Engine temperature

[otis71]

Having just getting my barn find 26 JD operable I was just wondering approximate top end temperature. It seems to be about 220 after a short run. The plugs look good and I'm using straight 50 weight oil. Is this normal? Should I go up to 60 weight?
Thanks

[T. Cotten]

Golly Gee, Otis!

Do you think a "short run" has it up to equilibrium?
Here's some relative temps from a smaller flatty (attached).

Reading temps from the outside of the motor may be quite deceptive,
And beware that heavier oil holds more heat. Its more dense.

Good luck!

....Cotten

[DanM]

Otis- where did you measure and how? Did you use a thermal gun?

[otis71]

I checked the temperature behind the inlet valve, feeling it was very hot it concerned me. I have since realized idling it heats up extremely fast and as soon as it gets air over it the temperature drops quickly. Rather be

[otis71]

Rather be cautious than learn by failure.