Colin: When I had my engine failure in a Cardinal in '71 I was told that over-heating results from flying it to lean and that became an issure because about 15 min before my problem developed I let down from 10,500 to 8,500 on a trip from Prescott AZ(PRC) to Santa Ana CA(SNA) at the Colorado River. I leaned for max power during a full power run-up at PRC, elev 5500 ft +/- and then enricht to a 50 rpm drop and know that I re-set the mixture after let down. It was a rented plane and I was accused of running it to lean. The trouble was that a factory inspection revealed all valves were servicable. I never rented from them again because I found out that they had 5 major mech. failures in 3months prior to my experience. Maybe coincidence but to me it was a possible indicator of poor maint.
And it would take a big move of the mixture to kill the engine quickly and if that would happen most would surely recognize what they had done immediately Don beverlyrai...@bellsouth.net wrote: > Jim > I have never heard of an engine quitting due to detonation by itself. If the > engine quits is is usually due to the engine damage done by the detonation, > not the detonation itself, if that makes sense. Most often the damage is to > the crown of the psiton, since detonation is usually accompanied by a rocking > of the piston back and forth on the wrist pin, causing a "slapping" of the > piston into the cylinder walls. This is where the damage occurs, usually > breaking some portion of the crown of the piston off and either sending the > piece out the exhaust, which sometimes also damages the exhaust valve, or > sending it into the oil pan. A quick compression check can easily discover a > damaged cylinder. This damage can also happen and the engine still operate, > possibly with decent power as Mark Jones found when he crushed the ring lands > on one of his pistons. It is possible for your mixture to be too rich for > the temp you were seeing, since you were on the upper end of the temp rang! > e, and at full rich would probably smother a standard set of plugs, which > with that heat would dry themselves. > > In engine diagnostics, we always went back to basics whenever we were trying > to determine and engine failure: 1) check fuel supply; 2) check ignition > capability - good spark; 3) check compression. Those are your three basics. > Without them in the right order, all else you check is worthless. Once you > determine these are right and in the correct order, then the ghost hunt can > begin. Worked for me for over 15 years.... > > Colin > N96TA > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html
