Disclaimer: I'm going back to my high school drag racing days here, so if
I'm way off, please let me know...

Wouldn't mods such as pistons and exhaust systems possibly result in a
change in the engines theoretical redline?

If so, and if one wanted absolute accuracy, would it not be necessary to
recalculate the redline?

I seriously doubt that you would see a significant change in redline, or
that it would have much impact, but it would seem that if you are making a
modification that affects redline you would not be able to use redline to
benchmark the changes without a recalculation.

Of course, you could simply use the "redline" on the tach, but that might or
might not be valid...

"Jay Masino" wrote in message
...
Dylan Smith wrote:
I'd agree with above redline, but *at* redline? The majority of aircraft
engines are certified (and I would dare say designed) to be run
continuously at max rated power, which is usually achieved at redline
RPM and sea level pressure. There are one or two exceptions you'll find
in lower horsepower aircraft (such as the turbocharged Rotax engines,
which incidentally sound very odd to fly behind if you're used to a
lumbering old O-320 - the 912S is geared and you're cruising with the
engine running at something like 5400 RPM)

Switch from 150hp pistons to 160hp pistons, and throw on a Powerflow
exhaust, and you'll be able to exceed it. Most people have their prop
repitched to be more of a cruise prop, but that's not neccesarily
required (it's not on my AMR&D STC). For me, I repitched slightly, but
wanted to keep the impressive climb (for a 140) that I aquired from the
mod.


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