Twin 67/80 Mono

[brad]

I have one haven't really had the chance to get it wet (have had it for at least 10+ years)

 

[brad nichols]

Would like to see a video of it running!! Looks very interesting.

Brad

 

[charles siler]

Be nice to see some videos. Thanks Charles

 

[Andy Greene]

Be nice to see some videos. Thanks Charles

I have a bunch of Jerrys running somewhere in the files- my favorite is whn he added steps and ran in twin rigger , DO NOT let him get lane 1, you wont catch it

 

[John Finch]

I designed the first Twin Craft mono as a twin engine hull because there were no hulls available at the time. I had been running a sightler 50 inch mono with twin OPS 65 engines before making the twin Craft at 56 inches in length. I set the oval records with the boat and it was a monster. Folks at the 1986 Internats called it a bathtub but it took the US1 and first in ovals. I then worked on smaller hulls for twin engine use. The 50 inch version at 13 inches width was the most awesome. I ran surface drive right out the transom with x470 props. I tries every hardware combination imaginable, counter rotaion, twin rudders, etc. Still have the notes on how everything worked. Counter rotaion was ok but same rotation worked better because with counter rotation the boat had no torque direction to stabilize with. The boat would rock a slow side to side in the straights with sub surface drive because it was basically floating on the two props with nothing to hold it from rocking. Settling the hull into the water with surface drive took care of that problem. Cornering is another whole thing. With counter rotation the boat does not have both props dragging the transom around the corner so it take an extra long rudder extension or twin rudders to accomplish a linear turn. Back in the 80s they didn't have the large servos we have today. I used a servo out of a robot or missle or something. It took a 7.2 volt R/C car battery to run the motor in it. Same rotation props makes turning a lot easier. I have had about at least 6 twin monos I can think of right off hand. The best was the 50 inch boat with twin rudders outside the props tilted somewhere arount 7 to 10 degrees outward with surface drive and x470 props same rotation. One servo on each rudder.

 

[John Finch]

Tip on engines..........two engines on the same mount, if using a large carb, may not run well. Intake tube resonance is disturbed on the first engine after the second engine is started. I used to have to go down on carb opening size when using one mount for both motors or they just would not both run. OPS 65s were fine. The OS max 65 with the larger 8b carb would not run on the same mount. Chased that problem for a year or two before figuring it out. Use a center stringer with two separate rubber isolated mounts!

 

[NAMBA860]

My twin gas mono

 

[Danny King]

Nice tight fit.

 

[Steven Bryant]

Very nice, who makes the inline zenoah engines?

 

[Tom Foley]

Andy , $1400.00 for engines and pipes , then two tanks to fu.. with , come on man !!! With just a single you were ready to be committed to an asylum LOL !!

 

[David Ashcroft]

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