GMCforum: GMCnet » Cad 500 and dash heater

Home » Public Forums » GMCnet » Cad 500 and dash heater

Show: Today's Messages :: Polls :: Message Navigator

Cad 500 and dash heater [message #71291]

Wed, 20 January 2010 14:17

Larry

Messages: 2875
Registered: January 2004
Location: Menomonie, WI

Karma:

Senior Member

I am running the Cad 500 in my 78' Royale. Last fall we traveled to Pueblo CO. for the international rally. After the rally, we saw a little of Colorado before being forced to come home because of snow, ice and cold weather. One of the things we noticed was that at temps below 32* or so, we were unable to get the engine temp above 140*, so the dash heater blew only...barely warm...air. I thought I had a bad thermostat. Pulled the thermostat out and tested it only to find that it worked fine. I got to talking with Bob Miller who also runs a Cad 500, and asked if he had problems with a lack of dash heat in cold weather. His answer was yes and he found the reason for it. The Cad 500 does not have heater outlets on the water pump..as does the 403 or 455 Olds. So the heater must get its hot water from the RR cylinder head. That water is split between the dash heater and the house water heater, and the return is to the hot side of the radiator. The hot water heater run does not have a restrictor in it, the house heater draws so much heat from the cooling system that it will not allow the engine temp to come up. So at Bob's suggestion, I put a PEX ball valve in the house heater line, and shut it off on our December 31st drive from Wisconsin to Florida. Without the house water heater in the circuit, engine temp went to 195* and we had lots of heat coming out of the dash. Enough to keep us warm during our single digit degree drive from Menomonie to Crossville TN.

So if you are running a Cad 500 and having trouble with low engine temp or dash heat during cold weather runs, shut off the water going to the house water heater...may improve engine temp and dash heat output.

Makes me wonder if this might also help out the 455...???

Larry

78 Royale w/500 Caddy
Menomonie, WI.

Report message to a moderator

[Message index]

		Cad 500 and dash heater By: Larry on Wed, 20 January 2010 14:17
		Re: [GMCnet] Cad 500 and dash heater By: Kosier on Wed, 20 January 2010 20:19
		Re: [GMCnet] Cad 500 and dash heater By: jimk on Wed, 20 January 2010 21:14
		Re: [GMCnet] Cad 500 and dash heater By: Ron on Wed, 20 January 2010 22:06
		Re: [GMCnet] Cad 500 and dash heater By: jimk on Wed, 20 January 2010 23:38
		Re: [GMCnet] Cad 500 and dash heater By: Matt Colie on Thu, 21 January 2010 08:12
		Re: [GMCnet] Cad 500 and dash heater By: jimk on Thu, 21 January 2010 09:49
		Re: [GMCnet] Cad 500 and dash heater By: USAussie on Thu, 21 January 2010 17:06
		Re: [GMCnet] Cad 500 and dash heater By: Carleton Douglas[1] on Thu, 21 January 2010 17:49
		Re: [GMCnet] Cad 500 and dash heater By: Matt Colie on Thu, 21 January 2010 18:17
		Re: [GMCnet] Cad 500 and dash heater By: GMCWiperMan on Thu, 21 January 2010 19:03
		Re: [GMCnet] Cad 500 and dash heater By: Larry on Thu, 21 January 2010 19:52
		Re: [GMCnet] Cad 500 and dash heater By: GMCWiperMan on Thu, 21 January 2010 21:02
		Re: [GMCnet] Cad 500 and dash heater By: Matt Colie on Fri, 22 January 2010 07:53
		Re: [GMCnet] Cad 500 and dash heater By: Kosier on Fri, 22 January 2010 10:26
		Re: [GMCnet] Cad 500 and dash heater By: Matt Colie on Fri, 22 January 2010 13:24
		Re: [GMCnet] Cad 500 and dash heater By: USAussie on Fri, 22 January 2010 16:36
		Re: [GMCnet] Cad 500 and dash heater By: jimk on Fri, 22 January 2010 19:33
		Re: [GMCnet] Cad 500 and dash heater By: Matt Colie on Sat, 23 January 2010 08:08
		Re: [GMCnet] Cad 500 and dash heater By: Larry on Sat, 23 January 2010 08:24
		Re: [GMCnet] Cad 500 and dash heater By: Matt Colie on Sat, 23 January 2010 10:02
		Re: [GMCnet] Cad 500 and dash heater By: USAussie on Sat, 23 January 2010 17:43
		Re: [GMCnet] Cad 500 and dash heater By: Larry on Fri, 22 January 2010 11:02
		Re: [GMCnet] Cad 500 and dash heater By: Larry on Fri, 22 January 2010 11:09
		Re: [GMCnet] Cad 500 and dash heater By: GMCWiperMan on Fri, 22 January 2010 18:40
		Re: [GMCnet] Cad 500 and dash heater By: Bob de Kruyff on Sat, 06 February 2010 20:42
		Re: [GMCnet] Cad 500 and dash heater By: USAussie on Wed, 20 January 2010 22:56
		Re: [GMCnet] Cad 500 and dash heater By: Kosier on Thu, 21 January 2010 18:20
		Re: [GMCnet] Cad 500 and dash heater By: Larry on Thu, 21 January 2010 06:31
		Re: [GMCnet] Cad 500 and dash heater By: Kosier on Thu, 21 January 2010 18:45
		Re: [GMCnet] Cad 500 and dash heater By: Kosier on Wed, 27 January 2010 22:32
		Re: [GMCnet] Cad 500 and dash heater By: USAussie on Wed, 27 January 2010 22:48
		Re: [GMCnet] Cad 500 and dash heater By: Kosier on Wed, 27 January 2010 22:51
		Re: [GMCnet] Cad 500 and dash heater By: Mr ERFisher on Wed, 20 January 2010 22:20
		Re: [GMCnet] Cad 500 and dash heater By: Larry on Thu, 21 January 2010 06:52
		Re: Cad 500 and dash heater By: Firefly on Thu, 21 January 2010 17:45
		Re: [GMCnet] Cad 500 and dash heater By: jimk on Thu, 21 January 2010 21:07
		Re: [GMCnet] Cad 500 and dash heater By: USAussie on Thu, 21 January 2010 21:47

Previous Topic:	[GMCnet] GMC Burnout -- Sorta
Next Topic:	Porkchop Klocking

Goto Forum:

-=] Back to Top [=-

Current Time: Sun Sep 22 06:37:36 CDT 2024

Total time taken to generate the page: 0.01593 seconds