Anybody know the weights on these big blocks ?

PA-75
RoJett-76
K-77
RoJett-67

Just curious how they compare.

A RO-Jett .76 is 360g.-ish with manifold screws...depending on prop washer (not prop driver).    Steve

Don't know if it makes a difference, but I was only interested in the rear exhaust. 
Do the RoJetts 67 and 76 share same case ?

So anyone know the number on the PA-75 ?

RO Jett 67 RE mine weighs 12.8 oz. I believe that the 67 is a 76 case and crank with
61 Piston and liner ,however the 61 liner is thicker than regular 61 thus making more stable run. I reviewed Richard Oliver post on the other forum.
RO Jett 76 Case , crank and rod, 61 piston and new thicker liner making it a 67 Long Stroke. This engine is very steady, lots of torque. Richard
O says it will swing any prop the 76 will. I have the SE and RE love them both. Another big plus is fuel economy. I use Byrons Heli fuel
15% all Synthetic 21% oil. Very smoothe I use the 15% to keep it in the 4 stroke mode. I do not use a pipe,

Interested in more about your 67RE muffler setup.   Prop, venturi size, fuel for pattern, launch RPM.   So no breaking in maneuvers ?

Pete see Stuka Stunt 9/24/2006 " New RO-Jett Coming next Spring 67 LS this is where he explains about the 76 Case, 76 Crank and rod , 61 piston and
new thicker liner for the 67 LS


Alan, I have run mine in the 8000 and below range with the RE on a Custom Scott Dinger muffler with a rather large exhaust outlet and fairly
big diameter muffler. I ran them between 7000- 8000 + depending on the prop. The Airplane was 670 Sq in and weighed about 58 oz.
I used the Discovery Retro Prop 13.4x5.9 when running it in the 7300 rpm range. Very slight break at the top of maneuvers cant hardly
notice it. i used 15% nitro so it would stay in he 4 stroke mode. LOADS of torque. When running it at 8000 +- I used an Eather 3 blade
12.5x5.5 which also worked well. I know that i am not using all the power but I am looking for speed control. I believer that is why
Richard had the engine made as it really governs itself. That is why I used the Yatsenko prop that worked so well on the Retro 60
in the 7000 rpm range. It also has an awesome sound at that RPM. I know this is not the "Pro Set up " but I really like it.
The SE was Run with the Muffler that RO Jett provides with the stinger drilled out as big as I could get it without ruining the engine.



I use all Synthetic fuel Heli fuel Byrons 15% Nito 21% oil and it runs great. Make sure and use a hot plug. RO Jett does not like lots of
Castor. I don't use any as I am not pushing the motor in any way at those RPM. This motor is very versatile and can be run with a higher
rpm lower pitch prop if you wish. The main thing is that it governs itself no runaway even in the wind! So to conclude mine runs similar
to the Retro 60. Notice I said similar not exactly like one. Venture is stock , also used a slightly larger one have to measure it. Hope this helps.

Thanks for the clarification Walter. Makes sense. I was going by what RO posts on the Ro-Jett web site: "This engine will be a long stroke 61BSE using the crank from the 76 to make a 67". Also looking at the description of the 76 he explains the BSE engines are made with a top and bottom case, the 76 being larger than the 61. I take it that the bottom half of the case is a BSE 61, the top a 76 with thicker liner and a 76 crank to make it a 67 (like you said).