drgwentzel
Pre-takeoff checklist
Flyers,
Sorry to beat an over posted topic, but I'd like to hear the consensus of the group.
I fly a 1971 Cardinal RG with an IO-360, 200 HP, CS prop, with an installed EGT, digital fuel flow computer, a digital tachometer and no engine monitor.
The POH has tables grouped by altitude, such as: 2500, 5000, 7500, 10,000, 12, 500, etc. Down the left side you pick your MP and RPM and off to the right it will give you the % power, GPH, TAS, duration and range.
Ok…fine, let’s take a very common situation: I am at 2500 feet MSL, 24 inches MP and 2400 RPM. If I look that up on the table it says I am at 71% power, I should expect a TAS of 154 mph, 4.9 hours endurance and a 755 mile range with no reserve.
More to the point it says I should lean to 10.2 GPH. When I set the GPH to what the POH recommends I notice that on the EGT that it is somewhere between 25 and 50 degrees ROP. I think even rarely it can be right at peak EGT.
I’ve heard that at or below a certain % power you can’t hurt the engine no matter where the red knob is and you can run LOP or even peak EGT and have no problems or concerns. Some have said that figure is anything below 70% power and others have said it’s closer to 65%.
I’ve heard it stated that 25 to 50 degrees rich of peak is the absolute worst place to be. It should either be 100 degrees ROP or 50 degrees LOP.
I’ve heard it said that never run LOP unless you have an engine monitor.
Can the group help me dig out the gold from the OWT’s? Should I follow the POH no matter what? Are the POH’s updated to modern data and wisdom or am I flying with 1971 information?
Can’t wait to hear the groups thoughts.
Gene
‘71RG out of N14
Sorry to beat an over posted topic, but I'd like to hear the consensus of the group.
I fly a 1971 Cardinal RG with an IO-360, 200 HP, CS prop, with an installed EGT, digital fuel flow computer, a digital tachometer and no engine monitor.
The POH has tables grouped by altitude, such as: 2500, 5000, 7500, 10,000, 12, 500, etc. Down the left side you pick your MP and RPM and off to the right it will give you the % power, GPH, TAS, duration and range.
Ok…fine, let’s take a very common situation: I am at 2500 feet MSL, 24 inches MP and 2400 RPM. If I look that up on the table it says I am at 71% power, I should expect a TAS of 154 mph, 4.9 hours endurance and a 755 mile range with no reserve.
More to the point it says I should lean to 10.2 GPH. When I set the GPH to what the POH recommends I notice that on the EGT that it is somewhere between 25 and 50 degrees ROP. I think even rarely it can be right at peak EGT.
I’ve heard that at or below a certain % power you can’t hurt the engine no matter where the red knob is and you can run LOP or even peak EGT and have no problems or concerns. Some have said that figure is anything below 70% power and others have said it’s closer to 65%.
I’ve heard it stated that 25 to 50 degrees rich of peak is the absolute worst place to be. It should either be 100 degrees ROP or 50 degrees LOP.
I’ve heard it said that never run LOP unless you have an engine monitor.
Can the group help me dig out the gold from the OWT’s? Should I follow the POH no matter what? Are the POH’s updated to modern data and wisdom or am I flying with 1971 information?
Can’t wait to hear the groups thoughts.
Gene
‘71RG out of N14