How light should I make the flywheel?

[RobStan]

Morning

How light should I make the flywheel? I'm using the car mainly on the road, with about 110bhp from the engine.


Cheers
Rob

[Seabass]

Are you machining the flywheel yourself? Personally I believe it should be left to someone with experience, having seen a car shortly after the (DIY lightened) flywheel decided to break apart. That experience would also enable them to advise you on how light the flywheel should be for a given application...

[RobStan]

I wasn't going to do it myself, no, but I was looking for advice from those who have a similar application which is mainly road going in a 1600m with about 100 - 110 bhp.

Any advice would be great, thanks
Rob

[tegwin]

Isnt there a haynes manual deadicated to tuning the crossflow engine?... im sure there was...

[Seabass]

Yep it's by Peter Wallage. Some decent info in there.

http://www.amazon.co.uk/Rebuilding-Tuning-Fords-Cr...

Edited by Seabass on Monday 11th May 21:40

[TVR_owner]

RobStan said:

Morning

How light should I make the flywheel? I'm using the car mainly on the road, with about 110bhp from the engine.


Cheers
Rob

If thats all you're doing leave it as is would be my advice.

[heightswitch]

TVR_owner said:

RobStan said:

Morning

How light should I make the flywheel? I'm using the car mainly on the road, with about 110bhp from the engine.


Cheers
Rob

If thats all you're doing leave it as is would be my advice.

Agreed. The std flywheel is known to be a bit heavy and across the range there are varying weights. The 1600 GT spec used to be the lightest. On a low tune engine though the throttle response differences are marginal. idle charecteristics can be affected though so probably best leaving as is.

I am assuming as part of your build as well as lightening and balancing all pistons, rods end to end you are also balancing dynamically the reciprocating mass??

if you subsequently do lighten the flywheel then you need to re-balance the reciprocating mass.

Neil.

[RobStan]

I'm not personally building the engine, but the company that is is balancing everything as they should. I was asking about the flywheel as I knew that if I was going to alter it, now would be the time.

Thanks
Rob

[Monkeythree]

RobStan said:

I wasn't going to do it myself, no, but I was looking for advice from those who have a similar application which is mainly road going in a 1600m with about 100 - 110 bhp.

Any advice would be great, thanks
Rob

For me it's a case of horses for courses. If you want the car to accelerate faster (and slow down quicker under engine braking) then lighten the flywheel. If you're more of a cruiser and not too fussed about speeding up and slowing down quickly then don't bother. If you do decide to lighten a standard flywheel they are around 10kg to start with and IIRC can safely (depending on how well it's done) be reduced to around 8kg. You can buy steel flywheels from places like Burton that are 7kg and still use the standard clutch or even down to 4 or 5kg but that means switching to a 184mm "race" type clutch.
Whether you've had yours lightened or bought one off the shelf you need to have the ROTATING conponents balanced as one assembly and then make sure you assemble them correctly aligned when you put the engine together.

[urraco62]

in french, but with a plan : (flywheel = volant moteur)
http://rcma.free.fr/kent/prep.htm

[timelord]

I fitted a Lotus Cortina steel flywheel to my 1600M,double dowelled on to the crank. It uses the larger Lotus 81/2" clutch, less savage than an uprated 71/2" version I ran before, destroying several diffs, my 1600M makes a very usable 100hp at the wheels using a 234 cam to maintain tractability. Geoff