[Supras] Lightweight flywheel+balancing

[berniek at technicaldevelop.com]

Yes, you are right on the premise that you think they will be careful.  No
doubt there are some, like the one in Oklahoma (R&L Machine?) used by
Arelene Lanman.  However, I found years ago that having a lathe and
Bridgeport, welding equipment saved a LOT of time waste, and doubts about
quality of work done outside.

I did find a decent shop to do some work, and had them resurface the head
and block.  But I've also seen too many instances where shops are a bit
careless.  As an example, a shop would not refinish camshaft bearing caps,
which I've done and have written about on this list.  They don't want to
understand that all of the wear is in the caps, and instead they talk
abopu align boring the cam journals, expensive and not necessary.

Getting the valve clearances right was a pain, and I can't imagine most
shops taking the time to do what we all read about with port cleanup,
correct valve jobs, and the patience to set clearances in shim and bucket
engines.  No doubt good shops exist, but here in North Central NJ they
seem few and far between.

Although the owner of the best shop I've found in Morris County NJ always
has a can of beer in his hand, he seems to not let it get to his head. 
The flatness of the head and block I can check with a precision
straightedge and feeler gauges.  Checking of flywheel and clutch I cannot
do without making up the ring anyway.

Making up the adapter ring for ball bearing to pilot hole adaptation on
the lathe takes about 20 minutes.

       BernieK

> or you could just drop it off at a machine shop ;-)
>
>
> ----- Original Message -----
> From: <berniek at technicaldevelop.com>
> To: <Supras at supras.com>
> Sent: Wednesday, January 31, 2007 5:59 PM
> Subject: Re: [Supras] Lightweight flywheel+balancing
>
>
>> While not as light as an aluminum flywheel, I got a chrome-moly flywheel
>> from AutoCom.  It a lot lighter than the cast iron stocker, and much
>> stronger.  The price was right, too, about half the cost of aluminum.
>> It
>> still needs to be installed as part of my JDM rebuild, now over a year
>> old
>> due to work considerations.
>>
>> When the inertia of the pressure plate is considered, the difference in
>> total angular inertia of the flywheel and clutch combination will not be
>> that much different than with use of an aluminum flywheel.
>>
>> Just a suggestion:  If you have a lathe, make up a ring which fits the
>> center hole of the new flywheel and a small ball bearing in the center.
>> If the ball bearing is sealed, take out the seals and grease, and put
>> clean oil in the bearing to minimize drag.  Put the ring and ball
>> bearing
>> in, put a shaft in the ball bearing, and stick the other end of the
>> shaft
>> in a vise.  The heavy side of the flywheel will roll to the bottom.
>> With
>> a Dremel tool, you can remove material from the heavy side to the point
>> where you can make the flywheel stop at any point, so its balanced.
>> Then
>> bolt the pressure plate on, and repeat the process with it.  Punch mark
>> them so they will go together during installation the same way.
>>
>> There is a way to do balancing in the car as well, which I did when
>> putting an aluminum flywheel in my Chevy powered Firebird.  Run the
>> engine
>> at the speed where the vibration is worst to get an idea of the
>> vibration
>> magnitude.  Then take the access cover off the bell housing, take out
>> one
>> pressure plate bolt, put a couple of washers under it, and reinstall it.
>> Run the engine again, and see if the vibration has gotten worse or
>> better.
>> Try this with each of the pressure plate bolts in sequence until you
>> find
>> the one or two at which the vibration is minimized.  Then change the
>> number of washers to obtain minimum vibration.  That worked like a
>> charm.
>> At one time I believe I saw a GM bulletin describing the same procedure
>> for balancing a Buick flex plate and torque convertor.
>>
>>            BernieK
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>
>