Scooterotica

Somebody likes this style of crank: http://www.twostrokeshop.com/two_stroke ... .htm#crank

Its a 58mm stroke, running 70-73mm pistons.

A couple of others....

Quote Sean....
"EXACTLY matey.............".what is it up against........?"
in a std engine/crank......it would hit a wall..............the flat webs............yes....?"

All these pictures are of really nice cranks including the Lambretta B pic ......but the thing that has been overlooked in one of my posts was the fact that the piston forces the fuel down after it coming in the inlet and the fuel then turns 180 degrees and back up the transfers....so therefore it needs the flat surfaces of the crank webs to bounce and flow off.... instead of being absorbed into and around the webs....imo the crank shape is great but not the tapered parts they need to be flat as are all the pics of the cranks that you are putting up....perhaps you could try one without the tapered part on the webs?.........anyway perhaps as i am a Southerner and not a Northener our laws of physics are different as we are nearer the equator?....

156 D wrote:......but the thing that has been overlooked in one of my posts was the fact that the piston forces the fuel down after it coming in the inlet and the fuel then turns 180 degrees and back up the transfers....so therefore it needs the flat surfaces of the crank webs to bounce and flow off.... instead of being absorbed into and around the webs....imo the crank shape is great but not the tapered parts they need to be flat as are all the pics of the cranks that you are putting up....perhaps you could try one without the tapered part on the webs?.........anyway perhaps as i am a Southerner and not a Northener our laws of physics are different as we are nearer the equator?....

Good point, maybe we have gone too far with the taper?

But....on a 'normal' Lambo crank.....does the crankcase area and its gasses not come into play on the downward stroke? Its not a sealed unit after all.....?

And on the crank we already have running in one Lambo....all Sean did was the taper, and NOT the bell shape....and that has 500 extra RPM, reduced vibration and better throttle response?

I don't know the answer 100% either way, im just asking questions same as everyone else.....and will let you know, when we know!

They even use this crank on animations....

156 D wrote:Quote Sean....
"EXACTLY matey.............".what is it up against........?"
in a std engine/crank......it would hit a wall..............the flat webs............yes....?"

All these pictures are of really nice cranks including the Lambretta B pic ......but the thing that has been overlooked in one of my posts was the fact that the piston forces the fuel down after it coming in the inlet and the fuel then turns 180 degrees and back up the transfers....so therefore it needs the flat surfaces of the crank webs to bounce and flow off.... instead of being absorbed into and around the webs....imo the crank shape is great but not the tapered parts they need to be flat as are all the pics of the cranks that you are putting up....perhaps you could try one without the tapered part on the webs?.........anyway perhaps as i am a Southerner and not a Northener our laws of physics are different as we are nearer the equator?....

was beginning to think it was just me.

With the HRC quote I was refering to such as 125RS a genuine race bike. Heres one below with a nice rounded edge to the webs......an improvement on std Lammy items me thinks? Could be worth a try....

(sorry for pic size)



Adam

Dan ....as the rotating mass has been decreased even more to the already lightened crank to increase the engine acceleration....Acceleration will increase and also get your extra 500 revs....you will probably have to change gear so much more that in theory that should be slower around a track....that`s one thing a dyno won`t tell you!.... apart from a race how can you measure the time between gearchanges needed?.......

156 D wrote:Dan ....as the rotating mass has been decreased even more to the already lightened crank to increase the engine acceleration....Acceleration will increase and also get your extra 500 revs....you will probably have to change gear so much more that in theory that should be slower around a track....that`s one thing a dyno won`t tell you!.... apart from a race how can you measure the time between gearchanges needed?.......

The dyno vs seat of pants vs GPS tests will all be done and will all be published. If it looks good on a dyno but is a dog to ride....i'll let you know.

Not really sure what 'measure the time between gearchanges' means, but if we are changing gear quicker.....then presumably we are accelerating quicker...and getting to top speed quicker. So if the option is 0-60 through 4 gears in 10 seconds, or 0-60 through 4 gears in 8 seconds....i'll take the 8 second option...as im accelerating faster, getting up to top speed sooner, and therfore spending longer at top speed.

But this is all theoretical bullshit (pardon my language) all we can do is tune it, build it, ride it, dyno it and GPS it.....thats it.

If its s**t, i'll tell you its s**t....if its good...i'll tell you its good, what else can i do?

Just had this thread on GSF pointed out to me: http://www.germanscooterforum.de/Lambre ... tml&st=400

Here's a translated version: http://translate.google.com/translate?p ... l=de&tl=en

If anyone posts on there, can they contact the guy and ask him to let us know how he got on?

Images.....

all of this is well beyond my comprehension but what i do like is the fact that you guys are out there pushing the boundries and doing so openly on the forum if it works fantastic if it doesnt then so what nothing but respect from me to all those involved