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AF Lightened flywheel

Posted: Mon Jan 16, 2017 1:59 pm
by Fruitjuice
What do people use to bridge/stuff the gap between an AF Lightened flywheel and the flywheel shroud?
Or do you just trim down the flywheel shroud so it sits deeper and untill it's close enough to the flywheel?

Re: AF Lightened flywheel

Posted: Mon Jan 16, 2017 2:09 pm
by ForemanBob
have a look on ebay at present... Taffspeed are selling a fan cowl spacer. Pictures describe exactly how it works

Re: AF Lightened flywheel

Posted: Tue Jan 17, 2017 8:49 am
by Fruitjuice
What material is this made from? Plastic or some type of foam? I assume this sticks to the inside of the cowl with glue or some sort of adhesive?

Re: AF Lightened flywheel

Posted: Tue Jan 17, 2017 2:07 pm
by belly
Get a thick nylon chopping board and cut a ring to fit, Secure with 4 M4 BOLTS

Re: AF Lightened flywheel

Posted: Tue Jan 17, 2017 2:38 pm
by Adam_Winstone
I start with an Indian cowling that was intended for long fin flywheel, then cut a strip off (at the correct depth) so that all original bolt holes are removed... I then drill my own at the new depth. The front of the cowling needs modifying to clear the 2 projections that the head cowling bolts onto (I used to reshape the cowl over then but I've just cut out corresponding slots on the last one) and then reshape the front flat section so that it meets correctly with the head cowl.

It takes a bit of messing about but once it is done, it's done!

Adam

Re: AF Lightened flywheel

Posted: Tue Jan 17, 2017 6:52 pm
by Knowledge
belly wrote:Get a thick nylon chopping board and cut a ring to fit, Secure with 4 M4 BOLTS
From IKEA

Re: AF Lightened flywheel

Posted: Tue Jan 17, 2017 7:20 pm
by garry inglis
why not buy a short fin cowling just a thought

Re: AF Lightened flywheel

Posted: Tue Jan 17, 2017 9:41 pm
by Adam_Winstone
^... still not ideal for the AF light flywheels (based on J Range flywheel casting) as the fins are very low compared to a standard Lambretta flywheel.

Re: AF Lightened flywheel

Posted: Wed Jan 18, 2017 6:07 pm
by YAMLAM
i`ve been running the AF flywheel since it came out in the late 80`s with a standard italian (short ) cowling, never had a problem . ( what problem is there meant to be ?)

Re: AF Lightened flywheel

Posted: Wed Jan 18, 2017 6:15 pm
by Adam_Winstone
^... me too, also without issue, however, the theory is that the cooling is considerably more efficient if the fins are closer to the cowling face. If you think about how the fan wants to work by forcing the air out of the cowling and into the head cowling, rather than just stirring it up a little inside the fan cowling, it does make sense that the fins do not want to be too far away from the inside face of the cowling.

Whilst I've not had issues with cooling being an issue, I do think that the theory makes good engineering sense and so have addressed the issue and not had any cooling issues with modified cowlings either. I guess this is a case of betterment, rather than fix.