SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: el mojado on April 29, 2018, 09:23:06 PM
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Would I be ok running a stock 454 balancer for a full roller 496? I fired up my engine and it had a bad vibration. I removed the balancer and noticed it had no weight in it. Which balancer is good to run? Do I NEED SFI in a cruiser?
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Need to know if it’s internal or externally balanced
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What rotating assembly?
Does your flexplate/flywheel have a balance weight?
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Just going to throw this out there.
It's difficult and expensive for crankshaft manufacturers to make molds and dies to produce properly designed end counterweights with enough mass in the correct location to balance the heavy internal components. This problem is compounded by increasing the stroke.
Increasing the stroke increases the distance between the center of rotation and the rod journals. Not only does this add mass to the crankshaft (where you don't want it), it moves the mass of piston and rod assembly further away, from the center of rotation, as well.
To counteract this, the mass of the counterweights need to be increased and/or moved further away from the center of rotation as well. Packaging constraints limit the size and shape of the counterweights, it needs to fit inside the engine block.
Externally balanced engines will have the required mass added to damper (balancer) and to the flexplate/flywheel. Internally balanced engines, requiring additional counterweight mass, will have Mallory metal ( https://en.m.wikipedia.org/wiki/Mallory_metal ) slugs installed in the counterweights, to provide the additional required mass.
Adding Mallory is very costly, therefore internally balancing this way is most often NOT done to engines that are not max-effort builds.
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I figured out that I had an internally balanced set up. Installed correct balancer and flexplate and vibration is gone
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