Welcome all 928 forum refugees!
User avatar
By Crumpler
#22197
Is it ?
Am I the only one that has had issues getting it on?
I’ve heard it’s a bastard to get off, but none about getting it on.

I heated the hub well past 300 degrees and iced the crank as well. No joy times three. The directions show Greg’s hands sliding it on “without resistance “.
I’m not going to pound it on and chew up the crank key.
It’s going back in the box, I gotta keep moving.
User avatar
By worf
#22274
One time I had to 'square off' the key; it has some damage from a previous owner's wrench's sledge hammer.

My SOP with the ATI damper hub is to heat to 350°F and wipe the crank nose with some machinist's oil.

I also always remove the key and polish-away any corrosion on the crank nose with 2000 grit sandpaper.
User avatar
By maddog2020
#22287
when you heat it up, it can take a while. the surface temp might show 350 but it takes some time at that temp to expand. I had to heat mine to 375 for over an hour before it slid on.
User avatar
By Erik N
#22290
maddog2020 wrote: Wed Sep 30, 2020 10:44 pm when you heat it up, it can take a while. the surface temp might show 350 but it takes some time at that temp to expand. I had to heat mine to 375 for over an hour before it slid on.
Honey, what's that smell? Are you cooking something?

Just cleaning the oven, dear...
User avatar
By Crumpler
#22341
Ahhhhhhh.
Ok, I got it. Not being the most patient person, I was using the kitchen stove and my IR gun for surface temps.
Certainly didn’t leave it in there for an extended period.
But, at least I have graduated into not being the sledgehammer guy ;)
User avatar
By Shifted
#22387
What does it take to remove it once it's been installed? Standard puller?

Is there an alternative available? Maybe from the Hans camp?
User avatar
By worf
#22397
Shifted wrote: Thu Oct 01, 2020 12:23 pm What does it take to remove it once it's been installed? Standard puller?
It depends on the specific crank. Or, IOWs, the tolerance on the cranks was the product of 70s technology and the hub is - presumably - 21st century.

I’ve had some that pull off nicely with a puller and others that required heat. As I posted on tOS, when you reach for a long cheater for the puller that means you need heat.

Is there an alternative available? Maybe from the Hans camp?
Yeah. IIRC someone GB pissed off on tOS is making one... or at least designing one.
User avatar
By SeanR
#22426
He did make it and I've had it in hand. Very nice piece of kit. But at his quoted price to sell, plus the damper, it's going to be way more expensive than Gregs if we want to sell it and make any money doing so. We've got a machine shop here local that is looking at making some for us instead. Since I deal with Roger for 99% of my parts, I have doubts Greg will be willing to sell my any parts since he's not dealing with Roger any longer, so I needed to find another avenue.

Image

Image
worf wrote: Thu Oct 01, 2020 12:47 pm
Shifted wrote: Thu Oct 01, 2020 12:23 pm What does it take to remove it once it's been installed? Standard puller?
It depends on the specific crank. Or, IOWs, the tolerance on the cranks was the product of 70s technology and the hub is - presumably - 21st century.

I’ve had some that pull off nicely with a puller and others that required heat. As I posted on tOS, when you reach for a long cheater for the puller that means you need heat.

Is there an alternative available? Maybe from the Hans camp?
Yeah. IIRC someone GB pissed off on tOS is making one... or at least designing one.
User avatar
By Shifted
#22729
I spoke to the guy who made that prototype. He's getting a quote for a larger quantity. His instructions look good. As long as it fits and works, it will be a nice alternative.

Sean, he made the following statement on Rennlist in the Frenzy thread:

"My apologies, but I'm trying to get hold of the gentlemen (retired Engineer) who expressed interest in the design features of Torsional Vibration Damper Hub I developed. Please PM me so we can continue our dialog. Thanks! Geza"

In case he's referring to you and you're not following that thread.
User avatar
By Shifted
#25048
Update:

The hubs are going to production, ETC mid-December. It will be a hub, mounting hardware and tool sold as a single kit. The damper itself is a separate purchase (ATI Damper Shell 917020). The planned price for the hub/tool is $295, but he is offering an initial discount. I don't know how long the discount will be good for, nor how broadly it will be offered. All I know is that he said to "pass it on to other 928 folks".

I've committed to two of them.

If you don't have have his contact information and want me to get you in touch with him, send me a private message with your contact information and I will forward it to Geza. He didn't give me leave to share his contact information (and I didn't ask), so I don't feel comfortable doing that without permission.

If someone has more or better information, please share :)
User avatar
By Crumpler
#25333
Just saw the roll out thread on RL.
Looks great, I like the concept of the pre drilled holes and hardware to get the hub off easily, that’s smart.

Let’s see how long it takes GB to chime in ;)
User avatar
By Shifted
#25338
The thread was just closed until they can extort Geza. It's painful to see that because it hurts all of us when individuals are blocked from sharing.
User avatar
By Shifted
#25340
I "reported" DR Bob's post with this message:

"This action is blocking community improvement and sharing. A well executed personal solution should not be treated so poorly by a board admin. It alienates the exact kind of people that the forum needs in order to stay healthy as the previous generation of experts move on (or are driven out by these kinds of actions)."
User avatar
By Crumpler
#25342
Christ, your kidding, wait your not kidding.
User avatar
By Shifted
#25343
Did I misunderstand the use of the button? :)

When you hit the button, they display a notice:

"Note: This is ONLY to be used to report spam, advertising messages, and problematic (harassment, fighting, or rude) posts."

And the dictionary defines harassment (https://www.dictionary.com/browse/harassment) as, in part:

"an act ... of ... intimidation"

Blocking someone from sharing their personal solution, that others may find useful, until they pay an exorbitant fee (extortion) fits the definition of intimidation (https://www.dictionary.com/browse/intimidation):

"the act or process of attempting to force or deter an action by inducing fear"

It's not only trying to have that affect on Geza, but it's deterring others, myself included, from contributing for fear of being blocked, banned or extorted.

And that's all I have to say on that subject :)
User avatar
By Crumpler
#25347
Having re-read Geza’s thread, there’s no overt sales pitch and no mention of cost, just information.
Yes, I assume they are trying to build a case to shake him down for vendor fee.

Where’s Erik? Does he still have a mod role?
I would have more confidence in his opinion.
User avatar
By Shifted
#25350
The fuel pressure regulator thread has direct references to selling it and it's been left alone for a long time. I think there are some favorites being played.
User avatar
By worf
#25356
Greg Brown is a paying advertiser with a product being copied by a member. Thus one has to assume one message to IB would get the thread killed.

Note: I provide *no* *judgment* of right/wrong in the above. Just the basic facts and a logical progression.

Presently I’ll send PM to @Shifted with contact info so I can get two.
User avatar
By Shifted
#25368
I think that you're right. However, I wonder if it's really a "copy" or just a design similarity driven by the narrow margins of variance allowed when trying to match a shaft of specific dimensions to a widely available damper with specific mounting holes. Doesn't 928 Motorsports have a similarly designed adapter? Probably for the same reasons. Sometimes, even if you've never seen an alternative solution, and design yours from scratch, it ends up being pretty much the same as someone else's due to the hard boundaries of engineering.
User avatar
By worf
#25384
Shifted wrote: Wed Oct 14, 2020 1:21 pm I think that you're right. However, I wonder if it's really a "copy" or just a design similarity driven by the narrow margins of variance allowed when trying to match a shaft of specific dimensions to a widely available damper with specific mounting holes. Doesn't 928 Motorsports have a similarly designed adapter? Probably for the same reasons. Sometimes, even if you've never seen an alternative solution, and design yours from scratch, it ends up being pretty much the same as someone else's due to the hard boundaries of engineering.
“Reasonably obvious to those skilled in the art” is, I think, the operative phrase.

I think it has more to do with IB’s practices as demonstrated on their other platforms now being spread to Rennlist. Specifically, removal of any reference to any product/vendor/source not supported through a paying advertiser. The spread began about two years ago.
User avatar
By Crumpler
#25394
It’s not IB’s jurisdictional discretion to say if a product is too close in function or in appearance to another product. Bottom line, that is why patents and lawyers exist.
I also suggest that the moderator in question could have ran his concerns past his overlord handlers without locking the thread preemptively.
But that, is another example why most of us are here and not there.
The irony is that locking the thread only creates more buzz and product awareness.
User avatar
By worf
#25406
Crumpler wrote: Wed Oct 14, 2020 3:09 pm
The irony is that locking the thread only creates more buzz and product awareness.
https://en.wikipedia.org/wiki/Streisand_effect
User avatar
By Crumpler
#25410
Of course, you probably know the thread has now been wiped altogether.
That prompted me to post an additional thread ;)
User avatar
By Geza-aka-Zombo
#25510
Interesting discussion here - Here's a little history you might find semi-entertaining. A few months ago on RL, I inquired about Brown's product as I was interested in buying one. Being a Mech. Design Engineer (>35 years design in the Aerospace/Defense industry), I asked a few questions (before laying out $700) about the product and was subsequently accused of trying to steal his design. Funny reaction, considering I even suggested, as a design improvement, he add the features I eventually designed into mine for hub removal - no charge. I guess he really lost it when, after he stated he was so impressed with the lack of visible vibration of the ATI damper as compared to the OEM, I had to inform him that the damper weight on the ATI is not visible during operation, and can't be seen resonating, hence it looks so smooth - but it better be vibrating, or else it isn't doing its job - not that he would know. After being told I don't qualify to get him coffee or take out the trash, or something to that effect, I moved on and decided to design and build my own damper hub. Certainly wasn't going to send him my $$

For those who think I copied the design, I've never seen it other than pictures on RL - Interestingly, if anything, he copied the 928 Motorsports damper concept that was developed with ATI (I believe 928 MS was first, but am not certain - correct me if I'm wrong). In any case, I started with a clean sheet of paper, ordered an ATI Damper Shell, took my engine apart, modeled it up in my CAD system, generated a detailed drawing and went out for quote to get 2 prototypes made. Previously, I made contact with a 928 guy in Sweden who gave me measurements on some cranks he had so I could get a range for proper hub diameter sizing. One of the prototypes is on my car and the other I brought to Frenzy to see if there was interest. Another funny tidbit - in the RL post, one of Brown's allies even bragged that he had developed the product thru many revisions, as if that was a good thing. In my business, you get it right the first time - REV Dash - Initial Release, no revisions.

At Frenzy, I showed it to folks who were interested as they passed by my car - didn't hard sell it at all. A gentlemen thought Roger should see it and called Sean over, who seemed immediately interested, asking "how quickly can you get me 50". Roger eventually came and we discussed the product. After getting back I got a quote for larger quantities and gave Roger a price - he declined, stating he thought he could get one designed/made cheaper - I wished him luck. It was fine with me as I never was interested in making a business out of this, only to offer a solution to the 928 community. Even as of this morning, I wasn't sure I wanted to proceed, but decided I would with 20 pieces as I made a commitment to a few folks. I posted some pictures and installation instructions on RL with no indication the product was even for sale - I thought I get some PMs showing interest, which I did, making me feel better about committing ~$5K to machined parts.

The post was promptly locked, I was PMd by a moderator, with all kinds of questions about my intent and was told I'd be "put on vacation" if I tried to bypass the locked post - I didn't even understand what that meant - I'm so naive. I answered the questions as best I could, and just before sending the PM back, I added a statement that they need not worry, I will be going on a permanent vacation from RL. That's my story - thanks for reading
User avatar
By Geza-aka-Zombo
#25518
Now, as far as the hub itself, it is not a complicated part but there are some critical elements that need to be considered. Material, hub bore and tolerance, damper back spacing, fastener clearance to AC pulley, engine clearance, etc. Additionally, ATI is not forthcoming with information - normally a product will have an ICD (Interface Control Drawing) drawing which gives hole pattern dimensions, etc. They won't provide one. I successfully worked around this. Material is a key element as it impacts several thing, including the problems people are having getting Browns hub on and off. If folks want to design there own - have at it, I gave a few hints. I ordered 20, I think ~7 are taken, if anyone want one, please let me know - Hub, fasteners and tool - $295 (If I were to order 50, it would be ~$70 cheaper - add that to a $300 damper you buy and it's quite a savings for a superior product. Cheers.
User avatar
By Shifted
#25539
Crumpler wrote: Wed Oct 14, 2020 4:32 pm Of course, you probably know the thread has now been wiped altogether.
That prompted me to post an additional thread ;)
I missed my window to reply, as they have now closed your thread as well. They are accomplishing their objective.
User avatar
By Crumpler
#25565
Meh, it’s fine, let it be my RL swan song. And the jack boots keep marching.
User avatar
By SeanR
#25577
Geza-aka-Zombo wrote: Wed Oct 14, 2020 11:40 pm Now, as far as the hub itself, it is not a complicated part but there are some critical elements that need to be considered. Material, hub bore and tolerance, damper back spacing, fastener clearance to AC pulley, engine clearance, etc. Additionally, ATI is not forthcoming with information - normally a product will have an ICD (Interface Control Drawing) drawing which gives hole pattern dimensions, etc. They won't provide one. I successfully worked around this. Material is a key element as it impacts several thing, including the problems people are having getting Browns hub on and off. If folks want to design there own - have at it, I gave a few hints. I ordered 20, I think ~7 are taken, if anyone want one, please let me know - Hub, fasteners and tool - $295 (If I were to order 50, it would be ~$70 cheaper - add that to a $300 damper you buy and it's quite a savings for a superior product. Cheers.
I think it's a great product, absolutely well designed and a fan of what you are doing. From a business standpoint, until the debacle with Greg and Roger, we were able to purchase them for less than what you are selling them for allowing us to make a little bit of money on them charging just a bit more than what you are selling them for. It only makes sense for us to go a different route since we are in need of making $$ when we sell them to customers. If we were to add 10-20% on top of the purchase price on yours, we would be about what Greg sells them for and it just doesn't make sense on our end. Sorry man, was excited to use a new and well designed product. It's all about the margins.

One of our own here in DFW has been looking at getting the hubs made for years and finally decided to get it done after the latest fiasco so he got in contact with his machinist. I don't know the price point his are going to come out at but I know it's going to be a fraction of the cost and put the entire damper assembly quite a bit less than both options, at least that's been the plan. Who knows what will really happen though.
User avatar
By Geza-aka-Zombo
#25579
Thanks for the reply, Sean - for the record, the price I originally quoted Roger was significantly less than what I'm selling for (because of my lower cost for increased order quantities). Since my original quote, I've gone to another vendor whose price is even less - by a lot (they are making my production units). Also keep in mind my product includes a tool, which is not free, and saves the customer >$40. It's too bad Roger didn't want to continue the dialog. Again, good luck with your design.
User avatar
By SeanR
#25613
Geza-aka-Zombo wrote: Thu Oct 15, 2020 11:02 am Thanks for the reply, Sean - for the record, the price I originally quoted Roger was significantly less than what I'm selling for (because of my lower cost for increased order quantities). Since my original quote, I've gone to another vendor whose price is even less - by a lot (they are making my production units). Also keep in mind my product includes a tool, which is not free, and saves the customer >$40. It's too bad Roger didn't want to continue the dialog. Again, good luck with your design.
All it takes is sending him an e-mail with revised prices. I've not heard anything more than what I posted above. Last I heard was a small savings for ordering 50 of them which is still $12,500.00 sitting on the shelf and that's a lot to keep in inventory when you only sell 6-8 a year. Hell, with Gregs, he'd sell 3 or 4 quickly when I would post in the Docs group about them when I was installing one. But that's only a couple times a year.
User avatar
By SeanR
#25615
As to the tool. Which I do like. It would get used maybe a few times a decade and only on those cars that I installed one on and it returns for its next belt job. I've had two of Gregs that I've needed to remove in the last year due to time on belts and I just used my normal hub puller with no issues. I honestly don't need another tool sitting in the box not being used for years at a time. Again, I love the concept.
User avatar
By Geza-aka-Zombo
#25624
Understood about the tool - it's more for the DYIer, like me.

Funny about the sales numbers - I've got commitments for 10 since yesterday, which I appreciate very much to the point where I upped my order from 20 to 30 sets, and am reducing the retail price by $35 to $260.

I'll email Roger and give him a new quote. Thanks!
User avatar
By SeanR
#25648
I think in the last 4 years I've installed around 8 of them. My biggest issue was always having to wait for someone else to get their shit together and get them shipped out, otherwise I could have sold more I'm sure. I'll have to ask Roger how many he sold over the last few years and see what his numbers are. From my perspective, I'd not want to buy in bulk if I knew I wasn't going to be able to sell them in a timely manner. I hate having to keep inventory on hand for expensive stuff anyway, I'd rather spend that $$ on cigars. I am seriously thinking about picking up a couple from you just to keep on hand in just in case. Let me mull it over a bit. What's your pricing w/o the tool?
User avatar
By Geza-aka-Zombo
#25660
Folks should realize, regardless of how their OEM damper rubber looks, it's shot. Mine looks fine, but the rubber is hard as a rock - it's not doing its job anymore at all.

My price from the machine shop includes the washer, so that's paid for either way, I suppose I would cut $10 off for the threaded rods, washers and nuts on the tool. Big fat washers with holes in them are always good to have around...
User avatar
By linderpat
#25861
Lets talk for a minute about the technical aspects of the damper - specifically, what harm is caused by an old worn out one? Can it harm the internals of the engine, and how do you know?
User avatar
By Geza-aka-Zombo
#25878
linderpat wrote: Fri Oct 16, 2020 6:46 am Lets talk for a minute about the technical aspects of the damper - specifically, what harm is caused by an old worn out one? Can it harm the internals of the engine, and how do you know?
The crankshaft has natural (resonant) frequencies (Fn), one in bending and one in torsion (twisting). Because it is well supported in bending via the main bearings, torsional Fn is normally the major concern – not that bending can be ignored. It’s just that, due to the physical design, the torsional Fn is normally much lower than the bending Fn. Lower Fn = greater deflections/displacement = greater stress. Greater torsional deflection in the crank (at Fn) also impacts the cam timing on the 928 as the cams are driven by the end of the crank that’s resonating/displacing.

The crank itself has very little internal damping - when it is exposed to a combustion forces at/near its Fn (which it will because the torsional Fn falls within the engine RPM operating range), it is going to “take off” and vibrate excessively at certain engine speeds, which increases stress in the crank significantly, due to the increased deflection. The Torsional Vibration Damper (TVD) is designed to dissipate this vibratory energy.

The TVD consists of a spring/mass/damper system tuned to the Fn of the crankshaft. As the cranks starts to vibrate at its torsional Fn, the vibration energy is transferred into the TVD, and the rubber portion, which acts as both the spring and the damper, dissipates vibratory energy, converting it through friction, to heat.

As the OEM TVD ages, the rubber (which is the spring/damper component) degrades and its properties change. Its damping capabilities (ability to dissipate vibratory energy) go down and its stiffness changes, which changes its Fn, so it is no longer tuned to the Crank. The result is that the crank sees increased stress which, over time builds up increasing fatigue, and ultimately failure in the crank. Another potential failure mode is due to what’s called cross axis vibration.

In a perfect world, when the crank is vibrating in torsion, that’s all it would be doing. But, because the various components involved are not perfectly square and balanced, the torsional vibration also imparts vibratory energy perpendicular to the crank rotation axis. So, not only is the crank twisting, but it is also bending at the front, external to the engine block. This external bending potentially causes premature wear on the crank seal and forward main bearing. Since the amount of cross axis vibration energy is basically proportional to the torsional vibration energy, employing a properly performing TVD reduces both, and the damage they cause. Because fatigue, by definition slowly builds up over time, I don't think there is a way to know the impact of a failing TVD, without systematic engine teardowns and inspections?
User avatar
By linderpat
#26157
Thanks for the explanation Geza. Does metal in the oil indicate wear from this?
User avatar
By Geza-aka-Zombo
#26187
I would think metal particles in the oil has multiple causes ranging from normal wear to catastrophic component failure, depending upon the specifics. A compromised TVD is probably on the low end of the range, closer to normal wear, as it is only during specific engine speeds that the crank resonance occurs and the TVD does it's thing. Based on research I've done in designing this hub (I'm not really in this industry) the Torsional Fn of cranks are generally higher in the rpm range (>4000 rpm), so, unless you are consistently running up in the high RPM range, failed TVD is not really a problem. However, when you do run the engine up with a bad TVD, bad things will happen to the crank and mating components.

If you think about it - and I don't know the history at all, just speculating - why do engines have these TVDs to begin with? I can see it now, 100+ years ago early during engine design and development, cranks started to break mysteriously. The engineers didn't know why until they studied what was happening, and figured out what the problem was. Then, they developed the TVD solution - problem solved - and moved on to the next issue.
User avatar
By Crumpler
#26298
Geza, now I’m getting pm’s on RL, people wanting to know more about “my” product :)
I will forward to you. I guess some thought it was my product in the aftermath of all mods dirty work.
User avatar
By Shifted
#26299
Crumpler, please send me details on the damper you are developing and selling. Thanks.
User avatar
By Landseer
#26310
Does there exist a vibration sensor that a hobbyist could use to assess for themself the vibration, say before and after installation?
User avatar
By Landseer
#26339
Lol.

No. really, 25 years ago there was maintenance technology to monitor bearing wear status in high speed packaging equipment by measuring vibration.

If somehow measurable on 928, before / after data could illustrate the need to replace. I get that they are all bad at this point. A bit of data would drive that point home. You'd sell more.

Kudos, btw, you sound like a really competent engineer!

Regarding whiner. Its a pattern that goes back years!
The same self proclaimed engine expert tried to discredit the pk tensioner, Constantine's black sea coupler to prevent thrust bearing failure, water pump solutions. and even fuel line replacement that was perfectly adequate for our application. Tries to beat down competition the wrong way for own gain. Bad case of not invented here syndrome. And a lack of understanding of the level at which engineering is performed.
User avatar
By JMW928
#26390
maddog2020 wrote: Sat Oct 17, 2020 11:52 pm the SR9000 Spincterometer is pretty accurate. Just ask Sean about it.
Yes, butt not everyone has, uh, access to it. 🤣
User avatar
By Geza-aka-Zombo
#26410
Landseer wrote: Sat Oct 17, 2020 10:43 pm Does there exist a vibration sensor that a hobbyist could use to assess for themself the vibration, say before and after installation?
Kind of - in my industry we use these SlamSticks a lot for data recording, for example during flight tests to record vibration and shock environments - Starting at ~$1K, it's pretty cheap for a big company, not so much for me, though I did consider getting one at one point to do exactly what was proposed - Before and after empirical data - could be used on the TT also testing the different TT bearings.

https://www.mouser.com/new/mide-technol ... slamstick/
User avatar
By Geza-aka-Zombo
#26412
Crumpler wrote: Sat Oct 17, 2020 9:28 pm Geza, now I’m getting pm’s on RL, people wanting to know more about “my” product :)
I will forward to you. I guess some thought it was my product in the aftermath of all mods dirty work.
Thanks - sorry you got in the middle, but I appreciated your RL post where you came to the defense of me posting the product I developed. Perhaps I'll PM you my email address in RL - feel free to PM it to those who contacted you, or not - whatever works easiest for you.

Rob Edwards has 17 inch phone dials custom made yo[…]

Hot Water Pressure Washer

You know you need it. You want it. In fact.....you[…]

I just heard a 992 Turbo for the first time today […]

Thanks Chris, yeah while the plan is low boost sys[…]