A T-stat thought...
 

Using a factory temp 195deg t-stat with a DeWitts radiator.
Indicated (verified) temp when rolling is 185-87. Oil temp runs 15 higher.

Do you suppose the t-stat is still closed when rolling?
Or should I try a 180-185 to experiment?

:cheers:

I'm not sure what you mean by "when rolling" (driving?) but if the water temp is 185 by the t-stat, it should be closed.

If your temp is staying at 185 and not increasing, you T-stat is passing water -either from leakage or it's opening enough to maintain temps.

do you still have the factory oil cooler on it?

I have a new 195 degree thermostat that you can have as I ended up buying a 160 degree stat. Has only been in the car for a test start to make sure the engine would fire and not leak any fluids/gasoline etc.
Freebie. Think I got it from NAPA.

Who's to say the T-stat opens at exactly 195? Are the radiator hoses hot?

TTS Datamaster verifys my car running in the 170s and I have a 180 degree t-stat. Might put a 195 back in next time around.

Mike

Yesterday on the freeway my 86 with 180* and Dewitts hit about 183 then the stat opened and it dropped to 176. It took several miles of stop and go traffic to get it back to 180. My guess is your t-stat was partially open.

My 87 has 2 senders. One in the head for the dash gauge. One in the intake for the ECM. The cylinder head is always around 15* hotter than what the ECM sees. To me, it makes sense that the head temps are higher than the intake. Combustion is going on there.

I installed the factory Water/Oil cooler which has not shown any value at this point.

Thanks for the offer Ron. For now I'm thinking to pull the stat and check with a thermometer. If this checks good then I'll try a lower temp unit for "effect"

:cheers:

T-stats are very flakey...
I learned the hard way to test every stat I install by boiling it on the stove and now I have the ability to verify the actual opening temp with a temp sensing scan tool. There have been several times when I thought I was "cooking" a 195 when it began to creep open at 160ish...or vice versa. The things are utilizing an ancient technology that is fairly reliable but not all that accurate.
From everything that I have seen, once a stat opens it never fully closes again until its wayyyyyy below its min temp...like near cold. Remember, t-stats only control the warm-up temp. After that, they have a meaningless existence as part of the machine.Once an engine reaches its min operating temp, it stays there with continous thermal energy thats constantly produced.