Flywheels and pressure plates, Can they be reconditioned? Options

[toadman]

I have several flywheels and pressure plates. I would like to end up with one good, balanced set. Some are more rusty than others so I would start with the ones in the best condition. I have several questions.

One local machine shop said they can recondition flywheels but they don’t have the critical measurements. There has been some discussion here on the proper thicknesses when reconditioning FWs. Is there a consensus now on what those measurements are? I think the concern is about clearance issues with the clutch disk and flywheel bolts.

Does it make sense to recondition PPs?

If yes, would a soak in kerosene or Evaporust be appropriate to remove rust?

If yes, are there critical measurements/thicknesses? What are they?

Any additional guidance would also be appreciated.

Thank you

[Dustin]

It's common to recondition flywheels. Take it to a better machine shop. They should have access to that data. I'd think this would be a qualifier for choosing a machine shop.

I'm sure you could recondition a pressure plate. I don't think it's common though.

[930cabman]

Flywheel grinding is a basic operation, pressure plate reconditioning I have not heard of. Maybe a Blanchard grinding machine

May want to consider lightening the flywheel when you are in there, just make sure the material removed is non structural

[brant]

I think you have to buy a new pressure plate
It’s the finger springs that loose their tension from heat

The trick on the flywheel is to take off material where the pressure plate mounts to compensate for material removed on the face
Staying within tolerances.

Check your Haynes. I “think” it’s in there but haven’t looked for it recently

[Dustin]

Do you think lightning your flywheel is always an upgrade?

[brant]

Depends on your driving style

But I always… run a lightened flywheel if I have the opportunity

Depends on how you drive also

[Jack Standz]

Personal preference is refurbished OEM German flywheels, just better steel in them. It needs to be machined properly. Find the diagram on this site with dimensions, as you need to machine the same amount from two locations to match the amount you remove from the clutch mating surface.

Also like lightening them some for a street motor, but not too much.

Get a new pressure plate and disc (for a performance street motor, preference is Centerforce dual friction one). Springs get tired and you lose clamping force and the faces get scored. You'll hate it when you have to pull the motor & transmission to replace a slipping or chattering clutch.

Have everything balanced. Happy times!

[Jack Standz]

Do you think lightning your flywheel is always an upgrade?

No.

Light car, light flywheel. Heavy car, heavy flywheel.

Lighten too much & you get a boolean type actuation of the engine's response. On & off. Spins up quicker, but spins down quicker too. Not so fun for street or traffic. A too light flywheel also is hard on the motor's thrust bearings. Discuss with whoever is machining your flywheel, like DPR, European Motor Works, FAT, etc.

[Dustin]

If you want to maintain speed using less fuel, heavy flywheel. If you want to drive like you're rallying your car, light flywheel.

A heavy flywheel spins up slower but also spins down slower.

A light flywheel spins up faster but also spins down faster. So you have to put more energy in to keeping the revs up.

That's my understanding anyway.

If you're driving on the freeway you want a stock flywheel, I believe.

[toadman]

Flywheel grinding is a basic operation, pressure plate reconditioning I have not heard of. Maybe a Blanchard grinding machine

May want to consider lightening the flywheel when you are in there, just make sure the material removed is non structural

One of my FWs has already been lightened. I am thinking of working with that one first.

[Jack Standz]

IIRC a stock flywheel runs about 17 pounds + or -.

And the lightened one in our 2056 is about 12.5 pounds, which works well for a street driven car. Maybe weigh your stock one and compare to the lighter one?

[Jack Standz]

Here's a link for 914-4 flywheel specifications:

http://www.914world.com/bbs2/index.php?showtopic=149714