Strick

The manual talks about weights needing to be transfered from the old flywheel to the new one. Are these bolted on or welded? I don't think super glue will work :D

bogus

I think they are just slid into holes...

sraft

The weights are installed into holes that are on the perimiter. Get a new set of weights (~$1/weight) and place them in the same locations as the old flywheel. The LT1 was final balanced by trimming the flywheel with these weights, so if you don't do this, you could end up with vibrations.

Strick

When you say "installed into holes" what do you mean? Are they screwed or keyway, HOW? Thanks :cheers:

Strick

This also leads to the next question, If they balance the rotating mass of the engine by adding weights to the flywheel, then what do guys do about balance when using a single mass flywheel?

Strick

[QUOTE,I would assume that the weights are placed into holes of the primary flywheel (the one with the ring gear), and held in place when the secondary flywheel is bolted to the primary flywheel. Please correct me if I am in error.[/QUOTE]

Interesting, does that mean you can take the dual mass wheel apart? I've asked the question before with no answer, so I'll ask again, Fidanza makes an aluminum DUAL MASS flywheel. What is done about the weights off the OEM flywheel? Anybody have one of these?

Strick

[QUOTE
The manual describes the dual mass flywheel (36.2 lbs.) as being a primary and secondary system connected by means of two rows of torsional damper springs, with the interface riding on ball bearings. The six bolt holes in the secondary flywheel are for mounting the pressure plate. The manual does not mention how the weights are secured to the flywheel, nor does it show the connection of the torsional damper springs and ball bearings.

Regarding the Fidanza dual mass aluminum flywheel, the following link shows the flywheel in two pieces with holes for positioning weights. I have not seen a comparable example of the iron flywheel....(scroll to the end of this link): http://www.fasttoys.net/8498ybodytrans.html ][/QUOTE]

I have the Helms Manual and this is why I'm asking the questions about the flywheel and how to swap the OEM weights. That's a neat flywheel Fidanza offers, but the question remains about the weights. I'm sure someone here has the answers.

Strick

I sent an e-mail to Fidanza and asked about the weights on the OEM flywheels and how they address this problem. Here is his reply:

Tom,
Yes, the factory inserted pins in each individual
flywheel to balance each engine assembly. They varied
in size and quantity. This creates many different
balance weight possibilities. The balance weight
difference is minimal, but due to the design of the 6
speed it is important. The only way to obtain the
correct balance on any replacement flywheel for this
engine application is to match the OEM imbalance for
each individual engine. This is why we have on our
instructions to have the aluminum flywheel balanced to
the original. Any machine shop with a balancing
machine can determine the amount of weight and
placement of it, then fine tune the aluminum flywheel.
The Fidanza flywheel balance weight is determined from
checking many OEM flywheels and confirming with
factory specs to create a median.
Thanks, Dave
Fidanza flywheels

Strick

I also asked him how the weights are installed. His reply:

Hi Tom, The weight is one piece of steel that bolts to
the flywheel with three 5/16" bolts. There are no
pins. The factory uses the pins in addition to the
162gram offset to fine tune. The balance shop will
fine tune the supplied weightto get the same results.
The instruction sheet says to bolt the weight on with
loctite on the threads then have balanced.
Thanks, Dave
>

Strick

And my last question:

> Hi Dave,
>
> Looks like a Fidanza dual mass flywheel for me. Is
> it okay to use the info
> you gave me on our Corvette Forum? A lot of guys
> want to know this info.
>
> Thanks again for your time.
>
> Tom
>
Hey Tom, Sure no problem, The more people know about
this the better. Thanks, Dave

So, it looks like the best way to go is their dual mass aluminum flywheel at half the price of an OEM GM dual mass. I wonder if they are noisey, too? Now to find a machine shop that can balance a flywheel to match my OEM one.

Any chance someone has done this? A Fidanza dual mass aluminum flywheel on an LT1?

sraft

Strick,

Sorry I didn't get back to you right away - I hadn't checked-off email notification and lost track of the thread. Everything that the Fidanza guys told you make sense. GM flywheels are probably built to zero-balance and then you add weights to trim it to you're engine, effectively imbalancing it. Regarding the factory pins, I think that they have little tabs on them that deform when the pin is pushed into the hole. Some people have resurfaced the GM flywheel, but GM stated that this should not be done. From the description of the way it's put together, I would think that grinding/machining the surface would get all kinds of metal particulates in between the halves, resulting in a greatly shortened life.

Let us know if you go with the Fidanza. It would be great to have an actual dual mass alternative to GM $900 hunk of metal.


[Modified by sraft, 10:21 PM 11/20/2003]