I've had the idea of installing two engines in a side by side configuration. I know this has been done before, and was wondering if any of you knew exactly how this was done, or if you have any ideas on how it could be done.?

I was thinking of having the two engines seperatly attached to the same box/flywheel (in a kind of pallerel connection). the other way of doing this would be by having one engine crank attached to the 2nd engine crank and then this engine attached to the gearbox in the normal way ( series type connection).
I was thinking of doing it the pallerel way as the series way, although easier, would mean that i would twice the amout of power going through one crank shaft.

What do all you experienced guys think out there?

Is it doable without spending a fortune?

Cheers, Marcus