Got my Berg's radiator the other day and it works great!
Had it running today, it idles fine but can't get steady high rpm. When I give it gas it spits and stumbles then noticed that the center of the exhaust manifold turned white checked with the infrared thermometer it was over 800 degrees the dark area was 500 degrees.
I'm guessing there is a leak and it is running rich causing it to overheat.
Am I guessing right and would this cause it to run rough at high rpm?
Too lean and/or retarded spark (timing) could cause that.
Lean cylinders will run hotter than rich ones. High rpm miss under no load points to ignition. What do you have? A stock T system with high end miss, I would look first at the timer, then the coils. If the engine stumbles under load at any rpm, look at fuel supply. Carburetion problems tend to affect all cylinders more equally but an intake manifold gasket leak will affect two cylinders only. Start with the basics. Do all cylinders have compression? If not, fuel, timing, and ignition don't matter.
The only time I ever got T a manifold that hot was a mistake. Started T up for a Sunday winter run,just around the farm. Let it sit in the shed running at fast idle with spark retarded for quick warm-up.Guy coming to look at cattle showed up early, so I had to entertain him till the folks got back from breakfast. It's a wonder it didn't seize up. I suspect something causing late spark
That's not good for the exhaust valves either! Your fuel is burning late and is actually still burning as the exhaust valves open. You need to advance the spark.
If the engine has been running, what do you expect?
I don't expect it to get so hot that white powder forms on the surface.
All exhaust passes through the rear of the manifold so they tend to get hotter around ports 3 & 4. The white powder is caused by oil or other substance getting so hot it turns to ash.
My money is on lean mixture and/or late ignition timing.
I think he has a leaking exhaust valve in 2 or 3
Like I said when I saw the thing turn white I knew something was not right, it never happened before.
I have since run it without any problem. I advanced the timer at higher rpm and I readjusted the float again and it is running smoother.
Thanks for the help!