Saw it in a thread about the Dart block buildup.

http://www.atiperformanceprodu...2.htm

What exactly does it do, I guess it has something to do with harmonic damning, feel free to address that too...

-PHiZ

 

It is a fluid filled dampner for the crank. The fluid in the dampner takes vibrations out of the crank. Vibrations rob alot of HP, plus they are hard on internals.

 

who wants to do a group-buy on these? i want one.

 

how much does it weights? because if is heavy then wouldn't that contrarest the idea of getting a lighter flywheel?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GZERO &raquo;</TD></TR><TR><TD CLASS="quote">how much does it weights? because if is heavy then wouldn't that contrarest the idea of getting a lighter flywheel?</TD></TR></TABLE>

Yes it is heavier and will add weight to the rotational mass ...Look at it this way , if you have a lightened flywheel then your actually not adding weight your just bringing it back to stock weight anyhow. If you were refering to my Dart build then the reason I went for it was to keep crank harmonics in check in high rpm situations. Not as much for for longevity but for oil pump fatigue prevention. With all the oil pump gears shattering I got nervous and felt this would help that from happening while keeping the motor perfectly balanced and vibration free(assuming all the prior balancing was done correctly). Also think about how much weight is on the flywheel side of the crank and how little there is on the crank pully side.. That alone will cause a secondary crank harmonic(vibration/woble) of the rotating assembly.
I have been researching oil pump failures now and have come to find out that my therory was not completely true and that the real reason is that the stock g rotor pump can suck oil vapor into itself at high rpm if theres a bubble in the system. Now that theres that vapor in there it gets compressed like a rotary engine and actually combusts. So from what I have learned so far is that the real reason the oil pump gears are shattering, is detonation in the oil pump itself at high rpm. Hope that kinda makes sence to you guys It does in my head..lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tbone &raquo;</TD></TR><TR><TD CLASS="quote">

Yes it is heavier and will add weight to the rotational mass ...Look at it this way , if you have a lightened flywheel then your actually not adding weight your just bringing it back to stock weight anyhow. If you were refering to my Dart build then the reason I went for it was to keep crank harmonics in check in high rpm situations. Not as much for for longevity but for oil pump fatigue prevention. With all the oil pump gears shattering I got nervous and felt this would help that from happening while keeping the motor perfectly balanced and vibration free(assuming all the prior balancing was done correctly). Also think about how much weight is on the flywheel side of the crank and how little there is on the crank pully side.. That alone will cause a secondary crank harmonic(vibration/woble) of the rotating assembly.
I have been researching oil pump failures now and have come to find out that my therory was not completely true and that the real reason is that the stock g rotor pump can suck oil vapor into itself at high rpm if theres a bubble in the system. Now that theres that vapor in there it gets compressed like a rotary engine and actually combusts. So from what I have learned so far is that the real reason the oil pump gears are shattering, is detonation in the oil pump itself at high rpm. Hope that kinda makes sence to you guys It does in my head..lol</TD></TR></TABLE>

Yeah, makes pretty good sense, you decided to sacrify engine aceleration for longevity, it is a good choice depending on what you use your engine for.
I also thought about that if you have this on the side of the crank and the lightweight flywheel on the other, if you balance your rotating assambly and you balance both ends of the crank it might be a super smooth engine, right?

and this liquid filled damper might absorb vibrations cause by high RPM and not by unbalanced engine.

Cool concept, cool idea, cool product.

thanks Tbone

 

wow, excellent explanation, Tbone. now what can be done to remedy it?

also, for anyone who thinks that the benefits of a good harmonic damper don't outweigh the "detriments," think about this: how much power and response is wasted overcoming additional friction due to harmonics without a good damper? my bet is more than enough to make this worthwhile. add in the cost of new bearings and other worn components... .

a nice group-buy price, and this should complement my ~7.5lb flywheel nicely.

 

What was the group buy price? I am to lazy to look.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by slofu &raquo;</TD></TR><TR><TD CLASS="quote">wow, excellent explanation, Tbone. now what can be done to remedy it?

also, for anyone who thinks that the benefits of a good harmonic damper don't outweigh the "detriments," think about this: how much power and response is wasted overcoming additional friction due to harmonics without a good damper? my bet is more than enough to make this worthwhile. add in the cost of new bearings and other worn components... .

a nice group-buy price, and this should complement my ~7.5lb flywheel nicely. </TD></TR></TABLE>

I don't think you gain anything from the killed vibrations and all that, but I do believe that it increases the life of the engine by a lot, which is something VERY good for a lot of us that build High performance engines to last a long time both at the street and at the track. That should be sufficient reason to buy it (off course, if you're one of us "daily driven people")