OK,,stupid guestion

[DAREDEVIL]

I always wonder, why if an engine is internal balanced , does it need a fluid dampener ???

Like i said,,just curious .

[Chris]

No engine "needs" a fluid dampener. And the only difference between an internally balanced engine and an externally balanced one is the proper counterbalance weights on the balancer and rear crank flange.

The "balancer" is actually a harmonic dampener. Every object has a natural resonant frequency. And excited in a certain fashion, those vibrations manifest themselves as harmonics- integer multiples of the resonant frequency of the object. And like the singer breaking the glass, those harmonics can compound until physical damage occurs. Thus the damper.

The "balancer" on your engine may or may not be participating in the dynamic balance of your rotating assembly, but all of them exist to dampen the harmonics that might otherwise lead to significant damage.

[DAREDEVIL]

Thanks, interesting to know.

So with an internal balanced engine i need a reg balancer not a fluid dampener ?

And what is or are the best ones ???

does it matter, or are they all the same ?

[DAREDEVIL]

I kind of like this one .......

ANY THOUGHTS ?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=370298081538&ssPageName=STRK:MEWAX:IT

[Chris]

The engine can't tell if there's fluid or rubber in there. They both dampen vibrations. And the only aspect of the damper that has anything to do with internal/external balance is the bob weight. And the damper itself can't discern if the weight is on the crank or on the inner hub of the balancer.

It's all in what you prefer- or who's story you like the best. Most builders use a non-fluid balancer as there have been reports of less perfect dynamic balance with the fluid units. But I'm sure you'll find just as many that will tell you fluid is the way to go. The only thing for sure is to buy an SFI certified piece.

[Chris]

I kind of like this one .......

ANY THOUGHTS ?

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=370298081538&ssPageName=STRK:MEWAX:IT

I've used that exact piece before. I personally wouldn't turn it 6K for an extended period of time but they're much better than a stock piece. Good pleasureboat piece. Wouldn't use it on a race engine.

My preference is for an internally balanced crank. I think you get better and more uniform balance when the compensating weights aren't hung all the way out on the ends. And I think that reduction in torsional movement results in longer life.

[Raylar]

Please remember there are no Stupid Questions! Only Dumb Mistakes!

Best Regards,
Ray @ Raylar

[PatriYacht]

ATI is the dampener I would buy.

[RedDog382]

ATI is the dampener I would buy.

Same here. ATI makes dampeners for both internal and external balance engines. ATI was the recommendation of Jay Signore who was the head of maintenance of the IROC fleet in NASCAR a few years back.

[MERPerformance]

http://www.klmperformance.com/fluidampr/harmonic-fluid-damper-fluidampr.htm
There you go. They make them for diesels, talk about harmonics. I have used them for many years.
I myself do not externally balance anything over a 4.000" stroke. I feel anyone that uses a counter weighted flywheel or balancer is lazy and not wanting to take the time and effort to balance the engine internally. You are taking that extra weight hanging out on both ends of the crankshaft along with the distance from the crank center. I have seen large stroke engines come through my doors with externally balanced cranks, the bearings are not always in the best shape. Stress cracks can also develope from these problems.
http://www.sterlingperformance.org/22.html
Look at the Scientific Atlantic Dynamic Signal Analyzer, It will tell you what harmonic balancer will be best for that appilcation.

[offthefront]

Please remember there are no Stupid Questions! Only Dumb Mistakes!

Best Regards,
Ray @ Raylar


I knew I had a purpose in Life .....:sifone:

[Velocity Vector]

I knew I had a purpose in Life .....:sifone:

That is the stupidest thing I have heard you say so far. Bada Boomp,,,:seeya: