Originally Posted by Rupester
MANY answers to this ... what RPM and altitude? ... ROP or LOP?
Yes, I understand, and you hit the nail on the head, that is exactly the information I am looking for. Not one specific set of data points but a range of data from several different settings. What kind of (average) speeds were seen at what altitudes with what mixture settings?
The reason for me asking is that Van's doesn't have any hard data for the 150HP engine. So I used the differences between the 118HP and the 160HP engines to come up with a formula to try and predict some estimates of my own. Just checking to see how close I actually got.
Catto told me the prop I have will provide me with a "little" more cruise than climb.
I don't know whether I will run LOP or ROP. Everything I did in training and all flights after was done in Cessnas and all were done at ROP. I believe I was ROP. At altitude, lean until RPM's drop a tad, then back a little rich to go back to RPM.
Please understand I'm not looking for "You WILL see these speeds." I'm just trying to get a ballpark guesstimate. I know every single RV-9 that is built, is different. Options, build technique, weight (etc.) all affect what the plane will do in the real world. I'm just wanting to see how close my formulas are to what the real world says.