Governor issue?

[acam37]

I am new to the constant speed community, so I may or may not have an issue. Whenever I take off and climb out, I am at full throttle and full forward on the blue knob. When I begin to level off and throttle back using manifold pressure, I have to wait up to 30 seconds before the RPM's drop, then I can adjust the prop to the desired RPM. Is this normal?

[Auburntsts]

Sounds more like your technique. With just a MP reduction the gov still is attempting to maintain max RPM which it will do until you reduce a significant amount of MP. Try not waiting for the MP reduction to drive an RPM drop. Reduce your MP and then pull the blue knob back immediately to set your desired RPM. FWIW unless I'm specifically trying to be slow, I normally fly WOT and never touch the throttle after takeoff until it's time to descend. In fact if I were to chart out which control (throttle, prop, or mixture) I spend the most time manipulating during an avg flight, that honor would go to the mixture by a large margin.

[DanH]

Manifold pressure controls torque.

Prop knob controls RPM.

The exception is only when MP is so low that the engine can't maintain the governed RPM setting. Only then does MP control RPM.

Assuming best power mixture, you can use any MP/RPM combination in the grid to the left of the "Limiting Manifold Pressure For Continuous Operation" line, which is found on the left side of the standard Lycoming power chart:

[rzbill]

If you are behind a -M1B, you can go after the blue knob right away before the throttle. There is no limiting line as there is with many if not all angle valve motors.

[cajunwings]

Once the power comes up on takeoff & the governor is controlling/maintaining the rpm by adjusting the prop pitch the rpm should not change if you don't move the blue knob. This is the "Constant Speed" part where the governor maintains the RPM you have requested with the blue knob. If 2700 RPM is your takeoff & climb number the governor will hold it there whether climbing, level or descending until you request a different RPM. Only if you make a big power reduction (like below about 2/3rds throttle) should the RPM ever change from where you have set the governor with the blue knob.

Don Broussard

RV-9 Rebuild in Progress

[BobTurner]

Originally Posted by acam37

I am new to the constant speed community, so I may or may not have an issue. Whenever I take off and climb out, I am at full throttle and full forward on the blue knob. When I begin to level off and throttle back using manifold pressure, I have to wait up to 30 seconds before the RPM's drop, then I can adjust the prop to the desired RPM. Is this normal?

Unless you are reducing the throttle a lot, the RPMs should not drop at all, until you slowly pull out the blue knob. e.g., if you set the MP at 22", the RPMs should stay at red-line, until you pull out the prop control.

[acam37]

Ok, I get it now. Thanks everyone for explaining it to me.