An Opinion

That was extra.

The lightweight airframe (and pilot) would tend to spin, along with the heavy engine !!!
This made maneuvering near the ground somewhat precarious, if you were upside down and trying to revolve at the time.
All the while remembering to blip the magneto switch, to keep the speed under control...
 
acotrel said:
I once ran into a friend of mine at a race meeting, whom I hadn't seen for a long time.
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acotrel, the most dangerous person on the track! :lol:

acotrel said:
With only 50 BHP, you don't have the luxury of making up time on the straights, it is more about cornering than it is with modern bikes. These days the manxs have trick suspension, great tyres, six speed boxes, extremely reliable motors with perhaps 5 more BHP, so it might be a bit easier.
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You are looking at more like 10 more BHP with the Molar Manx and I cannot see how it would not be easier BUT not easy.


acotrel said:
The IOM is dangerous, there is too much of it to be committed to memory.
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No disagreement on the danger but the memory is a matter of time and repetition. Having to deal with 37 miles for one lap is a lot. I seem to recall reading about Dave Roper's experience leading up to his win there. If I recall correctly he spent a fair amount of time cruising the roads off season on a Commando.

I recall my first time at Sears Point, California with the rises in the track leading into turns it was all blind until over the hill and then you see where you had to go. I joked to myself saying I would close my eyes, count to three and open them and then I would know which way to go.
 
acotrel said:
Rohan, Every time a piston goes up the bore of an engine, it reaches the top and reverses. Inertia has a major effect. One of the biggest things you can do to improve engine performance and reliability is to fit stronger but lighter pistons. That is why forged Mahle pistons are used in 500cc Jawa speedway engines. Getting weight off the little end is a good thing.
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+1

A heavier piston offers nothing but more stress and strain on the engine components. If you want to conserve energy in an IC engine then do it through a rotating mass (aka flywheel).
 
Old belt drive Triumphs already have a heavier crank than a Commando.
Apparently they don't chuff up hills as well with a lighter piston. ?

If I ever get this thing on the road, have a few pistons to experiment with.
Engines that are more related to traction engines don't have a lot in common with modern stuff. ?
You set the fuel/air mix (separate levers), and then adjust your speed with the ignition timing.

I just heard of someone that is remaking Phillipson pulleys, Oh joy. !
Although that is a later invention than this thing, it was a commonly fitted accessory.
Gives you slightly variable gearing, and sets itself automatically, more or less.
 
People sometimes have some funny ideas about what designs will work. I never believed in the long stroke commando engine until I raced mine, the torque is great - the bike is very versatile. I know of a young bloke who fitted a gardiner diesel truck engine into a Ford Falcon expecting great results. - Did not happen, the car was a hopeless slug. Might have needed an extremely high ratio diff ?
So what you see is not necessarily what you get. You can only try, then observe the result. What I do know is that if you fit lighter pistons into a modern motor, you can feel the improvement in acceleration. - Might be related to the usable rev range ?
 
A low revving diesel engine will never be suitable for a car or bike as they may produce a lot of low down torque; you really require both torque and an ability to rev when it comes to going uphill and down dale on tarmac.
Someone once adapted a VW diesel engine with a turbocharger and entered rallies; the high revs the engine achieved put it almost on par with the equitant size petrol engine.
 
Rohan said:
Apparently they don't chuff up hills as well with a lighter piston. ?
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Glad you added the question mark as we are asking the same. Besides, I did not realize until now you were referring to the performance criteria of "chuff up hills". In this instance one might consider thick crown and thick skirt pistons made out of tungsten alloy, Mallory metal or better still, depleted uranium.
 
acotrel said:
I never believed in the long stroke commando engine until I raced mine, the torque is great - the bike is very versatile.
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My belief here is that it is the confluence of relatively low rod to stroke ratio, a long stroke and superb head flow. Oh and light pistons. :p
 
Dances with Shrapnel said:
Glad you added the question mark as we are asking the same. Besides, I did not realize until now you were referring to the performance criteria of "chuff up hills". In this instance one might consider thick crown and thick skirt pistons made out of tungsten alloy, Mallory metal or better still, depleted uranium.
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The ? was because I haven't tried it for myself.

Veteran Triumphs run very well - they were very successful back in those days, sold in quite large numbers (compared to all other makers),
and were a very widely copied engine design.
And their heavy iron piston needs no sarcasm from you to perform very well either.
And won the 1908 TT, to prove it....
 
Dances with Shrapnel said:
acotrel said:
I never believed in the long stroke commando engine until I raced mine, the torque is great - the bike is very versatile.
Click to expand...

My belief here is that it is the confluence of relatively low rod to stroke ratio, a long stroke and superb head flow. Oh and light pistons. :p
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Since the Atlas is almost the same motor, and didn't get the same press,
we'd have to ask if the cam and the isolastics perhaps played a part here ??
 
Bernhard said:
A low revving diesel engine will never be suitable for a car or bike as they may produce a lot of low down torque; you really require both torque and an ability to rev when it comes to going uphill and down dale on tarmac.
Someone once adapted a VW diesel engine with a turbocharger and entered rallies; the high revs the engine achieved put it almost on par with the equitant size petrol engine.
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Thats funny ? - don't BMW and Audi currently have a diesel engine as their top of the line model.
Including wins at LeMans to back it up.
DAF got around that by their infinitely expanding pulleys belt drive system.
Mercs have had diesel engines in cars for generations.
Their tachos don't go very high...

Whather you'd call them low revving or not is another question.
But they don't use the same tacho or gearing as the petrol engines...
 
It'll never sell.
Unless it also dispenses beer...

Ride a Commando, a time machine to take you back 40 years.
Ride a featherbed Dommie, a time machine to take you back 55 years.
Ride a Model 7 Dommie, a time machine to take you back 65 years.
Ride a flat-tank 1920s Norton, a time machine to take you back 85 years.
Ride a v-twin 1907 Norton, take you back 100+ years.
Are we seeing a pattern here ?

Oddly ?, there are replicas of that 1907 beastie out there, on the road.
Some folks have it figured out... ?
 
So which pilot has the hardest tasks, 1098 Duci or 1907 in todays traffic? Rush hour or middle of the night?

The coolest example I saw of Norton single chugging power was of the total loss oil type ya set the throttle by lever, loaded with pillion let out the clutch or release or what ever and instead of heading down the road aim straight up a steep grassy hill immediately as set engine speed and merely sounding a bit louder w/o hardly any slowing or bogging = just took right off like nothing to it. Of course couldn't keep that pull faster d/t hp limits.
 
hobot said:
So which pilot has the hardest tasks, 1098 Duci or 1907 in todays traffic? Rush hour or middle of the night?
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Obviously you have to pick your road and your time - Sunday afternoon say, keep off the main roads.
Not many pilots of old bangers use them 100% of the time...
 
With a Belt Drive , a Siren & Flashing Lights should clear the Traffic , so as not to get stopped . these days .
 
The CanonBall run is cross many states and only allows pre WWII bikes IRRC. Most of em make it too, eventually, but we already knew that.

In a way this thread applies to Ms Peel, but in reflected inverse way, as I think the moderns are disadvantaged hard athletic effort dangerous unpredictable corner cripples, so part of my hobby goal is to make those modern rocket ship hot shot pilots feel the same way I do about their steeds. Peel is only 40 yr old design not as ancient as Manx's.

[video]https://www.youtube.com/watch?v=GhvI-dBuZoA[/video]

[video]https://www.youtube.com/watch?v=GH7y50PDooo[/video]

[video]https://www.youtube.com/watch?NR=1&v=Xd199_H48fk&feature=endscreen[/video]
 
hobot said:
The CanonBall run is cross many states and only allows pre WWII bikes IRRC. Most of em make it too, eventually, but we already knew that.
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Some of them require some serious rebuilding along the way.
That would have an 'extreme sport' event back in their day ?
 
Yes back in the day they'd of had no part supply over here either, at least the over seas brands. I wish I'd known about the collector side of mcyling a few decades ago as a Velocette or old Indian might still be with me on these modern endurance adventures.

I think breakage and engine siezues likely took more toll in the vintage days than now too, so throw that stress on top of rough surfaces on so so tires and shocks and forks. Sounds like a sport for the desperate risk takers few would risk today.

Still most my ridding was on a modern with race rubber and upgrade supensions and after Peel was put to sleep I'd try to take an easy wide intersection, kind of a slightly down hill bowl, like a commute on Peel, to end up freaking out with its front tire sliding and preventing as sharp an ending as I was used too. Some how or another got to combine the best of new and old and see what happens.
 
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