Lightened Flywheels

[Dolly-Nut]

Worth it and beneficial for fast road use? Your opinions please..?

[soe8m]

yes yes yes and yes.

They are way too heavy. I've got mine ready and will place some pictures in the motorsport thread soon. They can much lighter. Also a modern clutchcover can do about 2kg alone.
Before someone say's the smooth running at idle is less but it is not. If something has overweight does still run ok at ideal weight.

Jeroen

[maximus]

The revs pick up much faster.I cant believe what a difference it makes.

[Dolly-Nut]

How much lighter to go though, is there an ideal weight for a given engine size?
Where would one go about getting a modern lightweight cover to fit?

[soe8m]

Holland????

A modern Delphi is about 2kg lighter than the std B&B.

I will put pictures this week for you.

Jeroen

[Mad Mart]

Yes, definately go for it. Well you've been in my track Sprint...

I'd be interested in the Delphi clutch Jeroen.

[paulsprint]

And me as I've got to change the clutch soon

[SprintMWU773V]

Not a Dolomite but my Mazda has a lightened flywheel as it's an imported special edition and it makes a huge difference to spirited driving. Just make sure that whoever lightens it knows what they are doing lest you end up with one that is unusable on the road.

[KWM338R]

I don't suppose anyone has a drawing of a lightened flywheel do they? I can't imagine any of the machine shops around here have done a Dolomite flywheel before. How light can I go?

Cheers
Mark

[soe8m]

Be patience. There's not such a thing as a too light flywheel on a dolomite.

Jeroen

[Carledo]

I don't suppose the guy who lightened my (massively heavy) Carlton flywheel for the Carledo had ever done one before either but he was a very experienced guy and the job is largely common sense, there are 3 points of inflexure, the position of the ring gear, the clutch mating face and the boss that joins to the crank so the job entails removing as much metal as possible whilst retaining these 3 parameters. This is usually acccomplished by scooping metal from the engine side between the crank boss and the ring gear flange.
In my case the guy managed to remove nearly 4kg and brought my flywheel to within 1kg of the much thinner Cavalier SRi flywheel I originally fitted which wouldn't work with the Omega gearbox. I am fairly sure that more COULD have been removed but most engineers of this type are quite conservative and since the car does considerable road miles as well as drag racing I was quite happy to accept his judgement. It cost me £100 (including drilling out and retapping a couple of snapped clutch bolts and balancing after) which I thought was reasonable.
The effect on engine pickup is quite dramatic compared to a standard Carlton and the (fuel injected and ECU controlled) idle is rock steady at 650rpm.

Steve

[Dolly-Nut]

Is an 1850 flywheel slightly lighter than a Sprint's? Because I have a few and one (which I think came from an 1850) has a lip missing. I'll get pics tomorrow if I can find it. *Rimmer's say they're the same.
Are standard flywheels balanced?

[soe8m]

They are a sort of balanced but after machining they should be rebalanced. The best is to have the crankshaft incl. the front pully and clutchcover balanced at once.

Jeroen

[sprint95m]

Is an 1850 flywheel slightly lighter than a Sprint's?

There are two different 1850 flywheels.
215720 was used up to engine number WF23467E and TKC 0411 was fitted thereafter.

The earlier one has a six hole mounting onto the crankshaft.
TKC0411 was also used on the Sprint, this having an eight hole mounting. The ring gear is the same for both.



Ian.

[Dolly-Nut]

Yes you're right.
I checked all my flys earlier and they're all the same except one which seems to have a slightly deeper cut (<1mm) to a section. It's obviously not been machined I think it's just down to bad manufacturing tolerances.

I've found these available from the U.S of America - http://www.ebay.co.uk/itm/TRIUMPH-TR7-D ... 35c245cb73
http://www.ebay.co.uk/itm/TRIUMPH-TR7-D ... 5899634b3e