I do not normally do product reviews. But I will now. In July or so I posted on my t-stat experiment. I was concerned about 220F+ temps. The t-stat was AC Delco 195. See pic below. That day was 90F or so and at 70mph the gauge went a touch beyond 220.
http://temp.corvetteforum.net/c3/pau...ille02_034.jpg

So I dropped down to a 180F t-stat. Foolish. No difference. As pointed out to me by members, either a 180 or 195 would be fully open at those temps. So I went back to a 195 but a Stant Superstat. And a Prestone SuperFlush that you love to hate.



Today hit 90F again. So back on the same city/highway circuit. The temp gauge never wavered from 195-200 or so. I do not know if it was one or the other changes but obviously I am pleased. I believe the Stant is the determining factor but I cannot explain why.


[Modified by paul79, 8:01 PM 9/8/2002]


[Modified by paul79, 8:01 PM 9/8/2002]

 

I'm curious about something. One of these days I'll make a boiling water test of two or three thremostats. I'll bet that the actual opening range of the stats is plus/minus 10 degrees, maybe more.

I'll also bet that the flush did you more good than the stat change.

Glad you have the improvement. :cheers: :cheers:

 

Yes, you could be correct. Unfortunately I combined two variables in the experiment. Bad planning I realize. And I have read after my original post that the Prestone flush has given some members serious problems with leaks, particularly at the heater core. That I cannot understand unless the cooling system is terribly weak at the outset. The flush compound is only in the engine for 10 minutes. I double-flushed with water twice for 10 minutes each time to get the chemicals out before putting in the new anti-freeze/water combo. No problems as noted.

I do worry about the 24-year-old rad so I have ordered a new GM unit for spring installation. I posted on the correct choice but there were no replies. So I went with a non-A/C unit with a 1 1/2" inlet size. That is what I have. Apparently there are eight of these left in GM inventory in Lansing, Michigan. I should have mine this week.

I consulted Dr. Rebuild (Geoffrey) by e-mail on the choice. His reply was very informative as to the difference between A/C, L-48, L-82, HD, 1 1/4" vrs. 1 1/2" inlets (inside diameter), 2" vrs. 2 5/8" cores, etc. All those choices that confuse you in the catalogues. They confused me. Many thanks Geoffrey! But after looking at the options I boil it down to this:
-If you have A/C go with the 2 5/8" core (should be 1 1/2" inlet)
-If you have an L-82, W/O A/C, the core will be 2" but with 1 1/2" inlet
-If you have an L-48 W/o A/C, the core will be 2" but with 1 1/4" inlet
-The HD (heavy duty) in the catalogues refers to a ZN1 trailer package; only 2001 sold in 1979. Basically ignore that RPO.