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Author: Subject: Flywheel Lightening
dave1888

posted on 17/8/05 at 12:57 PM Reply With Quote
Flywheel Lightening

Been quoted £40-£50 to lighten the flywheel of my Zetec 1600. Do I have to have it Balanced as well.






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darren(SA)

posted on 17/8/05 at 01:34 PM Reply With Quote
Most definately! balance whatever you can on your engine,

cheers

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MikeR

posted on 17/8/05 at 01:53 PM Reply With Quote
I talked to a pro engine builder a few years ago. Asked about getting everything balanced and he said "do you race" i replied "no" and he said he'd do it but it would be a waste of my money.

still not at that point yet, but i'll probably balance everything for the hell of it anyway.

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NS Dev

posted on 17/8/05 at 02:49 PM Reply With Quote
I would want to balance it as well, but...............there's not much point doing it on it's own, it needs to be balanced while bolted to the crank and front pulley etc, otherwise the dynamic balance won't be right anyway.
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Bob C

posted on 17/8/05 at 03:26 PM Reply With Quote
The flywheel is effectively a disc - it doesn't require dynamic balance like a long thing does (eg crankshaft).
So it's quite easy to check/balance it DIY; just balance it on a spike (you'll need to turn a wee mandrel to sit in the middle hole) & check where you need to put a weight to make it balance level.
I think some manufacturers may balance pulley/crank/flywheel as an assembly, but that sounds like a nono re: replacing parts.
Bob

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kango

posted on 18/8/05 at 04:09 AM Reply With Quote
What is the minimum a 1600 XF flywheel can weigh?
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NS Dev

posted on 18/8/05 at 07:38 AM Reply With Quote
quote:
Originally posted by Bob C
The flywheel is effectively a disc - it doesn't require dynamic balance like a long thing does (eg crankshaft).
So it's quite easy to check/balance it DIY; just balance it on a spike (you'll need to turn a wee mandrel to sit in the middle hole) & check where you need to put a weight to make it balance level.
I think some manufacturers may balance pulley/crank/flywheel as an assembly, but that sounds like a nono re: replacing parts.
Bob


Balancing was one of the things at college that I never quite grasped, but does the altered weight of the flywheel (even though it's short and concentric)hanging on the end of the crank not affect the dynamic balance of the crank along it's length?

I'm probably totally wrong but I thought it did?

For once I'm prepared to learn!!

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Bob C

posted on 18/8/05 at 09:24 AM Reply With Quote
I can't pretend to be authoritive, it's just one of those things I've given some thought to & come up with my own theories about.... Anyway my theories go along the lines of:
a disc can be static balanced and then you can spin it at any speed & it won't wobble.
a long thing (eg crank) could have a big eccentric weight at one end and a balancing opposing eccentric weight at the other and it would statically balance perfectly. But if you spun it it would wobble like crazy, effectively oscillating about its middle rather than jumping up & down.
So according to my theory front wheels need to be dynamically balanced or they'll wobble the steering wheel, but back wheels on a live axle only need static balancing, static balance at each end of the long thing (axle) equating to overall dynamic balance!!
I look forward to everyone else's theories!
Bob

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NS Dev

posted on 18/8/05 at 09:26 AM Reply With Quote
I guess as long as the flywheel is balanced then, the crank should stay in dynamic balance.............but likewise, I'd be interested in other opinions!

[Edited on 18/8/05 by NS Dev]

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Locost82

posted on 18/8/05 at 09:34 AM Reply With Quote
After my crank disaster I phoned Burtons for a balancing quote. They'd balance a crank, flywheel, pulley and clutch plate for £60 + VAT for a 1300 X-flow which I thought was reasonable.
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darren(SA)

posted on 18/8/05 at 09:38 AM Reply With Quote
Hi Kango,

I think its 5kg? (standard being 8kg need to check),

The guys that did mine don't recommend taking anymore off as there have being a some serious injuries from flywheel shattering in a lotus. They recon if you want lighter, u'd need a special ali one, not the standard cast.

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NS Dev

posted on 18/8/05 at 09:40 AM Reply With Quote
never wise to lighten a cast iron flywheel by much.

As you say, either ally or steel lightweight one is needed to go superlight.

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kango

posted on 18/8/05 at 07:27 PM Reply With Quote
Will it be noticable if I go to 5 Kg. My understanding is that it will only rev up faster.
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JoelP

posted on 18/8/05 at 08:21 PM Reply With Quote
id say lightening will increase how fast it revs up, and balancing will increase the technical rev limit, in hand with other stuff like valve springs etc...






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Bob C

posted on 19/8/05 at 07:31 AM Reply With Quote
lighter flywheel does give marginally better acceleration in the lower gears, I did the sums for a 1 ton car that did 60 in 2nd at 6000revs - it got there 4% faster with a couple of kg off the flywheel
Bob

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darren(SA)

posted on 19/8/05 at 08:58 AM Reply With Quote
have a look at the following link

click here

if you can't view it, I can post it.

Only lighten if you are going to do some other mods, it would be a waste by itself.

let me know if you interested in what to do to your Xflow, and by whom (in JHB), I did a lot of research and got help from a lotus 7 racer, Clive Wilmot back in the day

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dave1888

posted on 19/8/05 at 09:24 AM Reply With Quote
That article looks like it was copied from the Puma racing site ?






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kango

posted on 20/8/05 at 04:11 AM Reply With Quote
For now I only want to do the things that will not brake the bank. I have a set of 40 delortoes so still have to do the head and get a cam, valves and valve springs..
But first I have to get it on the road.
So was just wondering what the effevt of the flywheel would be. I am buisy with covering the ousside of the car and this will not be stopped by not having the flywheel.

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