[SEL] BSA 420cc Engine

[Jerry Evans]

At 06:00 PM 16/08/2009, you wrote:
>Date: Sun, 16 Aug 2009 15:37:47 +1000
>From: "Domeney Brothers" <dombros2 at clearmail.com.au>
>Subject: [SEL] BSA 420cc Engine
>
>Hey there all out there in engine (and tractor) land,
>Can anyone advise me of the bore diameter of the BSA 420cc industrial (not 
>motorbike) engine, please?
>Were there two models? I see some websites mention two, but they do not 
>specify the difference.
>As always, all and any assistance will be gratefully received and appreciated.
>Teddee.

Hi Tedee,
         There is a manual available on Paul Evans's site:
<www.internalfire.com>
         for a small donation that goes to a good cause.
         It is described as a "BSA Portable Industrial Engine" and the 
manual describes a 320cc engine - I see no reference to a 420cc engine but 
Peter has a lot more knowledge of these things than I do.
         Peter, could a different shape piston account for 100cc on this 
size bore?

         Tedee a friend of mine has a beautifully restored one here:
<http://www.oldengine.org/members/evans/gb/bsa.jpg>
         He has mounted it on a raised stand - the engine is mounted on 
this stand on a single vertical shaft supported on a roller bearing. The 
result is that the whole engine rotates slowly on this axis as it is 
running. It looks like one of those adverts where the camera rotates around 
the subject. A bit hard to describe in a few words but it does attract a 
lot of attention from spectators at a show.

Keep the revs up (or down)
Jerry Evans
Near Johannesburg in Sunny South Africa.
Etched Brass Engine Plates made to order:
<www.oldengine.org/members/evans/plates/index.htm>