Re:FAA approves hundreds more engines to use unleaded avgas
by userbinator on Friday October 29, 2021 @11:10PM
(#29045671)
Also, aviation engines are in general pushed far closer to their operational limits than a regular car engine. The latter might see full throttle and need to generate its rated power for a few percent of its life. Failures are not too dangerous. The former needs to generate rated power for a far larger fraction, and is also held to much higher reliability standards. Hence the requirement for high octane fuel and massive displacements relative to power output.
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Re:FAA approves hundreds more engines to use unleaded avgas
by lutorm on Saturday October 30, 2021 @02:51AM
(#29046621)
The difference in operational regime is true, although it's my impression that automobile engines are pushed through some very severe tests as part of their development. For example, this movie, https://youtu.be/GNPB3RtHN2M, claims that KIA tests their engines for 300 straight hours at full throttle.
As for reliability, I'm not convinced. In practical terms, I think automobile engines are far more reliable than aircraft engines. When was the last time your automobile engine broke an exhaust valve, cracked a cylinder head, or had a magneto come apart?
Re:FAA approves hundreds more engines to use unleaded avgas
by userbinator on Sunday October 31, 2021 @01:41AM
(#29054742)
When was the last time your automobile engine broke an exhaust valve, cracked a cylinder head, or had a magneto come apart?
Exactly. An automobile engine is subjected to far less stresses in normal operation. 300h at full load is considered an extreme torture test for one, while a typical aircraft engine is meant to run for over 1000h between overhaul ( https://en.wikipedia.org/wiki/Time_between_overhauls ) and spends a significant amount of that time at full load --- that's normal operating conditions.