Radial vs in-line engines

[reflected]

I was thinking about WWII planes and I realized that most radial engines were much more powerful than in-line engines.
Let's take the Corsair or the Thunderbolt for example, with their 2000+ HP P&W, whereas Spits and 109s were a little above 1000. Is there a technical explanation for that?

[Davedog74]

because your comparing 1940 engines with later engines,

[reflected]

Is that so? OK, I was wondering about that too.

Then, what decided between an in-line and a radial engine when they designed these machines? I guess radials were easier to cool but they produced more drag, but I might be wrong.

Wait, I'm not sure those late war Griffons or DB-s ever reached the 2200 HP of a P&W ? So there might be something after all?

[Davedog74]

seafire 47 had 2300 hp but was post war most fighters were radials post war,so i guess radials were the way to go,im pretty sure they took more of a beating,im sure the real experts on here will tell us why

[Welshman]

MK 14 spit was 2035hp

[Sternjaeger II]

the debate Radial VS Inline is as old as the planes they were installed onto.

They both come with pros and cons, here are the most common ones:

Radial PROs
Very high TBO/extremely dependable
Resistent to damage/gives protection to pilot
air cooled, no need for cooling ducts/radiators etc
huge displacement/HP

Radial CONs
lotsa drag/bad forward visibility
oil thirsty
strong gyroscopic torque (the rotating crankshaft counterweight and big prop blades can cause the plane to torque itself out of delicate situations like pre-stall if full throttle is applied, still present on inline engines, but not as strong)
avgas thirsty
needs big supercharger
heavy

Inline PROs
streamlined engine
lighter than radial
more fuel efficient
lighter superchager
better fwd visibility

Inline CONs
needs liquid cooling/radiators
more susceptible to damage (can't fly with one or more pistons damaged)
shorter TBO


I suppose it's down to pilot's preferences and for the tasks assigned.

One of the bigger question marks in the history of warfare for me was the use of Mustangs in Korea, when P-47s would have probably done a better job.

[Tacoma74]

The way I've always looked at it is that a big radial may produce a lot of power and be very torquey, but they're is enivitably a quite larger amount of drag introduced to the nose of the plane. A 109 on the other hand for example has a more "bullet shaped" nose with the inverted v-12, thus being more streamlined and needing less power to pull it through the air.