Oddball engines and prototypes

[WilDun]

O yes, it's a wonderful layout if you want to put one cylinder of an air-cooled V-twin right behind the other .

The Ariel Square Four also comes to mind with two air cooled cylinders directly behind! - lots of little eccentricities (spellcheck never said a word!) and exceptions in all sorts of engines.
Someone told me that the in the old VW flat 4, the ignition timing had to be different to the others in one of the rear cylinders.

[husaberg]

The Ariel Square Four also comes to mind with two air cooled cylinders directly behind! - lots of little eccentricities (spellcheck never said a word!) and exceptions in all sorts of engines.
Someone told me that the in the old VW flat 4, the ignition timing had to be different to the others in one of the rear cylinders.

Sharing the exhaust ports on the first two versions ohc and ohv version wasn't a receipe for instant success either
I know a guy who had three MK2 at once. (he likely still has them)


Less well know was the 18 Degree OHC V4 matchless the Silver Hawk.
Matchless Silver Hawk

https://en.wikipedia.org/wiki/Matchless_Silver_Hawk
Check out the rear suspension 1930.

[Grumph]

I remember an article in an Aussie magazine written by a guy restoring a Silver Hawk.
The cylinder block is one piece and weighs, well, a lot apparently - cast iron of course.
When assembling the pistons into the bores, angled bores remember, he found it pretty well impossible to do.
From memory he finished up laying the engine on it's side, blocking the barrel up to the right height - and getting help....

[guyhockley]

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New edition of Classic Racer has an article about a replica of an Alpha 250 twin in a Ducati frame built by the brother of John Kirkby who raced one back in the 60s. Mainly pictures, no real technical information. Pretty bike but no silencers so I guess it's not going near a track. Has a "Mick Hemmings lightweight gearbox", probably would have been Albion or Villiers originally, I would have thought. Single Gardner carb twisted to almost horizontal with the float chamber quite a way behind it, could be a source of fun and joy, I would think...

[WilDun]

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...... replica of an Alpha 250 twin in a Ducati frame built by the brother of John Kirkby who raced one back in the 60s. .........Single Gardner carb twisted to almost horizontal with the float chamber quite a way behind it.........

That one (ie with the inboard disc valves fed by one carb ?) came up not so long ago (on the ESE thread?) and I think Husa supplied some pictures (before and after) it was burnt along with a lot of other precious stuff when the premises went up in smoke) so at least it hasn't all been lost by the sound of things!

[guyhockley]

The article says that he was charged £325 in 1968 for the engine (and had to promise to win his first race!). 3 months later, Alpha were taken over by Smiths Industries who cancelled everything to do with racing and ordered all speed and engines to be scrapped. He had to return his engine to Alpha and was paid back £150...
In 1991 he started classic racing on a TD1 and looked around for another Alpha.
"Eventually one was found (the original prototype engine) and purchased.
It had escaped the crusher by being buried under a coal heap..."
That's according to Classic Racer, but:
http://www.villiers.info/Alpha/index.htm

[WilDun]

"Eventually one was found (the original prototype engine) and purchased.
It had escaped the crusher by being buried under a coal heap..."

Very thorough article on the Centuri - basically answers all the questions I would have liked to have had answered 50 odd years ago, that engine was one I would been happy to have seen being successful.
I guess Smith's is the same company which does the Smith's racing Triumphs today and about to produce the racing triple engines for Moto2.
Pity they were unable to make a success of the Alpha, but obviously they must have known what they were doing, being able to stay in business - unlike most of the other British companies, but I'm sure they didn't just concentrate on bikes!

[tjbw]

...

I guess Smith's is the same company which does the Smith's racing Triumphs today and about to produce the racing triple engines for Moto2.

...

I had assumed it was Smiths Industries who bought Alpha. You've probably used their speedometers on your British bikes. They also make instrumentation for cars and aircraft.

However I just checked, and it's a different company:

http://www.gracesguide.co.uk/E._and_H._P._Smith

Smiths racing is sponsored by yet another Smith company:

http://www.smiths-gloucester.co.uk

[WilDun]

It becomes a bit hazardous to make assumptions or jump to conclusions with names like Smith, Brown, Jones etc!

[Grumph]

All this talk of Villiers conversions is giving me ideas for an update on my 197 special...

I've even found a period watercooling conversion writeup, done on a 9E. Can hide a lot of mods under a waterjacket.

[husaberg]

All this talk of Villiers conversions is giving me ideas for an update on my 197 special...

I've even found a period watercooling conversion writeup, done on a 9E. Can hide a lot of mods under a waterjacket.

What frame Greg?

[guyhockley]

With that user name it should be a Greeves (that previously had a Triumph engine in it?).
I presume this is known about.

[husaberg]

With that user name it should be a Greeves (that previously had a Triumph engine in it?).
I presume this is known about.

Brian Woolley built a square bore and stroke or maybe oversquare water cooled 250 with Bert Greeves blessing unfortunately the cases and cylinder were porous.
Edit it was a Disc Valve as Well. Last page
By the next year the Yamaha had become that dominant that it was not worth while making new ones.
https://www.kiwibiker.co.nz/forums/a...3&d=1322903848
https://www.kiwibiker.co.nz/forums/s...post1130207683

[guyhockley]

Rarer than a Ryger?
Definitely oddball. Homologated in the 70s but wonder if anyone actually ran one.

[tjbw]

Rarer than a Ryger?
Definitely oddball. Homologated in the 70s but wonder if anyone actually ran one.

Yes oddball indeed, 4 overhead exhaust valves, reed crankcase inlet. It started life as a McCulloch mac 101 123cc two stroke engine.

http://www.vintagekartscollection.co...ulloch-miracle

My guess is that it's a uniflow two stroke. In which case the exhaust cams are set so only 2 valves open for each exhaust activity.

Here's a pic that TZ posted on ESE in 2011