Originally Posted by Dom
Thanks for all the helpful advice, I've been a bit worried about the timing myself so now I think I'm going to go fit a timing chain between the two engines on the right side so that both clutches are still used with one big chain on the left as I'm not sure how well one clutch would take the extra power.
i realize now the cranks must be fixed together! not the output sprocket or the clutch.
so stack the engines like you have done allready and weld a sprocket to each small bevel gear. thus a chain to connect the two added counter shaft sprockets locking it at 180 degrees.
like this a single carb will be excellent.