running too hot,

Grumpy

The Grumpy Grease Monkey mechanical engineer.
Staff member
Too hot intake temp=Vapor lock

So when I put my 454 together initially, I installed a 170* thermostat with the misaligned thought it would help keep the motor cooler during the break in period. Wrong!
The T-Stat never closed to allow the water to be cooled off by the radiator and fans. I didnt think much of it as the gauge pretty much hovered at 200*. Not too hot unless doing a lot of starting and stopping but the colder winter temperatures helped. Now that is has started warming up, the Vapor Lock monster struck.
Here's my thoughts
T-stat not closing my intake temp running between 200-215* too hot for winter fuel.
Another thing I found was with the stat not closing it was creating more pressure in the cooling system than the radiator cap could hold.
I put a hotter stat in and now the motor is maintaining the rated temps.
Thoughts?

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the T-stat controls the flow of coolant , exiting the engine, too allow the engine to reach its intended LOWER operating temperature, this also requires a radiator cap that allows the radiator too built pressure to 15-17 psi.
once its reached that temp it stays open until the coolant temp drops BELOW the rated temp, your issue of over heating, has ZERO to do with the T-stat remaining open, the MYTH that the coolant needs to stay in the radiator longer to allow the heat to dissipate to outside air flow is just that , A MYTH, think about that, every second the coolant flow is blocked by the closed T-stat the engine heat load INCREASES on the coolant in the engines coolant passages, your radiator surface area, coolant passage number and configuration, fan ducting fan cfm rating determine cooling efficiency.
once the t-stat opens and stays open the max temp is controlled by the radiator and air flow and surface areas cooling or heat transfer rates.
now its possible if the cooling system has better than average cooling capacity and the outside air temps are reasonably cool, the t-stat will constantly cycle and coolant temps will remain in the 170-f-180-f range, as the coolant will be constantly cycling from the radiator thats cooler than the engine as the t-stat controls the flow.ID also point out that all radiators collect crud and become restrictive to flow and much less effective at transferring heat to outside air flow over time, especially if the wrong coolant or water containing excessive mineral content are used so you might want to have yours cleaned out, rebuilt or replaced, if thats needed, after taking it out, an inspection indicates the correct course, a new aluminum radiator, in the largest size quality, radiator, that fits you can afford, is usually a good idea, if it needs replacing.
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the rotating assembly bearings ,wrist pins and complete valve train,valve springs, lifters, valves and valve guides and the pistons and rings are where a great deal of the engine heat is generated, and those components are initially cooled with oil flow that absorbs and transfers the heat collected , and transported from those components to the block and coolant, so having a constant flow of pressurized oil flow over those parts are mandatory for maximum durability.thus adding a larger capacity baffled oil pan and an oil cooler will generally enhance and extend an engines life span.

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putting some thought into selecting the correct high flow capacity fans and matching shroud, and carefully measuring the clearances available ,
and installing and using ,a high fin count aluminum radiator goes a long way towards increasing cooling efficiency, ideally you,ll want an aluminum radiator
and ideally with a multi pass design with large coolant transfer tubes.
yes its VERY LIKELY your current radiator size is woefully undersized and the area its mounted in can,t be easily increased, if you have significantly increased your engine power out put! 3-&-4 row aluminum radiators that hold more coolant volume, allow the liquid to transfer heat more efficiently, and allow the coolant to pass thru a bit slower.
adding an auxiliary oil cooler with a powered electrical fan can reduce the heat load on the radiator
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http://garage.grumpysperformance.com/index.php?threads/oil-system-mods-that-help.2187/

http://garage.grumpysperformance.co...sion-and-oil-cooler-increases-durability.176/

how many of you gentlemen go to a computer, print out related wiring diagrams ,get out a multi meter and a shop manual and actually read the shop manual, and step thru the indicated testing procedures? check for voltage ohms resistance, loose connections, etc. and have actually used the shop manual, multi meter and printed wiring diagrams ans instructions to isolate and solve a problem on your car?
ITS NOT ALWAYS EASY BUT IT SURE BEATS RANDOM GUESS WORK EVERY DARN TIME

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THE DIAGRAM ABOVE HAS THE CORRECT WIRE COLORS FOR THE 1996 CORVETTE

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1996 radiator cooling fan relay how to test

Hello all, I have a 1996 Vette LT-4, radiator cooling fans are not coming on. I have checked the fuse panel on the passenger side of the dash, I have also checked the maxi fuses in front on the battery. am now desirous of checking the cooling fan relays, how to do this? thanks in advance for any/all guidance


There are three relays involved.
You can identify the relays by the color of the wires at each relay socket.

Turn the ignition On.
At the relay socket.

Ground the Dark Green wire and both fans should run at low speed.
Ground both the Dark green wire and the Dark Blue wire and both fans should run at hi speed.




the earlier c4 corvettes had a simplier wire diagram for fans
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these charts are for the 1985-89 vette cooling fans
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for more details read the links below


http://garage.grumpysperformance.com/index.php?threads/how-radiator-caps-work.7718/

http://garage.grumpysperformance.com/index.php?threads/correct-thermostat.5607/

http://garage.grumpysperformance.com/index.php?threads/how-the-cooling-system-works-basics.853/

http://garage.grumpysperformance.co...g-fans-one-mostly-over-looked-component.2756/

http://garage.grumpysperformance.com/index.php?threads/thoughts-on-cooling.149/
 
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