Thread: 283-327-305? harmonic balancer

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Are a 283-327 and 305 balancer all the same? If not what is the difference? I am told to put a 283 balancer on my 350 to make it respond better out of the turns. Can anyone help make me smarter in this area?

Thanks

First of all, it's a harmonic damper, not a balancer. It uses an outer ring of metal and a metal inner hub, separated by an elastic material to allow the outer ring to move slightly back and forth in relation to the inner hub. This slight movement cancels out the small harmonic vibrations created on each power stroke. When a cylinder fires, force is imparted to the rod journal of the crank and the metal has enough elasticity that it bends slightly, yielding to the pressure from the piston/rod. It will only bend so far though and when it meets enough resistance, it springs back the other way, past center until it again meets enough resistance to make it spring back the other way. If left unchecked, these harmonics will destroy the crankshaft in short order. The outer ring on the damper performs this service for the crank.

The longer the stroke, the further the crankpin can bend. That's why you see bigger dampers on longer stroke motors.

You can use the 283 damper on your 350 and take your chances. It may work well and it may not. I can certainly understand wanting to reduce the flywheel effect from the larger damper.

Perhaps some other members of the board can share some direct experience in this area.

GM Performance parts sells a 6 3/4 damper

6272221 6.75" Torsional Damper
This cast iron torsional damper (harmonic balancer) is used on most 1969 and later production 305 and 350ci small-block V8s. It is recommended for V6/90º racing engines and V8 applications with limited clearance. 6.75" diameter balancers have also been used successfully on drag racing small-blocks in classes which permit the use of cast iron dampers. The timing mark is 10º before keyway center line.

I agree with Tech, playing with dampers could cause problems.

If you want to dampen (instead of damp) the engine vibration....... just wait till you blow an engine because of harmonics....you'll be P*****

Be sure you don't put a 400 damper on any other small block, they're externally balanced on the damper and flywheel. I've put bigger dampers on engines and had no trouble.

Are all stock 350 "harmonic dampers" the same size, I just checked a motor I just recieved ($free.50) and noticed that damper was smaller than the other ones that I have.