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Spitfire 1500 Flywheel Weight

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Hello All

              What is the weight of a standard flywheel?

I gave my spare one a light skim just to clean it up.

Now I am getting close to building the engine and I was wondering if it was worth removing a bit more weight?

I have just weight it and it is 7.5 kgs

You all probably know what I am doing to this engine.

I still want it drive able when touring just a bit more umph ( 90/100bhp!) I have 74 bhp  @ 4500 rpm at the moment(Throttle plates were  only opening 80% !)

So what is all your considered opinion?

Roger

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I don't know, but I think I was going as far as was safe in gettiong this 2.5L 'wheel done.

2.5 saloons have 12kg 'wheels, this is 7kgs.

There have been several flywheel threads on Triumph Experience recently, icluding an  extreme example, which I don't recommend!

John

reduced wt flywheel (1).JPG

Edited by JohnD

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I know the Vitesse/GT6 standard one is a fair bit lighter than the saloon and TR6 one. 

Peter Cox had my Vitesse flywheel machined down to 6Kg from I think about 9Kg, but to look at it its hard to see from where.

For a road car and a 4 cyl, you maybe don't want to go too light, the flywheel does store energy, so through gear changes it can help preserve momentum, not so important if you have a lot of torque, but whilst a light flywheel helps the engine spin up quicker, it also spins down quicker. With a light flywheel lazy gear changes aren't as easy, so no lift, dip the clutch, reach over and slowly pull the lever, whilst your doing this the engine revs are dropping fast.

Alan 

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1500 has the pot clutch.  When you skimmed the friction surface Roger, did you also skim the pressure plate mounting surface (top of the raised ring) by the same amount?  You need to.

Re the weight.  Never really had any strong feeling that the 4 cylinder cars or the Vitesse/GT6 particularly needed it (for road use).  Saloons...... whole different story, they weigh as much as small moon.

Also, plain old weight is not necessarily a reliable indicator of how the flywheel will perform.  Weight removed from close to the outside edge will have a much greater effect than weight removed from near the centre.

I'd respectfully suggest not removing as much as this one.  Unless you feel you'd like shorter legs that is.

http://www.triumphexp.com/phorum/read.php?8,1411945

Another well engineered product from PRI (Moto Cancelli) - not!

Nick

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This is a pot clutch flywheel (or that's what I call it - maybe they are really called something different as you get some, err, strange results if you google it.....)

s-l300.jpg

1500 clutch is normally 7.5".  If you have a 6.5" and flat flywheel you are using 1300 gear......

 

Nick

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48 minutes ago, Nick Jones said:

This is a pot clutch flywheel (or that's what I call it - maybe they are really called something different as you get some, err, strange results if you google it.....)

s-l300.jpg

1500 clutch is normally 7.5".  If you have a 6.5" and flat flywheel you are using 1300 gear......

 

Nick

Hello Nick

                  B*****cs I think I must have a 1300 flywheel

Will have a look at it all tomorrow!!!!!!!!!!!!!!

Roger

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From memory my 1500 was just under 8kg stock.

I had 1kg removed from it,  it was quite drastic but i felt it needed it. 

In my opinion having drive the car a bit now, on the road i think it was a tiny bit too much. I think just over 7kg is about right. 

Blurry cam after skimming.

DSC00354.thumb.JPG.a5334d93ac1a88133cee234f5376b091.JPG

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On 1/12/2018 at 8:30 PM, Nick Jones said:

This is a pot clutch flywheel (or that's what I call it - maybe they are really called something different as you get some, err, strange results if you google it.....)

s-l300.jpg

1500 clutch is normally 7.5".  If you have a 6.5" and flat flywheel you are using 1300 gear......

 

Nick

Hello Nick

                  Mr Numpty here!

I have checked my flywheel today(after doing some free DIY! at my daughters.!)

But yes are right that,s the type I have got I cleaned up the front face so it is flush the ring gear(but the clutch face was good so did not need maching) and machined all the rear face and removed a bit more.

I was wondering about maching the rear flush with ring gear? what do we think?

Or perhaps  leave it at 7.5Kgs?

Roger

DSC06012.JPG

DSC06014.JPG

DSC06017.JPG

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Don't machine it flush with the ring gear  on that side as I think you'll find there's a step the ring gear sits against to stop the starter hammering it off........

Nick

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5 minutes ago, Nick Jones said:

Don't machine it flush with the ring gear  on that side as I think you'll find there's a step the ring gear sits against to stop the starter hammering it off........

Nick

Hello Nick

                  Yes Thinking about you are right.

I think I will just leave it as it is now it is fully machined all over(I think I have enough work as it is?)

I bet it is out of balance now because I have machined it all over and there is one hole drilled for balancing!(when there was rough casting!)

I am tempted to fill the hole up!(a nice tight fitting plug loctited in!)

Roger

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I think Roger has a very good balancing company on his door step (the people I use) They do balance crank with pulley, flywheel, clutch cover and plate. Just remember to permanently mark exact orientation of clutch cover to flywheel. My factory clutch cover bolts are actually forged with unique numbers on each bolt, and the flywheel is stamped so that even the bolts go back in the right places. Bet not many people knew the factory did that!

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1 hour ago, oldtuckunder said:

I think Roger has a very good balancing company on his door step (the people I use) They do balance crank with pulley, flywheel, clutch cover and plate. Just remember to permanently mark exact orientation of clutch cover to flywheel. My factory clutch cover bolts are actually forged with unique numbers on each bolt, and the flywheel is stamped so that even the bolts go back in the right places. Bet not many people knew the factory did that!

Never spotted that bolt thing - are sure it was a factory feature?

In an ideal world I'd like to get the Vitesse rotating parts balanced again.  Not a sweet as it should be at high rpm.  It was so-called done (and the clutch cover drilled to the point where I worry slightly about my feet!), but I don't feel it's right.  The flywheel did have a little work done afterwards, but that was only to open out the centre hole to take a ball-race pilot bearing for the Toyota box, but that really shouldn't have affected it.  Means taking it all to bits again though.......

Nick

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7 minutes ago, Nick Jones said:

Never spotted that bolt thing - are sure it was a factory feature?

 

Yep original flywheel (much lightened) and original bolts, see attached, NB Clutch Cover numbers are of course recent.

Alan

numberedbolts.thumb.jpg.343584e23916759a0f8166d6929b055c.jpg

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