Flywheel lightening

[vitesseefi]

Triumph Spitfire flywheel spotted on another forum.

Seems to be the standard cast iron item but with a whole lot removed. Would you want it whizzing round by your feet? Spitfires only have a cardboard transmission tunnel too.......



Nick

[phillipm]

No, corners are too sharp with big stress risers, they've just fillet the corners instead of using a parabolic arc.

[tristanh]

Is a stock one a solid, hole free item?

[vitesseefi]

Dec 16, 2017 19:35:28 GMT tristanh said:

Is a stock one a solid, hole free item?

Yes.

Nick

[welshpug]

in itself not a bad thing but that is quite poorly executed as Phill highlighted.

its the bellhousing material you need to worry about not the transmission tunnel, if it breaks through that it'll come throuih whatever is there !

I'm guessing these engines don't really spin up to a particularly high rpm, but still a fair bit of inertia in whats left if it does break up and start flinging bits out

[tristanh]

Dec 16, 2017 22:51:22 GMT vitesseefi said:

Dec 16, 2017 19:35:28 GMT tristanh said:

Is a stock one a solid, hole free item?

Yes.

Nick

Jesus. Ballistic blanket required!

[Deleted]

Darwin Award winner right there...Oh well,look on the bright side,it's only painful if you survive.
I have seen what a flywheel putting itself back into kitform can do.It embeds the remains of your feet into the lower A pillar as it escapes captivity. Not a sight I wish to see again. 😳

People don't realise the amount of energy stored in a flywheel,and more importantly,what that energy can do,if unleashed in an uncontrolled manner.Lightening a stock ,cast iron flywheel like that is totally irresponsible and whoever machined it should be held accountable. Cast iron is prone to cracking at the best of time,adding all those stress risers in there is a recipe for disaster. It's not only the car occupants feet that are in the firing line,but anybody nearby,should it disintegrate....

[vitesseefi]

Yeah, those were my thoughts also. The owner was objecting to my suggestion that it was lethal though. Apparently it came from a "reputable" aftermarket parts supplier in the USA.

He's been quieter since I posted links to a number of "burst" videos. Hopefully they've got him thinking more seriously about personal safety!

I couldn't find the one I wanted though, which was particularly nasty as it showed blood on the inside of the windscreen of a racing Metro after a flywheel burst punctured the bulkhead and the driver's femoral artery. Don't know if he lived or died but it didn't look promising. Probably removed for reasons of good taste, but IMO should be required viewing for anyone thinking about fitting a flywheel like that!

Triumph Spitfires typically have cast-iron bells, which are pretty chunky but brittle. There are a few ally ones out there too either aftermarket or from early cars. I would suspect that either would just add to the shrapnel load.

Nick

[Deleted]

Admittedly it's a much heavier flywheel,but by the same token a tractor gearbox and engine is a structural member and built with no weight considerations. A lot stronger than an automotive gearbox. Nothing wrong with a lightflywheel as long as it's made from a suitable grade of steel and is well designed...

[njw]

I had the viscous fan shatter on the 540 a few weeks ago, having seen the damage a disintegrating plastic fan can do just looking at that flywheel scares the curse word out of me.

[ChasR]

I'm surprised the nuns and kittens mockers aren't here to say 'it's fine'.

But yes, that is really bad! It is surprising what people do. But when cost is involved on either side these things will almost always happen, whether someone is trying to save cash or someone is out for a quick buck.

That Flywheel could take out someone's legs in a Spitfire!

[mk2cossie]

Dec 18, 2017 12:10:24 GMT ChasR said:

I'm surprised the nuns and kittens mockers aren't here to say 'it's fine'.

But yes, that is really bad! It is surprising what people do. But when cost is involved on either side these things will almost always happen, whether someone is trying to save cash or someone is out for a quick buck.

That Flywheel could take out someone's legs in a Spitfire!

Completely agree with you there. Especially when I've heard how little flywheels cost from TTV for a new one piece flywheel.
And think how much the flywheel cost to have machined and balanced in the OP on here

[chris y]

I've got a TTV lightweight flywheel fitted, fantastic quality item.
Having some work related involvement in precision machining, in my opinion the TTV item was very cheap.

I've never seen the aftermath of a failed flywheel before but in any case, even with other options for machining I went for a well engineered British made quality item. Having seen the tractor video I know I did the right thing.

[mercedeslimos]

Is this a hazard of a longitudinal engine or does it affect transversely mounted units too? Not a flywheel, but one of my old lecturers had a torque converter detach itself and launch through the bonnet of a car being revved hard in park. Through the roof of the garage too.

[Badger]

Dec 19, 2017 0:40:58 GMT mercedeslimos said:

Is this a hazard of a longitudinal engine or does it affect transversely mounted units too? Not a flywheel, but one of my old lecturers had a torque converter detach itself and launch through the bonnet of a car being revved hard in park. Through the roof of the garage too.

Happens on transverse as well, but in a different direction where there's somewhat less chance of intercepting the driver (dependent on arrangement!) and there's usually a bulkhead and other gubbins in the way which may slow bits down. On a longitudinal arrangement you tend to only have the drive tunnel. Dangerous in both arrangements though.

To be fair I first saw that and thought it didn't look too bad... until I compared it to an original flywheel! Would NOT be doing that with a cast item.

[vitesseefi]

Minis and Metros shoot the shrapnel straight at the driver....... others, it depends on the direction of engine rotation, which way the engine is fitted etc. The Honda in the earlier link shoots the shrapnel out the front.....

It's BAD whatever!

Nick

[slater]

It makes no difference which way the engine rotates.

[aaronb]

I just saw this on here

Looks like he wanted a bonnet ornament



Flywheel decided to sod off lol

[bstardchild]

Dec 18, 2017 20:34:32 GMT chris y said:

I've got a TTV lightweight flywheel fitted, fantastic quality item.
Having some work related involvement in precision machining, in my opinion the TTV item was very cheap.

I have two of them one for each of my project cars (they both have brothers already in use in other cars) and also can confirm that they are very well designed and built and of a quality material

That spitfire one would worry the heck out of me

[sweep]

Man I wish I saved the pictures I saw a few years back of a Chaser that had a lightened cast jobbie let go, the ring gear was up the road, part of the wheel had left the car through the bonnet/scuttle panel, and the other had took an enormous chunk out the tarmac. Frightening.