dans new crank

[davidblythe]

I can buy that Dan, something like that would appeal to me

[Andy Pickering]

I for hope this does work for you dan....so if one of the benefits is more lubricaton to the crank..surely it would be less chance of crank failure ..or am i not getting it

[sean brady scooters]

i am sure that crank big end lube is improved..............

[156 D]

Dan Quote
"Anyway...................we can be judged by the forum-masses, based on the results of my back to back dyno run when i compare the same engine with 2 cranks. "

"A believer!!!!"



I for one will not judge your results as i am sure others will not either....I thought the idea for this thread was to see what reaction you would receive from the forum,and i do think the forum has responded well to your tuning work....i think what you don`t understand is that the forum members are trying to make you think exactly about what you are doing so that other things may become clearer...remember...500 heads are better than one ........I have not incurred that you need here a high PC for performance but only mentioned that you do have less than what you started with ,so therefore you have to compensate somewhere for the lack of it.....the vast majority of the gas to be pumped up the transfer ports comes not from the crankcase but from under the piston as it descends, and the gas has to do a 180 turn to go up the transfers. Note that there is no pumping action from the crankcase, due to less PC.... there is however a ramming effect from a correctly designed inlet tract which can increase the gas pressure prior to primary compression starting, from this it can be seen that some tuning effort could wisely be directed to the underside of the piston.... ......also the fact that the exhaust will be sucking the fuel up the transfers due to less PC rather than the crankcase pumping them up.......Anyway good luck with your new Dyno......

[Andy Pickering]

i am sure that crank big end lube is improved..............

Well that alone would be a great improvment ..and im guessing the lower vibration factor, as with any two stroke engine be it scooter/ motorbike/ jetski etc etc you can tune them to death but in nearly all cases they vibrate the hell out of the rider and bike...

[sean brady scooters]

now heres a thing for you to consider ................
as regards crank case volume..............combined with inlet tuned lengths................etc.

as yet,the best approximations/theorys/equations etc are all based on the fact that the crankcase acts as a ressonating flask .................of varying volume.............
and so.........regarding this.............would it not make sense to make the lambo crankcase as near a flask shape as poss...................?

[Stokie]

I have a Mon-Fri job ........ i'm a family man with the usual wife/kids ..... so working in a scooter workshop in evenings and weekends ......

... would get me a divorce !

I've not got the first idea if the crank will work or not but it looks fancy and I wish I had the skills to do that kind of work.
The dyno results will be interesting - as will the feedback regarding how the motor feels - ie more or less vibration.

Good luck with it all Dan ... but don't forget the Mrs & Kids !

[Adspeed]

Thanks for that Dan, I'm not so sure, but thats what forums/discussions are about hey

No worries bud.

Out of interest (dare i ask!!!) what are your objections/opinions as to why it wont work?

Why the - 'Dare I ask'? At least I post my views constuctively rather than just PM'ing them about......you know who you are!! Speak up!!

I could always become a forum 'Yes' man.........nah I probably couldn't thinking about it.

Just reckon the flow is disrupted worse than roadworks on the A1. We spend a lot of time flowing things like the inlet which Sean has done, then it enters under the piston and look what its up against.....



I'm not sure there will be a great difference either way to be honest but that to me doesn't represent better flow

Adam

[sean brady scooters]

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

[drunkmunkey6969]

Why the - 'Dare I ask'?

It was just tongue in cheek mate, as if to suggest you might say somthing blindingly obvious that we had overlooked.....and then i would feel silly etc. Nothing else.