Under drive crank pulley, any one interested?

[pulsar gtr]

Hi All,

I talked with a friend of mine who is a machinest and gave him a RWD crank pulley to price me on an aluminum one.

Here is the price, if I get 10 buyers, he can make it for 260USD each plus shipping.

Please post your thoughts and input on this matter.

might be a bit price Thank you,

RafiPULSAR GTR

[JICdrifter]

if it was a little cheaper shipped i would be interested for sure

[RMiller]

Same here, cheaper and I'd be on it.

[pulsar gtr]

Hi,

So, would you please let me know what kind of price range would some one pay for such thing, as I might be able to negotiate something, I doubt I can but it is worth a try.

PULSAR GTRRafi

[cortina-mk1]

whats he doing about the damper part of it?

[RMiller]

I want to know the same. How much less would the aluminum save?

[Turbogixxer]

whats he doing about the damper part of it?

It is probably solid AL. The only problem with making a "damper" with no way to adsorb the turning/shaking for forces of the crank is that the crank does not spin freely under load (RPM). With a solid AL (or a pulley without a way to adsorb the forces) pulley, the crank actually twists. This will cause alignment problems with the block (read: bearings).

[pulsar gtr]

Unfortunately, he will be illiminating the Damper part, it will be one solid piece made out of aluminum and it will weigh half what the stock one would.Theoratically, yes, there will be some vibration, thats why there is dampers, but all after market aluminum pulleys such as the ones for 300zx (Z32) and Sr they illiminate the damper.

PULSAR GTRRafi

[sdtouge]

any idea on the price yet? i might be interested in one, but the price above was def. too high.

[Turbogixxer]

all after market aluminum pulleys such as the ones for 300zx (Z32) and Sr they illiminate the damper.

care to explain why it will not hurt the engine? Just because aftermarket companies make then, it does not make them right. I hope you have good proof behind this.

[NeedCAforS13]

correct me if I'm wrong, but I've heard that the only reason the stock one has a rubber damper is for when the A/C clutch kicks in, it helps absorb the shock. If you eliminate the A/C, you theoretically don't need the damper. There was a HUUUGE thread on FA about this exact topic a long tim ago.

Sean

[pulsar gtr]

Well, The reason I believe it won't hurt the engine is because you have a living proof of about 10 of my local buddies including myself that are using them on our 300zx z32 for years now and We haven't encountered any problems with the crank, or bearings or vibration.

And if you want more proof, just go to Twinturbo.net and ask for yourself because tons of people are using them and if any one ran into problems wiht them, I would know as I check that website on daily bases and read a lot of stuff about it . It got thousands of members, so usually if they encounter a problem, one would hear about it.

I hope that is a good proof for you Turbogixxer, I suggest you do your homework before you start shooting your mouth.Because these type of pulleys are used on tons of different engines and models and I have been around for a while to see whether they real cause real problems or not, yes there are the odd cases to cause damage to the engine, but that damage most like was there before of the installation of the pulley due to mis maintnance of the engine by their owners.

I usually, don't go lecture people but your comment seemed a bit Arrogant, and the purpose of this thread is to see if any one is interested in this type of pulley and the suggested price.If you don't have any thing to add regarding the price or your interested in getting a pulley. I suggest not to add any of your smart comments.

PULSAR GTRRafi

[boost_boy]

Well, The reason I believe it won't hurt the engine is because you have a living proof of about 10 of my local buddies including myself that are using them on our 300zx z32 for years now and We haven't encountered any problems with the crank, or bearings or vibration.

And if you want more proof, just go to Twinturbo.net and ask for yourself because tons of people are using them and if any one ran into problems wiht them, I would know as I check that website on daily bases and read a lot of stuff about it . It got thousands of members, so usually if they encounter a problem, one would hear about it.

I hope that is a good proof for you Turbogixxer, I suggest you do your homework before you start shooting your mouth.Because these type of pulleys are used on tons of different engines and models and I have been around for a while to see whether they real cause real problems or not, yes there are the odd cases to cause damage to the engine, but that damage most like was there before of the installation of the pulley due to mis maintnance of the engine by their owners.

I usually, don't go lecture people but your comment seemed a bit Arrogant, and the purpose of this thread is to see if any one is interested in this type of pulley and the suggested price.If you don't have any thing to add regarding the price or your interested in getting a pulley. I suggest not to add any of your smart comments.

PULSAR GTRRafi

I agree with you Rafi in the fact that lecturing is not your style! I don't know much about underdrive pulleys, but I can say that I've heard mixed reviews on them. I would love to see you guys get in on this buy and see if there's a difference in acceleration as opposed to just leaving everything stock. As for damage to the crank and bearings theory, if you guys have proof that people are using this equipment without splitting their cranks in half and chewing up bearings, then experience wins again. Sean, I'd let this thread ride to see the outcome. Guys, the floor is yours and Rafi, how does it feel to have to get a little cyber-physical ? Dee

[RMiller]

Using a solid crank pulley on a z32 w/o damage doesn't prove anything about using them on a CA. I would say that even if it was I-4 vs. I-4, but it's a V6! Different stresses in different directions.

I don't remember how much the stock pulley weighs, maybe 10 lbs? If you knocked off 5 lbs it seems like a pretty significant gains would be realized, but you could get well over 2X the results with a lighter flywheel. And I don't know if it was even supposed to underdrive the accessories or just be lighter, probably the latter.

Maybe a better idea would be to get the PS, alternator, and water pump pulleys made with an underdrive.

[Jezz_s13]

I and a few others over here might be interested in a set of bigger (underdrive) pulleys for the ancils (water pump, pas and alternator) if the price is right.We are looking at something about 15-20% bigger.

I'm a bit dubious of undamped pulleys. Very actually.

FYI the stock RWD pulley is 7.2lbs on the missus kitchen scales, ally underdrive ones I've seen for the SR are 1.5lbs.

[pulsar gtr]

Personally, I am not in a big favor for removing the damper, but the fact is, that was option I was given, The pulley will be made from aircraft alluminum grade, and will weigh no more than 1/2 what the stock one is.doing the pulley itself, I doubt you will notice a difference, but with a lighter flywheel, a person should notice a difference.

Boost boy, thanks for stepping up man, I don't usually get fired up easily as you know, I have been around for long time and basically this is my hanging place as I have lots of respect to all memebers and visa virsa, If a person wants to bash some one with their wise & smart comments, this is not the place as you know. If I caused any inconvient, my apologizes to all.

Guys, I have gotten few interesting responses, but none gave me a rough price that I could take it back to the machinest to see if he can agree on the price. Any input on prices or ideas are very welcome. Remeber the price that was given to me, is if we get 10 pulleys made.

I will keep every one posted.

Thank you,

RafiPULSAR GTR

[Turbogixxer]

Well, The reason I believe it won't hurt the engine is because you have a living proof of about 10 of my local buddies including myself that are using them on our 300zx z32 for years now

Believe? You are basing your product on that fact that you think it works that way?

Figure this, the load (inertial and compressive) on the engine is ^3 per RPM. So, the load on the bottom end is ^3 per RPM. So, the higher you go, more the load. Most of the load is on the TDC and BTC. That means the rod wants to push striaght down, but it cant because it is connected to the crank. Now, you do not think the crank will want to twist or have vibration? You think a solid AL pulley will absorb the vibration/twist?

We haven't encountered any problems with the crank, or bearings or vibration.

How did you test for vibration of the crank?

And if you want more proof, just go to Twinturbo.net and ask for yourself because tons of people are using them and if any one ran into problems wiht them, I would know as I check that website on daily bases and read a lot of stuff about it . It got thousands of members, so usually if they encounter a problem, one would hear about it.

Thats great, You hear of the electric supercharger? I heard it works great. :/

the purpose of this thread is to see if any one is interested in this type of pulley and the suggested price.If you don't have any thing to add regarding the price or your interested in getting a pulley. I suggest not to add any of your smart comments.

Well, you are selling the product. I am sorry I added stuff that will hurt your sells. But, you should know, with selling any product. You should know how/why it works.

I hope that is a good proof for you Turbogixxer, I suggest you do your homework before you start shooting your mouth.

Look above. I think I did my homework, can you say the same?

Because these type of pulleys are used on tons of different engines and models and I have been around for a while to see whether they real cause real problems or not, yes there are the odd cases to cause damage to the engine, but that damage most like was there before of the installation of the pulley due to mis maintnance of the engine by their owners.

Using a solid crank pulley on a z32 w/o damage doesn't prove anything about using them on a CA. I would say that even if it was I-4 vs. I-4, but it's a V6! Different stresses in different directions.

Rmiller is right.

[themadscientist]

Turbogixxer, you do seem to enjoy lecturing people and whether you mean to or not take a superior tone with everyone. I guess that's just how you are but you might find people more receptive to your point of view if you work on that. I think it's good if everyone throws in their knowledge and opinions though, everyone benefits.

[Turbogixxer]

don't usually get fired up easily as you know, I have been around for long time and basically this is my hanging place as I have lots of respect to all memebers and visa virsa, If a person wants to bash some one with their wise & smart comments, this is not the place as you know. If I caused any inconvient, my apologizes to all.

No reason to let emotions get to you, But this is a Technical forum. It is for info to be exchanged and have Constructive Criticism. I know, I know. I am a d!ck sometimes, but it is the internet. :p

[pulsar gtr]

Dude, I am not selling the pulleys as I am not making a penny of them, I have seen tons of people asking for them and that was a reason to approach the manchinest and get the info from him. Whether this idea is a go ahead or a dead stick, I won't make or lose money of it.

I am not saying the aluminum pulley will illiminate the vibration, My point is that was the option that was given to me by the machinest, and if it works out, great, if it doesn't, who cares.

Regarding the Z32 pulley, I do agree that both engines are different as one is inline 4 Vs. the V6, but both have will cause vibration.My comment regarding other Z32 owners is stays where it is as I have been using this pulley for over 3 years and I haven't noticed any noticable vibration or damage to the engine I do inspect my engine regularly.

The bottom line if some one is interested in a ""NON-DAMBER" PULLEY, please add your input and the what kind of prices we should pay, and if your not, well, too bad too sad, we move on to other stuff.

PULSAR GTRRafi

[Turbogixxer]

Turbogixxer, you do seem to enjoy lecturing people and whether you mean to or not take a superior tone with everyone. I guess that's just how you are but you might find people more receptive to your point of view if you work on that. I think it's good if everyone throws in their knowledge and opinions though, everyone benefits.

Honsetly, I tried that. But look at it this way. I quoted the most repected guys here, they came back with nothing to share but "I know from experiance". Well, if you know from experiance, then you should know why it did not work. Remember, I have all of 24 posts, and most people think the more posts you have, the more you know. So you can see where I am going with this.

Anyone can throw info at me, and I will read it and exhange back with them info. I may not be right, they may not be right. I am FAR from knowing everything and I know I will not know everything.

When you stir the pot a bit, it is great because you get info that may not have been talked about before.

[pulsar gtr]

Hi,

I don't claim I know my stuff to the tooth, I am always open to learn more, and I have been right and wrong in the past.I have been here for a long time but I only have about 700 posts to my name, some others been here for less time but have much more posts, The # of posts does give any one the right be smarter.And yes I did annswer your questions and I did say that I have to agree that the vibration will continue to be there, but it might not be severe.

Any way this conversation went off topic from the original Thread, and I do suggest for the Moderators to lock it up as it is going no where.

Thank you,PULSAR GTRRafi

[themadscientist]

I firmly agree with you and I personally like shaking it up and throwing things up on the wall to see if they stick. Your posts don't raise my ire because I focus on what you are trying to say and not how you say it, I enjoy having to turn on my brain, occasionally I have seen the responses and some of them do ring kind of "yeah so" and some don't. You seem to have a lot of info and book-learning is good and required but don't discount opinions because they are based on actual experience and not lab testing. Everything I do is seat of the pants and by-ear and most of the knowledge I currently posess while based on technical study has been tempered by BANG! "whoops, better not do that again" so I value real world experience.I am enjoying this discussion on the merits of the damper however out of respect for the thread starter it is starting to become a little off topic with the heated banter so I think that should stop.Now as I said I am enjoying the discussion and I don't want to lose the opportunity to talk about That subject. I would encourage you to start a thread about just that subject so the discussion can continue unabated without stepping on Pulsar's thread.

[Turbogixxer]

I will add.

The reason why pulsar gtr had good experiance with solid pulleys is this.

Like I stated before, RPm has a great affect on load the bottom end will see. The greater the RPM, the more the load on the bearings/ crank will have.

Now, more stock dampers are made for daily driving. That means idle-4000 RPM. As you see, rpms are not that high. So when you put a solid pulley on it a motor and do not rev it high (when I say high, I mean from little bit below the redline to while, while over it), you will not see problems with running a solid pulley. But EVERY build is different, so saying it work for you, well, it may not work for me. BUT with saying all that, I will say this. If you run a solid pulley, time is against you. The longer you ran it, the more it can hurt you. But, the avg high performance engine does not have a long life to begin with. Something happens within a 1-2 years (aka: miss shifting, hydro-lock, etc).

IYou seem to have a lot of info and book-learning is good and required but don't discount opinions because they are based on actual experience and not lab testing.

I read then use what I read on cars I am building. I have been messing with cars for a long time now. I started really young with cars.

I wish this site had PMs.
Modified by Turbogixxer at 9:17 PM 2/12/2005

[RMiller]

Tact is your friend on the internet. You can't distinguish tone in writing near as well as you can orally.

Rafi-10 buyer's ain't going to happen. Not enough gain for the price, even if there wasn't any uneasiness about the dampener. Now, $260 for ac, ps, alt underdriven would be another story. That could probably happen.

Basically, if I wasn't concerned about the dampener and the Al crank pulley saved me 5 lbs I would be very interested at $250 shipped. I hope that answered your questions.

[pulsar gtr]

Hi Rmiller,

Thanks for your input man, much appreciated.I said it earlier in the thread, personally, the price is too high as I have seen others going for much cheaper, but I guess that is the cost of trying to get something customized.

If any one knows a machine shop that might be able to do it for cheaper price, let us know.

PULSAR GTRRafi

[pulsar gtr]

Well, this topic is turning into an interesting learning curve. I did a bit of research so far, and it is not as much as the RPM is the factor in causing an issue, it is more of the quote from http://www.machv.com/tip11cranpul.html

"The dampener is designed to absorb torsional and vertical vibrations from the crank. MOST underdrive crank pulleys (with the exception of the Buschur Racing model) do not have a harmonic dampener at all.

Torsional vibration is a twisting vibration caused by the pulses of each combustion event. The force of the piston causes the crank to deflect ever so slightly in the direction of the force, and when that force goes away the crank ever-so-slightly springs back. At certain frequencies the crank can resonate, making the vibration much worse. This is where the harmonic dampener comes into play"

obviously, the engineers designed a damper in the pulley for the above reason which will allow the engine eventually last few hundred kKM without encountering any failure that might have been caused by the vibration.

When I started the thread, it was intended to let the memebers here know that there might be an option in getting a lighter crank pulley where the machinest can only offer it without a damper.

I guess at this time the aluminum crank pulley is a dead stick due to the effect that it might cause on the engine in LONGER PERIOD OF TIME.

Thanks,PULSAR GTRRafi

[f s t caz]

personally, in owning a performance car and modifying it, i'm already accepting the fact that what i do is going to decrease the lifespan of my motor. Once i get it and turn the boost up, it's not going to last another 200,000 miles, but seriously, who is going to own their car for that long? There's not many. Most people these days build a project and sell it within a few years anyways. I bet that within the time they own the car, they will never see the negative effects of an underdrive pulley. If their motor dies within the time they own the car, i'm sure they'd love to point the finger at the UD pulley. It makes a good scape goat and takes the blame away from their direction and from poor maintenance or poor tuning (oil starvation causes bearing wear - running low oil b/c he/she didn't check it often enough, not changing the oil frequently enough, a weak oil pump, etc. detonation will also cause bearing wear). In my opinion, there's a lot of other things that will contribute to my motor's inevitable wear and death, an underdrive pulley won't help, but it certainly won't cause anything to happen tomorrow, or next week, or even within the next year or 3 that i own the car. the only reason i dont get in on this is because I don't have the money now, won't have it soon, and just getting 10 people to commit on the interweb is next to impossible. We'd need a forum with 1000 active members that post on a regular basis in order to get 100 that would say "wow, thats rad, i'm in," 25 to reply to a followup email saying "yes, i'm still interested. just let me know where to send payment" and then 10 to actually send payment.

thanks for trying to help out though. Wasn't there someone else who tried to get a batch of UD pulleys a few months ago?

[Jezz_s13]

here's another bit of good anti UD pulley propaganda...

http://www.epi-eng.com/ET-TorsAbsrbrs.htm

the 240Z did have a straight six though so vibrations/resonance etc will be greater, a V6 has a short crank so probably better.

Check all of this out...http://www.epi-eng.com/ET_TOC.htm

and some basics if that's a bit much.http://www.epi-eng.com/BAS_TOC.htm

All a very good read and pretty simple to understand.

I know that these things work on lots of engines but I just don't think it's a good idea.

I would definately be interested in some ancil pulleys though.

[WeldingHank]

i had an undrive/lightweight solid Al pulley on my previous car. it was an I-4 and i had no problems with vibration at all. if the price is right, i will order one for my CA as well.