My 1-ton lists the net horsepower on the door post as 78 at 3300 RPM IIRC. These were developed in the 20s and 30 and by the 261 days they claimed to coax 150 hp at 4000 RPM for 1962. Olds was the first to use turbocharging on the 215 ci aluminum V8. I think that was about '63. They advertised 215 hp. There was a Buick version of that engine too, perhaps without the turbo. Eventually the design was sold to Rover and appeared in their 3500 model.
At the same time Chev was developing its inline 6s, Curtis Wright along with Pratt & Whitney were developing the multi row radial aircraft engines in the 20s and 30s.The last of the reciprocating aircraft engines on airliners had a scheme to return exhaust energy back to the prop. Curtis Wright built these supercharged 3350 cu in, 18 cylinder monsters with a sort of reverse trubocharger in the exhaust system. Pratt and Whitney built what were known as Corncobs, four cylinders deep and 7 around at 4460 cu in. When you look at the plumbing you can see why airlines went to jet engines. There is one at the Museum of Flight in Seattle.
The radial engines I had any experience with 50 odd years ago were Prat & Whitney R1830s. They were a supercharged 14 cylinder radial, ubiquitous on assorted aircraft used in Viet Nam, DC3s, C47s and many others. They leaked enough oil to pose an occasional fire hazard. The corncobs were even worse, notorious for that. At least a 216 leaks out the bottom rather than starting fires.
Stovebolts were produced concurrently with the radial aircraft engines. By '57 Boeing had the 707 jet in production. And by 63 GM had a new L6, the 230/250/292. GM was a little slow on the uptake perhaps but then a Stovebolt was a good deal more reliable than the radial piston engines pushed to the technological limits in their final years.
