Radials

[4RG.I.'S]

A couple of points that haven't been brought up are efficiency and maintenance.
The Pratt has 5 more cylinders to feed and maintain (in 2 rows) and it weighs more (64 lbs from what I've read). While it should mean better performance and slightly higher takeoff power (250 HP from what I've seen listed) I believe if the fuel efficiency were calculated it would be higher than the Wright.
Then looking at the mechanical aspect of it, those 5 more cylinders mean 10 more spark plugs for service or maintenance and a lot more areas and parts to wear and places to be inspected. Warbirds are never cheap and more parts mean much more expense.
Not being the owner or operator of either, I can only speculate but it seems that possible that the cost of running a P&W would be more per hour.
But I really love the logo!...

[shrike]

Continental and Lycoming both have engines in the 360cid class. The six cylinder Continental makes 5% more power, and is smoother, but at the expense of a greatly larger parts count (both due to 50% more cylinders and design architecture), more stringent wear tolerances and a 20-25% higher overhaul cost.

[John Dupre]

One interesting thing to note is the Curtiss model 75 Hawk. In the P-36 it used the P&W R 1830 but in other versions for France it used the Wright R-1820. The Finnish Air Force ended up flying both version but preferred the Wright version since it was faster. With 6 fewer cylinders I imagine it was lighter but is that all that accounts for the speed differential? The Finns ended up converting all of their Hawks since they needed the Wright engines for their Brewster F2A's which were even faster than the Curtiss.

Ditto the Grumman F4F (Pratt R-1830) versus Eastern/General Motors FM-2 (Wright R-1820) but don't know if there was any performance differential.

I have seen the F4F-4 (P&W) at 320 MPH top speed and the FM-2 (Wright) at 332. The version of the Wright engine was more powerful than the F4F-4 P&W.

[Rajay]

I have seen the F4F-4 (P&W) at 320 MPH top speed and the FM-2 (Wright) at 332. The version of the Wright engine was more powerful than the F4F-4 P&W.

I was going to ask if that could be the result as much of comparing early development engines to late ones since I believe that I've read that early R-1820 series engines had as little as 850 hp in some early model B-17's (the YB-17's had R-1820-39 engines) for example whereas later versions of that engine such as the -97 used in the B-17G had 1,200 hp and in the UF-2/CSR-110/G-111 variants of the Grumman Albatross had as much as 1,525 hp. Similarly, early Consolidated PBY-1's had 900 hp P&W R-1830-64 engines whereas late model PBY-5/5A's had 1,200 hp R-1830-82 or -92 engines.

But apparently not so. According to Wikipedia, the F4F-4 had a relatively late-development P&W R-1830-76 engines rated at 1,200 hp and the FM-2 simply had a more powerful Wright R-1820-56 rated at 1,350 hp.