The sound of an old Detroit Diesel is something to behold. It has the most distinctive sound of any engine in any vehicle. I’m sure it is due to it’s two stroke design, and the reason for the nickname “Screaming Jimmy”
It is a rare thing to see a two stroke Detroit now a days, but the 12V71 is one of the most rare. Of the trucks with open hoods, I saw 3 of them at the 90th Anniversary of Hayes Trucks in Port Alberni, BC over the July 1st weekend.
With an old Detroit it’s easy to figure out the displacement. A 12V71 is a twelve cylinder in a V configuration with 71 cubic inches per cylinder, so, it is an 852 cubic inch engine. The horsepower rating is harder to figure out, but without turbochargers, the 12V71 has a factory rating of 450 hp..
Introduced in 1057, the 71 Series was one of the most popular engines in the 1960’s and early 1970’s, with 6, 8 and 12 cylinders being used in various sizes of trucks. In 1974 the 92 Series was introduced bringing the 6V92 and 8V92 into popular use on the nation’s highways.
Hayes also used Rolls Royce engines in some of their trucks.
This P16 Pacific is powered by a Cummins Signature 600. The 600 hp. engine is probably a later repower. Many of the trucks at the show were also powered by Caterpillar engines but I missed getting an under hood shot of one.
In the best light…