Author Topic: Matchless overhead cam parts  (Read 108 times)

Offline cardan

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Matchless overhead cam parts
« on: June 05, 2026, 01:51:07 PM »
Here's some unusual bits: lumps of a 1920s overhead cam Matchless single, engine number L/R 1618

I don't think I know of a complete survivor in Australia, so I guess they're a bit rare? Or perhaps I don't know much about Matchlesses! Any interest?

(Edit: OK, there is at least one! https://club.shannons.com.au/club/bike-news/old-bikes/matchless-lr2-a-rare-beast/ )

Leon
« Last Edit: June 05, 2026, 01:57:22 PM by cardan »

Offline R

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Re: Matchless overhead cam parts
« Reply #1 on: Today at 12:09:12 AM »
Oooo Aaaah, a rare bird indeed !
It looks a little incomplete to even contemplate - unless you already have most of one !

That engine must be almost unique in having that head 'sideways' like that ?
Wonder if cooling is better that way ??

Offline cardan

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Re: Matchless overhead cam parts
« Reply #2 on: Today at 03:11:00 AM »
I like the head - viewed from above, the angle of the inlet and exhaust ports look to give a nice swirl.

The "sideways" nature of things does seem weird, particularly for a vertical single cylinder. But there was precedent in the sporting ohv Douglas twins, beginning with the Sports model in 1920, running through the Dirt Track and into the 1930s. Like the Matchless, all very sideways! Even earlier was the racing Matchless ohv V twins in the 1914 (?) TT, which used an unusual MAG (Motosacoche) twin with sideways heads. I wonder if the Matchless designers had one of these engines in mind when they began work on the LR in the early 1920s.

The missing bits - particularly all the top end of the valve gear - is certainly a problem, but it's the sort of thing that lurks in sheds as a curiosity, interesting but useless!

Leon

Offline 33d6

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Re: Matchless overhead cam parts
« Reply #3 on: Today at 06:03:37 AM »
I replied to this but my reply seems to have gone missing. I know these engines quite well. I'll hang on and see if my answer pops up otherwise I'll have to type it all out again which I don't want to do if I can avoid it. Watch this space!!! 

Offline 33d6

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Re: Matchless overhead cam parts
« Reply #4 on: Today at 08:30:09 AM »
It hasn't appeared. I'll start again.
This engine never did well, I think mainly due to its dismal lubrication system. Introduced in 1923 it ha the same system as its 350 side valve stablemate. Namely a total loss system that merely pumped oil into the engine to just splash around and hopefully oil everything. In this engine, being of ohc operation the oil line entry was up on the cam gear so you got steady drips on to the valve gear before it theoretically dripped down the cam drive at the cylinder rear to the timing gear train and hopefully after that through in to the crankcase where the big end and piston got what was left. Given the pump was driven as usual practice from down on the timing gear you can imagine how long it took before any oil got up to the cam gear and then started its long drip down to the bottom end. Valve guide lubrication to the exposed valves may have happened on the way through but don't hold your breath. 
It wasn't a happy arrangement and Matchless fiddled around with it for years eventually fitting a duplex Pilgrim pump with the top and bottom ends each getting their own feed.
By this time the factory only fitted it as an alternative 'sporting' engine in their 500ccc ohv single Model V series bikes and this is the version sold by Shannons. The engine did not survive the across the range change to dry sump lubrication in 1930 but that year the new 400cc  Silver Arrow was the Matchless pride and joy. Who needed to be reminded of a dud 350 ohc effort.
I know the Shannons bike quite well. I knew both the original gatherer of all the parts and the next owner who finished it. They were good mates. Both gone now. It would be a very interesting bike to own but definitely one to trear cautiously.