The Wright 3350 that was on our DC-7.See the wheel in first 3 rd. of photo.. That is a P.R.T. Power Recovery turbine.

Turbocompounding added about 550 horsepower at take-off power and 240 horsepower at cruise settings over a similar non-turbocompounded R-3350. These power increases were achieved with a weight penalty of about 500 pounds. Operation of the PRTs is fully automatic.