Help Understanding Piston Engines w/Constant Speed Propellers

[AndyClark20]

Thanks, I missed that bit

[NixonRedgrave]

Definitely worth starting from my OP and reading through it all. There is a ton of awesome material here.

[JWATTS0275]

Thank you for this thread and the contributors, I have personally learnt so much.

[PIPERARROW6878]

Excellent ground school .
When the props are out of sycn you can actually feel and hear the imbalance When you exercise the props ( pull back the prop levers) in a piston twin the drop in prop rpm and engine load is very noticeable In a carbureted engine is said to be squared when the throttle and rpm match as 25 in manifold and 2500 rpm .In a turbo it can be over squared as the engine manifold numbers will be higher .AS an aside my dad lost an engine at 2500 ft in a Beach Sierra .AS the drawing shows the engine oil is routed to the constant speed prop and in my dad’s case that tube fractured and led to
dumbing of the crankcase oil and forced an off airport landing.

[CaptainRude91]

I’ve added some of the info in this thread into guides:

[Advanced GUIDE] Constant Speed Propeller System

Introduction The purpose behind the constant speed propeller system is to achieve a high propulsive efficiency over a wide speed range. A fixed pitch propeller is only efficient over a very small speed range. A fixed pitch propeller optimized for climb will have good performance during take-off and climb (low speed) but during cruise the blade angle is too low. A fixed pitch propeller optimized for cruise has good cruise performance (high speed), but during take-off the blade angle is too large…

[Advanced GUIDE] Free-turbine Turboprop Engines

Introduction Lets start with saying that there are two types of turboprop engines. A fixed shaft engine works essentially the same as a piston engine with constant speed propeller. Manifold pressure is replaced by a torque gauge, there is a reduction gearbox between the engine and propeller system, otherwise its essentially the same, there also is only one RPM gauge. If you understand the constant speed propeller principle in connection with piston engines, this kind if turboprop engine should b…

[Advanced GUIDE] Propeller Basics

Definitions First it is important to understand the following definitions when talking about propellers: Blade / Pitch angle - This is the angle between the propeller plane of rotation and the chord line of the blade. On a fixed pitch propeller this angle is fixed, on a Constant Speed Propeller (CSP), this angle is adjusted to balance engine power and propeller power absorbed, controlling the propeller RPM. Washout or twist - The blade angle on a propeller blade is not the same along the whol…

[beezzez]

I am a bit baffled by the propeller system of the Diamond DA40.
Whatever the throttle setting, the engine speed edges into the amber, It never settles in the green.
Is it the same for other people?