I did a little work with throttle position on a g-62. I think they are at 28 deg which is about tops for thise motors. Our 5.8 I had up to 32 and it just got hot and vibrated a lot. so 28-30 was the range. I wasn't able to change the spark timing on the G-62 but by playing with the mixture and a cylinder head and exhaust gas temp I was able to get it to make maximum power and live at full throttle. What really was interesting was that just throttling backa little say about 500 rpm the temps dropped dramatically. I did the same thing with the 5.8 in the Mustang. If I ran it with a small high pitch prop at about 8000 rpm it would get very hot and the mixture was critical. But if I loaded it down with a larger diameter and less pitch to about 7200 it ran much cooler. EGT ran about 900 F as I recall. I can't remember the CHT but I think it was less than 300 F. If you run slightly rich it seems to be a little cooler but the power actually drops off a bit too. Oil % made a difference too. the Amzoil at 50:1 actually ran hot untill I convinced myself to run 75:1. I never got to 100:1 as they claim. But it seems like it would work. An ounce and a half of oil in a gallon of gas just doesn't sound healthy in our models.

If you could retard the timing some within limits, it might help reduce the heat. I don't know. In the race cars every time we tried retarding the timing it got hot and the EGT got high. power went down. If it was advanced too far about the same thing. You had to stay with in the range.

We are knocking on the door of some endurance flying with the B-25 and G-45's . I'll be looking at fuel consumption EGT and CHT. I hope we can monitor them in real time along with airspeed and rpm. We'll be doing some bench testing in the spring.