Questions about AC piston engines that I've never dared to ask
I would be thankful for any knowledgeable responses to this, apologies if already posted and answered, have searched:
(Just a note, when talking car engines, I'm talking about pre-1990's engines with a carburettor. Similarly, when talking AC engines, I'm talking about the Briggs and Stratton league engines that are powering the prehistoric aircraft that I fly :-)
1. How come that a typical 320 cubic inch (5244 cubic cm) SEPL aircraft engine only produces between 140 - 160 horsepower ? A typical European car with half the displacement produces the same power ! Is it the American tradition of "big, heavy, low power" engines" ? (Ever rented a a 6 cyl 3.0 L American car and wondered what was going on out there (if anything but noise) ?). Or, is it that it needs to operate at a relatively low RPM, like a ship's engine ? Please don't gimme the "reliability story", or the "AC engines operate at max power most of the time story", even a VW Polo 1.0 can "cruise" at 150 km/h for 250 000 km @ 7000 rpm, just see how the Germans drive them on the autobahn !
2. How come that these engines are so vulnerable to carburettor icing ? Cars have been driving around at varous altitudes for 100 years without this problem, or ?
3. How come that car engines haven't had a leaning mechanism ? The same engines are running in Amsterdam (height: 0ft) and Madrid (height: many ft :-)
4. I often hear that "torque" is what's important in AC engines, not horse-power. Just wonderig what the difference is between a VW Polo 1.0 plowing the autobahn at 150 km/h and a Piper Cherokee plowing through the air at 100 Kts ?
BTW, I had an interesting experience some months ago. My friend and I started talking engines, I bragged about the "huge" engines in the SEP aircraft I fly. He has a Porche 944 S2 (3.0L, 211 HP, reportedly the largest 4 cyl car engine ever made). Ended up with us test driving / flying each other's vehicles. I had the most fun !