Pulley removal/Prices/Shocked

[4AU4LIFE]

Well after attempting to remove my BBSC pulley, with NO success, I decided to take it to the stealership and let them tackle the job.
Luckily I work for a company that owns a Acura shop(Duval Acura) so I called them and got a quote on it from them. Being the good consumer and thrifty shopper I then called the only other Acura shop(Acura of Orange Park) in town and did the same.
The first call netted me a return call in less than 30 mins with a quote of $210. I was satisfied with that but waited the other price also. The call to the competitor and was told only one person wrote up service for NSX's and he was busy but would promptly call me back. Well, if you consider 6hours promptly, then that's what it was. The person sounded rather young and unsure of himself. I slowly explained to him 2xs of the job I needed done and was told to hold on just a moment. Ten minutes later he comes back and sounds even more confused than ever. He said that he couldn't really give me a quote because the labor book didn't list that job. Something as simple as swapping crankshaft pulley's blew his mind. Finally acting frustrated he states, 'Well bring it in and I'm sure we can do it for around $400-$500!!.' I was in total shock. Needless to say, my car didn't go there for the work.
This is what shocked me. When I picked up my car this morning they had put the old (BBSC) pulley in the car and I looked down at it and was blown away. The OEM balancer was grooved for the splines on the end of crank, the aluminum pulley wasn't!!! It was only lined up with the key weight. I was a little more than disturbed when I saw that. I hope that all current and future BBSC buyers are aware of this and don't have a problem.

 

[Yellow Rose]

Fear Not

This is what shocked me. When I picked up my car this morning they had put the old (BBSC) pulley in the car and I looked down at it and was blown away. The OEM balancer was grooved for the splines on the end of crank, the aluminum pulley wasn't!!! It was only lined up with the key weight. I was a little more than disturbed when I saw that. I hope that all current and future BBSC buyers are aware of this and don't have a problem.

Maurice - before you spout off about something incorrectly again, I will take a few moments to explain the basics of splined vs keyed fits of a pulley onto a shaft. I'm an ME, so go with me on this.

The reason a pulley / shaft is keyed or splined is to resist the rotation of the pulley on the shaft. What resists the rotational force is the keyway or the splines via tangential contact surface area. For an item that is heavy (such as the cast iron factory pulley assembly), you need lots of tangential surface area, and this is accomplished with multiple splines. This is because comparatively speaking, the factory pulley has a greater polar moment of inertia that will take more rotational force to accelerate and will produce more counter-reactive forces when decelerating.

In contrast, the aluminum BBSC pulley is much lighter; therefore, has less rotational inertia; therefore, needs less tangential contact surface area; therefore, a keyway is perfectly adequate.

Simply analogy.....a twelve-point cap screw can resist more stripping torque on the head than a six-point cap screw. Why? More contact points between the socket and the cap screw's head.

So, all the BBSCers with the aluminum hub, 92NSX got you worked up for nothing. 92 - in another thread you pointed out that "I always look for little stuff to correct you on". Well, as long as you post misleading information, you bet I will correct your mis-posts. OK, maybe it wasn't misleading because what you posted was correct. However, your post may have needlessly raised concern with some BBSCers that might've resulted in a swarm of phone calls to MB. My post here is to caveat your post and explain that splines are not a must have on the lightweight aluminum pulley. You were making an apples-to-oranges comparison, that needed correcting.

 

[MiamieNeSeX]

Re: Fear Not

This is what shocked me. When I picked up my car this morning they had put the old (BBSC) pulley in the car and I looked down at it and was blown away. The OEM balancer was grooved for the splines on the end of crank, the aluminum pulley wasn't!!! It was only lined up with the key weight. I was a little more than disturbed when I saw that. I hope that all current and future BBSC buyers are aware of this and don't have a problem.

Maurice - before you spout off about something incorrectly again, I will take a few moments to explain the basics of splined vs keyed fits of a pulley onto a shaft. I'm an ME, so go with me on this.

The reason a pulley / shaft is keyed or splined is to resist the rotation of the pulley on the shaft. What resists the rotational force is the keyway or the splines via tangential contact surface area. For an item that is heavy (such as the cast iron factory pulley assembly), you need lots of tangential surface area, and this is accomplished with multiple splines. This is because comparatively speaking, the factory pulley has a greater polar moment of inertia that will take more rotational force to accelerate and will produce more counter-reactive forces when decelerating.

In contrast, the aluminum BBSC pulley is much lighter; therefore, has less rotational inertia; therefore, needs less tangential contact surface area; therefore, a keyway is perfectly adequate.

Simply analogy.....a twelve-point cap screw can resist more stripping torque on the head than a six-point cap screw. Why? More contact points between the socket and the cap screw's head.

So, all the BBSCers with the aluminum hub, 92NSX got you worked up for nothing. 92 - in another thread you pointed out that "I always look for little stuff to correct you on". Well, as long as you post misleading information, you bet I will correct your mis-posts.

LOL

 

[4AU4LIFE]

I was wondering how long it would take you(Andy) to have something to say about my post.
I do appreciate you explanation about it. I'm not an ME so I guess I'm stupid or so you would like to think.
I understand what you were saying and already realized that but was simply making a statement about what the BBSC comes with. Nothing more, nothing less.
BTW, try to be a little quicker on your corrections of my posts, it took you a couple of days this time. Then again, maybe you were to busy correcting others.
Have a great day.

 

[Yellow Rose]

I'm not an ME so I guess I'm stupid or so you would like to think.

Looks like my sarcasm is rubbing off on you.

I understand what you were saying and already realized that but was simply making a statement about what the BBSC comes with.

Oh, so since you have sold your BBSC, you are the official TV commercial spokesperson vs letting MB's website do the talking?

BTW, try to be a little quicker on your corrections of my posts, it took you a couple of days this time.

My PC at home crapped out, so for the time being, I only visit here and check e-mails M-F. But believe me, I wished I could've replied some fifty-nine views of your post before I did. Wonder how many were BBSCers that are scratching their heads in wonderment over the weekend? At least from my post forward, I have "saved" their curiosity.

Have a great day.

I will.....I'm driving a forced induction NSX. Sorry, couldn't resist that one. Peace.

 

[KGP]

Oh, so since you have sold your BBSC, you are the official TV commercial spokesperson vs letting MB's website do the talking?

With all due respect, there's really not that much information on the BBSC web, and has not been updated since 6/03. In fact, nothing at all in there regarding the pully. However, I certainly understand why, as MB has quite a workload and is not exactly an HTML giant anyway. With that said, I surely do appreciate your explanation about the pully, as I have wondered about it myself.

 

[Yellow Rose]

Website Details

With all due respect, there's really not that much information on the BBSC web, and has not been updated since 6/03. In fact, nothing at all in there regarding the pulley.

Perhaps I should not have made a reference to a website for details. MB's website does not detail every last nuance of his kit, neither does MJ's website of his kit (that has yet to materialize), neither does CT's website of their kit. Afterall, those are details that they designed, not us.

Kinda like "Oh my gosh everyone, the hardness of the spider coupling's elastomer insert is only 70 Durometer on Brand X's kit but it is 80 Durometer on Brand Y's kit." My position is as long as it works and does not age-crack, what difference does it make how hard the rubber is? As long as the BBSC hub does not shear off the keyway, what difference does it make if it is not splined? Answer - it makes no difference from a technical perspective.

92NSX had a misfortunate experience with the BBSC and despite him getting a free engine repair, in my opinion, when he discovers something about the kit that he doesn't like (even if that part works just fine) he posts about how "blown away" or agast he is. I admire his enthusiasm and thirst for knowledge; however, let's not be too subliminally biased when posting about the BBSC. He got a fresh engine, was to receive the updated SS box, but sold his BBSC and subsequently points out its "flaws" that are not flaws because.....?

 

[MiamieNeSeX]

Re: Website Details

With all due respect, there's really not that much information on the BBSC web, and has not been updated since 6/03. In fact, nothing at all in there regarding the pulley.

Perhaps I should not have made a reference to a website for details. MB's website does not detail every last nuance of his kit, neither does MJ's website of his kit (that has yet to materialize), neither does CT's website of their kit. Afterall, those are details that they designed, not us.

Kinda like "Oh my gosh everyone, the hardness of the spider coupling's elastomer insert is only 70 Durometer on Brand X's kit but it is 80 Durometer on Brand Y's kit." My position is as long as it works and does not age-crack, what difference does it make how hard the rubber is? As long as the BBSC hub does not shear off the keyway, what difference does it make if it is not splined? Answer - it makes no difference from a technical perspective.

92NSX had a misfortunate experience with the BBSC and despite him getting a free engine repair, in my opinion, when he discovers something about the kit that he doesn't like (even if that part works just fine) he posts about how "blown away" or agast he is. I admire his enthusiasm and thirst for knowledge; however, let's not be too subliminally biased when posting about the BBSC. He got a fresh engine, was to receive the updated SS box, but sold his BBSC and subsequently points out its "flaws" that are not flaws because.....?

Well written once again Andy. Keep these wannabe go fast guys in line.......

 

[DONYMO]

Andy, I understand that the BBSC eliminates the harmonic balancer in favor of this pulley (I think) you are talking about.

Is it ok to remove the harmonic balancer's function from the engine?

 

[KGP]

I hear ya.

I respect the points you made, and appreciate them. As to the web and the kind of information, I do believe there is information that should have been posted there, but wasn't. As we now know, the original SS box was flawed and did not manage the timing correctly. In one of my not too recent conversations (8/03) with MB he stated: [paraphrase] "Didn't you read my notice about not running your BBSC equiped car above ~5,500 rpm?" Answer: "That's news to me." Because of the serious nature of the SS box flaw, I explained that I felt an notice should be posted on his web and also to post a link on Prime notifying owners of the issue. Subsequent to my discussion, I have questioned well over a dozen early model SS box BBSC owners as to whether they got any such notice that was mentioend to me. Answer: "Huh?" or "No." My point is that it is pretty easy to make availble relevant BBSC (or any other product) support information available via the web, and I certainly would have liked that bit of information before 8/03.

Originally posted by AndyVecsey
Afterall, those are details that they designed, not us.

Are you infering that you have something to do with the BBSC design?

Thanks for your past and future contributions, both publicly on the forum, and privately to me in the past.

 

[Yellow Rose]

Andy, I understand that the BBSC eliminates the harmonic balancer in favor of this pulley (I think) you are talking about. Is it ok to remove the harmonic balancer's function from the engine?

What I have been told but have not confirmed, is that the Acura Legend comes with a solid hub from the factory. What I have been told but have not confirmed, is that the Legend and the NSX share oil pan gaskets. If this is true, one might infer that a solid hub on the NSX is perhaps acceptable. There is an accrued mileage in the "hundreds of thousands" of miles with BBSCed NSXs. I have not heard of a single crankshaft episode related to the BBSC solid hub. I would also venture that many of these cars visit the track and / or get goosed on the street. So there is some credence to an NSX maybe not needing a harmonic balancer. If so, then why does it come with one from the factory? If in fact the bottom end of the Legend's and NSX's engine are of similar geometry, and the Legend has a solid hub, perhaps Tochigi added the harmonic balancer to the NSX for insurance. With Honda's conservative reputation, they figure that an NSX owner will push their engine harder than a Legend owner would.

 

[DONYMO]

From a mechanical engineer's standpoint, what does a harmonic balancer do? Does it reduce vibration frequencies or something along those lines? Would problems related to lack of a harmonic balancer be isolated to the crankshaft?

 

[KGP]

... what does a harmonic balancer do?

From a quick Google search:

Crankshafts vibrate with a twisting motion due the torque variation that results as each cylinder fires. This vibration is at its worst at some critical RPM. On a V8, this RPM is typically in the 4-5000 RPM range. If you operate the engine at this critical RPM without a harmonic balancer excessive vibration will eventually BREAK THE CRANKSHAFT. DON'T LEAVE IT OFF.

A harmonic balancer modifies the vibration characteristics of the crankshaft and flywheel assembly. They are made from of a heavy steel ring mounted over a thin layer of rubber on the outside of a center hub. The rubber acts as a spring. The ring twists on the rubber to cancel out crankshaft torsional vibration. Some energy is removed as heat in the rubber but the balancer's primary function is to store energy and return it to the crankshaft at just the right time to suppress vibration.

Can you confirm anything from the above text, Andy?

 

[Yellow Rose]

Are you infering that you have something to do with the BBSC design?

I saw pix of the prototype BBSC two years ago, before it was unveiled at NSXPO 2001. I still remember who was in the room when MB showed us in Dallas. We were like a bunch of giddy children waiting for Christmas presents. At that time I was more interested in the mechanical aspects of the kit, having since become rather intimate with how the Comptech kit bolts together in a very different fashion. When I saw the very first BBSC kit in action at Acura of Brookfield, MB and shared ideas on mechanical components. Specifically he asked me to look into some different coupling arrangements. I came up with a an idea or two; however, his crown jewel of the spider coupling with elastomer insert is better than my ideas. So to answer your question, I did not have any direct involvement with the BBSC design, per se. On the other hand, when he was building my engine last year there were (and technically still are) some serial number 001 firsts, with respect to various component configurations of the BBSC kit. Each step of the way MB and I discussed what should and shouldn't be done. So in that sense then maybe I had a little involvement in the design of the kit. But let's be realistic, although I had the final say of what parts went on my car. It was his tireless devotion to perfecting his kit. Even afterwards, there were a few things I decided to do differently but identical in original function.

Thanks for your past and future contributions, both publicly on the forum, and privately to me in the past.

You're welcome, and thanks for the thanks.

 

[Zishan]

Originally posted by AndyVecsey
When I saw the very first BBSC kit in action at Acura of Brookfield, MB and shared ideas on mechanical components. Specifically he asked me to look into some different coupling arrangements. I came up with a an idea or two;

Tisk tisk, someone didn't proof read.

 

[Yellow Rose]

From a mechanical engineer's standpoint, what does a harmonic balancer do? Does it reduce vibration frequencies or something along those lines? Would problems related to lack of a harmonic balancer be isolated to the crankshaft?

Let's take our friend the shock absorber. Technically the term is dampener because it dampens ocsillations. The energy of the shock is absorbed into the fluids in the form of heat which is dissapated to the atmosphere. (Technically, they are not anti-sway bars, they are called anti-roll bars, but I digress.) For a simple mass-spring-dampener system, the tire is the mass, the coil is the spring and the shock absorber is the dampener. In theory, without a dampener if a mass is excited (vibration term from Mechanical Engineering) the mass-spring assembly will oscillate forever. Well, not forever, but you get the picture. Hav you ever seen that 1962 Cadillac roling down the street going boing-boing-boing-boing as the bumper goes up-n-down 12"? The cause is no or bad shock. Is it determental? No. Is it uncomfortable ride? Depends on the occupants of the car of what the amplitude and frequency of the oscillation is.

The above paragraph relates to linear motion. For a rotational analogy replace the wheel / tire with rotating elements of the drivetrain - transmission gears, clutch, pistons / rods - and you have the mass. Replace the suspension coils with shafts and you have the spring. Replace the shock absorber with the harmonic balancer and you have the dampener.

So in my Cadillac analogy one may infer that a harmonic balancer isn't required. Well, in some situations it simply is not. But what about the situation where the amplitude and frequency of vibration is high, then a harmonic balancer would be required. But careful, the torsional vibration analyst considers a harmonic balancer a mass and a spring. What if in the computer model it is replaced with an aluminum solid hub? The spring is gone but the mass is considerably reduced.

Assuming I have not put you to sleep, to answer your questions.

Does it reduce vibration frequencies or something along those lines?

It can, but its main function is to absorb vibration energy. For the layperson the two functions are the same; however, technically they are different.

Would problems related to lack of a harmonic balancer be isolated to the crankshaft?

Not necessarily. The torsional vibration engineer can "tune" a system to shift stresses so they happen at different RPM points and at different places in the drivetrain. Say, I just thought about something. People "criticize" the lack of the factory harmonic balancer in the BBSC. Show of hands.....how many of you brag about that super lightweight flywheel? Guess what you just did? You violated the engineer's tuned system by shifting the stress point from point A to point B within the drivetrain. But noooooobody warns against a lightweight flywheel do they?

 

[Yellow Rose]

Minor Detail

Can you confirm anything from the above text, Andy?

.....If you operate the engine at this critical RPM without a harmonic balancer excessive vibration will eventually BREAK THE CRANKSHAFT. DON'T LEAVE IT OFF.....

That assumes you operate the machine at a constant speed for all of its life. A car engine is different.....you pass through stress points every time you drive you car. However, you pass through those stress points so fast (mili-seconds) that the engine does not have time to become damaged. Now granted, over time, there is a phenomenon called "stress creep" that may catch up with you, but that is really a different sector.

 

[DONYMO]

Thanks

Thanks Andy...very enlightening

 

[sjs]

What I have been told but have not confirmed, is that the Acura Legend comes with a solid hub from the factory. What I have been told but have not confirmed, is that the Legend and the NSX share oil pan gaskets. If this is true, one might infer that a solid hub on the NSX is perhaps acceptable.

But not wisely IMO.

...There is an accrued mileage in the "hundreds of thousands" of miles with BBSCed NSXs. I have not heard of a single crankshaft episode related to the BBSC solid hub.

With all due respect, which is plenty, the combined miles of cars running a BBSC has little to do with whether there are long-term consequences to deleting the harmonic balance. There are very few with significant BBSC mileage and none with 100k.

...If in fact the bottom end of the Legend's and NSX's engine are of similar geometry, and the Legend has a solid hub, perhaps Tochigi added the harmonic balancer to the NSX for insurance. With Honda's conservative reputation, they figure that an NSX owner will push their engine harder than a Legend owner would.

And I suppose a BBSC equipped car will be less so?

As I recall, you have already modified your stock pulley to accept the wider belt, and I believe that is the only prudent thing to do because everything else is speculation and second-guessing the engineers who designed it.

 

[4AU4LIFE]

It seems I have started a very good little thread in which we are all learning something, myself included.
You (Andy) are correct about me receiving a fresh motor. And what is wrong with that? It was destroyed because of the fault of another individual, not myself. I do believe that is why they took out an insurance policy against that very thing.
I did choose to remove the system due to lack of support and communication and fear of what would happen later down the road if anymore problems arose. I couldn't chance it. I'm not on MB's christmas list I'm sure.
Either way, I'm very happy with my current set up and hope you are too. I wish you nothing but many trouble free boosted miles.

 

[WOODY]

As I recall, you have already modified your stock pulley to accept the wider belt

is this a reference to the MJ pulley available through dali?

 

[sjs]

As I recall, you have already modified your stock pulley to accept the wider belt

is this a reference to the MJ pulley available through dali?

Not directly. Andy had one done custom and MJ later started offering an equivalent solution.

 

[chudson1549]

Do your research,
the BBSC is NOT the only SC that replaces the pulley. GruppeM SC replaces the pulley also....or should I said the pulleys just like the BBSC.

 

[sjs]

Do your research,
the BBSC is NOT the only SC that replaces the pulley. GruppeM SC replaces the pulley also....or should I said the pulleys just like the BBSC.

Well, that is interesting, but perhaps not something I would have been able to research on my own even if I had wanted to. The topic has been discussed here several times as well as on the tech list and AFAIK no one, including MB, has ever mentioned that before. Very odd.

So thanks, more info is always good, although I don't think that is necessarily solid proof of anything just yet. I've heard that there was cooperation or consultation from Honda when that kit was developed, but even if true that doesn't mean they blessed every mechanical detail. However, it is useful as additional information and my lend some credence that the risk is not high. Of course, we don't have more than one or two members here with that SC. Perhaps they can confirm this and tell us how many SC'd miles they have on their car.

BTW, I don't recall anyone saying that it is the "only" SC that replaces the pulley.

 

[ChrisK]

What I have been told but have not confirmed, is that the Legend and the NSX share oil pan gaskets. If this is true, one might infer that a solid hub on the NSX is perhaps acceptable.

This is true I believe of the G1 Legend (86-90) which shares the same part number for the oil pan itself, thus I believe would indicate it being the exact same part which I also heard is true. So, it would make sense that it also uses the same oil pan gasket. I have little understanding on the subject you guys are talking about but just wanted to mention that