Alpha Motor

[rarpos7]

I have this Alpha motor that I know little about. It came to me in a Cotton motorcycle. The serial number is CAA 16.
Can anybody give me some assistance with information?

Thanks,

[Brian Thompson]

Here you go Ross, some good info from John Wood's excellent website to get you started. The Alpha singles are mentioned further down the page....

http://www.alpha-centuri.info/

Brian.

[rarpos7]

Thanks Brian, That does give some broad information, but not much about my specific engine.
The barrel looks like a Dot unit, but I am unsure.

Cheers,

Ross

[John Wakefield]

Barrel and head looks to be Parkinson according to this thread, and comment by Dick Faggetter https://www.greeves-riders.org.uk/fo...-s-this-barrel

[Dogsbody]

Pete Bates has a couple of Alpha Centauri and knows more about them than anyone I know. PM me I will try to find his email address.

[IanCordes]

According to page 31 of the Villiers Single Improvements Handbook by Rob Carrick & John Wood, it fits the description of a Marcelle barrel & head. The outside fin on the Parkinson head is flush with the edge. The Marcelle outside fin is 'set in from the edge with a large V slot in centre'. That is quite distinctive. The Parkinson barrel has seven fins while the Marcelle has, like yours, eight.
There is an interesting section on the Alpha engine in Roy Bacon's 'Villiers Singles & Twins', p20-22.

IanC.

[trialrider17]

It is a Marcelle head and barrel.
the first pictures are of a Dot Marcelle and the other picture is my old Sprite with a Parkinson head and barrel.
Simon

[IanCordes]

That's it Simon, the differences are clear. That is what you said on the other thread that Colin posted, which John linked to.

I rather like the look of that Dot.... Not that your Sprite is not very nice too, of course!

Ian

[rarpos7]

I should have looked at my Dot machine. The barrels are very similar, as are the other two barrels on my shelf.

[sherpatensing]

I have an Alpha engine currently fitted in my 1961 MCS. The engine number is CAV M16 so not that different to yours. It is likely that the ‘A’ may denote Alpha, and the ‘V’ Villiers. Mine uses a Villiers gearbox and primary cases whereas yours uses Albion?? Hence CAA??
I don’t know what the ‘M’ denotes and yours doesn’t have it..!!
Mine has a Stefa mag and Greeves square barrel which has had the ports ’tidied up’.

[John Wakefield]

'M' may denote Marcelle

[rarpos7]

I think that the CAA stands for C ? A Alpha A Albion. I have another Alpha motor prefix CAV85 which I think denotes C ? A Alpha V Villiers.