CSH needed here too/Rad fans on 165 on/off

[Dave Zug]

If the sensor were in the RAD then think of the other state.. if the 
rad is satisfied but the head is hot and the stat opens then the fan 
will not come on until the hot flows from the head into the RAD... 
where it should have been on based on the hot head. I think it takes 
5 or 6 seconds at most if I had to guess.

we have this dilems in building controls constantly. imagine a 
variable speed water pump in the mix.. on a reeal cold day the demand 
for engine cooling is not great, thus the pump is slowed way down, so 
when the engine cracks the stat a bit, it takes a while for the cool 
water to hit the head - and the cool water is 25 degrees cause its 
going thru the radiator sooo slow. 

it depends on where the sensor is I guess - before or after the head.

you can apply hardware or even valves etc to maintain the temperature 
- good for situations where consistancy is an issue but for trips to 
the store.. they might call whats there good nuff. the err is on the 
side of better emissions.. but warranty? which is more valued at 
corporate?



> From:          Mike Rolica <mrolica at meridian-mag.com>
> To:            "'gmecm at efi332.eng.ohio-state.edu'" <gmecm at efi332.eng.ohio-state.edu>
> Subject:       RE: CSH needed here too/Rad fans on 165 on/off
> Date:          Fri, 5 Nov 1999 16:17:54 -0500 
> Reply-to:      gmecm at efi332.eng.ohio-state.edu

> HEY EVERYONE GOT MY TRUCK BACK YIPEEEEE.  Custom rad is excellent looks
> beautiful!! Now for the efi stuff.
> Just wondering how the ecm controled rad fan stuff works.  How can it know
> when to turn on the fan and when to turn it off? If the temp sensor is in
> the head?  Should it not be in the rad?  Ie, once the head reaches the turn
> on temp, is the motor not going to get hotter until the rad catches up?
> Then for turn off is the motor not going to have to reach like 170  which it
> never will because of the thermostat.  How can you keep a consistant temp in
> the motor is you are not contoling the fans off of the rad temp (outlet
> specifically?)    I'm confused.
> Mike Rolica
> EXT. 260
>  :-)
> 
> 
> 	-----Original Message-----
> 	From:	Aaron Willis [SMTP:darkmonahue at awwwsome.com]
> 	Sent:	Friday, November 05, 1999 3:53 PM
> 	To:	gmecm at efi332.eng.ohio-state.edu
> 	Subject:	Re: CSH needed here too
> 
> 	At 08:44 AM 11/5/99 -0600, you wrote:
> 	>I'm qualified.
> 
> 		Spent all afternoon chasing down unexplained short
> (suspected voltage
> 	drain) due to finding continuity between negative battery post and
> good
> 	earth with positive terminal disconnected...imagine that.. ;-)
> 
> 	>List keeps growing.
> 	>
> 	>Good judgment comes from experience.	
> 	>Experience comes from bad judgment.
> 	>
> 	>Jim Sloan
> 	>leroy at sunflower.com
> 	>Lawrence, Kansas
> 	>
> 		Aaron Willis
> 		Garage TE51 International  http://surf.to/garage-te51
> 		ICQ # 27386985
> 		AOL IM: hemiyota
> 
> 
~~~
Dave Z. www.delanet.com/~tgp