A different type of aircraft engine

[N941WR]

I seem to remember a very different type of aircraft engine design that was actually certified but can't remember the name of it. (Old age is setting in.) Maybe if I describe it some of you might come up with the name.

The main power shaft (not a crank in the traditional sense) had a thick face sticking up in a radial fashion. Kind of like thick pie plate welded in the center. The "pie plate" was wave shaped and the "pistons" rode on the outside edge. Each piston would drive back and forth, along the same accesses as the power shaft.

If I remember right, this thing was certified a number of years ago (1940's - 50's?) but was never put into production.

Anyone know what I'm talking about?

There was talk about it running very smoothly with low noise and fuel consumption numbers. I think I remember reading it failed simply because it was "different".

[alanrv8]

I think you're thinking of the Dynacam engine.

[Rotary10-RV]

The engine you're thinking of is the Dynacam. It was VERY heavy didn't produce competitive power and was prone to cooling problems. It did get certified somehow, though it never made production. I don't know if they ever sold one.
Bill Jepson

[N941WR]

Only their web site is no more.

A Google search turned this up:

Engines
Dyna-Cam ... High power, low weight, 200 horsepower gasoline engine for boats,
industrial applications, military applications and FAA certified for aircraft ...

I couldn't find any more details than that. No pictures, nothing. It's as if it didn't exist.