Engine HP given RPM, MP and PA

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cessna170bdriver
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Joined: Mon Apr 22, 2002 5:13 pm

Re: Engine HP given RPM, MP and PA

Post by cessna170bdriver »

Bruce Fenstermacher wrote:OH NOoo my head is hurting reading and thinking about what Joseph and others have said. :lol:

It is simple or at least I thought it would be if I could figure out how to use the chart. Tachometers are harder to read and less stable that manifold pressure gauges. So I use mine to set power. It is simple. I'm at full power and I want to go to my economy cruise setting I pull the throttle back to 21.5" MP and level off. Eventually the RPM will settle down to about the same RPM because I always cruise at about the same altitude. Thats it, I don't chase the tach.
K
I just wanted to know what my power setting where based on the MP rather than the tach.

But like many things it is just not that simple.
Bruce,
The new mechanical tach I installed at overhaul time in 2006 is rock steady. I can tell whether the needle is pointing to the low side or high side of a line. The old one had about 50 rpm or so waver, the main reason I replaced it. That said, I do prefer using my manifold pressure gauge to set the throttle, then verify with the tach.
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
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