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CAUTION: Light flywheel on OEM crank.

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Old 01-21-2010, 06:54 AM
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Boozt
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Default CAUTION: Light flywheel on OEM crank.

Just thought I would throw this out there..... I lost a stock motor with FI and other mods at the track (road race). I was down in Milpitas for a tune on my Z With the new GTM long block and Osiris tune, (dumped the Utec) and the tunner and I were going over my mods. When I mentioned my light flywheel he speculated it may have contributed to my blown motor. He has seen a number of FI high HP cars with light flywheels that don't like stock crank balance over sustained higher RPM such as 30 min track session at WOT. Now that I have a balanced crank via GTM there should be much less to worry about (plus forged internals, blah, blah, blah....).
Anyway, the caution is towards runing a light flywheel on a stock crank and more so with FI. Ok, don't crank up the flamethrowers on me.....I am just passing on some interesting information I was given.
Old 01-21-2010, 08:19 AM
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davidv
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I do not debate what "somebody said." Cannot verify. "Somebody" is not here to support their claim.
Old 01-21-2010, 10:22 AM
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I'm still not understanding how a lightweight flywheel contributes to blowing motors. What's the reasoning behind this? It seems like your stock internals might have cause the blown motor over the flywheel.
Old 01-21-2010, 11:54 AM
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hellsoldiers08
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well some times people get what they call " balance engine" meaning everything runs smoothly and little to no vibrations from parts. I think what he is saying is because of the light flee wheel it caused the motor to have alot more vibration. When something is spinning and one side is heavier it can cause a rather big vibration from the moving montion( but i think not enough for the driver to feel). This is all what i think and i could be wrong. Just 2cents.
Old 01-21-2010, 12:24 PM
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musubi
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Originally Posted by hellsoldiers08
well some times people get what they call " balance engine" meaning everything runs smoothly and little to no vibrations from parts. I think what he is saying is because of the light flee wheel it caused the motor to have alot more vibration. When something is spinning and one side is heavier it can cause a rather big vibration from the moving montion( but i think not enough for the driver to feel). This is all what i think and i could be wrong. Just 2cents.
Ah, thanx
Old 01-21-2010, 06:05 PM
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hellsoldiers08
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did i get something mixed up?? lol
Old 01-21-2010, 06:07 PM
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BonesZ33
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any more solid info on this topic.. never heard such things.. I've only heard of having the correct counter weight on rotary type engines since they are rotating..
Old 01-21-2010, 06:27 PM
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jonnylaw
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I always thought that a lighter weight flywheel would cause less stress on the crank than a heavier stock one.
Old 01-22-2010, 04:04 PM
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Z1 Performance
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nm , post deleted

Last edited by Z1 Performance; 01-24-2010 at 05:08 PM.
Old 01-23-2010, 01:50 AM
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Quamen
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Originally Posted by hellsoldiers08
well some times people get what they call " balance engine" meaning everything runs smoothly and little to no vibrations from parts. I think what he is saying is because of the light flee wheel it caused the motor to have alot more vibration. When something is spinning and one side is heavier it can cause a rather big vibration from the moving montion( but i think not enough for the driver to feel). This is all what i think and i could be wrong. Just 2cents.

That doesn't really make sense in a centrifugal manner because a flywheel is round. In a longitudal manner I am fairly certian that the flywheel end is the heavy end stock and that a light weight flywheel would bring it closer to balance.
Old 01-23-2010, 02:29 AM
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Tac-M
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so, you blew up a boosted stock block on track .... that is nothing special to me. that is why i don't have boost in my track toy. flywheel has nothing to do with that.


also, please tell us what year is you car , and what additional cooling are you running .

Last edited by Tac-M; 01-23-2010 at 02:32 AM.
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