Scooterotica... just another forum?

General scooter chat, any scooter related non technical info.
Adam_Winstone
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Hi all,

Whilst I enjoy my time on this website, chatting Lambretta and showing an interest in Vespa, dealer innovations, dyno charts, etc, etc, to me this has always been a forum. Sure, a very good forum but that was the extent of it. The Scooterotica Garage has always seemed like some remote dealer that I'd had no dealings with and Sean Brady was simply a name that I saw/read on this site. However, that changed for me today!

A year or so ago I started to put out feelers to UK dealers that I thought might be able to split a crank and do some modification work for me, which seemed to run into a brick wall with those that I tried. Sometimes the brick wall came in the form of "Can't be done!", at other times it was a case of me choking at the price that I was being quoted for the work. However, I'd noted the bespoke crank modification work that Sean and Dan were sometimes showing within the Vespa Tuning section of this site so thought I'd drop then a private message. Within a couple of days I had talked through my requirement and had a very reasonable quote for the work to be carried out. I'd supply the crank, rod and bearing that I wanted to use as a base, he would do the work. Typically, me being me, I then somehow shelved this idea until a month or so ago but then made contact again to see if the offer/quote still stood. Sean confirmed that he was still prepared to take on the work for me and I sent the crank his way.

The modifications that I had in mind relate to a crankcase induction motor that I've been lucky enough to get involved with at an early stage of development and take the development work that a.n.other had done and start to play with ideas of my own (for the record, the crankcase motor development work has been continued by the original designer to be a truly lovely motor to ride and way ahead of my own dabbling). Having worked the crank induction casing to my own format, what I needed was for a crank to be reworked to give better gas flow from the reed block into the casing, via modified webs. This modification would be a fairly straight forward (conceptually) chamfer to the inner edge of the web, however, that would require my crank to be split and the webs accurately modified (to retain balance), then for the crank to be rebuilt and trued. One dealer approached said that this could not be done as it would have to be machined and that it would therefore clash with the pin bosses, making it impossible to do. Sean's attitude was quite different and he said that it could be done, with the quote not breaking the bank.

So, today I got the crank back from Sean and I'm thrilled with the standard of workmanship! Sean has got it absolutely as I specified and with a level of craftsmanship way above what I was expecting. I've been so disappointed with some of the other crank work that I've had done by other UK dealers (poorly assembled and then welded on the p155!) that it makes a really pleasant change to be overwhelmed, rather than underwhelmed.

It seems as though I was wrong about Scooterotica simply being a very good scooter forum... the Scooterotica Garage and the workmanship of Sean Brady really is something that I'd previously overlooked.

Thanks Sean, great work.

Adam

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LI150
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Sean has done some work for me in the past and I concur his craftsmanship and work is second to none
timexit17
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Fascinated and intrigued by this Lambretta crank induction idea now.............

Advantages as you see them?
Better fuel economy?
Much reduced spit back?
Adam_Winstone
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To get the ball rolling on the benefits of crankcase reed induction... all the benefits of standard reed induction, no inlet port on barrel allows additional barrel wall area to be used for extra transfer feed and port area/volume, unlike boosts ports (in front of the reeds) the crank induction port can feed directly into the casing and flow around the back of the crank in the direction of crank rotation... whereas a boost port can only flow mixture if the incoming charge splits and tries to reverse on itself to go up the boost - this last point allows a crankcase reed induction to benefit from improved flow in a uniform direction so also gives the benefits of 'power porting' (Bell or Jennings?) as you now have the combined benefits of reed and directional control.

Well, those are some of the theoretical benefits... now to see if they are borne out in practice ;)
holty
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sounds very good, im building an engine along the same lines, in using a barrel off a seadoo its rotax 76mm diameter im having a 64mm crank made specialy for the job, what cylinder you using ?
best regards,
holty
:D
Adam_Winstone
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^... sounds like an interesting project.

My cylinder is a version of Ron Moss's Avanti TT3 kit, which Ron has gone on to develop further for a customer. The idea was for usable power, rather than highest BHP at high revs, and the couple of thousand miles that I've put on mine so far, whilst developing a setup that I'm happy with, show it to have a lot of potential. Power delivery is currently smooth torquey tourer but if you wanted to tune it for high figures then I'm sure it could handle that role nicely. I don't intend to start chasing revs or horses with mine, which is why I've only based this modified crank around a fairly common Race crank spec of webs, rod and bearing, rather than starting to look to swap out rod/bearing and having the pin welded.

Whether the crank is up to the application is my risk, however, I'm really happy with Sean's work that he carried out.

Adam
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sean brady scooters
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must say that another great benefit of crankcase induction is the cooling affect and lubrication of the big end ,vespas very rarely suffer from big end failure and there is a very good reason why a lot of modern two stroke motors follow this design from chain saws to mini moto.s and the many twist and go scooters ...:)
Sean Brady Scooters - 01765 690 698
YAMLAM
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i love this kinda stuff,(way over my head ) but great reading.
win or lose have a booze
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sean brady scooters
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looking forward to seeing some more posts/piccys Adam ,and more about that motor in general :)
Sean Brady Scooters - 01765 690 698
Adam_Winstone
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All in good time ;)
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