LocostBuilders - powered by XMB

Lightened standard pinto flywheel

sebastiaan - 19/12/09 at 03:27 PM

Guys,

What do we think of this:

lightened flywheel. Too much?

I'd be fully ok with running a lightened flywheel that has had the "lump" taken off the back and been rebalanced. This seems a tad more extreme. Came from a grasser and i coudl have it for very little outlay. Anybody got PERSONAL experience with thi kind of flywheel modification?

MakeEverything - 19/12/09 at 03:40 PM

No, but if its been raced and is still in this condition, then its proven to work surely?

Might make your engine more prone to stalling and maybe a bit lumpier, but will certainly accellerate a bit better.

Looks a bit worn where the clutch plates meet?

RAYLEE29 - 19/12/09 at 04:53 PM

Hi, if its not steel then that much lightening is frightening
if your putting it in a sevenesque car imagine it explodind and taking yours and passengers feet off
imho if you want an ultralight flywheel buy a steel or ally one not a modded oe one
a little lightening on an oe is ok but that much really is asking for trouble
Ray

Bluemoon - 19/12/09 at 05:09 PM

The number of balancing drilling is making alarm bells go off in my head... I guess that was an amateurs attempt..... Personally I would not use it..

Dan

sebastiaan - 19/12/09 at 05:28 PM

quote:
Originally posted by Bluemoon
The number of balancing drilling is making alarm bells go off in my head... I guess that was an amateurs attempt..... Personally I would not use it..

Dan

Good point that!

TA,
Sebastiaan

mcerd1 - 19/12/09 at 06:53 PM

I got a steel one for mine

Its not cheap, but its even lighter and alot cheaper than new legs

marcjagman - 19/12/09 at 07:19 PM

I'm tempted to go with makeeverything on this one, if it's already been thrashed in something else then it must surely be proven as reliable.

nz_climber - 19/12/09 at 09:20 PM

quote:
Originally posted by marcjagman
I'm tempted to go with makeeverything on this one, if it's already been thrashed in something else then it must surely be proven as reliable.

The other way too look at it is, it now has a whole lot less hours before it fails, just a matter of time I would say..

Lightning a OE flywheel that much is asking for trouble - and I like my legs

MakeEverything - 19/12/09 at 11:02 PM

quote:
Originally posted by nz_climber

quote:
Originally posted by marcjagman
I'm tempted to go with makeeverything on this one, if it's already been thrashed in something else then it must surely be proven as reliable.

The other way too look at it is, it now has a whole lot less hours before it fails, just a matter of time I would say..

Lightning a OE flywheel that much is asking for trouble - and I like my legs

I disagree. Its not like bearings that fails (statistically) after so many hours running, or an engine after so many miles....

If its crack tested, and balanced, then there shouldne be any issues. Its not like its a 1L flywheel going on a 3L engine. the loads are the same, i not less on a road car to a race car.

boggle - 19/12/09 at 11:07 PM

how can it explode?????

not a personal fan of lightend flywheels on road cars, you tend to loose a fair bit of inertia on hills.....

snapper - 20/12/09 at 07:43 AM

makeverything, I get the feeling from your comments that you really want to use it, whatever anyone says.
To me it looks dangerous, it will only take one small fatigue crack and it will let go like a bomb.
In a grasser there is less stress as there is generally less traction off the line and shorter periods of stress, that said they are usually lifed i.e. use for a season (like the rods) then discard.
There are a lot of grasser/lightning rod engines and other bits on ebay because those racers would not use the bits again for fear of failier but are happy to sell the cr4p on to others.
User beware on that flywheel, by all means take off the extra weight from a standard flywheel by the accepted meathod but double dowl it to the crank.
Remember drag racers have scatter blankets round the bellhousing.

sebastiaan - 20/12/09 at 10:37 AM

Hi,

Just to clear this up: It was me that was contemplating buying / using this; not makeeverythting. I'll give it a miss though.

Thanks all!

MikeRJ - 20/12/09 at 11:23 AM

quote:
Originally posted by boggle
how can it explode?????

It's cast iron which is weak in tension; the primary force the material within a flywheel experiences. These forces at high RPM are very large, and a crack developing can lead to catastrophic failure. This is the reason that drag cars and tractor pullers etc. have a thick kevlar "scatter blanket" wrapped around the bellhousing to contain the flywheel in the event of failure.

quote:
Originally posted by boggle
not a personal fan of lightend flywheels on road cars, you tend to loose a fair bit of inertia on hills.....

You get less inertia all the time, that's the whole point of them - more power at the wheels during acceleration.

I have seen the results of a flywheel in a mini failing that had lightened in exactly the same way (i.e. large holes around the periphery). There is no way in hell I would ever use that flywheel; the cost of a steel flywheel is peanuts compared to the possible outcome of a big chunk of cast iron failing at 7000RPM right next to your legs.