This may have been covered before,(what hasn't) but, can anyone tell me anything about the Rojett 67 Long Stroke. I am specifically interested in the side exhaust version,(if it exists).

   I picked up a ROJETT .76 &  .67 RE     I run them both on a Header Baffle no pipe setup . I use a high pitch prop . I use an APC 12-7 . I opened the venturi to .205"  it starts first flip runs like an electric motor smooth. Wide power band . I will get another this month. I cant tell the difference between the . 67 & .76. Not as powerful as my PAs but powerful & easy to use. They are physically identical. 12.6 ounces without header.
     John

Those PA's must have been seriously powerful.

  A 12-7 with an in-flight revs of around 8500 isn't much prop for a 67 or 76, so he is nowhere near the limit. People have run that on an stock ST46 in hot weather. Sounded bad on the ground but OK in the air.

    I think most people running the 76 on a muffler wound up with something like a 14-6 and 15-6 would not be out of the question (as far as the engine goes). PA75, I would expect about the same but maybe even a 15-5 2-blade. I have run 13.5-3.75 3-blades at a launch RPM 0f around 9700 on the teeny little RO-Jett 61. Engine didn't mind that, but my right wrist did.

  No one is coming close to the limitations of these engines because you run out of tolerance for larger props long before the engine runs out of capability. And in any case, larger diameter is the '70's way of defining power.

   Brett

  I picked up a ROJETT .76 &  .67 RE     I run them both on a Header Baffle no pipe setup . I use a high pitch prop . I use an APC 12-7 .
     John

John, is the Rojett 67 more economical on gas than the 76.

   Hi Mr. Proparc , my .67 & 76 use the same amount of fuel. I think its 5 ounces for over 7 minutes, that's in a solid 4 stoke the whole flight , very little break in maneuvers. 

    15% All synthetic