I wasn't really interested enough in such a comparison to do it but have received several repeated PM requests to repeat the test I did last year comparing no thermostats to Stant thermostats (here:
https://www.fordbarn.com/forum/showthread.php?t=113979) but this time comparing Stant thermostats to Shewman's "High Flow" thermostats. So, I did it exactly the same way I did it last year but on two consecutive days rather than a few days between. The ambient temperature on the first day when the Stant was tested was 92° and on the second when Shewman's was tested 90°. The details of the test are otherwise described in last year's thread referenced above. The data from the test is in the attached PDF file. Hopefully
VeryTangled will graph them again for us like he did last year.
The data confirms what I predicted about Shewman's stats last year here:
https://www.fordbarn.com/forum/showthread.php?t=112889 Post # 85. Because Shewman's stats do not completely shut off the water flow when closed the engine takes much longer to warm up to proper operating temperature (3 miles/7 minutes longer) and that operating temperature is not maintained (it drops 40° below the stat setting) when going down a long descent with no throttle. (Many have not even been able to get their engines up to operating temperature in the winter with Shewman's stats. See here:
https://www.fordbarn.com/forum/showthread.php?t=121447) Then, on the other end, because Shewman't stats have a much lower flow than the Stants when fully open (33% less) they allow the engine temperature to raise much higher faster than the Stants, up to 10° higher. That is enough difference to boil or not boil over (and was for me). One other big difference - the Stant stats are $18.00 a pair compared to Shewman's at $50.00 per pair. I'll be putting the Stants back in.
NOTE: THIS TEST WAS ONLY OF SHEWMAN'S STATS FOR THE 59A ENGINE NOT THE ONES FOR THE 8BA.
Here is the graph of the data later created by
VeryTangled with his graph of the elevations he made last year added by me and the numbers re-aligned by
51 MERC-CT to read a little easier.
