Lightened pulleys etc

it seems to me that some people/shops often talk about 'potential' problems (without any unbiased, factual evidence whatsoever) a lot when it comes to parts that they don't sell themselves. not sure if this is the case here or not, but if it was (for argument's sake), then it wouldn't be the first time in history that scare-type tactics were used in order to try to scare people off of a competitor's product and direct them to their own competing product.

realistically, i wonder if these shops also tell people about 'potential' problems down the road with things like the parts they actually sell, high HP engine builds, cranking boost way up and the list goes on. i can name tons of things that could 'potentially' have problems down the road. there are way more serious things you can do to your car that would 'potentially' blow it up than just sticking some pulleys on it.

with the number of pulleys out there, even if two guys said "we had some vibration and we think our engines might have blown because of them," that's just not enough evidence to support the negative hype being tossed around. two out of tens of thousands maybe had an issue? i'll gladly take the chance of installing one and i'd love to take those odds with me to the casino or lottery booth any day of the week!

 

Well, casino odds are way better if u play ur cards right, and lotto.. Well u won't go belly up any time soon by purchasing numbers

 

Ive got to add my bit since ive had about 12 of these engines balanced and it has to be said that from stock they are not well balanced, despite what people say. the cranks need a shitload taken off them . pistons arent too bads but stock rods are miles out.

fitting aftermarket rods and pistos can help as they are well balanced but anyone who thinks that fitting those and a solind front pulley gives them a balanced motor is dead wrong.

having said that i dont go out of my way to discourage my customers from fitting one, however if they are getting a motor rebuilt i always encourage getting the whole assembly balanced

 

i think i got 1 or 2 here ....

 

Yep all motors need to be balanced and if out of balance why would you want more problem by putting a non harmonic balancer on? VG's are nowhere near as good as the newer VQ30 we checked and factory pistons and Rods were less than .5 of a gram out together. I balance all the pulleys on my race motor as well as the engine itself. I have no formal qualifications, never claimed to have. I employ experienced and talented expensive top class mechanics, and regularly pay automotive and motorsport engineers for their time, and I listen well, my cup is not full. I also read lots of performance books, like the one down the bottom, as well as how to set up race cars, not much Autosalon. I have been working on cars since 1982, and raced since 1984. I regularly race my zed, in fact 14 times in last 12 months and it is very reliable and fast. I have numerous friends in V8 Supercars and Porsche Cup series, as well as many other forms of motorsports. I started importing ztt's back in 1995 and started Unique Auto Sports in June 1997. We prep and build a lot of race cars, yes real world and more and more over the years, real world not just dyno queens, with off the shelf parts from China. It is often not popular but we are into function first and looks second. This is a perfect example of bling sells, and with bling comes blinkers it seems.

Grant from Performance Turbo's in Perth had two big zed motors have bearings fail after fitting these alloy pulleys, years ago. This was one of them, I sold him the pullley and warning bells rang out.



There are well proven cases years ago for RB26 motors failing, and not just one or two, 100% failure in every case, and why not sold even on EBAY. The internally balanced RB as discussed is more prone but VG are not mysteriously immune either. For those on the fence talk to an automotive engineer or an engine machine shop. ANY ENGINEERS OUT THERE ??? It is not doom and gloom, just not a smart upgrade, with questionable at the least side effects for minimal gains. 95% of zeds will probably not have a problem or noticeable, just dangerous for big hp, particularly a race car, and they will flog out bearings faster. Show me a serious race car that has one? DO you think the Nismo GT500 R35 GTR has one. Not a hope.

Yes I often ask who is telling me the info on a product, and regularly challenge suppliers to prove their claims. I have been known to correct magazines for publishing incorrect statements or claims. We have done numerous tests over the years for suppliers products, as well as many tests for magazines on our dyno. We often disprove and other times prove claims. I often talk customers out of spending money on parts that I knwo won;t work on their cars, rather than take their money.

VUK how many pulleys have you balanced, and if so how far out are they? Real world.

For those interested in a more in depth and independent technical explanation of this topic, the reference book is Advanced Engine Technology, written by Heinz Heisler MSc,BSc,FIMI,MIRTE,MCIT. Heinz Heisler is the Head of Transportation Studies at The College of North West London. His book is distributed in this country by the SAE (Society of Automotive Engineers).

 

Adding aftermarket rods and pistons will always require a full balance when doing a rebuild- at least this is what our builds consist of.

The pulleys as stated in our hundreds of installs and thousands sold within the market have a zero failure rate. This is our experience as stated so from our position we have no reason not to install or recommend these. This is the point I am trying to get across

Regards,

Vuk@AMS

 

no one is disputing the facts with regards to the R32. not sure why you keep going there...

you say that "95% of zeds will probably not have a problem." where'd you come up with 95%? seems like 99.99% from what i can tell, and even more likely 100%. after all your raving about knowing all this, we still don't have a single concrete example of a street-driven Z with a failure due to a pulley alone. unless i'm missing something here...

oh, and yellow300zx's ride doesn't look like a racecar to me, so he'll be fine if he gets one. after all, he's the one inquiring about this for his car, and there happens to be factual, independent evidence out there to back up that they work on streetable high HP Zs, such as vuk's 750+ HP Z and a pile of other high HP Zs that come out of his shop.

 

No one who isnt you give two sh*ts about what you do to your engine so if you want the lightened pully, then based on the evidence, its a great idea and go for it. If you want a balancer, then based on the evidence thats a great idea as well so go for it as well!!!

I dont reckon this argument should be based in recorded success or failure rates. I reckon it should be based on theory.

the fact behind the two differing opinions are based completely in theory and therefore all these opinions and pieces of web info and dyno charts and 256,897,996,798,000,000,000 300zx's that didnt have any problems are almost irrelevant.

the facts are that Basically the harmonic damper, is designed to dampen the torsional vibrations within an engine. For high hp, high rpm engines the crankshaft may be flexing quiet a lot, if it happens to be driven at a natural frequency, then the amplitude of vibration may reach the point where things break (one of the common examples is that the front pulley can actually strip), by adding a damping element to the system, the peeks of the vibration particularly around the natural frequencies, may be kept to sensible levels.

The above is THEORY based on SOUND ENGENEERING PRINCIPLE. The zed has a short crank, the GTR has a long crank, the metelurgy is different, one is red, one is blue, one spins faster, someones car has a whole in it, somones thermo fan is made out of titanium, someone has a prosthetic dick are all situational differences that could effect the REAL LIFE examples. Not valid arguments for or against.

300zx engines may not be affected by the change in pulley at all, balancing might be so good that it doesnt matter BUT

the engineering realm indicates that IN PRINCIPLE it would be better practise to have a harmonic dampner than not too. This opinion comes from massive amounts of research with massive amounts of cash involved in order to provide for a much much more important industry than the car industry.

So, whack your one piece non-harmonic dampening pully on your VG30 cause the evidence suggests that your engine will be fine but understand that JP's advice to go with a harmonic balancer is based in much sounder theory than advice to the contrary.

 

Sorry for the late reply I was out playing tennis lol! Life is all about balance.

I will state again that we have had zero failure rates with the hundreds of direct installs and thousands of installed units within the largest Z market (NA) bar none which includes numerous top Z tuning shops state-side.

Once again we are talking about different motors. The VQ blows up quite nicely with boost as low as 5 psi with all various forced induction kits on the market over time as well! This is with the OEM pulley! The VG motor is alot more robust hands down if we are trying to compare these? This is way off topic as is the RB26 reference.

My stance from my very first reply for the readers is that as a fully licensed Red-Seal technician and shop owner within Canada I have seen zero failure rates with the hundreds of direct installs and the thousands of units used within the largest Z market (NA). This includes complete tear downs after puleys have been used for years!

As a side note I have owned and worked on Z's since 1992 Along with several other of Nissan's Flagship Cars including the R35 that has had solid pulleys installed with zero negative effects by yours truly

Once again my position from direct installs concludes that:

a) the solid pulleys on the VG have a zero documented failure rate
b) Great bang for the buck upgrade with proven independant dynos showing results within the biggest Z market/continent

All the other references and off-topic yapping adds little to the members initial question.


Regards,

Vuk@AMS
www.amszstore.com

We can argue till the cows come home and go off topic but I will stick to these two main points I have been making from the get go!

 

zero failure doesnt make it a sound principle/ good idea, only a safe bet

 

they make prosthetic dicks? really? but do they hang slightly to the left or are they balanced? if they're non-balanced, will the person's whole body break as a result? lol

 

sure it does. if it was a shoddy principle and bad idea, as you could be alluding to, then it wouldn't work and in turn wouldn't be a safe bet now, would it?

the fact that it's a safe bet is the main thing. nothing in life is 100% certain, except death (and taxes as they say, especially in canada anyway).

geez, they've had catastrophic failures on things like the space shuttle. you'd think those guys would know what they're doing...

there's always a chance things can go wrong with anything, but the odds (which is all you can play at the end of the day) say that the pulley's all good for his application.

 

Hey VUK how many have you balanced, or did I miss this?

 

These are just simple facts and direct experience from our camp and from the largest Z market/continent (NA). Theories and perceived predisposed hearsay do not hold much water without proof for the VG application. The solid Pulleys have been used for over a decade on VG's making it a proven power gainer with documented failure rates! My two points I have been making based on direct installs and experience.

For the record the Z32's pulley is a Torsional Dampener and not a Harmonic Balancer used to balance the motor

For those not convinced they can retain the stock pulley which weighs about 13 lbs.

Plenty of other mods for the Z are safe bets as well while not being a good idea! This notion can be looked at in several lights by different shops/individuals based on interpretations of theory or direct first hand experience. Not everyone will come to the same conclusion which is fine!

Regards,

Vuk@AMS

 

ROFL FKN CLASSIC!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

Only after you answer how many you have installed directly or the number of documented failure rates you have witnessed in house?

I see the argument is getting way off topic from the intended quesion but I can't resist and hell I barely sleep

When you've installed as many as I have and seen the direct power gains (which you doubted) and zero failure rates then we can continue this chat N'est Pas?

The rotating assembly is balanced with every rebuild by our very highly priced 'accredited/certified' engine shop we employ

Till then I will leave you with a teaser pic of one of our pulleys we offer:



My stance for the record again is that:

a) zero failure rate on the VG
b) proven power adder utilized by the top tuning shops in North America

Regards,

Vuk@AMS

 

Lol, communication over the internet will always be misinterpreted...

So to the OP, yellow300zx, based on the posts in this thread, I think we can say this:

A solid crank pulley in practice has been proven to provide gains to our engines, with a few workshops swearing by them. There are a few insistent zero failure rate stories as well as a few bad stories about solid crank pulleys, but the whole concept has NOT been conclusively tested and proven.

You would be running the solid crank pulley based on a majority of success stories which points to a positive outcome for your car, but just keep in mind the other side of the argument has not been thoroughly explored.

Just observations from a bystander .

 

Hey man, I totally agree, no failure = no probs.

the arguments for so far are
1)no proven case exists to the forums knowledge of a pully being the sole cause of a failure

the facts remain,
1) it is possible for natural frequency to excite in a crankshaft / engine situation
(in a zed although less likely, this is still possible. The likelyhood is based heavily on what mods, how good the balance job is and various other situational occurances)
3)it is possible that without dampening the excited natural frequency can cause failure
4)it is possible for that frequency to be absorbed using the correct dampning

now although there is no failure (presented here) directly linked to pullies on VG30's, how many cases are there of bad balance jobs combined with pullies being the cause of failure???
many would simply blame the balance job but could the result have been offset if a balancer was used.

there are many things that can cause failure and in order to make desisions about which items to use, one should assess the facts.

putting a non balancer pulley in place of a balancer is similar to me (as a project manager for land development) informing homebuilders that they should drain all roof water into rear yards....chances are, if the development has been built with the correct sand spec then the water will drain and no problems will occur, but its simply bad practice and would be the wrong advice. This is why local govt make sure that a developer is held accountable and required to design to best practice standards at the time.
Advising people that pullies will be ok because of precedent fails to recognise proven factual evidence that pullies are not best practise.

I realise that no one has reported problems with the pulley install and maybe never will but it doesnt change the fact that its a bad idea compared to a balancer.

 

tease me with a picture of a silver ams pulley set Vuk and ill tease you with an order

generally known as a dildo lol

 

Mine was (by AMS) and I believe all rebuilds done by AMS are. +600whp (with complete set of AMS pulleys) and no vibrations here.

I thought he was a Hobbit?