V Type or Horizontally Opposed Engines

V Engines or Horizontally Opposed Engines. While they are not exactly the same thing, they do have a similar concept to each other. A V engine has two banks of cylinders set at a V angle to each other. A Horizontally opposed (flat) engine also has two banks of cylinders set at a flat angle to each other. When comparing a flat to a V engine, there is very little difference. If one were to build two engines of the same displacement, same valves, same intake and exhaust systems, etc. -- they would likely perform nearly identically. Displacement is displacement.

A flat engine has a low center of gravity and fits into a smaller space. A V engine tends to be more cubical in shape. One advantage that a flat engine has is better cooling. This is why more light general aviation air cooled aircraft now use the flat engine.

• Curtiss OX 5
• Curtiss OX 6
• Hisso
• Liberty
• Harroun 8
• Sturavent
• Curtiss V2
• Aeronca E113C
• Cleone
• Lawrence
• Long Harlequin