Vintage? Triumph Crankcase Half

I have just been given an old Triumph aluminium outer engine case, which I’d love to identify. Sorry, no pics as I don’t have a camera.

It is essentially round with the word Triumph in a semicircular casting above the centre of the case (which has a circular hole in the centre, the metal from the circle coming up out of the casing.) At the top of the case is a flat section, with one bolt hole at each end. This contains Numbers and Letters stamped into it and this section stands proud of the main circular casting.

Looking at the case, the left hand edge of that flat section is stamped 242276. Adjacent to the right hand bolt hole are the stamped Letters HSA. Behind this ‘numbers’ casting is a largish semicircle which I’m guessing was mated to a Barrel.

Counting those two bolt holes at either end of the engine number, there is a total of Nine bolt holes, with four of them being in ‘flanges?’ on opposite and equidistance sides of the case. Additionally, either side of the centre, cutout of the case, are two bolt holes, one with what looks to be a brass or bronze nut (reminds me of a sump nut). This one is right to the edge of the circular case, whilst it’s oppo on the left is around ¾ of an inch inboard of the round edge of the case. These two holes are ‘blind’ in that they don’t go right through the casing.

This is all the information I can glean from the casing sorry and yep, a picture is worth a thousand words but I don’t own a camera.

Any help from the experts out there will be most appreciated.

Thanks.

No cellphone for pics even?

Nope, I don't even have a cellphone. If I could have, I would have.

Thanks.

If your using a laptop take a picture with that.

Does it look like anything in here:

https://www.google.com/search?source=univ&tbm=isch&q=Triumph+motorcycle+1957+crankcase&client=firefox-b&sa=X&ved=2ahUKEwjQx_Gf-M3sAhUbOisKHUczCOMQjJkEegQIBRAB

Thanks for the Link. Very interesting, it was. If you look at Yeomans Vintage Triumph Spares at
https://www.yeomansmotorcycles.com/Vintage-Triumph-Spares.html
the engine case I have here looks remarkably like the cases Yeomans show in their very first photo of early 1920’s matching engine cases.

I hope this helps to put someone on the right track because I still can’t make head nor tail of why the numbers and three letters are not leading me to the year and model of the case I have.

The only material difference I can see between my case and Yeomans cases is that mine clearly has the word TRIUMPH centred on the top half of the case, below the stamped numbers and that the right side bolt hole on the case has a brass bolt in it.

If it helps any, my case was given to me from a family member in Australia and he at one time had both halves but he lost the second case a long time ago. It was found on a farm in NSW.

Thanks for the Link. I might be the last person in NZ not to have a phone or camera but its never been a problem till now.

Solved. Triumph Model H, approx 1921, 1922 although full build records etc are not available due to Triumph works being bombed and burnt out during WW2.

It was a 550cc single, 4hp, 3 speed Sturmey Archer gear box, chain drive to the front sprocket, belt final drive, produced between 1915 and 1924. Some 57,000 were built and some 3000 were used by the British Army during WW1.

Exported to NZ and Australia, amongst other places so I have the remains of an Australian bike. I don't think I have enough to start building a bike but it has been an interesting and ultimately satisfying search.

Thanks to those who read this Thread and offered comments etc. But I still don't have a camera.

I have the left hand side engine case.

Interesting. They are called a Trusty and aren't uncommon in vintage circles. I have seen 2 in the South Island in recent years. Although the part may be popular
They were the first real Triumph motorbike. No pedals.
I'm assuming the HSA stamping refers to H Triumph with Sturmey Archer gear box.

Yes, they were called the Trusty, but they were not the first bikes they so named. There was a bike before WW1 that first gained that honour.

And yes again, the first true motor bike they ever built, without pedals, which is why a large and noisey section of bike purists in the UK insist that the veteran era end with their last Model because they had pedals and that the Model H was the first of the 'Vintage' era. And their first bike with an integral three speed Sturmey Archer so you are right again. Actually my old push bike was fitted with a Sturmey Archer 3 speed gear lever on the handle bars, now I think of it. And that was a long time ago.

It has been an interesting journey of discovery and my brother in Queensland is delighted to know what it was that he had.