Author Topic: M20 stuff  (Read 1802 times)

Offline tombeau

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M20 stuff
« on: 22.02. 2011 07:37 »
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

Online Brian

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Re: M20 stuff
« Reply #1 on: 22.02. 2011 08:41 »
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".

Offline andy2565

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Re: M20 stuff
« Reply #2 on: 22.02. 2011 09:14 »
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.
near wolves uk,will keep riding as long as can stay upright,tribsa,tt500,2xJAP grasstrackers+jawa.gold flash.triumph metisse,and others.

Offline LJ.

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Re: M20 stuff
« Reply #3 on: 22.02. 2011 09:15 »
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!  *angry*
Ride Safely Lads! LJ.
**********************
1940 BSA M20 500cc Girder/Rigid- (SOLD)
1947 BSA M21 600cc Girder/Rigid-Green
1949 BSA A7   500cc Girder/Plunger Star Twin-(SOLD)
1953 BSA B33  500cc Teles/Plunger-Maroon
1961 BSA A10  650cc Golden Flash-Blue
1961 BSA A10  650cc Golden Flash-Red

Offline BSA_54A10

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Re: M20 stuff
« Reply #4 on: 08.05. 2011 12:27 »
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
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