Engine RPM

strand10 · Dec 31, 2022

Engine question for the group.

PA18-150. O320 red line is 2700 but I only get to about 2550 at full throttle. Is that normal?

frequent_flyer · Dec 31, 2022

strand10 said:
Engine question for the group.

PA18-150. O320 red line is 2700 but I only get to about 2550 at full throttle. Is that normal?

At what airspeed and with what prop?

strand10 · Dec 31, 2022

Static TO, fixed pitch Sensenich M74 AM2

frequent_flyer · Dec 31, 2022

strand10 said:
Static TO, fixed pitch Sensenich M74 AM2

I'm no expert on this engine and prop combination but 2550 seems to be at the high end of allowed static rpm according to the TCDS.

https://dyzz9obi78pm5.cloudfront.net/app/image/id/615b7002e63f1db3487b2534/n/1a2.pdf

If you got full rated rpm while static you would be over red line very early in the takeoff roll.

stewartb · Dec 31, 2022

Static and takeoff are different things. Your TCDS specifies the static RPM range.

strand10 · Dec 31, 2022

Yep. Just watched a video of a TO and it settles out at 2400ish on full power application. Thanks. All makes sense now.

cubdriver2 · Dec 31, 2022

But what is it at 60mph climbing and WOT in level flight.
Remember an 0320 only makes 150 HP at 2700 rpm

Glenn