How can I calculate 75% and 65% power settings for rv4 lycoming I0-360-180b, 82" pitch wooden prop, no manifold pressure gauge, con it be done on rpm? I need to break in new engine.
Thanks in advance
Mark
Mark,
MP+RPM=%Power. Roughly transcribed that the first two numbers of MP and RPM added together should equal 48 for 75% power. Since you have no MP gauge, here is what I did for years with my RV-4.
The best way to calculate 75% power without a MP gauge is to calculate your max RPM at SL with test flights. Flat out at SL full throttle 2700 RPM is close to 100% power. 2400 RPM would be roughly 75% power, 2300 65%. At 8500' Full throttle would be around 2600 RPM and an estimated MP of 20-21" depending on your intake system. 2600 would be 75% power and 2500 RPM roughly 65% as previously mentioned.
How can I calculate 75% and 65% power settings for rv4 lycoming I0-360-180b, 82" pitch wooden prop, no manifold pressure gauge, con it be done on rpm? I need to break in new engine.
Thanks in advance
Mark
I would say....... install a Van's manifold gauge. They are cheap, easy to install and will give you the information that you need.
And you will forever use it.........
Density Altitude would make the most sense to me and is what I used; though I also had a manifold pressure gauge. I used ECI's excellent break-in recommendations:
