Mechanically-challenged newby 6A owner here with a few 0-320D2J / 70CM series powerplant questions I?d love some assistance with. If it matters, engine time is approx. 600 since overhaul, prop is unknown history prior to 2002 when installed on this aircraft.
Q1: There is a yellow arc on tach between 1850 and 2250 RPM and red line at 2600 RPM. I get the 2600 RPM max operating limit as it is plastered all over the OM. As for the yellow arc, this is original marking on the tach, not taped/placarded. I cannot find anything in either the engine or prop operating manuals, nor the POH that addresses this. Can anyone point me to a reference here?
Q2: At my first conditional (Dec 16), it was discovered the #1 cylinder has a stuck valve guide. Mechanic suggested a regiment of Marvel Mystery Oil to address valve and excessive oil usage. Compressions 70/79/77/78. Would someone please comment on (a) the risks associated with a stuck valve, and (b) the appropriateness of the use of this additive. I am burning about a quart of oil per 5 hours tach time.
Q3: At 3k feet (I have not even been close to 8k) with wide open throttle, the engine is only pulling 2350 rpm and 139ktas. On takeoff roll and in climb, I?m in the yellow arc at 2000-2100 at full throttle. These numbers seem a little low compared to performance numbers seen here and elsewhere. Prop logs reflect that prop was repitched from 81 to 79 several years ago. Any words of wisdom?
Thanks so much!
David
Q1: There is a yellow arc on tach between 1850 and 2250 RPM and red line at 2600 RPM. I get the 2600 RPM max operating limit as it is plastered all over the OM. As for the yellow arc, this is original marking on the tach, not taped/placarded. I cannot find anything in either the engine or prop operating manuals, nor the POH that addresses this. Can anyone point me to a reference here?
Q2: At my first conditional (Dec 16), it was discovered the #1 cylinder has a stuck valve guide. Mechanic suggested a regiment of Marvel Mystery Oil to address valve and excessive oil usage. Compressions 70/79/77/78. Would someone please comment on (a) the risks associated with a stuck valve, and (b) the appropriateness of the use of this additive. I am burning about a quart of oil per 5 hours tach time.
Q3: At 3k feet (I have not even been close to 8k) with wide open throttle, the engine is only pulling 2350 rpm and 139ktas. On takeoff roll and in climb, I?m in the yellow arc at 2000-2100 at full throttle. These numbers seem a little low compared to performance numbers seen here and elsewhere. Prop logs reflect that prop was repitched from 81 to 79 several years ago. Any words of wisdom?
Thanks so much!
David