Alright. So, I haven't sold my Merc engine and gearbox (and I probably didn't really try that hard either). So I think I'm going to use them still.

I need a way to make this engine transmit it's power to the gearbox. They bolt together bellhousing wise, but they were never made to come together as a unit. So I'm not really aware of any off the shelf flywheel and clutch assembly combos that work properly. Plus I'd like a lightweight flywheel and clutch assembly as well.

First off, clutches. Both of the following clutches would be overkill for my intended naturally aspirated engine and probably won't be so flash for driving on the street (which would be limited anyway), especially with a light flywheel . However, they are very cheap even though they might need relining of the clutch discs and the plates and pressure plate might need work. They both have 26 splines, but might not be the right diameter for the input shaft as well.

But, they're light and they're smaller diameter which is a consideration for the flywheel (below)

Twin Plate





Triple Plate




Secondly, flywheel. I'm thinking of keeping the existing automatic flex plate with ring gear (It's steel/iron, but is full of holes and probably not too heavy) and making an aluminium flywheel.

Any reason I couldn't make the flywheel myself and then get someone to balance it?

The bonus of using one of the above clutches, is that I wouldn't require a steel friction insert, as these both have a bottom friction plate. And secondly, I could make a flywheel small enough that it would actually fit on my lathe at home.

I also need to make allowance for a support bearing for the gearbox input shaft in the flywheel itself as the gearbox is short nose. Like below.




Am I not considering something?