This has been an interesting day. I rigged up the thermocouple monitor to a type J thermocouple and to a 12v ni-mh battery with a small Dean's rc battery connector. I tested the calibration on my stove with a pan of boiling water. Water boils at 212 F at sea level. I'm at 1600 ft elevation, so 211 is probably dead on. If it had been within 3-4 degrees I would be happy. Then I drilled a 1/16" hole in the manifold on the runner to the number 2 cylinder, and siliconed and zip tied the tc in place. I taped the monitor on the dash and went driving. Once the engine was up to full temp, air temp in the runner was right there at engine temp - 175 to 185F. Driving around at light part-throttle lets the air move slowly through the manifold, giving it time to reach full engine temp. What about heavy throttle, when air should flow through quickly?
I hooked up my 12k lb flatbed trailer (3200 lb empty) and headed up I17 north of phoenix to the New River area. It was about 85f mid day, ac on, and going a steady 75 mph up the hill. Runner temp still hovered around 180. I slowly gave it throttle, expecting temps to drop, but it actually rose, to as high as 188f. Maybe low manifold vacuum told the egr valve to dump in exhaust gas, raising the runner air temp. Then I dropped it into 3rd gear (3200 rpm) and gave it full throttle. Finally I saw a drop in runner temp, but only to 153f, and after a few seconds it popped right back up to 180+.
There you have it. I don't think it matters if it's 65 or 115 outside, with a cold air intake system or not, light throttle or heavy. The cavernous L29 intake manifold will heat the intake charge to full engine temp no matter what. It's kind of disappointing, but hopefully the coatings and heat shield will help..