Forum

[Thack]

Presto writes: "At 5000 rpm the flywheels complete 83 full revolutions a second; the piston makes 166 full strokes a second; each second the piston comes to a dead stop 322 times; the piston accelerates from zero to 50 ft/sec in less than 1/300th sec; in less than 1/150th sec the piston accelerates from a dead stop to over 35 mph and decelerates from 35 mph to a dead stop again within a distance of only 90 mm (3½ inches); the valves will be fully open for no longer than about 1/1000th of a second."



Yes, but so what? How does this help us decide on a good cruising speed for the iron barrel?



Personally I think the iron barrel engine is a piece of junk (yes, I owned one), and although I've no idea how close the various bits come to their stress limits, I'm inclined to think that a 1950s design would be best suited to 1950s driving speeds.

[Presto]

Thack, I wasn't pretending to 'help' anyone with those figures. I was just wanting to tell it for the 'fun' of it! But no problem if those figures do nothing for you - for me they are almost fantastic, that our primitive little engine is working so hard to take us down the road at round 45mph! Happy day!

[Presto]

As for the engine being 'a piece of junk' - everyone to their own view on that bit of subjectivity!

[Thack]

Fair comments, Mr Presto!

[PeteF]

I didn't say you couldn't blow 'em up. Just more difficult

[devon john]

Cafeman i understand what your saying but such things as 30 -40 limits need tobe keeped to so a speedo is a good idea !!!!

evan if the bullet ones a very optimistic,,, mine at 70 the sat nav says 60 ..

but as you say the bike has a sweet spot and you don't need a speedo to find it ..

john