Cliff:
Shock cooling must be the subject of the month on this board. There have been lots of posts (including some of mine) that deal with this.
With the C-182, just work on keeping the CHT in the green and take steps (via the cowl flaps) to provide the proper air flow across the cylinders at the proper time. In the descent, if the CHT starts dipping too low, reduce the rate of descent by holding the nose up. Think "Commercial" pilot. Smooth going up, smooth going down. A nice 500fpm each way on high performance engines is a good way to increase their life span.
C-182 vs. the Dakota - Well first thank Mr. Lopresti. He designed the Commanche series while he worked for Piper. The engineers consulted him again for the Cherokee series. What he did was create an air gap at the rear of the cowling that was exactly the same size as the air intakes at the front. Then by using the baffling (those sheet metal pieces with the pieces of rubber attached) he forced the airstream up over the cylinders and out the rear of the cowl. The shape of the air inlets is not compromised by a climb (unless overly steep) or a descent (again if not overly steep). Basically, the Cherokee series has a consistent airflow and therefore the engine never really gets super hot or cold. In the higher performance series, Piper also added an oil cooler to help keep the engine running cool. Finally, and I don't want to start a flame war on the board - but the O-540- A series Lycoming in the Dakota is slightly less fickle than the Continentals in the C-182. This is basically because Lycoming came along later and with 20-20 hindsight, saw that by increasing the size and density of the sylinder cooling fins, the engine would stay cooler and more stable.
Good luck with all.
Shock cooling must be the subject of the month on this board. There have been lots of posts (including some of mine) that deal with this.
With the C-182, just work on keeping the CHT in the green and take steps (via the cowl flaps) to provide the proper air flow across the cylinders at the proper time. In the descent, if the CHT starts dipping too low, reduce the rate of descent by holding the nose up. Think "Commercial" pilot. Smooth going up, smooth going down. A nice 500fpm each way on high performance engines is a good way to increase their life span.
C-182 vs. the Dakota - Well first thank Mr. Lopresti. He designed the Commanche series while he worked for Piper. The engineers consulted him again for the Cherokee series. What he did was create an air gap at the rear of the cowling that was exactly the same size as the air intakes at the front. Then by using the baffling (those sheet metal pieces with the pieces of rubber attached) he forced the airstream up over the cylinders and out the rear of the cowl. The shape of the air inlets is not compromised by a climb (unless overly steep) or a descent (again if not overly steep). Basically, the Cherokee series has a consistent airflow and therefore the engine never really gets super hot or cold. In the higher performance series, Piper also added an oil cooler to help keep the engine running cool. Finally, and I don't want to start a flame war on the board - but the O-540- A series Lycoming in the Dakota is slightly less fickle than the Continentals in the C-182. This is basically because Lycoming came along later and with 20-20 hindsight, saw that by increasing the size and density of the sylinder cooling fins, the engine would stay cooler and more stable.
Good luck with all.
