Dating a Sloper engine

[BEVANC]

Hi folks,
Could anyone suggest a likely date for a 500cc ohv Sloper engine with number XW1652  (looks like a 6, but might possibly be 1852). It has been suggested that it could be 1930, but I'd appreciate some guidance on that.

My bike is definitely 1929, which raises another question: were there any significant differences between the 1929 and 1930 engines (I know that the frame was updated, but not sure about the  engine) ?

Cheers, Bevan

[Gadorey]

Hi Bevan,

Your engine Nr is for a 1930 4.93HP S30-12 OHV, and the matching frame Nr should be XX ....

It doesn't necessarily mean your bike left the factory in 1930 - it just means it's a 1930 model year. The model year change for most bike and car manufacturers was done in late summer early autumn to present the new models at the autumn auto shows. For the Brits notably the Autumn show in London. So if you Nr is an early one, your bike could have well been delivered in 1929. As an example my Sloper has engine Nr XP2836 and Frame HL11649 which puts it as matching nrs 1930 S30-13 OHV 2 port de luxe. However it was first registered in November 1929. So, it was a model year 1930, but produced in late '29. I also have a 1954 Ariel Red Hunter that is exactly the same - model year 55, but produced and registered in late 54.

To find out exactly when it was produced and despatched and to whom and where, you probably have to go through the club. You might also find out how it left the factory - colour, options, etc.

As far as differences, there are none as far as I can tell. I have a 29 and a 32 parts manual and most of it is all the same. The frame changed at some point to the forged back bone, but I think that was it. Mine already has the forged top member. The differences were mainly options one could order - 4 instead of 3 speed, foot front brake pedal (mine just has the hand lever), racing pistons and valves and sparking plugs, lighting system, etc.

Hope it helps,
Gui

[JulianS]

XW prefix is for 1930 season S30-12 4.93hp OHV "Sloper"

The 1930 models were produced from late July 1929 through to July 1930. Only around 2300 made.

Original frame with XX prefix frame, with introduced for 1930 season forged top member, like the catalogue picture below.

[BEVANC]

Thanks for the info gentlemen,

The XW1652 engine is for sale, scruffy and missing rockers & rocker box. I was considering buying it in an effort to acquire spares for my S29 (engine P 12434). Price is uncertain at the moment.

There is another engine (P 12174) for sale on our N.Z. online auction site which seems more or less complete, but I fear it will go out of my price range (its already at NZD 2000)

Cheers, Bevan

[JulianS]

Does this service sheet add any information?

[BEVANC]

That's interesting, thanks Julian.