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QUESTION ON VAUX XE FLYWHEEL
TOO BADD - 22/3/08 at 03:22 PM

Does any one know how light an xe flywheel can be taken to without going to a 71/4 " clutch.... ie keep standard one. Thought I might as well as the engine is out to change the rear crank seal.


ned - 22/3/08 at 03:55 PM

its not really how light, it's how weak it becomes. You don't want machined too thin cast flywheel disintegrating at several thousand rpm, makes a bit of a mess.


TOO BADD - 22/3/08 at 04:10 PM

There is a couple of new 'ultra lightweight' steel flywheels on the bay @ £ 125 plus post and I am condidering this route.


ned - 22/3/08 at 04:18 PM

I paid £95 odd for mine a few years back, takes a 7.25" clutch and weighs 3kg. Engine revs up very nicely with it on

Make sure you get it balanced up properly and along with whatever clutch you opt for.

Ned.


philw - 22/3/08 at 04:56 PM

If you get an early xe flywheel they are lighter than the later ones, by about 2-3kgs IIRC.


TOO BADD - 22/3/08 at 06:20 PM

Dunno if mine is an early but it is from a 91 engine. Just spent 2 hrs heavy duty web searching info. Found out that 1kg removed from a flywheel equates to losing 39kg's from the chassis in 1st gear...12kg's in 2nd and so on. So having a 2kg lighter flywheel is the same as losing me out of the car. Well...nearly!


philw - 22/3/08 at 06:29 PM

How heavy is the one you have? and whats the block number? it will begin with HH or HG

[Edited on 22/3/08 by philw]

[Edited on 22/3/08 by philw]


TOO BADD - 22/3/08 at 06:39 PM

Just weighed it on the fat scales and it is about 6kg's. Autosprint had a little fettle with it when I first built the engine in 2002


philw - 22/3/08 at 07:15 PM

Thats about right 6kgs, the next step is a steel one as has been said before, i use a manta flywheel 5kgs but i have a different bottom end.


TOO BADD - 22/3/08 at 07:42 PM

The steel ones seem to be about 5.5 kg's which would still be an improvement on 6. £££'s for 1/2 kilo.....don't know.


ned - 22/3/08 at 07:54 PM

this is my setup, very light, and so was my wallet...

http://www.locostbuilders.co.uk/upload/IMG_1445.jpg
http://www.locostbuilders.co.uk/upload/IMG_1444.jpg
http://www.locostbuilders.co.uk/upload/IMG_1514a.jpg

a friend of mine had this one specially made smaller diameter to keep the centrifugal forces down aswell:
http://www.locostbuilders.co.uk/upload/IMG_1906b.jpg

Ned.

[Edited on 22/3/08 by ned]


philw - 22/3/08 at 08:09 PM

quote:
Originally posted by TOO BADD
The steel ones seem to be about 5.5 kg's which would still be an improvement on 6. £££'s for 1/2 kilo.....don't know.


I thought the steel ones were 3kgs ish


MikeRJ - 22/3/08 at 10:14 PM

quote:
Originally posted by TOO BADD
Dunno if mine is an early but it is from a 91 engine. Just spent 2 hrs heavy duty web searching info. Found out that 1kg removed from a flywheel equates to losing 39kg's from the chassis in 1st gear...12kg's in 2nd and so on. So having a 2kg lighter flywheel is the same as losing me out of the car. Well...nearly!


Not quite that simple, it depends where the weight is removed from. The weight in the centre of a flywheel has negligible effect compared to the weight on the outside edge.


ned - 24/3/08 at 01:15 PM

Mine was advertised as just under 3kg's though I've never bothered to weigh it.

quote:
Originally posted by philw
quote:
Originally posted by TOO BADD
The steel ones seem to be about 5.5 kg's which would still be an improvement on 6. £££'s for 1/2 kilo.....don't know.


I thought the steel ones were 3kgs ish


ned - 24/3/08 at 01:17 PM

quote:
Originally posted by MikeRJ
quote:
Originally posted by TOO BADD
Dunno if mine is an early but it is from a 91 engine. Just spent 2 hrs heavy duty web searching info. Found out that 1kg removed from a flywheel equates to losing 39kg's from the chassis in 1st gear...12kg's in 2nd and so on. So having a 2kg lighter flywheel is the same as losing me out of the car. Well...nearly!


Not quite that simple, it depends where the weight is removed from. The weight in the centre of a flywheel has negligible effect compared to the weight on the outside edge.


Agreed, hence often skeletal or drilled round the outer section outside the fricton area where the mass makes the most difference and why for ultimate/race applications a smaller flywheel is preferred where regs allow to get the weight as near the centre as possible.

Less mass to spin up and down allowing the engine to rev free-er.