M20 stuff

[tombeau]

I know a lot of guys here dabble with M20s.
A mate just aquired a BSA M20 motor from a Clifford Rotovator.
Its quite interesting: alloy "head" with the fins pointing the wrong way, and what we think is provision for a hand crank.
I hadnt come across one before.
He has an M20 so is pleased to get this.
Anyone know of any problems when using one of these in a bike?
Cheers,
Iain

[Brian]

I've never seen one with the fins pointing the wrong way as you describe but the M20 motor was used as an industrial motor in all sorts of things.

Basically the motors are all the same and can be used in bikes.

I have had my M20 for 30 years, terrific bikes. Not the most powerfull thing but dead reliable. I am lucky enough to know the history of mine from when it was sold as army surplus. Here is a photo of mine "before and after".

[andy2565]

japanese engines were similar with the fins going across the head and used in rotorvaters etc,dont see why you cant use it,just change the head from a road bike,spares are still cheep for the m20.

[LJ.]

Lucky man! The barrel is perfect as there is no weathering corrosion around the exhaust port. I was also lucky to get one of these barrels, I'm stuck with the alloy head though, thankfully the normal motorcycle one bolts on okay.

Edit: Here is a picture of the Rotovator type alloy head, complete with all its fins! 

[BSA_54A10]

the fins point the wrong way because it would have had a cooling fan attached to the crank and may or may not have has a cowling to direct the cooling breeze