Anybody got any information about lightening either the standard norton flywheel or custom fabricating a lightweight one? I have access to all the machinery I require and have a nice piece of EN40 but other than look at photo of Maney's masterpiece or copy the original don't know where to start. There's very little info on the web so I'm hoping someone has done this before and is willing to share some information. I really want to do it myself out of sheer bloody mindedness!! Engine is or rather will be 850 with PW3 and flowed head.
Flywheel lightening
- Thread starter myjota
- Start date
- Status
- Joined
- Oct 19, 2005
- Messages
- 18,978
myjota,
I and many others would highly discourage dealing with the shatter prone
cast iron factory flywheel. I might even have some posts saved
on racers milling down factory flywheel, but that was back in
late iron age.
In general most lighten flywheel by 4-7 lb off factory ~28 lb crankshaft.
But I got what you seek the measures off Ms Peel's
last of a kind, Ron Fratturelli's special 4.5 lb lighter, 1/2" less OD
flywheel cut from 3 plates. It helped Peel literally run out
from under me if not gripping and bracing before throttle snaps
in lower gear. It idled fine at 600 rpm and was a treat to
creep around on grass slopes lugging on hi throttle no problemo.
I highly recommend lighter fiy wheel. Help toss toward the ground
easier yet still just missing it each time.
Here's the graphic page measures, but also had a water jet
CNC program encoded at a machinist here, if that helps.
http://s184.photobucket.com/albums/x93/ ... graph2.jpg
hobot
I and many others would highly discourage dealing with the shatter prone
cast iron factory flywheel. I might even have some posts saved
on racers milling down factory flywheel, but that was back in
late iron age.
In general most lighten flywheel by 4-7 lb off factory ~28 lb crankshaft.
But I got what you seek the measures off Ms Peel's
last of a kind, Ron Fratturelli's special 4.5 lb lighter, 1/2" less OD
flywheel cut from 3 plates. It helped Peel literally run out
from under me if not gripping and bracing before throttle snaps
in lower gear. It idled fine at 600 rpm and was a treat to
creep around on grass slopes lugging on hi throttle no problemo.
I highly recommend lighter fiy wheel. Help toss toward the ground
easier yet still just missing it each time.
Here's the graphic page measures, but also had a water jet
CNC program encoded at a machinist here, if that helps.
http://s184.photobucket.com/albums/x93/ ... graph2.jpg
hobot
Check out British Classic Bikes, they made a 905cc motor that looks real bad http://www.britishclassicbikes.de/HPVer ... Itemid=114 The absolute worse you could do is get some inspiration from what they did. Years ago, I had my stock flywheel cut down, but the engine balance was not done right and it shook worse than a Harley, but acceleration was really much better.
Jean
Jean
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