Tri Cub engine mount

[Threebone]

Gentlemen,
I recently acquired a Sperry-Rand Tri Cub. It's pretty complete except for the engine. I tried putting a 5HP Briggs on and discovered that a previous owner modified the engine mounts. Does anyone have a photo, preferably with dimensions of what this should look like and where/how the engine should line up?

Much thanx!
Steve

 

[Cuda54]

As long as the chain from the clutch and sprocket is straight you should be fine.

 

[wildman]

Unlike most minibikes and trikes with 1-piece plate, the Tricubs had 2 strips that made up the engine mount. The photo is the Sperry Minicub frame and this frame is essentially identical to 5hp Tricubs. I modeled the 8hp Tricub frame in CAD. I can provide the dimensions from this, but I'm not 100% certain that the engine bolt pattern is exactly the same as 5hp Tricub and Minicub.

Lets see some photos of your project.

 

[wildman]

I modified my 8hp Tricub frame model to reflect the 5hp configuration. I don't have any bare frames around here so the 5-7/8" dimension is based on actual measurement to the bolt on an installed engine and it's position in the slot is not known. If you end up making new strips or a plate, I'd make the slots a bit longer because you need some adjustment to fine tune the crankshaft to jackshaft center distance to match the torque converter std belt range. Also note that the top of the mount strips are not flush with the top of the side plates. They stick up about 1/8". All these details could affect the shaft spacing .
I also confirmed that Briggs 5hp bolt pattern is 3-1/8" x 6-3/8" and 8hp is 3-3/8" x 7-5/8".