Page 87 of 213 FirstFirst ... 3777858687888997137187 ... LastLast
Results 1,291 to 1,305 of 3183

Thread: Oddball engines and prototypes

  1. #1291
    Join Date
    10th February 2005 - 20:25
    Bike
    1944 RE 1
    Location
    Auckland, New Zealand.
    Posts
    2,243
    I would be very interested to know who made the gearbox - normally it would have been Burman, Albion etc. where the input shaft and the output shaft were concentric (quill shaft - direct drive in top gear therefore in theory more efficient) - not the same layout as the modern boxes, (the little "buzz bombs" of the sixties changed all that), because you couldn't have them in top gear for more than a minute at a time anyway! - I do know, I rode one a lot!
    In the case of the layout of common style boxes back in the day however, the gearbox shaft and output sprocket would now rotate "backwards" with the gear primary drive, that's assuming of course that the engine rotated "forwards". - (I'm sure I could have said all that using a lot less words!)
    Did they make their own gears or did some of the gearbox makers do a special one for New Imperial?

    That machine is an example of the direction the British Industry should have been taking - just shows that we don't recognize forward thinking when we see it - until it's too late!
    We get a picture into our "blinkered" heads of what a motorcycle should look like and anything different is considered "rubbish"!
    Strokers Galore!

  2. #1292
    Join Date
    1st May 2016 - 13:54
    Bike
    Vintage 2T
    Location
    Brisbane
    Posts
    431

    Oldy but Goody

    .
    Here's a pic of the Excelsior Two-stroke triple. fitted in a bike.
    Click image for larger version. 

Name:	X32T+bike.jpg 
Views:	37 
Size:	369.2 KB 
ID:	329763 One off, Nice Job. Could do with a triangulated swing arm rear end.
    Interesting exhaust, it's a chrome plated version of the 'standard' system fitted to the later Berkeleys.

    Click image for larger version. 

Name:	engine+sml.jpg 
Views:	31 
Size:	45.2 KB 
ID:	329764 The Berkeley Race Tuning manual recommends many subtle mods to the engine.
    Enlarging & matching the transfers at the cases, adding transfer relief at the top of the pistons.
    Inlet & exhaust ports cleaned up & polished. Carby mods & jetting settings.

    Recommended not changing exhaust port height but definitely fitting the exhaust chamber shown above.
    "A number of cars made during 1951 and early 1958 are fitted with exhaust systems not suitable for use
    with tuned engines. The type recommended incorporates an expansion chamber extending across the
    front of the engine and is prominently marked part No TMB 751 2 cylinder TMB 1115 3 cylinder.

    "This type of exhaust system, which embodies adequate silencing with a minimum of backpressure is
    designed in such a manner that very little carbon wi1l form inside it".


    Of course, general Two-stroke technology still had a lot to learn in the late 50's.

    Cheers, Daryl.

  3. #1293
    Join Date
    13th June 2010 - 17:47
    Bike
    Exercycle
    Location
    Out in the cold
    Posts
    5,626
    Quote Originally Posted by WilDun View Post
    I would be very interested to know who made the gearbox - normally it would have been Burman, Albion etc. where the input shaft and the output shaft were concentric (quill shaft - direct drive in top gear therefore in theory more efficient) - not the same layout as the modern boxes, (the little "buzz bombs" of the sixties changed all that), because you couldn't have them in top gear for more than a minute at a time anyway! - I do know, I rode one a lot!
    In the case of the layout of common style boxes back in the day however, the gearbox shaft and output sprocket would now rotate "backwards" with the gear primary drive, that's assuming of course that the engine rotated "forwards". - (I'm sure I could have said all that using a lot less words!)
    Did they make their own gears or did some of the gearbox makers do a special one for New Imperial?
    Pretty sure it's Burman internals - and the motor rotates backwards too.

    Haven't seen very many crossover sleeve gear (direct top) boxes. Aermacchi and Laverda are the only ones that come to mind.

  4. #1294
    Join Date
    1st May 2016 - 13:54
    Bike
    Vintage 2T
    Location
    Brisbane
    Posts
    431

    Still trying to learn.

    Quote Originally Posted by Pursang View Post
    . Two-stroke technology still had a lot to learn in the late 50's.
    I still do, in mine.

    So back to the original point, put up by Frits.

    Is it possible to use the energy of one exhaust, to boost the power of another cylinder?

    Carefully timed waves from a std expansion chamber system? A third of the length of a regular one, maybe?
    Losses of energy where it needs to divide into 3, and one cylinder is trying to exhaust when another one needs the timed return pressure pulse.
    Might work, if the pressures added at the junction, but will they then go back down the pipe to repeat the process???

    Helmholtz wasn't a lot of help either.

    Can we just build enough pressure in a simple chamber, and hold it long enough to push the over-scavenged mixture back into the cylinder?
    Don't want so much, that it interferes with the scavenge flow from the exhausting cylinder either.

    So are we looking for Pressure, or Energy density or Mass flow or What?

    Need some data.

    Does any-one out there have 'instantaneous' pressure readings, from a chamber of known dimensions?
    These need to have been sampled at 100,000 to 500,000Hz.
    Samples at lower rates will just give averaged results, which won't really help.

    For example, the average pressure in a working two-stroke crankcase is a quite low, positive number.
    (Some 'experts' have even claimed that there isn't enough pressure for transfer to occur.)

    Pressures in a crankcase range in the order -14 to + 30 psi. but they change quickly.

    I want to know what the pressures in an exhaust pipe (not just at the exhaust port) do and exactly when they do it.
    BMW had sensors all over those headers in the earlier pic.

  5. #1295
    Join Date
    10th February 2005 - 20:25
    Bike
    1944 RE 1
    Location
    Auckland, New Zealand.
    Posts
    2,243
    Quote Originally Posted by Grumph View Post
    Pretty sure it's Burman internals - and the motor rotates backwards too.
    That would all make sense - all the gearboxes that I saw (ie pre - 66, before the secondhand Jap stuff had filtered through to us plebs) were the Burman type -
    First new style box I saw was on my 1966 Suzuki T20 six speeder (every gear was needed too, albeit only for a fleeting moment!) That layout was to set the trend right up till the strokers started to disappear (up till today in fact!).
    But changing gear a lot was the cool thing to do in those days!
    Strokers Galore!

  6. #1296
    Join Date
    19th October 2014 - 17:49
    Bike
    whatever I can get running - dirt/track/
    Location
    San Francisco
    Posts
    382
    Quote Originally Posted by Grumph View Post
    Haven't seen very many crossover sleeve gear (direct top) boxes. Aermacchi and Laverda are the only ones that come to mind.
    Guzzi singles too.

  7. #1297
    Join Date
    13th June 2010 - 17:47
    Bike
    Exercycle
    Location
    Out in the cold
    Posts
    5,626
    Quote Originally Posted by Michael Moore View Post
    Guzzi singles too.
    Should have remembered that one - my brother has an Airone 250.

    Can't remember if the Benelli/Motobi singles do too.
    Seems to be an Italian thing....

  8. #1298
    Join Date
    20th January 2010 - 14:41
    Bike
    husaberg
    Location
    The Wild Wild West
    Posts
    11,823
    Quote Originally Posted by Grumph View Post
    Should have remembered that one - my brother has an Airone 250.

    Can't remember if the Benelli/Motobi singles do too.
    Seems to be an Italian thing....
    They likely got the idea of some old pasta machine in the bologna museum.
    supposedly Ducati use a geartooth pattern all of their own.
    Quote Originally Posted by Katman View Post
    I reminder distinctly .




    Kinky is using a feather. Perverted is using the whole chicken

  9. #1299
    Join Date
    20th January 2010 - 14:41
    Bike
    husaberg
    Location
    The Wild Wild West
    Posts
    11,823
    Quote Originally Posted by WilDun View Post
    I would be very interested to know who made the gearbox - normally it would have been Burman, Albion etc. where the input shaft and the output shaft were concentric (quill shaft - direct drive in top gear therefore in theory more efficient) - not the same layout as the modern boxes, (the little "buzz bombs" of the sixties changed all that), because you couldn't have them in top gear for more than a minute at a time anyway! - I do know, I rode one a lot!
    In the case of the layout of common style boxes back in the day however, the gearbox shaft and output sprocket would now rotate "backwards" with the gear primary drive, that's assuming of course that the engine rotated "forwards". - (I'm sure I could have said all that using a lot less words!)
    Did they make their own gears or did some of the gearbox makers do a special one for New Imperial?

    That machine is an example of the direction the British Industry should have been taking - just shows that we don't recognize forward thinking when we see it - until it's too late!
    We get a picture into our "blinkered" heads of what a motorcycle should look like and anything different is considered "rubbish"!
    If you are meaning the New IMP gearbox it appears to have been made by them, or at least for them.
    I note the oil for the engine was also contained in the engine, actuallyin its own sump. seperate from the gearbox oil much like an Royal Enfeild bullet or a CRF450 honda.
    As i mentioned it also has a gear primary drive as well.

    If you are meaning the MC1 that has a Burman designed to take the 5 speed but only fitted with a 4 speed for inital testing
    I guess the Burman likely was the only 5 speed freely available at the time becuase Norton used it also on their works 500 and 350's in preference to their own gearbox.
    https://www.kiwibiker.co.nz/forums/s...post1130374991

    As far as i know All the villiers gearboxs up to the starmaker were based on Albions or made by them
    The starmaker was a new design full needle roller set up.
    As far as i am aware in the 3 and 4 speed villiers gearboxs any set of gears made or any gear can be used for any gear you want. thus you can use a second gear to make a very high first gear etc if that makes sense.
    the Enfeild albions and the early 8E 4 speed gearboxs have a kickstart on the inside (or was it outside) of the gearchange shaft.
    They also had a gear indicator so you could see what gear you were in. (Not that that was a problem)
    From memory some albions also had a seperate netural lever on the gearbox.
    On the villiers engines we had gearing changes were normally made on the Engine sprocket because the gearbox sprocket was buried behind the clutch.
    Racing royal endfields were the same, both had the primary case held on by only one bolt so it was a doddle to do.
    Quote Originally Posted by Katman View Post
    I reminder distinctly .




    Kinky is using a feather. Perverted is using the whole chicken

  10. #1300
    Join Date
    22nd November 2013 - 16:32
    Bike
    STRIKE trike & KTM300 EXC TPI
    Location
    Perth, Western Australia
    Posts
    878
    Harley (ie Hog) gearboxes are still old school, non crossover. Must be a piss off changing the chain or belt.

  11. #1301
    Join Date
    10th February 2005 - 20:25
    Bike
    1944 RE 1
    Location
    Auckland, New Zealand.
    Posts
    2,243
    Quote Originally Posted by husaberg View Post
    If you are meaning the New IMP gearbox it appears to have been made by them, or at least for them.
    I note the oil for the engine was also contained in the engine, actuallyin its own sump. seperate from the gearbox oil much like an Royal Enfeild bullet or a CRF450 honda.
    As i mentioned it also has a gear primary drive as well.
    Yes, I was meaning the new Imperial - wonder who the designer was - forward thinking!

    Quote Originally Posted by ken seeber View Post
    Harley (ie Hog) gearboxes are still old school, non crossover. Must be a piss off changing the chain or belt.
    How the hell did HD manage to keep going for so many years without actually thinking ahead? Mind you, those gearboxes still make some sense when you can actually keep them in top gear almost forever!

    Maybe a lot of companies tried too hard to change everything, when it perhaps didn't need changing! look at those fantastic racing machines of the sixties, I (and a lot of others) loved to watch and listen to them but they were totally useless for your average rider to enjoy having a replica to take on the road!
    We were all pissed off when the 125's were restricted to 6 speed and 1 cylinder but maybe they (the rulemakers) did us a favour and made us find other ways to wring out more torque and higher power as well! - bucket racing is still keeping a lot of people happy trying to do just that!
    Maybe the environmentalist are doing the same, eventually forcing us to clean up our act and making some innovative discoveries on the way! - look at how quiet but still powerful bikes are now compared to 25 years ago (except HD of course, but I heard they eventually had to go and have a quiet word with Porsche!).

    Now if we had a big efficient V2 two stroke with fuel injection, no smoke and no huge exhausts and able to pass all the emission tests........ no?.......maybe not! Has the two stroke gone forever or is there still a niche for it? - we'll just have to rely on Flettner and one or two others to get around that one!
    Strokers Galore!

  12. #1302
    Join Date
    20th April 2011 - 08:45
    Bike
    none
    Location
    Raalte, Netherlands
    Posts
    3,341
    Quote Originally Posted by WilDun View Post
    How the hell did HD manage to keep going for so many years without actually thinking ahead?...
    Maybe a lot of companies tried too hard to change everything, when it perhaps didn't need changing!
    Now that is one thing you cannot accuse Harley of!
    As I keep saying (because Europe's largest Harley-Davidson museum is just down the street from where I live), HD is the best motorcycle in the whole USA
    (until someone there starts producing a second brand).
    Click image for larger version. 

Name:	speed harley.jpg 
Views:	13 
Size:	18.6 KB 
ID:	329773

  13. #1303
    Join Date
    4th June 2013 - 10:03
    Bike
    2010, specialised bike
    Location
    United Kingdom
    Posts
    289
    Quote Originally Posted by Frits Overmars View Post
    Now that is one thing you cannot accuse Harley of!
    As I keep saying (because Europe's largest Harley-Davidson museum is just down the street from where I live), HD is the best motorcycle in the whole USA
    (until someone there starts producing a second brand).
    Click image for larger version. 

Name:	speed harley.jpg 
Views:	13 
Size:	18.6 KB 
ID:	329773
    Haha, love that speed limit image, wd Frits.

  14. #1304
    Join Date
    10th February 2005 - 20:25
    Bike
    1944 RE 1
    Location
    Auckland, New Zealand.
    Posts
    2,243
    Quote Originally Posted by tjbw View Post
    Haha, love that speed limit image, wd Frits.
    They are entitled to say what they like about HD in America, I did once hear a guy in USA (who didn't actually ride bikes) confidently pronounce that the Harley was "the fastest motorcycle in the world"! ........ But we do need to acknowledge that despite their low tech, their low power, their low ground clearance, their low everything in fact (except maybe noise and price) they did actually survive all through the world! - that's against all odds, quite impressive really.

    Much as it is distasteful to some of us, we have to ask the question - why did they survive? and why didn't the two stroke (in motorcycles)
    Strokers Galore!

  15. #1305
    Join Date
    13th June 2010 - 17:47
    Bike
    Exercycle
    Location
    Out in the cold
    Posts
    5,626
    Quote Originally Posted by WilDun View Post
    Yes, I was meaning the new Imperial - wonder who the designer was - forward thinking!

    How the hell did HD manage to keep going for so many years without actually thinking ahead? Mind you, those gearboxes still make some sense when you can actually keep them in top gear almost forever!
    Don't know who the New Imp designer was - but it wasn't forward thinking at the time. It was lateral thinking solving a problem that didn't exist at the time.
    At that point in time - early 30's - OHC was the way forward. More HP !! Frames were developing, brakes were getting better but the separate transmission was still quite adequate for the job. It was also well suited to being made on relatively simple machinery by small companies who sold the same product to many end users.
    The race version of the unit construction New Imp was the last pushrod engine to win a "pure classic" TT - 1936 Lightweight. I understand that the race version cost a fortune because to get it as light or lighter than their already successful non unit 250, they had to cast most of the engine in magnesium...

    HD simply had a big enough domestic market for whom their products were adequate for use. If you can sell everything you make domestically, there's no real incentive to produce anything better. Exemplified by the period of AMF ownership where they frankly stagnated.
    I'm sure there are Eastern Bloc examples of the same design stagnation due to the domestic demand.

Thread Information

Users Browsing this Thread

There are currently 2 users browsing this thread. (0 members and 2 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •