reply to message #92097] Thu, 15 July 2010 21:45 Go to previous messageGo to next message
g.winger is currently offline  g.winger   United States
Messages: 792
Registered: February 2008
Location: Warrenton,Missouri
Karma: 0
Senior Member
Just read Ken H. trip report, soooooo,,,220+ looks not so bad in hot weather with the AC on. Of course I'm assuming he had the AC on.,,,,Paul (not quite as bad, 85 degrees at 9;44. But I still had to run the AC on the way TO work) Leavitt
Re: Trip Report [message #92101 is a reply to message #92097] Thu, 15 July 2010 21:58 Go to previous messageGo to next message
Larry is currently offline  Larry   United States
Messages: 2875
Registered: January 2004
Location: Menomonie, WI
Karma: 10
Senior Member
Paul,
That Cad runs normally hotter than the Olds. Took my coach to Indiana last Sunday and was running in 90* weather with AC on. Water temp went to 205* and the fan clutch came on and dragged it back down to 195. That cycle would repeat itself about every 10-15 minutes. No engine oil temp, but my trans temp ran mostly at 165* and oil pressure at 45lbs. From all I've read, the Cad performs well at temps of 200-220. Mine seems to run best when it is that hot. Sounds like you have a bad fan clutch though. I'd be looking at replacing it.


Larry Smile
78 Royale w/500 Caddy
Menomonie, WI.
Re: [GMCnet] Trip Report [message #92106 is a reply to message #92097] Thu, 15 July 2010 22:15 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Paul,

On our 500 mile trip last week, in 93*-95*F weather, with some pretty good
hills, the H20 temp ran 225*F to 235*F with the oil temp about the same.
I've got a 13 psi radiator cap but even with that if I didn't run at fast
idle for a few minutes before shutting down, I'd lose some coolant.

I never heard the fan engage. It feels OK cold with the engine stopped, but
I don't hear it on startup nor do I ever hear it engage; the cockpit sounds
pretty quiet to me, especially considering that the hatch is not yet well
sealed.

I suspect that after a longer run than you've had you'll have higher
readings also. Everyone I've heard, including the books, say to expect
220*F+.

Ken H.


On Thu, Jul 15, 2010 at 10:35 PM, Paul Leavitt <leavittpaul@yahoo.com>wrote:

>
>
> Finally got a chance to do a test run, 95 degrees, about 200% humidity and
> alot hotter than I wanted for the first long run. Had driven up to get it
> inspected. Runnin a bit rich, went down one size on the mains. Cooled down
> the inside with the roof AC. Unplugged and drove to dinner at the wifes
> favorite Mex. resturant. 3 miles to the interstate, 7 miles on the service
> road and after dinner back on the interstate. AFR looked pretty good, little
> bit rich at WFO. Slight bog when the seconarys start to open, might be a bit
> loose on the air flap spring. BUT,,, notice the temp climbing, 210 on the
> elc. full sweep autometer gage. 200 on the new oil temp. Shut off the AC
> about 1.5 from the restraunt and it came down pretty quick to 195. On the
> way home I decided to let it ride. 215, almost 220 on the water, 205 on the
> oil. Oil is in one of the unused "IN" ports on the remote filter before the
> RAD cooler. Water is in the front of the block where the vac. thermo valve
> was. Original wa
> ter temp gage looked normal. No coolant when I stopped either time.
> Strange,, the fan clutch never came on. Can't remember the fan clutch coming
> on at start up or when we got off the hiway. Still got alot to do. So, any
> Cad. conversions have yours run this hot??? Larry?? Ken?? What was the
> hottest air temp??? Dash AC on?? Oil temps?? Thanks,,,,Paul {runnin hot in
> the state of Misery(oops,,,missouri)} Leavitt
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist



Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] Trip Report [message #92107 is a reply to message #92106] Thu, 15 July 2010 22:19 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Paul,

I should have mentioned that those H20 temps are from the EFI CTS, as read
out on the EBL Flash WUD. I have never gotten around to calibrating the VDO
in my new dash; it runs 10*F-15*F behind the stated numbers. The oil temp
is on a VDO also -- it's likewise uncalibrated, but was close to what I saw
on the Olds where it had been calibrated.

Ken H.
Americus, GA
'76 X-Birchaven
www.gmcwipersetc.com


On Thu, Jul 15, 2010 at 11:15 PM, Ken Henderson <hend4800@bellsouth.net>wrote:

> Paul,
>
> On our 500 mile trip last week, in 93*-95*F weather..
>
_______________________________________________
GMCnet mailing list
List Information and Subscription Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist



Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] Trip Report [message #92112 is a reply to message #92106] Thu, 15 July 2010 22:51 Go to previous messageGo to next message
Bob de Kruyff   United States
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
Senior Member
On my last trip into the mountains, my coach ran consistantly at around 190-195 even when climbingin 110F ambient. I've learned how to judge the temp based on the cycling of the fan clutch. All of a sudden the temp rose to 210 and I realized the fan clutch wasn't on. On my way back I installed a Hayden extreme duty clutch and guess what--it didn't seem to come on and my temp ran about 210 all the way home--which is way higher than it ever did. I'm starting to realize that an-off-the-shelf fan clutch is a crap shoot as far as engagment temp. I moved the bimetallic spring to "outside" the notch and now it's on all the time. Rather than try another unit, I'm going to cut a new groove in the housing to engage the spring about half way in between. The clutch I removed appeared to be the original and has 'MH" stenciled on it.

Bob de Kruyff
78 Eleganza
Chandler, AZ
Re: Trip Report [message #92134 is a reply to message #92097] Fri, 16 July 2010 05:56 Go to previous message
g.winger is currently offline  g.winger   United States
Messages: 792
Registered: February 2008
Location: Warrenton,Missouri
Karma: 0
Senior Member
Thankyou, Larry, Ken and Bob. I remember that Doc Fromer wrote in his book that it was a waste of time to try and cool a Cad down to the lower temps that other engines run. The fact that it cooled 15-20d. in a mile when I switched off the ac told me it wasn't "abnormal". But i thought the oil temp was a little high. Guess not. Back to work,,,,PL
Previous Topic: [GMCnet] Wanted - GMC Original Hubcaps
Next Topic: Transfer Switches on eBay
Goto Forum:
  


Current Time: Tue Oct 01 08:30:38 CDT 2024

Total time taken to generate the page: 0.01209 seconds