GregBBRD

I do.

Thanks for being patient.

JWise

No problem - don't want to rush perfection. Thanks again!

dr bob

Yes. The correct spelling, I remembered after looking at a 3300-series rack today, is Don Bently.

For those playing along at home, Don Bently was one of the world 'gurus' of vibration analysis for machinery. His company, Bently-Nevada, offers world-class detection and analysis systems for rotating machinery. He and his team operated a mini-university in Minden, Nevada (south of Reno and Carson City) that offered training in the science and methods. As luck would have it, I was working on a gas expander at a project site just south of Reno, one with a habit of tossing turbine blade tips. So I spent some time in Minden doing finite element analysis runs on the turbine wheels to add another dimension to the work Don and his group were doing for us. It was a pretty serious education.

The company has been absorbed by the great GE empire, and Don has since moved on to the afterlife.

FredR

Bob,

My spelling was "diplomatically" corrupted! I am mighty impressed.

Bently is Mr Vibration Analysis - a true rock star in his field as it were. I dare say other companies make such kit but I have never seen or worked with such because the oil majors I have worked with specify B-N and nothing else. Always worked first time straight out of the box unless you got the wires crossed.

I remain confused about the "one size fits all concept". Does that mean my GTS damper might have been a better bet after all [unless the fitment is mechanically different]?

Still struggling to understand how such kit can stop HP robbing timing errors- presumably by absorbing vibration energy pulses it minimises the tendency for the crank to wind up under torsion?

Update- just found some interesting articles on the ATI website- seems these things come into their own from about 5700 rpm onwards and that for systems that work as designed. I get the impression these things are engine specific tunable and this makes me wonder if the implications of bolting on superchargers are fully understood.

Rgds

Fred

Speedtoys

OK Greg...put one next to my alternator...k?

Chris Lockhart

You definitely have me thinking about mine as well Seth. I just torqued my crank bolt last weekend wouldn't you know. LOL. Would've been a great time to replace it with the ATI unit.

Carl Fausett

No problem, Seth.

Please allow me the opportunity to give you a comparative price for that item if you do decide to look into it.

GregBBRD

How does one tune for resonance when you don't know the actual resonance values for what you are working with?

ATI obviously offers different hardness "O" rings to "tune" their dampers, yet they don't even offer different dampers for different strokes and rpm ranges on either small block or big block Chevy cranks....where huge amounts of each crankshaft variation was made in the thousands and thousands, if not millions.

Every crankshaft design is going to have a different resonance....so unless you test each crankshaft, it's a guessing game, at best.

I'd submit that any "random" change, by guessing, you could be making things worse instead of better, right?

GregBBRD

You need to compete with my quality, before you worry about competing with my price.

I've bought dampers and hubs from ATI....and rejected their hubs.

I'm through my 3rd revision of the hub.....trying to make it perfect.

Guy

Just to further confound the color discussion on stock dampers. My 81 had light blue. My 79 has black. The 79 appears to be steel while the 81 is aluminum

Carl Fausett

I'm sure I will have no trouble with either one.

But Greg, I'm curious: when I first posted about our new dampener that we were having ATI make for us several years back you hated on it (not really a surprise, pretty automatic with you).

Now you post you have been buying them apparently 10 at a time, and finding defective hubs (says you) and having to revise the design also.

Odd - if they are that bad, why are you buying them? And what made you change your opinion from back when I posted the first time about them, such that now you are using them too?

I have bought and installed a few, and always been impressed with their quality and their tech support when I needed it. I like ATI. They do a good job for us.

eohrnberger

Hi!

I realize that this is a thread for 928 crank accessory drive damper, but I've got a '91 944-S2, which is 1/2 of one of these engines. Is there a suitable replacement for the 3.0L M44 inline 4?

The shop has got mine for belts and water pump, when they pulled the crank accessory drive damper, pointed out that the rubber between the 2 halves of the pulley is showing its age, and appears to be pretty close to letting go.

Any hints, pointers, or suggestions, greatly appreciated.

Rocinante

Thanks all for the education provided in this thread. No doubt a surprise to my high school physics teacher, I actually understood most of it!

RajDatta

I have an S2 harmonic balancer for sale if you are looking.

Speedtoys

Do I still have one in the queue?