You’re right. The Cessna 185 POH doesn’t mention max continuous cruise or max cruise but the chart does show, for example, @2,500 ft, 2500/25hg, is 76%. Then it says at 65% leaning to peak is fine. I interpret this to mean that at 76% you can hurt the motor?
Excellent thanks Bill, all good to hear, particularly when lining up with the knowledge imparted by Mike Busch and Savvy Aviation. The only area where perhaps you disagree with his assessment is your statement that operating up to 460F CHT in accordance with the manufacturer’s testing criteria will do no damage, assuming not exceeding max continuous power. Really…? Isn’t 460F somewhat on the warm side for long term operation, especially when considering the properties of how the metal in cylinder heads behaves when above 400F? Your discussion on the dangers of low oil temperatures makes sense, and without mentioning Busch’s name I feel you may be referring to folks following his guidance. He does also mention the dangers of excessively low oil temperatures, but neither of you put a minimum figure on it, instead telling us the oil manufacturers like to see a sustained 180C. That’s fine, but in certain cold areas and climates folks may be sat with oil at 170, or 160C … are they in for trouble? A bit like the CHT discussion, if it falls within manufacturer’s temperature limits for sustained operation, how does a pilot know if he or she is doing damage long term? Your information re. low internal cylinder pressures and piston ring performance is an area I haven’t heard Mike Busch talk about. Good to know thanks.
Great information! I'm really impressed with the excellent way that Bill was able to present useful information while walking through the minefield of so many different ways that manufacturers recommend to operate their engines. Thanks for taking the time to do this!
For a more correct and consise review, find a video by Mike Busch, or better yet buy his books. Much more to learn... this, is like cutting a good steak with a blunt knife.
Hello , very good video , good work . I saw it all to the end , and even understood 95% (flew gliders in the past) of it . Could i ask a question : from an environmental point of view , will it be able in the future to fly general aviation aircraft-engines that do not run on avgas(100LL) that contains lead in order to prevent detonation ? How far does technology stand towards that goal ? Do Lycoming O-360 engines (Mooney 20C) still need this leaded fuel ? Also , how far is the evolution in the USA of the production of carbon-neutral Power-to-liquid synthetically produced fuels through green energy (e-fuels) for the aircraft industry ? Thank you . Erwin , Belgium .
I am a pilot but am very involved in cars, supercharged Chevy LS engines to be exact. Unleaded car gas is safe in most non turbocharged/supercharged aircraft engines, EXCEPT, alcohol is not allowed in any quantity at all in aircraft fuel. No one will deliver unleaded pure gas in a tanker that has never had alcohol adulterated fuel. The gas tanker can never be totally emptied so some alcohol remains. Just so you understand the war on corn, alcohol hold, attracts and can lead to contamination of the fuel system with water. That water, if we fly high enough can freeze between tank and cylinder causing the engine to fall silent. Here in the Midwest we can’t get pure gas. Thus it is not easy to use unleaded.
You’re right. The Cessna 185 POH doesn’t mention max continuous cruise or max cruise but the chart does show, for example, @2,500 ft, 2500/25hg, is 76%. Then it says at 65% leaning to peak is fine. I interpret this to mean that at 76% you can hurt the motor?
Excellent thanks Bill, all good to hear, particularly when lining up with the knowledge imparted by Mike Busch and Savvy Aviation.
The only area where perhaps you disagree with his assessment is your statement that operating up to 460F CHT in accordance with the manufacturer’s testing criteria will do no damage, assuming not exceeding max continuous power. Really…?
Isn’t 460F somewhat on the warm side for long term operation, especially when considering the properties of how the metal in cylinder heads behaves when above 400F?
Your discussion on the dangers of low oil temperatures makes sense, and without mentioning Busch’s name I feel you may be referring to folks following his guidance. He does also mention the dangers of excessively low oil temperatures, but neither of you put a minimum figure on it, instead telling us the oil manufacturers like to see a sustained 180C.
That’s fine, but in certain cold areas and climates folks may be sat with oil at 170, or 160C … are they in for trouble?
A bit like the CHT discussion, if it falls within manufacturer’s temperature limits for sustained operation, how does a pilot know if he or she is doing damage long term?
Your information re. low internal cylinder pressures and piston ring performance is an area I haven’t heard Mike Busch talk about. Good to know thanks.
Yes, Mike does address ICP. CHTs are a proxy for ICP
Great information! I'm really impressed with the excellent way that Bill was able to present useful information while walking through the minefield of so many different ways that manufacturers recommend to operate their engines. Thanks for taking the time to do this!
Glad it was helpful!
For a more correct and consise review, find a video by Mike Busch, or better yet buy his books. Much more to learn... this, is like cutting a good steak with a blunt knife.
Also Mike has access to George Braly's knowledge, the engine test cell data.@@apfelsnutz
Do you have a point of contact? I’m having an issue with my IO-550B with all the right cylinders not firing off on start but eventually starts firing.
Hello , very good video , good work . I saw it all to the end , and even understood 95% (flew gliders in the past) of it . Could i ask a question : from an environmental point of view , will it be able in the future to fly general aviation aircraft-engines that do not run on avgas(100LL) that contains lead in order to prevent detonation ? How far does technology stand towards that goal ? Do Lycoming O-360 engines (Mooney 20C) still need this leaded fuel ? Also , how far is the evolution in the USA of the production of carbon-neutral Power-to-liquid synthetically produced fuels through green energy (e-fuels) for the aircraft industry ? Thank you . Erwin , Belgium .
I am a pilot but am very involved in cars, supercharged Chevy LS engines to be exact.
Unleaded car gas is safe in most non turbocharged/supercharged aircraft engines, EXCEPT, alcohol is not allowed in any quantity at all in aircraft fuel.
No one will deliver unleaded pure gas in a tanker that has never had alcohol adulterated fuel. The gas tanker can never be totally emptied so some alcohol remains.
Just so you understand the war on corn, alcohol hold, attracts and can lead to contamination of the fuel system with water. That water, if we fly high enough can freeze between tank and cylinder causing the engine to fall silent.
Here in the Midwest we can’t get pure gas. Thus it is not easy to use unleaded.
Thanks for chiming in DW!
So I take it you don’t agree with WOT operation as per Mike Busch?