Eliminating balance shafts
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Joined: Aug 2006
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From: Halli Wood
just cut the stupid belt, that was what I did, and I run 1 year and 4000 miles, with out any problems. Slight improvement in acceleration, very good mod!, and the best is that its free (if you have at least a little experience )
engine harmonics. need to do some reading if you want to understand anything other than what cowtownracer has said in laymans terms.
to elaborate a little: everything that rotates in the engine must be perfectly balanced. This goes against nature; nothing can be perfect.
If nothing is perfect you have to make do with what you have, and in order to offset vibrations from the revolution of the (mainly anyway) cam and crank shafts balance shafts are used. The balance shafts are turned by belts(egk's diy balance shaft delete
) and directly interfere with vibrations created by the cam and crank sensors. newtons law says for every action there is an equal and opposite reaction. the balance shafts negate that reaction by absorbing the reaction instead of the motor doing so. (a more accurate but less clear way to explain it would be the balance shafts create opposing vibrations to the cam and crank shafts)
there is still a ton of vibration no matter what you do, so they use balance shafts to offset the damaging vibrations that tend to perpetuate themselves (harmonics gets involved here) and use flexible materials in areas that are subject to extreme random vibrations (such as engine mounts) so the car doesn't rattle itself apart (or blow up, depending upon how off balance the internals are
) in a year or so.
that's why the OEM crank pulley is sometimes referred to as the harmonic damper, by the way. the pulley actually has this function built into it in the form of a rubber spacer between the hub and rim of the pulley. vibration produced by the crankshaft is amplified (due to physics laws) by the crank pulley, the rubber surround offsets (not completely, nature isn't perfect) these vibrations.
all in all you would be shortening the life of your engine. anything you do to remove safe guards is going to shorten the life of your engine. that's pretty much a fact of modding your car though, so MORE POWER!!!
to elaborate a little: everything that rotates in the engine must be perfectly balanced. This goes against nature; nothing can be perfect.
If nothing is perfect you have to make do with what you have, and in order to offset vibrations from the revolution of the (mainly anyway) cam and crank shafts balance shafts are used. The balance shafts are turned by belts(egk's diy balance shaft delete
) and directly interfere with vibrations created by the cam and crank sensors. newtons law says for every action there is an equal and opposite reaction. the balance shafts negate that reaction by absorbing the reaction instead of the motor doing so. (a more accurate but less clear way to explain it would be the balance shafts create opposing vibrations to the cam and crank shafts)there is still a ton of vibration no matter what you do, so they use balance shafts to offset the damaging vibrations that tend to perpetuate themselves (harmonics gets involved here) and use flexible materials in areas that are subject to extreme random vibrations (such as engine mounts) so the car doesn't rattle itself apart (or blow up, depending upon how off balance the internals are
) in a year or so. that's why the OEM crank pulley is sometimes referred to as the harmonic damper, by the way. the pulley actually has this function built into it in the form of a rubber spacer between the hub and rim of the pulley. vibration produced by the crankshaft is amplified (due to physics laws) by the crank pulley, the rubber surround offsets (not completely, nature isn't perfect) these vibrations.
all in all you would be shortening the life of your engine. anything you do to remove safe guards is going to shorten the life of your engine. that's pretty much a fact of modding your car though, so MORE POWER!!!
Last edited by DangerousDan; Jul 3, 2008 at 12:48 PM. Reason: clarity, if that's possible
engine harmonics. need to do some reading if you want to understand anything other than what cowtownracer has said in laymans terms.
to elaborate a little: everything that rotates in the engine must be perfectly balanced. This goes against nature; nothing can be perfect.
If nothing is perfect you have to make do with what you have, and in order to offset vibrations from the revolution of the (mainly anyway) cam and crank shafts balance shafts are used. The balance shafts are turned by belts(egk's diy balance shaft delete ) and directly interfere with vibrations created by the cam and crank sensors. newtons law says for every action there is an equal and opposite reaction. the balance shafts negate that reaction by absorbing the reaction instead of the motor doing so. (a more accurate but less clear way to explain it would be the balance shafts create opposing vibrations to the cam and crank shafts)
there is still a ton of vibration no matter what you do, so they use balance shafts to offset the damaging vibrations that tend to perpetuate themselves (harmonics gets involved here) and use flexible materials in areas that are subject to extreme random vibrations (such as engine mounts) so the car doesn't rattle itself apart (or blow up, depending upon how off balance the internals are ) in a year or so.
that's why the OEM crank pulley is sometimes referred to as the harmonic damper, by the way. the pulley actually has this function built into it in the form of a rubber spacer between the hub and rim of the pulley. vibration produced by the crankshaft is amplified (due to physics laws) by the crank pulley, the rubber surround offsets (not completely, nature isn't perfect) these vibrations.
all in all you would be shortening the life of your engine. anything you do to remove safe guards is going to shorten the life of your engine. that's pretty much a fact of modding your car though, so MORE POWER!!!
to elaborate a little: everything that rotates in the engine must be perfectly balanced. This goes against nature; nothing can be perfect.
If nothing is perfect you have to make do with what you have, and in order to offset vibrations from the revolution of the (mainly anyway) cam and crank shafts balance shafts are used. The balance shafts are turned by belts(egk's diy balance shaft delete
) and directly interfere with vibrations created by the cam and crank sensors. newtons law says for every action there is an equal and opposite reaction. the balance shafts negate that reaction by absorbing the reaction instead of the motor doing so. (a more accurate but less clear way to explain it would be the balance shafts create opposing vibrations to the cam and crank shafts)there is still a ton of vibration no matter what you do, so they use balance shafts to offset the damaging vibrations that tend to perpetuate themselves (harmonics gets involved here) and use flexible materials in areas that are subject to extreme random vibrations (such as engine mounts) so the car doesn't rattle itself apart (or blow up, depending upon how off balance the internals are
) in a year or so. that's why the OEM crank pulley is sometimes referred to as the harmonic damper, by the way. the pulley actually has this function built into it in the form of a rubber spacer between the hub and rim of the pulley. vibration produced by the crankshaft is amplified (due to physics laws) by the crank pulley, the rubber surround offsets (not completely, nature isn't perfect) these vibrations.
all in all you would be shortening the life of your engine. anything you do to remove safe guards is going to shorten the life of your engine. that's pretty much a fact of modding your car though, so MORE POWER!!!
a better explanation can not be written of this
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Joined: Aug 2006
Posts: 570
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From: Halli Wood
there only in there to eliminate a few vibrations people my not like (I cut the belt and the vibrations added were minimal and I could only feel it on WOT) stupid confort things companies make...
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Joined: Aug 2004
Posts: 929
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From: A
Just read what DD said.
To elaborate slightly, inline 4 cylinders are inherently unbalanced, as are 60 degree V6s (the next most common engine) and American-style V8s. 4 cylinders in particular aren't much better than single cylinder engines.
That's the reason for those huge weights on the crankshafts of 4 bangers (among other engines). Those weights are the most basic and essential vibration-reducing component. Those weights reduce (and almost eliminate) what's called primary imbalance. For reasons I shan't discuss, 4 cylinders (and others) still have what's called secondary imbalance.
Boxer engines (I think both 4 and 6 cylinder types) are inherently balanced, as are inline 6s and V12s. 90 degree V6s may or may not be inherently balanced, I don't remember. Whatever the case may be, 90 degree V6s are quite rare these days.
This wikipedia article is quite thorough, for anyone interested.
http://en.wikipedia.org/wiki/Engine_balance
Also a random fact, Mitsubishi introduced the first balance shafts in a 4 cylinder. This allowed much larger and more powerful 4 cylinder engines. Prior to balance shafts, 4 cylinders HAD to be small, weak and reasonably slow-revving.
My old car had the GM 2.5L iron duke engine. It did not have balance shafts and you sure as hell knew it.
To elaborate slightly, inline 4 cylinders are inherently unbalanced, as are 60 degree V6s (the next most common engine) and American-style V8s. 4 cylinders in particular aren't much better than single cylinder engines.
That's the reason for those huge weights on the crankshafts of 4 bangers (among other engines). Those weights are the most basic and essential vibration-reducing component. Those weights reduce (and almost eliminate) what's called primary imbalance. For reasons I shan't discuss, 4 cylinders (and others) still have what's called secondary imbalance.
Boxer engines (I think both 4 and 6 cylinder types) are inherently balanced, as are inline 6s and V12s. 90 degree V6s may or may not be inherently balanced, I don't remember. Whatever the case may be, 90 degree V6s are quite rare these days.
This wikipedia article is quite thorough, for anyone interested.
http://en.wikipedia.org/wiki/Engine_balance
Also a random fact, Mitsubishi introduced the first balance shafts in a 4 cylinder. This allowed much larger and more powerful 4 cylinder engines. Prior to balance shafts, 4 cylinders HAD to be small, weak and reasonably slow-revving.
My old car had the GM 2.5L iron duke engine. It did not have balance shafts and you sure as hell knew it.
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