Most Powerful Recip Aircraft Engine

[MIflyer]

5000 hp at 7755 cu inches and 6000 lb weight. Compare this to a P&W R-4360, 2800 hp at 3600 lb.

I think I have seen this engine in the Smithsonian.

 

[SaparotRob]

The tune-ups on that thing had to be a nightmare.
BTW how much does your Ercoupe weigh?

 

[MIflyer]

1240 lb max gross weight. Calculated weight is about 800 lb. Actual measured weight is about 900 lb. We are still looking for the stowaway.

 

[Joe Broady]

Compare this to a P&W R-4360, 2800 hp at 3600 lb.

It's true the original idea was to introduce the R-4360 at 2800 hp. But according to G.E. Armbruster ("History of the R-4360") it never happened because the new engine soon showed itself capable of a 3000 hp rating. Eventually the R-4360 had a 3800 hp rating in the C-124 with single stage 2-speed blower and B-36 with turbos. I'm sure its power could have been pushed higher had there been a customer demand. Armbruster says an engine taken from production was run at 3000 hp for 100 hours, 3500 for 50 hours, and "in excess of 4400" for 20 hours. Peak power reached in this test series was 4850. On disassembly "this engine was still in serviceable condition."

His document has no date, but it seems to have been written early in the Wasp Major's career. For instance, he says, "the most recent airplane to fly has been the giant Consolidated Vultee XB-36 ... at the present time 100 of these airplanes are scheduled to be built." The high power test runs occurred "about one and one-half years ago." He doesn't say which dash number was in the test, only that it was "not in any way similar to the more fully developed R-4360-35 now in Production [for the B-50]."

Pratt & Whitney Wasp Major (R-4360)

 

[MiTasol]

A couple of other high power piston engines

Dobrynin M-250, VD-3TK, and VD-4K Aircraft Engines 4300hp from 59.5L/8760 cu in. This one made production

Napier Nomad Compound Aircraft Engine 3125hp from 41L/2500 cu in. Flight tested

Yakovlev M-501 and Zvezda M503 and M504 Diesel Engines 6,000hp from 143.6L/8760 cu in. Mass produced as a marine engine.

 

[MIflyer]

On disassembly "this engine was still in serviceable condition."

The Lockheed Super Constellation used four R-3350 rated at 3200 hp each. On the other hand, it was known by some as "a three engined airplane with four engines." A retired USAF General I know described catching airline flights from DC to LAX in the 50's, leaving while it was still dark and then having the Sun come up over Arizona and looking out to see how many engines they still had running. A friend of mine who was crew on EC-121's out of McDill, looking for traffic between Cuba and Latin America in the 60's, and shutting down two engines to increase their loiter time.

The R-4360 was on the Boeing 377 Stratocruiser and the KC-97, rated at 3500 hp. Maybe it was more reliable than the R-3350, but a Phd who had been an enlisted maintenance on the B-36 said there was a long running argument as to whether the airplane used more oil than fuel.