Even with a balanced harmonic balancer, there can be different sizes. Big hunken
ones are good for a stroked motor or a workhorse or a super smooth Cadillac idle
and a lightweight one for quick revving motors. The correct name is vibration
damper, it smooths out the pulses from each piston firing off. Balanced
vibration
dampers have a cutout in them and are easily detected. The flywheel or flex
plate
on the otherhand will have weights welded on. They are not interchangable.
john dorsey wrote:
> let me add one thing, this is all true of our old trucks, but many newer
> vehicles Do have balance weight built into the harmonic damper (and the
> flywheel). I only add this in case someone trys to use a late model
> damper. I belive that all the small block chevys EXCEPT the 400 are OK,
> but I doubt any V-6s are.
>
> --
> John Dorsey
> Wauchula, FL
> '49 Chevy Panel http://www.strato.net/~jrdorsey/truck.htm
> '52 GMC Firetruck http://www.strato.net/~jrdorsey/fire/fire.htm
> '51 Chevy suburban http://www.strato.net/~jrdorsey/burb/
>
> Jack Halton wrote:
> >
> > Deve et al,
> >
> > The term "Harmonic Balancer" is something of a misnomer, as it doesn't
> > really "balance" anything. It is referred to in the GMC manuals as a
> > "crankshaft damper" which reflects it's true purpose, which is to dampen
> > torsional vibration from the crankshaft, inherent in any inline engine. The
> > bigger the "damper", the more rubber it contains, and the better it can do
> > it's job. The 235 has a longer stroke than the 216, so it needs more
> > damping. In theory at least, it's likely that by using a 216 pulley, the
> > damping effect will be reduced, perhaps causing the damper and pulley, as
> > well as the flywheel on the other end, to eventually loosen and come off.
> >
> > This happened to me with a stock 228 GMC engine, not from swapping
> > parts, but just due to normal wear and deterioration of the damper/pulley
> > assembly. It was not a pretty result, taking the fan and radiator out when
> > it happened.
> >
> > All of the above is mainly a concern at higher (>3000 RPM) engine
> > speeds. So it may be that you can get away with the smaller damper/pulley if
> > you don't push things too hard. Drilling the snout of the crank for a
> > retainer bolt would eliminate the problem, but you may be reluctant to do
> > this...at least be aware of the onset of a light "knocking" noise that seems
> > to come from the water pump area. It can often be traced back to a loose
> > damper/pulley.
> >
> > Jack Halton
> > 51 GMC 1/2 ton
> > Winter Park FL
> > ----- Original Message -----
> > From: "Deve Krehbiel" <dkrehbiel@kscable.com>
> > To: "OleTrucks" <oletrucks@autox.team.net>
> > Sent: Thursday, October 05, 2000 10:17 AM
> > Subject: Re: [oletrucks] Disquised 235's
> >
> > > My concern with adding a 216 Harmonic Balancer to a 235 is the "Balancer"
> > > part. The 235's HB is larger and has more centrifugal weight around the
> > > outer edge than a 216's. Is there any reason to be concerned about that?
> > > Would doing that result in an unbalanced engine and cause premature engine
> > > wear?
> > >
> > > On the hand crank issue, keep in mind that after 1950, they stopped
> > putting
> > > the hole in the grille and grille pan to recieve the crank.
> > >
> > > Deve Krehbiel
> > > Hesston, Kansas
> > > 1950 3100 * 1949 3600 * 1948 4400
> > > www.speedprint.com/Deves50/index.html
> oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|