Harmonica balancer.....

mrvette

Phantom of the Opera
Joined
Mar 24, 2008
Messages
15,194
Location
NE Florida
I got a what seems to be elementary question to some of the ME's on this site.....but I ask it anyway.....

in back of the engine we have a flex plate tied to a heavy converter, or a flywheel tied to a heavy clutch set up of some sort....

SO in front, just why is the front 'ballancer have a rubber insert in there?? WTF?? back end don't need it, that's where the power goes....why the front???

so ME it would seem to make a slightly larger/heavier thing and bolt it on forever....CASE CLOSED??? it's either balanced or NOT why the rubber in front????

:hissyfit::banghead::gurney:
 
I got a what seems to be elementary question to some of the ME's on this site.....but I ask it anyway.....

in back of the engine we have a flex plate tied to a heavy converter, or a flywheel tied to a heavy clutch set up of some sort....

SO in front, just why is the front 'ballancer have a rubber insert in there?? WTF?? back end don't need it, that's where the power goes....why the front???

so ME it would seem to make a slightly larger/heavier thing and bolt it on forever....CASE CLOSED??? it's either balanced or NOT why the rubber in front????

:hissyfit::banghead::gurney:

It's a (torsion) damper, not a balancer. Big difference in function. (Yes, I know a 400 and a 454 have a balance weight on them but that's irrelevant for the discussion.)
 
I got a what seems to be elementary question to some of the ME's on this site.....but I ask it anyway.....

in back of the engine we have a flex plate tied to a heavy converter, or a flywheel tied to a heavy clutch set up of some sort....

SO in front, just why is the front 'ballancer have a rubber insert in there?? WTF?? back end don't need it, that's where the power goes....why the front???

so ME it would seem to make a slightly larger/heavier thing and bolt it on forever....CASE CLOSED??? it's either balanced or NOT why the rubber in front????

:hissyfit::banghead::gurney:

It's a (torsion) damper, not a balancer. Big difference in function. (Yes, I know a 400 and a 454 have a balance weight on them but that's irrelevant for the discussion.)

Yes, I have heard the term DAMPER, but I don't understand why it works, as in at some RPM< the thing has to be fighting the crankshaft length and con rod pulses.....the concept don't make a whole lot of sense to me....
 
All about the firing order- the cylinders fire and make pulses that try and twist the crank. One would not be a real big deal, but when multiple cylinders fire it sets up a vibration in the crank.

Here is an article from ATI that explains it better than me:

http://www.atiracing.com/products/dampers/damper_dinan.htm

Good article, and funny in that ATI and I are old friends from when he owned a transmission shop in Silver spring Md.....just not 4 miles from me....

I knew Jim Beattie and Sherman Slye back when....after about a 15 year absence from the scene, I needed to have a 400 rebuilt again....only had 300k miles on it, so I walk into the store/waiting room, corner Sherman, and say 'this trans has to have some sort of extended warranty on it, really loud to get attention, he looks at me knowing he knew me.....and I continued on that it was 300k miles and 15 years, and it don't snap second gear good as it used to.....whole group went to laughter.....:rofl::bump: you know how it is, zing our buddy time....:tomato:
 
Working in machine shops for years. I've used different methods to reduce vibrations while cutting metals. Rubber straps clay/dumdum and even bungy cords. If you let vibrations run free they start small and then build in a few seconds. I've purposly let a part run free and you will see an irregular finish on the surface. Something you may not know is castiron is a deadner compared to steel. So remember a fly wheel is cast. Also any assembly at the rear has more mass, which equals better absorption. With an automatic transmission the torque converter is filled with oil, another absorber. So why rubber on the harmonic balancer. Simply it fools or gives the effect of a larger piece of iron. Another point, I've run steel weldment machines. Steel will absorb frequences, but not as well as cast iron and cast iron does not absorb as well as rubber and rubber not as well as oil. Oh what about oil filled balancers?

Ralphy
 
Working in machine shops for years. I've used different methods to reduce vibrations while cutting metals. Rubber straps clay/dumdum and even bungy cords. If you let vibrations run free they start small and then build in a few seconds. I've purposly let a part run free and you will see an irregular finish on the surface. Something you may not know is castiron is a deadner compared to steel. So remember a fly wheel is cast. Also any assembly at the rear has more mass, which equals better absorption. With an automatic transmission the torque converter is filled with oil, another absorber. So why rubber on the harmonic balancer. Simply it fools or gives the effect of a larger piece of iron. Another point, I've run steel weldment machines. Steel will absorb frequences, but not as well as cast iron and cast iron does not absorb as well as rubber and rubber not as well as oil. Oh what about oil filled balancers?

Ralphy

I love this forum, it's like going to M/E school, years ago, when I had a chance of understanding some lecture, here I get the information and understand without the krazyness.....
 
Just run that engine to 7000rpm without a balancer and you'll immediately understand what it does and why you need one :D
 
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