Elmer

Some guys with 396's are reporting their temperatures are on the "halfway" point on the gauge (which is 180). My 396 runs at the "halfway" point, which is 210. I wonder if GM had these beast running generally "halfway" at "warmed-up temperatures" no matter what the gauge number said. I know this sounds crazy, but what the heck,...I wonder who has checked their temperatures with an InfaRed or other solid temperature calibration device ? Sorry If it sounds like I am overdoing this subject, but I want to get to the bottom of it.

Thx Elmer in Dallas :cheers:

chitown65

Elmer,
I have checked my BB with an IR and an external gauge and found that I am running 5 to 10 degrees cooler than my gauge indicates (210 midway point). During hot days or aggressive driving my 396 would run 210 to 215 on the gauge. The IR shows the actual temp at 197 to 205.

I heard that in 66 many 65 owners were complaining about running hot. Gm's response was a replacement gauge that was recalibrated and had 220 as the mid point. Does anyone know the midpoint temp on a 66 and 67 BB gauge?

chitown65

Elmer,

Sorry for the misinformation. My gauge (original) has 180 at the middle and the replacement guage I mentioned should show 210 at the middle. I also played around with a resistor that will move my operating temp more in line with the IR gun but have not cut and soldered yet.

Chris

Blkblt

My '66 427/425 runs a "210-250" gage, and I believe it is the original one (albeit rebuilt). I carry an IR therm all the time and have the car baselined at about 3¡-5¡ cooler than gage readout at 210¡. Even on a hot day up the mountains, it seldom reaches anything more than about 212¡, then comes down to less than 200¡ almost immediately. My normal highway running temp is about 185¡-190¡, with in-town lugging ranging around 200¡-205¡. Tough to find an L72 that runs that sweetly. :yesnod: :D
*******

********************
Jeff
ÒThe Silver BeastÓ. Ô66, L72
:seeya 'in and :D 'in

Elmer

Thanks for the feedback guys. Any idea where I can purchase an IR device so I can check my temp ? :cheers:

pittsaj

I have recently been talking with a few people that I have run into at local car shows.
They are original owners of these cars, when they were new.
They are telling me that they ran 180 to 190 when new..
Even long idle in traffic would hardly bring them to 200... Never ran 210..

We have a few original C2 owners on this forum..
Why are they not speaking up???

Many here are running direct drive fans. electric fans as backup, water wetter, etc.. etc... and still running 200+

I too have heard all the stories that they just run hot..
The problem as I see it is these temps just keep going up and we keep justifying them..
200, 210.. now 220…
If this isn’t too hot, then what is??

Yeah, we are all running hot does that make it right... or are we all looking at 35 year old radiators?????

There are a few here that run at 180 to 190… and they all have new radiators...

I have to believe that what we are all seeing is the early signs of radiator failure..

Just doesn't seem worth all the effort we all keep putting ourselves through..

I for one, love to drive my car...
I hate to have to constantly keep looking at my temp gauge...
I don't for any of my other cars.

I have a new Dewitts radiator in the mail…

I'll keep you up to date..


BTW,
If you are using an IR gun to check your temps, make sure it is calibrated..
Easy to do just boil some water on the stove and check for Approx 212
Make sure you turn the fire off first...
I found that mine was way off...
Good luck

Tony



[Modified by pittsaj, 10:02 PM 9/8/2001]

Ganey

Have a Rad. shop rod out the rad. from time to time- about every 10-15 yrs.

Temp. Check
Get a good thermostat like a 180 Robertshaw high flow thermostat labeled Extra Performance & available at Auto Zone or a Nissan 280ZX from Nissan dealer. You can verify opening temp. w/ boiling water. Mount temp. sender in intake manifold up front. Rad. cap off & can use an A/C temp. gauge in rad.
When thermostat opens gauge is at 180.

:cool:


[Modified by Ganey, 8:28 AM 9/9/2001]

JohnZ

Go to http://www.autotestsys.com and look for the Raytek MT-4 I.R. Gun - $79.95; best diagnostic tool for cooling systems I've ever had. Consistently confirms that Corvette temp gauges read high (especially if the senders have been replaced), and that 99% of cooling problems (assuming shroud, fan & clutch are in place) are caused by dying radiators.

Elmer

John, thanks, I'll check it out....Elmer

Elmer

John, I visited their website and plan to purchase the unit you recommend. Thx..Elmer :cheers:

0Tom@Dewitt

I think something that was touched on here need a lot more attention. All (everyone of them) the replacement sending units are way off calibration and typically run high. In fact, they are usually 20-30 degrees off. The guages used in the 60's use a different sending unit than do later models. But most companies now sell one sending unit fits all. They don't. If you look at some of the popular reproduction catalogs (paragon is one) there is a disclaimer that the sending units may give you a bogus reading. This is where the the resistors come in. I found the best thing to do is to search out that box of old junk parts and find the original sending unit that probably still works better than anything else you can buy today. Many people that "think" they are running hot, really are not that bad. This probably doesn't help me sell more radiators but it is a fact. If you confirm the temp and/or recalibrate the guage with an IR gun, and it still show your over 200, then you might need to invest in a new rad. td

Elmer

Tom, thanks, see my last post reply on the Harrison Radiator posting....Elmer :cheers:

Larry W Smith

Hi,
Can anyone aadvise if any 65 396 cars came with a temp gauge with max reading of 250 degrees. I know NCRS says all 65's had 240 reading gauge. Mine has 250 but of course over the past 50 years who knows. Thanks
Larry Smith