Hi!I just had a quick question regarding engine cooling. As you know, the intakes on each side of the propellor (for reciprocating-engine aircraft) are for the engine air intakes. Case in point: Cessna 152 nose and cowling http://www.airplanemart.com/aircraft-history-and-specification/photo/lg/Cessna-152-Single-Engine-High-Wing-Airplane-N49419.jpgI was just wondering: once the cold, clean outside air enters the intakes and cools the cylinders, where does the now-hot, dirty air go? As you can see, the aircraft has no visible outlet for the air to go. Does it go to the oil cooler? Does the air exit through the cowl flaps (in aircraft that are equipped with cowl flaps)? Is it used for carb heat? Or does the air get mixed with the exhaust and simply blown out the exhaust pipe?

Under the aircraft at the nose gear (just aft). Take a look there! Also explains why larger engines have cowl flaps in that position. :( The oil cooler is positioned just so to catch some of the passing air. Still more air is caught and circulated around baffling and exhaust shrouds, etc,etc. Pretty darn simple!

I'm assuming you're referring to this?Exhaust air exit on a Piper Comanche above, on a Cessna 152http://www.flickr.com/photos/23650130@N04/2253682792/in/photostream/1950s Navion with cowl flapshttp://www.flickr.com/photos/23650130@N04/2253681962/in/photostream/Thanks for helping me out!:smile:I just have a few more questions. What is that air exit called? Is there a special name for this opening? And why is the oil cooler positioned there? I thought oil coolers don't like hot, grimy exhaust air :(

I'm assuming you're referring to this?Exhaust air exit on a Piper Comanche above, on a Cessna 152http://www.flickr.com/photos/23650130@N04/2253682792/in/photostream/1950s Navion with cowl flapshttp://www.flickr.com/photos/23650130@N04/2253681962/in/photostream/Thanks for helping me out!:smile:I just have a few more questions. What is that air exit called? Is there a special name for this opening? And why is the oil cooler positioned there? I thought oil coolers don't like hot, grimy exhaust air :(

Good pictures there.For a name I usually call that the lower cowl opening. Never thought of or heard of a specific name.The oil cooler all depends on the manufacture and the engine they have. Turbo charged aircraft usually put the cooler in one of the cowl openings or give the cooler its own duct. Lot's of normally aspirated Cessna's have them behind all the cylinders. This air usually doesn't get to hot because it is in contract with the cylinders for a very short period. During winter ops most of the airplanes I fly require plates over the oil coolers to block the air to help the oil warm up to operating temperatures.