6 vs 4 Cylinder Engines

[wheelsup]

Short version,

Make smooth power changes in flight (any competent aviator should be doing this anyway).

Don't let your CHTs get above 400 in the first place (I don't care that the manufacturers say that 450 is OK).

Avoid EGTs from 100 ROP - 50 LOP.

Reduce power as required to make a normal 500 FPM constant airspeed descent, and "shock cooling" will never be a problem (if it ever existed at all).

Sweet now let's come back down to reality, we had to accomplish steep spirals and emergency descents in a training environment, lots of sub 20 hour TT guys not knowing how to operate an aircraft in general let alone a 300 hp complex plane, like I said the engines were champs...(students were great too and learned fast).

IIRC the Bonanzas and Barons we had didn't really utilize the mixture control, it had some sort of altitude compensating fuel pump on it. We didn't even mess with it...full "rich" setting even at 10k-12k ft doing maneuvers, the stuff we did to those planes would make real owners cringe...

 

[USMCmech]

Sweet now let's come back down to reality, we had to accomplish steep spirals and emergency descents in a training environment, lots of sub 20 hour TT guys not knowing how to operate an aircraft in general let alone a 300 hp complex plane, like I said the engines were champs...(students were great too and learned fast).

My point exactly.

Even with all that "abuse" the engines ran just fine. A normal pilot flying from point A to point B following those basic rules will NEVER hurt an engine.

I'll add one more rule, never let your airplane sit for more than 14 days (preferably 7). If you can't get to the airport, have some CFI who needs the flight time fly around in circles for 30 minutes.

I'm convinced that 2 factors play into the "big bore 6 cylinder engines will shatter if you don't baby them" myth. Most of these airplanes sit unflown for far too long, and when they are, the owners want to get all that speed they paid for so they lean for best power and run the engines way too hot. How often does that 421 in the hanger next to you fly? Once every 6 weeks maybe?