Engine only warms up to 140 - Page 3

Bill Bess · #41 (**permalink**) 04-09-2009, 07:18 AM

Well, here is my two cents !

Verify the t-state is good, verify the gauge is good, make sure the fan is working and that the temp. goes up to normal while sitting at intersection lights (180 to 210) and then back to 180-185 while running with no fan on.

The weather will affect the temp. as stated....damp, dry, cold, hot etc. Here in AZ it gets up to 120 degrees on summer days, my cobra FE motor runs 190 with no fan on at speed and crepes up to 200-210 while sitting at idle.

As far as too cool and possible wear...I ran numerous boat engines in cold lake water at 130 to 160 degrees for years..never had a wear problem or engine blow up even when I hammer the darn things.
Relax, just keep it in range and do what ever it take based on the outside temp.
Hopefully you will out live your Cobra!

Havasu Bill

mr0077 · #42 (**permalink**) 04-09-2009, 08:06 AM

If the radiator perspires it will dissipate heat better in dry weather and low humidity...otherwise, I'd guess wet weather or high humidity would be better for heat dissipation.
You should NOT ignore the condition, you NEED to get the motor up to proper operating temperature, or start putting away money for an overhaul sooner than you should.
Just my $0.02...

patrickt · #43 (**permalink**) 04-09-2009, 09:13 AM

Quote:

Originally Posted by mr0077

If the radiator perspires it will dissipate heat better in dry weather and low humidity...otherwise, I'd guess wet weather or high humidity would be better for heat dissipation....

You would guess wrong. Forget evaporative cooling for the moment and think convection (that's air moving over your skin, or a horse's skin, or through the fins of a radiator). Did you know that a good 20% of heat dissipation in a horse is through convection, and not sweating? Yep, another trivia point for those bar room wagers. And to increase the rate of heat dissipation through convection in your horse (or through you, for that matter, or your radiator) is to 1) Increase the air flow, 2) Lower the Temperature, or 3) Lower the Humidity. I can't give you an authoritative reference for radiators, but I can for horses. Equine Clinical Nutrition by Lewis, page 247 discusses cooling by convection and humidity. You can read it on Google books if you like (or just take my word for it).
Here you go: http://books.google.com/books?id=vpu...tion#PPA247,M1

Afterthought -- Let's put John (shelby racer) on the spot, since he's a veterinarian, and see if he knows off the top of his head what percentage of heat dissipation in a horse is through convection.

Or if he happened to ever own a car that overheated only on really humid days, like I did....

mr0077 · #44 (**permalink**) 04-09-2009, 10:39 AM

No, Patrick, I believe YOU are wrong. Radiators and horses (and physics and physiology) are somewhat different.

Radiators cool by radiation and convection, with convection being the major means of cooling by far. Skin cools by radiation, convection and evaporation. Evaporation works best in dry air, but convection works best in higher humidity, because of the ability of the air-borne water vapor to absorb BTUs better than dry air. Water vapor absorbs almost exactly twice the BTUs that dry air absorbs for a given temperature rise. In addition, moist air has a higher heat transfer rate than dry air.

Sorry about getting the thread off-track, Snakebit. Let us know what you find.

patrickt · #45 (**permalink**) 04-09-2009, 10:45 AM

Quote:

Originally Posted by mr0077

No, Patrick, I believe YOU are wrong.

Both evaporative cooling...and heat loss through convection are impaired with increasing ambient temperature and humidity. That's a direct quote from my authoritative text. To prove me wrong, you're going to have to beat that with something equally, or greater, in authoritative weight.

EDIT -- You know, something that says "Heat dissipation through convection increases with higher humidity." C'mon, I double dog dare you....

Rickd · #46 (**permalink**) 04-09-2009, 12:42 PM

Patrick, now that is some creative segue - EQUINE CLINICAL NUTRITION !! Good job.

patrickt · #47 (**permalink**) 04-09-2009, 12:44 PM

Quote:

Originally Posted by Rickd

Patrick, now that is some creative segue - EQUINE CLINICAL NUTRITION !! Good job.

Thank you very much.

And you know that Ken has been scouring the internet for the last three hours trying to come up with something that he can cite to show me I'm wrong. Evidently his search has been fruitless.

Snakebit · #48 (**permalink**) 04-09-2009, 12:56 PM

What have I started!! I'll check out the thermostat this weekend, but temperatures are only going up to 50. I may change the water pump pulley from a 5 1/2" to a 6".

patrickt · #49 (**permalink**) 04-09-2009, 12:59 PM

Quote:

Originally Posted by Snakebit

What have I started!!

The problem is that most of us have "Type A" personalities -- even on the stupid stuff.

You know, like throwing down a "double dog dare."

Although, it's pretty hard to let a double dog dare go unanswered....

Snakebit · #50 (**permalink**) 04-09-2009, 02:24 PM

That's what I love about this site! Got a cooling problem and the Sham Wow guy even chimes in.

blykins · #51 (**permalink**) 04-09-2009, 04:23 PM

With his beat-up prostitute.

mr0077 · #52 (**permalink**) 04-09-2009, 07:15 PM

Patrick, now how can I fight horsh!t with physics?

I unsubscribed from the thread because it got so far off track and because I'm right...I'm not trying to pick a fight. I don't want to argue and don't need to prove it, just take a look at psychrometric charts and the specific enthalpy of moist air v. dry air. The physics of it tell me that since the specific heat of water vapor is double that of dry air, moist air will absorb more BTUs than dry air (admittedly only ever so slightly, because the actual percent by weight of water vapor in air at 100% humidity is very low).
What cools horses is different than what cools horsepower.

Over and out (on this thread).
Actually, only one last comment: Maybe this short exerpt will explain the difference between animal cooling and radiator cooling...
http://books.google.com/books?id=j58...r+than+dry+air

patrickt · #53 (**permalink**) 04-10-2009, 10:34 AM

Quote:

Originally Posted by mr0077

Patrick, now how can I fight horsh!t with physics?

Well I was just about to cite the International Journal of Biometeorology that found that moist air was not a better thermal conductor and they concluded that by investigating clothed versus nude men. Yep, I'm not making that up. http://www.springerlink.com/content/7258v904rn154738/

But, before I could come up with some really good punch lines to go with that, I was informed by a learned engineer that NASA concluded many years ago that there is no difference between moist and dry air in forced convection heat transfer and he was kind enough to forward me this cite. http://ntrs.nasa.gov/archive/nasa/ca...1984008420.pdf

I still think I'm right.

jhv48 · #54 (**permalink**) 04-10-2009, 10:37 AM

What was the original question?

patrickt · #55 (**permalink**) 04-10-2009, 10:43 AM

Quote:

Originally Posted by jhv48

What was the original question?

Ken (mr0077) had taken the position that clothed men at rest, in an indoor British environment, had a higher rectum temperature. That was clearly disproven by this study http://www.springerlink.com/content/7258v904rn154738/ which I pointed out to him. Evidently, he took umbrage to my post....

undy · #56 (**permalink**) 04-10-2009, 10:52 AM

Quote:

Originally Posted by patrickt

Ken (mr0077) had taken the position that clothed men at rest, in an indoor British environment, had a higher rectum temperature. That was clearly disproven by this study http://www.springerlink.com/content/7258v904rn154738/ which I pointed out to him. Evidently, he took umbrage to my post....

It anus a good topic of discussion, no matter how long you sphincter about it...

mr0077 · #57 (**permalink**) 04-10-2009, 05:35 PM

You guys crack me up! Patrick, that was FUNNY about the clothed v. nude men...I still think I'm right, but only technically. I tend to agree with NASA from a practical standpoint, as water vapor is less than 4% of the total weight of air at most, so if it (water vapor) absorbs at twice the rate of dry air, its increased rate of absorbing BTUs is negligible, so let's have a beer and see if that cools things off better than wet or dry air...
Let's see, what WAS the original question??!? Snakebit was going to change the T-stat, I think...how did it work out?