I know we have talked about cooling before, but I have a 160 degree stat in my big block, aluminum radiator, twin fans. Question, do I need the stat? I dont care if it takes sometime to warm up, my main concern is keeping cool. It runs about 185 to 190 on the road, above say 35mph, in town the fans are on all of the time. My stat is a stewart high flow job, but is it better to have the water going through the system faster or slower. Thanks for th input!

 

You are running under 200 in all conditions.Leave it alone.


[Modified by FeedVaal, 11:08 PM 6/20/2002]

 

The problem you can run into by not running a stat is in some situations the flow of coolant is so great that it doesn't stay in the rad long enough to give up it's heat :cheers:

 

That's right on the flow. It eventually becomes a self seeking heat level that will be too high. The t-stat slows down the flow so the coolant in the rad. has a chance to cool down. A lot of people run without one, but in my book not a good idea.

 

Thanks to all for the info, I am going to keep the stat in there.

 

:cheers:

Olivier

 

Heat transfer in an engine such as ours is mostly due to conduction.
Heat transfer happens at variable rates, depending on the difference between the two surfaces where the transfer occurs. Here's a web page with the details for those who wish to see a second opinion:

http://www.pha.jhu.edu/~broholm/l39/node13.html

Basically it's saying that the rate of heat transfer (dQ/dt) is equal to the thermal conductivity of the material (k) multiplied by the contact area (A) multiplied by the difference in temperature between the two materials in contact (dT/dx). In our engines the only thing that changes on the right side of the equation is (dT/dx) which gets smaller as the flow rate gets slower because the coolant is in contact with the engine longer, thus the coolant gets hotter and the heat transfer rate slows down. Thus, higher flow rates results in higher heat transfer rates.

Here's 8,000 other web pages on the subject:

http://google.yahoo.com/bin/query?p=...n%22&hc=0&hs=0

If you read and understand all 8,000 pages then you will see that heat transfer will occur faster when the fluid flows faster because if the coolant is in contact with the engine longer it heats up and thus the difference between the engine and the coolant will be less and as a result the heat transfer will slow down.

If you still insist on saying that the coolant can flow too fast to work properly then...well...OK...I admit it...there IS a speed at there is actually a reduced heat transfer rate...and that speed is near the speed of light, and I doubt that ANY water pump will achieve those speeds.

Are you still with me? If so then you will want to increase the coolant flow so that the heat transfer rate is higher and thus cool the engine faster. The cheapest way to do this is to reduce an obstuction to that flow by pulling the thermostat out. There ARE other ways, for example using two thermostats like with big blocks. Using different coolant additives like water wetter which changes the coolants' thermal conductivity (k). Larger radiators change the area of contact (A) to cool the coolant down faster. Larger fans to get the air to flow faster through the radiator. Many other ways...and ALL of them are more expensive than just pulling the thermostat.

 

Ah, the now infamous "stat" or no "stat" debate! :lol:

I'm with RockNRoll. After numerous blown head gaskets due to "Stat" failures, I began removing the stat from all my "performance" vehicles years ago. I've had no ill effects on pollution control equipment, driveability or gas mileage. For piece of mind, on the vehicles I have as daily drivers, I always drill 4-5 holes into the stat before installling. This assures me that if the stat fails there will still be flow thru the stat.

In my current SB Vette I removed the stat completely and run about 135-140 with a BB radiator! When I transplant my 454 I will do the same----No stat! :eek: It works for me.
There has been mention on this forum about the amount of increased engine wear that can be attributed with running an engine at a lower temperature. Well with the amount of miles I put on my Vette yearly, I'll be long gone before accelerated engine wear could be attributed to the absence of a "stat". In otherwords it was negligible.

If you still insist on retaining the water in your block, you can always use the stat restrictor plates from Moroso. These take the place of the stat and have different sized openings for you to choose. I use one in my Stang.
Plus, if you now have a 160 stat and your normal operating temp is reading 185-190, your stat is always open anyway! :eek:


[Modified by 1970 Stingray, 4:02 AM 6/21/2002]

 

I have an article on how to improve cooling in the tech section at my page.

 

While some say "everything is debateable & a matter of opinion", that is garbage! Many argued the world is flat! Auto. engineers & mfrs. & others know that engines have an operating temp. range!

You do not specify a/c, so assuming no a/c, you do not want the el. fans running when not needed so you want them staged to cut off/on 1 el. fan at 180-200 & the other off/on 200-220 for example.

:cool:

 

The engineers desinged the motor to work at specific heat range, anything below or above will have adverse effect on the motor. If you are at 195 degrees then don't worry about it :D

 

IMO The quicker the car warms up the better, just ask Keith (427V8) or anyone with forged slugs. Mine runs better at 180 than at 100 so the faster it gets there the faster I can start going faster. :lol:


[Modified by Fevre, 9:04 AM 6/21/2002]

 

I run without a stat but that was only after I changed to Evans NPG coolant (yes it's expensive). Go to there website and read the intro and tech sections. They must of been reading the same material as RockNRoll. http://www.evanscooling.com/main2.htm