Flywheel question

[vercingetorix]

Its always one more thing with this beast!

Took the flywheel into the machinist today to be checked before I install it because I saw a couple of small cracks in the surface and he said it would be fine if I didn't mind my foot being blown off when it exploded. (I actually know a guy this happened to)

So now I'm looking for a flywheel for an L28. My question is are the 240/260/280 flywheels inter-changeable? Or do I have to identify a specific one and if so how? MSA only carries new competition but no stock.

Thanks All,

H Houghton

[Diseazd]

All 240Z and 280Z flywheels are interchangeabe. However the Turbo and 2+2 flyheels have a larger facing (240mm) versus the stock flywheel.

[vercingetorix]

Thanks D,

After searching the site for awhile last night I found a couple of threads dealing with flywheel size/clutches etc.

Probably should have started there before posting. Oh well. I really appreciate any response I get.

Best,

H Houghton

[Diseazd]

No problemo! :classic:

[Unkle]

Why not go aluminum lightweight at this point ?

Stock heavy and wavy seems a step backwards !:bulb:

[subtle_driver]

Aluminum is weak and gets damaged easier than steel in my experience. The pressure plate bolts got ripped out of the Aluminum when I was autocrossing my Z.

I actually Prefer chromoly, or a heavier flywheel. It makes more torque! Faster up hills!

[ozconnection]

Aluminum is weak and gets damaged easier than steel in my experience. The pressure plate bolts got ripped out of the Aluminum when I was autocrossing my Z.

I actually Prefer chromoly, or a heavier flywheel. It makes more torque! Faster up hills!

An aluminium flywheel has a friction surface on it so that the clutch plate doesn't actually run directly on the aluminium. Look at the aluminium unit built for our engines by Fidanza. I have one and its design is sound in this regard.

As for your bolts ripping out, I would perhaps suggest that there were some fundamental problems with your installation.

The bolts were perhaps too long, bottomed out and whilst torquing the bolts the softer aluminium threads were stripped.

There should be locating dowels installed in the flywheel so that the pressure plate can be suitably located on the flywheel (to ensure correct balance during machining) and take the sheer loading forces that the clutch and flywheel experience. Without the locating dowels and/or the correct instal of the bolts, this could have potentially led to your experiences with aluminium flywheels.

As for more torque, the engine provides the torque. A lighter flyweel will allow faster engine acceleration due to less inertia. A drag race engine may benefit from a heavier flywheel, to keep the wheels turning as the clutch is dumped on the start line, preventing the engine from bogging. In most other situations, a lightened flywheel should see some benefit, allowing the engine to accelerate more quickly.

If your own testing has proven the heavier flywheel to work best (for you) then go with that and be happy with your choice.

Cheers.

[steve91tt]

An aluminium flywheel has a friction surface on it so that the clutch plate doesn't actually run directly on the aluminium. Look at the aluminium unit built for our engines by Fidanza. I have one and its design is sound in this regard.

As for your bolts ripping out, I would perhaps suggest that there were some fundamental problems with your installation.

The bolts were perhaps too long, bottomed out and whilst torquing the bolts the softer aluminium threads were stripped.

There should be locating dowels installed in the flywheel so that the pressure plate can be suitably located on the flywheel (to ensure correct balance during machining) and take the sheer loading forces that the clutch and flywheel experience. Without the locating dowels and/or the correct instal of the bolts, this could have potentially led to your experiences with aluminium flywheels.

As for more torque, the engine provides the torque. A lighter flyweel will allow faster engine acceleration due to less inertia. A drag race engine may benefit from a heavier flywheel, to keep the wheels turning as the clutch is dumped on the start line, preventing the engine from bogging. In most other situations, a lightened flywheel should see some benefit, allowing the engine to accelerate more quickly.

If your own testing has proven the heavier flywheel to work best (for you) then go with that and be happy with your choice.

Cheers.

Well said!

[Oiluj]

What they said, but depending on your cam, your idle smoothness may suffer with an light flywheel.

[ozconnection]

What they said, but depending on your cam, your idle smoothness may suffer with an light flywheel.

That's true and that's an accepted tradeoff when we decide to instal a performance cam, isn't it?

[Oiluj]

That's true and that's an accepted tradeoff when we decide to instal a performance cam, isn't it?

Yep. But the lighter flywheel can add to making the idle less stable than with the heavier stock part.

I love the way a lighter flywheel revs, but since it's a "street" car, didn't go that route on mine for exactly this reason. It's aways good for someone to know the full impact of a potential change before investing their time & money...