[Truckedup]

Let's say we have a non supercharged engine peaking at 6000 RPM at sea level.Now let's move that same engine to 5000 feet.And let's say the carb and timing has been adjusted for best power although there's still a loss in power from the elevation.
Will the power still peak at the same 6000 rpm?

[hcompton]

Originally Posted by Truckedup

Let's say we have a non supercharged engine peaking at 6000 RPM at sea level.Now let's move that same engine to 5000 feet.And let's say the carb and timing has been adjusted for best power although there's still a loss in power from the elevation.
Will the power still peak at the same 6000 rpm?

Yes in the real world the difference should not be more than a few rpm and the cam tells the engine how fast to turn at its max effectency point. As long as it can still pull in enough air to turn the rpm cam wants to live at it will still be fine. At 10000 feet you will have some problems and need more air to reach the cams rpm range.

[vinniekq2]

At 5000 feet you will lose a lot of power.My airplane would tach out at sea level but at 5,000 feet I would lose 10% or more RPM.
I would like to see dyno graphs on this story

[timothale]

I had a buddy that was a partner in a chrysler hemi dragster back in the 60's, they built the engine to run at higher altitudes, won most of the races in denver and salt lake and pocatello .. He said the california racers tried to just run the blower more rpm and it didn't work for them at higher altitude . When the local guys went down to LA or Fremont slowing down the blower didn't work for them. Las vegas was half way in the middle. altitude and driving distance and they were closer to the other cars. He said the static compression ratio Cam, blower speed and carbs all have to be matched for the altitude.