Need a flywheel for my 348 Challenge

Yup Mitch we are in complete agreement:

Summary and recap:

DMFW can absorb vibrations that SMFW cannot
DMFW can be converted back into a SMFW without excessive risk
The risk is not zero with respect to bearing loads
Some drivers will not like the vibrations of a SMFW


Now in the meantime what the are we going to make those darn three seals out of? The current material is just not acceptable. I think a round or square cut rubber or viton o-ring would just get bound up and ripped apart between the two shafts.

 

This has become interesting as all points made have good merit.
The other cars you spoke of that are converted to solid FW, do they also have a dampner on the front of the crank? If this is the case, the DMFW is only a shock loading devise. One thing that I think is getting lost is the weight of the grease doing the dampning, not the mass of the spring loaded parts.
Try the thin square cut o rings under the teflon ones, much the same as the 355 uses in the TOB / slave cylinder, to expand the teflon rings. As I mentioned, I have seen this done before on other cars when they were quite new. Some of these cars appeared to have never been apart, so I question if it was done on assembly at the factory. I still contend that there is something else that is just not right regarding the seals as there are so many that do work correctly and remain dry. This is not saying that they are a good design, but if the shaft is running out of true or the flywheel is shaking around then even the best designed seal will leak.
I am forced to think back to when I was first cutting my teeth on Ferrari race cars, and the saying that was thrown at me every time I wanted to change something regarding design. "So you think you know more about this than the design engineers that spent many millions designing this car?" What it made me do is take a very hard and long look at what I wanted to do from a sceptical view point. In a number of instances I was right due to the advances in technology, but it did make me think a lot. Sure, it had something to do with the fact it was the first 250 GTO and worth 8 figures. That statement made by Dr. Bodin has stuck with me for many years now, and is used to critique every design change I do.
Thank you all for the excellent debate! Wonderful food for thought by all.
Fatbillybob, I will shoot you pics of the car today, I was under a deadline the last couple of days.
Dave

 

Yes! Though of course it still remains a wear point, and over time/ usage will require replacement or repair.

Totally and enthusiastically agree.

That said, engineering is all about compromise. So, if your particular performance goals or operating environment is different from the designers, change it to your liking. i.e. run 100% distilled water (with water pump lube mixed in) in the cooling system if you live in Southern California, or tweak the suspension to favor race track handling over highway comfort.

However, Ferrari is a business, and Bean Counters do determine design or content frequently. In the particular case of the triple seal, my experience is that they fail and cause other issues rarely but occasionally. Say about 1% of all 348's I saw over a decade (8 of 80+/- chassis). Subset of racecars, 1 in 12 over seven years (yes, seals were replaced as standard proceedure when performing major clutch system overhaul, not just a disc, so we may have changed some that were on the way to failing, hard to say). It's just natural that as these cars age, seal replacement is required. Or, as Dave mentioned, there may be run-out issues too.


Best regards,

Rob Schermerhorn

 

Guys,

I agree and disagree with the millions of $ to design and why I would know any better. But, I am truely a cynic. I totatlly agree with your statement without exception if you add in the clause, "as long as it is the cheapest way Ferrari can make it and get away with it." You see you can't design that part, that car "any better for any cheaper". I have experienced alot of cars and Ferraris/Italian cars are the worst made cars in modern world. I'm a nobody. Do I think I can make a better wiring harness than Ferrari? YOU BET! Does anyone think any of those Ferrari millions were spent on making any GTS ferrari top not leak? Feraris get huge attention and service by owners and still leak. You could find a old 280zx rotting in the "pick a part" junk yard with better seals of its T-tops. Can I make a better Fusebox than the one in my Mondial Cabriolet? Absolutely! And who slaps those 348 Geraboxes together other there anyway. Remember I'm nobody and I have fixed the same problem in 4 of those boxes. Who engineered those 355 exhaust headers? Ferrari leather sucks. The leather in my jeep was better after 70,000miles and standing on it with skiboots than the Ferrari leather in any of my 3 Ferraris with less than a total of 70,000 miles between the 3 cars . I can design that better too. The list goes on. At Ferrari I have no idea where the thinking stops but there is no evidence past the inception of a concept that anyone is thinking.

 

You pose a damn good arguement! Once Fiat moved in things did change quite a bit. Having watched the workers at the factory for a week straight, it leaves one question, why? Seems Ferrari is one of the lowest paying jobs that can be had in the car manufacturing in Italy, but an avenue into the automotive market. So say a few of the locals.

 

You're all making me sort of wish that I wasn't running an AP twin plate race clutch in my car. It weighs nothing compared to the original, revs like a motor bike and I love driving with it...now I find out I'm destroying my engine? *sigh* maybe I shouldn't read this forum!

 

Aircon,

Please put your old crappy Ferrari clutch back in. Also your car runs more solid in the feel with about 500lbs of balast in the front bonnet. Then maybe my slow POS 348 can keep up with you on the race track!

 

Sounds like a plan. Are you sure 500lbs is enough?

 

and yet we still love them!!!

Vincent.

MD

Great to hear that everything worked out for the best.

 

That is what this place is all about. Ferrari owners helping each other out. Especially the 348 brotherhood. LOL.

 

Sounds intriguing!

 

Dave or Rob, do you have a source for OD o-ring for 355 DMFW.