EricL

AND

Quote:

Originall posted by Doom878

I address the mechanic as expert issue (and I'm not putting them down -- ok?

Linear analogy to rotational damper:


force -------> mass1 -------spring/shock----------> mass2.

An impulse to move mass2, is slowed down by the spring/shock, and mass2 starts moving slowly. Because it is a spring/shock, it will not continue to vibrate and thus start even more violent oscillations.

At the end of the exciting pulse, the mass2, slowly "dissipates" its energy in the rubber and imparts its energy in a slow/damped way back into mass1.

Just so you guys understand, there have been bridges and other structures built before chaos and non-linear dynamics were developed completely and these structures and bridges could be destroyed by light winds or other phenomena that any engineer at the time would have laughed at. What happens is vibrations can "excite" a system and/or in the case of a chaotic system, can force a system into unforeseen vibrational modes (with destructive consequences). The bottom line is, there are some things that seem harmless, but can cause catastrophic failure (I think I'll pass on the 12-page diatribe/dissertation on these systems). Unnatural resonance modes can create huge forces at a macro level with very small repetitive energy inputs (the energy is small but continuous and builds into a destructive force – hence damping gets to be very important.)

(Load, speed, and other factors can be of great import and if a damper was designed for the system, everything could fine until someone hit just the right load and rpm…)


Failure of the Tacoma Narrows Bridge in 1940



A lot of very smart engineers didn’t this there were any design problems. But, torsional resonance (in some part) caused this bridge to come down…




Needless to say, you can build a giant overbuilt bridge, and have a light wind bring it down (when all of the best engineers say it can't ever happen). I'll look up the info on that event if anyone is interested.

RE: techs knowing about stuff that they don't need to know in their day-to-day operations

To the folks that think an Acura tech should know the answer (perhaps he does…, but…):


Here is the problem -- they don't teach ASE certified mechanics about control systems design, non-linear dynamics, and time domain and vibrational analysis. So, just because I have a very "hip" mechanic that says, "you will be ok, doesn't insure that everything is fine" (Hey, maybe it is. I’m just pointing out that techs at dealers don’t usually read-up on Advanced Engine Analysis, non-linear dynamics, and modeling…

It's one more opinion and if they install it, it isn't like a client is off the hook (Example: My guys tossed on my headers -- what if had turned out that issue caused the exhaust valves to burn. Do you think that just having a mechanic say, "I'll put it on... I don't see a problem" will fix things with Acura when the engine needs a tear down?

This is not a hack at why Acura techs should spend years getting into mathematical chicken scratch. They are there to fix and maintain the cars, and that is priority #1 (and not a dissertation in engine resonance. They are there to fix the cars, not modify them (exceptions to speed shops, etc).

Look, if nothing else, I'm going to call Dinan and UR to ask some question about why they are telling different stories. But, outside of my purchasing a pulley myself and cutting it open, this is an open issue (at least based on what matt is telling me).

<------------------------------->



Matt, you say, "from what I’ve noticed looking at it there is no rubber or mechanism involved. i do think it uses an inertia ring like the photo though".

So, you say I've noticed that there is NO rubber or mechanism.

AND then you say

I DO think that is uses an inertia ring like the photo though.

Sorry to seem harsh, but the inertia ring is all you need to have a very effective damper.

So

1. Is it solid for sure (yes/no)?

2. Is is solid for sure (maybe, not sure)? (Please explain)

3. How is the unit like the picture as you indicate.


This is not some "mind fart"...

mattg

the inertia ring is welded or bonded somehow to the rest of the pulley. look at the last stock pulley pic and you will see a thin disc of metal on the outside. inside of that is the thicker ring, looks like nearly an inch thick. those pins or ?? that you see must play some sort of roll in the bonding of the pieces. like i said i haven't seen any evidence of rubber but i will examine it further when i have a little time. drags in 6 hrs.

Doom878

Wow I gotta give you guys credit. You guys sure put a lot of info and thought into your posts. That bridge example kicked ass.

I agree with what you say too that not all ASE certified and Honda certified mechanics know their stuff. You do have to feel comfortable with who you're asking and I should've specified that when you talk to a mechanic you talk to a well-reputed one. I'm confident with mine because he has to know his stuff very well since he has a night job teaching mechanics at a local university. I know he's not an engineer or anything but he knows his stuff. Besides if the car breaks down all you gotta do is swap back in the stock pullies and tell them "I was driving and the car just stopped driving."

Samer007

here is a pic of a blue one:



More

ZodiakTL

dampner or no dampner.. noone is gonna know for sure until one of us either blows the engine, or we all drive 50k miles and nothing happens... i dont think any one mechanic can give an authoritative answer on this.... companies like honda spend millions of dollars in research costs to make sure nothing goes wrong.. and things still do.... i.e. our trannies... so all these discussions only serve to make people more paranoid... its the same thing for the AEM pullies, they may not replace the crank pulley, where i suppose the effect would be most seen, if there were any, but the other pulleys are made on the same premise... lighter=more power... nothing is perfect, and for those of us who chose to put the UR pulleys on, we chose to be the guinea pigs... so the rest of the folks can either do the same or wait to see if all goes well or not... its the same for every other go fast product out there... just my .02c

EricL

I didn't say DON"T DO IT YOUR GOING TO BLOW YOUR ENGINE!!!!

I just said that a there were issues that could make it a VERY safe mod vs. a mod with some big questions. I get to hear about people with tranny problems all the time, so it would be stupid to not tell someone the potential good and/or bad consequences of a mod (and it doesn't even take $3500 for a new tranny to experiment on) . I think I've presented the advantages (in detail) and have also presented some of the possible pitfalls.

You seem intelligent, do you want more info or less info to make your own informed choices. If not for the "inconsistency" in statements between Dinan and UR, I wouldn't have even given this any more thought...

The issue here is just about finding out an answer to a simple question: Is the pulley solid, or is there an articulating chunk of metal inside it...



RE: the stock pulley:

**** If it's solid -- you’re ok (PERIOD)

**** If it's got a piece of metal inside that can "articulate", you now have a damper, and an engine can break in all kinds of different ways (hey, you think the tranny issue is messy…this could be nothing or a real problem….)

juice

I don't undrstand why it is so dificult to find out if the stock pulley is balanced or not!!!!!!!!!!!!!

Nashua_Night_Hawk

I think that EricL is more concerned that the stock crank pulley has a dampning device. The UR is 100 Balanced, no need to worry about the UR pulley is not balanced.

However, clearly the UR pulley does not have any kind of dampning device. So, if the stock Pulley does have one than UR pulley does not, then: "... ...Houston, we've got problem..."

ZodiakTL

well, i suppose the only way to find out for sure whether its solid or not, is to cut it in half. anyone wanna find out how much the stock crank pulley costs? just in case i cut it in half and then have to put it back on

BNut

Just remember that the installation of a pulley like this is VERY important.

AEM's pulleys did not cause alternators and power steering pumps to fail. IMPROPER installations caused them to fail. I have over 40k mile with the AEM pulleys, but guess what, I went to a reputable import shop that has a history of doing good work.

Unless AEM's pulleys are egg shaped, not balanced, etc, they can not cause the alternator or power steerin pump to fail.

They CAN however cause the battery to drain because of the insufficient amperage produced at idle in the V6 Accord.

Nashua_Night_Hawk

HELMS state specifically not to use impact wrench on the crank pulley. Not to remove the bolt or tightning it with an impact wrench.

Now... I can see that removing the crank pulye is a bitch It is torqued to 181lbft!!! but what about installing the UR crank pulley? There is no "boxed wrench insert" to hold it place while torqued.

I would love to hear from UR how to keep the UR pullye in place and get it torqued to 181 lbft!

Why no impact wrench, simply it would destroy the crank bearings

So, bad installation means messing up the crank bearings.

When I will go to the do the installation, I will go with HELMS instructions in hand, and make sure that the I and Mech would go through the HELMS instructions and 100% of those instructions are followed.

I do not want to mess up my engine becasue of an ignorant Mech or "quick-sloppy" work....

Be aware.

ZodiakTL

not arguing, but to put ur mind at ease, i'm pretty sure there is no way u can use an impact wrench with the amount of room there is in the engine bay... i'm pretty sure that is not a concern

Nashua_Night_Hawk

I think if you remove the passanger side wheel, the inner wheel well, you would expose the crank pulley big time.

Also, I saw a perforate piece of plastic (a big circle) in the wheel well, once cut you get access for the crank pulley.

As for me, I do not want to get that piece cut (mud and road gunk is an issue for me). I prefer to uninstall the whole wheel well and re-install it. I am may be a bit pickky..

ZodiakTL

well.. thats why i paid through the ass to have acura, and more specifically jens, do it

Doom878

For Accord that is correct.

mattg

mine was put on w/ an impact at tha acura dealer. i guarantee you that's how most mechanics will do it.



BTW, after further examination of the crank pulley, it does have a rubber layer, so it is a harmonic balancer. EricL and i are trying to find answers on this issue as we speak. hopefully we can get to the bottom of this.



my initial review, 14.32 @ 98.09.

my car loses traction between the 1-2 shift now.

it runs very smooth.

i think my mpg is going up substantially.

i don't wanna have to take the crank pulley off.

Doom878

Oh yeah. I forgot about that. I usually get gas every 4 days. I haven't gotten gas in like 5 and I'm just under half a tank.

Nashua_Night_Hawk

The issue of stock crank pulley having a harmonic dampner is something to worry about.... After all AEM does not make such crank pulley fearling problems with loss of the harmonic device...

Now please keep us imformed!

EricS

Why do people keep going off about 181 ftlbs? It ain't that dang tight. Get a 2' cheater bar and you only need to exert 90ftlbs, 3' cheater 60 ftlbs, etc.

One way to loosen it without a pulley holder, here's a trick the MR2 guys use. Put your breaker bar on the crank pulley bolt and rest it against the ground. Then just blip the starter. The torque caused by trying to start the car will easily loosen the bolt.

To tighten it, if you have access to the flywheel, just jam a screwdriver or such in between the teeth, then start cranking on the crank pulley bolt.

[disclaimer: do not hold me responsible for anything, if you try any of the above methods]

SiGGy

I see a fiberglass cutting wheel and a 6" circular saw in someones future.........



I'll have to agree after building many V8 engines, I would definetly do my homework (as I am) before doing the pullys. What does the helms book say it is, crank pully or harmonic balancer? On the chevys I've worked on the balancer and the pullys were seperate. 4 bolts held the pullys on to the balancer. Much easier to distinguish.

The reason one should not use an impact gun on the crank is because of the vibration/resonance you will send through the crank shaft when using it. It will defintely damage the crank bearings.

Someone in cali or FL goto a nice speedshop and ask their head mechanic what it is. He'll know for sure if it's a honda/acura shop. Of course anyone with a good electronic stethiscope \w digital sampler could just as easily compare a before and after with the pickup set directly on the block near the crank. Saying of course you know how to read it.

Or even a regular analog one if you have good ears. Hard to find a good mechanic that knows how to do that anymore...