F355 flywheel help needed asap!

Cool! Looking forward to the how-to!

 

+1!

 

Can't find the taper spec either...I assume you already found the WSM info, 0.8 micron roughness, 1mm max reduction in thickness.

And a +1 on the how to!

 

could you be confusing that with the 360? The 360 has a taper spec the FW looks like a shallow bowl. the 355 is flat i'm pretty sure. Those also have grease and a bunch of parts inside. How would your guy balance it? IMO the only way to go is convert it to solid and balance it. Otherwise what do you do? Balance it empty and assume the small internal parts all weigh the same? If you put all the parts in do you spin balance it or static balance it? Static requires that all the internal parts are perfectly in line how do you do that? Spin balance means no grease because you can't evenly distribute it unless you spin it up pretty high??? It all sounds dicey to me.

 

355 Flywheel is .008”, but it’s not a linear taper, it’s a parabola,, which make for grinding fun ;-))

J

 

How do you balance a parabola?

 

+1

Not sure why Ferrari chose such a complex design for what is typically just a big chunk of iron but balancing this assembly does not seem straightforward at all.

My understanding has been (possibly wrong) that the grease and internal stuff served to "self-balance".

 

I believe the parabola is the surface of the flywheel itself so balancing is a non-issue. How you grind a parabola is another story. Probably require a CNC grinder that rotates the workpiece as well as generating the required surface shape.

 

Balancing a parabola is the same as any other balance job, preferable on a dynamic machine, easy job on the right equipment.

<Why did Ferrari choose such a complex design?>
They didn’t, an unleashed engineering department whom was a few days from unemployment did. All the 355 owners are now living with the effects of the Ferrari full employment act.

Not sure what’s perpetuating the need to go to this extent other than self fulfillment; and the pleasure derived from outsmarting the Ferrari brain surgeons. 180g of Kluber is enough to take care of the balance imperfections, later iteration were for noise control and usher the 355 into the out of warranty and customer pay faze.

J

 

It has been awhile but when I rebuilt my flywheel a straight edge across the clutch surface face didn't reveal anything except a flat surface. It had 30K on it. And by the way, it didn't take care of the rattling that I had hoped to eliminate by replacing the grease. I didn't take the flywheel to check the balance because it was assumed that this is something that would be handled by the factory.

ken

 

It's there, and was proven to me by JH355. Also Ferrari of Seattle mentioned it to me as well. FoS did not think it was the end of the world if you grind it out on a 6 speed manual car, but it is very important for smooth engagement on a F1 car. They had apparently seen F1 cars with bad chatter after clutch jobs performed by independants that were not aware of this spec.

 

So what is the actual spec that we would need to give to a shop who's machining it for us? Just for future reference...

Alternately if somebody has a new flywheel I'll offer to check the contour with a CMM, just send me a PM.

 

5 axis VMC
3” diameter 80g ruby cup stone
600 RPM
Tip cutter 3 deg
Interpolate to 5.1875 R
.0005” / pass
Max removal .019”

Or send it up here !

J

 

My 348 ran better when I gutted the OEM flywheel cut the spider thing off and welded the spinning parts and converted the flywheel pack to a solid flywheel. I raced it for years. The balancing cost me maybe 20bucks and the resurfacing of the clutch without marcel was 15/plate! I never had any problems with this and lost a bunch of rotating mass too.

Can somone explain to me how a parabolic flywheel surface can be of any advantage at all? I just don't get it. The plates don't folow this curve. Does the pressure plate have this curve too?

 

When you opened it up, what was the condition of the grease? Contaminated with transmission lube, gone, or still there and still clean? What parts besides the grease did you replace? The bearings, the triple seals, the o-rings? Did you weigh the grease - about how much do you think you used?

Thanks!

Randy Lee

 

After you "solidified" the flywheel did your 348 rattle at idle in neutral with the clutch engaged? Or any other time?

 

My experience and associated comments with flywheel grease and component balancing which may be helpful:

http://www.ferrarichat.com/forum/showthread.php?t=152737

 

For what it's worth, thanks in advance for the howto. It will definitely come in handy when the time comes for me to perform the same job on mine.

 

Jm3, what is the name and location of the balance shop you recommend in Northern California?

 

Sounds like the way to go. Thanks Jay for the recommendation! After you had everything balanced did you have to still put heavy sides opposite to each other like the factory manual instructs, or was that no longer an issue? If you don't mind me asking, about what was the fee for the balance work? How much grease did you use with everything balanced? Do you still get the "rattle"?