took apart and rebuilt 2 of least damaged of the 5 known engine couplers Bill Tenney used to couple 2 Anzani 250s to run C Alky? or D? in the NOA back sometime in the 1960s. I never seen anything like them. They again now run so smooth you can easily rotate them either direction with your thumb and forefinger doing the twisting. There is nothing inside or out indicating who or what company built these twin engine couplers though its obvious they look custom built. What is so cool about them is that you can set the twins to fire cylinders at whatever degree per multiple cylinders you divide by, right around the degree clock by gear measurement meshing points. With Anzanis there is no way to tell if he ran the twins firing each engine 180 degrees part in pairs or set them to fire alternating and firing at every 90 degrees of rotation?

What is really eye popping is the pre-cut and pre-punched for drilling 9/16 inch thick adaptor plate to fit 2 of some size of Merc 4 cylinder between 30 to 40 and 44 cubic inches as twins like the Anzani 2 bangers, but it was never drilled and finished. Eight cylinders of Merc with 8 stacks configued exhausting rearwards? Lifting an Anzani twin block C Alky is one thing! I was told by old hands that they were very heavy and went very fast. What about a 8 cylinder (twin coupled) Merc? Ouch! Class F? or old Class X?

Does anyone out there recall any information on these couplers Bill Tenney used?? Who was the daredevil NOA driver and on what?