I agree with what jfb has posted, as I usually do.

Since I notice you have an 89, I would like to share the changes I made to my 89 and the results.

Pulled the radiator and cleaned out both the radiator and condensor. It is the second time I have pulled the radiator and it was not too bad, but still was amazed at the amout of stuff in there. This is fairly easy on an 89, and since the AF should be flushed about every two years anyway, when it's time I pull the radiator.

I changed the thermostat from 195 degree to 180 degree. I used a Robert Shaw High Flow, was looking for a Stant SS - but could not find in 180*.

I have a Z51 and the aux fan. I installed a 200* aux fan switch to replace the stock 230+* switch in the drivers side head between #1 and #3. So the aux fan now engages at 200* and shuts off at about 180*.

I had Craig M burn a chip to turn on the main fan at about 195*. I believe in the chip solution to insure that the fan will shut off above 30 mph or whatever the orginal design called for. The fan is a detrement to cooling when air is already being forced through the radiator, and this load will reduce the life of the fan motor.

Cooling system was completely flushed multiple times and finally filled with a mix of Green AF and deionised H2O.

Worst temp in bumper to bumper on an extremely heat soaked block with 95+ degrees outside temp was 205* (overshoot that came down, but due to heat soak). This was extreme and usually as soon as the main fan comes on the temp drops to the thermostat temp.

This winter, it liked to run about 170* on the highway and would never go over 185*. This 170* due to the nature of the RS stat. Still looking for a Stant Super Stat for the next flush to see if it will regulate a little tighter.

Oil gets plenty hot on the bearings and cylinder walls and around the rockers to insure burnoff of water and volitile chemicals with a coolant temp of 180* or even 170* I believe.

Biggest thing I worry about is temp swing, and would like to contain that more with a better thermostat. In summer I see 180 to 205, in winter I see 170 to 185 so it's not bad.

So on an 89 at least I like the improvement of the total package in containing engine temps within a reasonable range (to me). I think I can get it a little tighter, and will work on this next year with the flush.

 

I've run the same 160 stat for 5 years now without any problems.

 

Hey
I actually look foward to seeing this question posted from time to time. Its like what came first the chicken or the egg, and every time I read it I agree
with everyone. jfb always makes his case very well, so do the pro 160 fans.
I'm no mechanic but I feel it depends on how you are using the car and the climate you are in. I live in a hot climate and often drive over an hour at highway speeds, so I use the 160 and am confident I am burn off the contaminates.
I will say I have over heated and blown a motor in a tuarus about ten years ago, and that really stunk. I prefer to run somewhat cooler and the stat and fan setting alow me to acomplish that. I may be shorting the life of the engine but getting cought on a one lane bridge in traffic, during construction, with a pregnant wife really shortened the life of that Taurus. (thankfully it was a company car).

Gonzo

 

I recently changed mine stat and replaced it with a 195. In traffic, I see 231, then the fan kicks on and Im back down to 205ish. Freeway, I dont see past 205. I am thinking about having the prom written to have the fan come on earlier since the Texas heat can reach an nice 110 ambient during the summer.


PeteL, we have Stant SS (SuperStats) 180s here for about $6. Im sure S&H on it US Priority isnt more than $3.50. Be more than happy to shoot you one for $10ish shipped (whatever it costs me to buy and ship). Email me and let me know if you need some help getting one.

 

Ok, I gotta ask - how hot is too hot?

I'm new to Corvette's and I learn something new every day here on CF. Just today while in mild traffic - I flipped my digital dash to the Coolant guage and it showed 225-228 but once I got off the main road and was able to open it up a little - she was back down to 205 when I got back to the office. Today is unseansonly warm for my area - 72 and still climbing. I remember at times last year that I saw high 220's alot and even higher (once hit 240's in OCMD on the boardwalk parade but I was revving the engine just a tad bit too much!!). I also notice that the oil temp is around the same temp too. My car is a 92 LT1 auto that will see the track about 20 times this year.

I've had the car for 1 year now and no problems due to overheating (outside of the normal waterpump/Opti-crap problems).

Thanks!!

 

hmm yeah i got the Stant Superstat aswell but as you read i picked up the 160 rather than the 180 i think i should go exchange it sometime soon