6 cylinders vs 4 cylinders
11-03-2006, 03:56 AM
#41
Originally Posted by MyGreenMax94
Yes,i have been around a few old v8's in my time..They do look different and function in a different way[i.e. counterweight type] but still accomplishes the same goal as all other types of dampers..
Our pulley has rubber dampenening material in between the outer and inner parts of the pulley..This is just a different way of accomplishing the same goal as the other type of vibration damper..
The automotive industry makes little if no difference in the two dampers functions...The only difference is their design..
http://en.wikipedia.org/wiki/Harmonic_balancer
http://www.tpub.com/content/engine/1.../14037_106.htm
No engine is immune to engine vibration from the crankshaft,so more then others[i.e.older domestic v type engines]..They were not built with as close of tolerances as todays modern engines..[thus most likely the reason why the nissan engines do not have major issues when it is removed and replaced with the aftermarket underdrive pulley].....But even the newest/most modern engine has some vibration from the crank
Our pulley has rubber dampenening material in between the outer and inner parts of the pulley..This is just a different way of accomplishing the same goal as the other type of vibration damper..
The automotive industry makes little if no difference in the two dampers functions...The only difference is their design..
http://en.wikipedia.org/wiki/Harmonic_balancer
http://www.tpub.com/content/engine/1.../14037_106.htm
No engine is immune to engine vibration from the crankshaft,so more then others[i.e.older domestic v type engines]..They were not built with as close of tolerances as todays modern engines..[thus most likely the reason why the nissan engines do not have major issues when it is removed and replaced with the aftermarket underdrive pulley].....But even the newest/most modern engine has some vibration from the crank
Originally Posted by nismology
Removing OEM pulley = slightly more vibration...negligible if any
Removing harmonic damper = mechanical suicide
Removing harmonic damper = mechanical suicide
I don't know about you, but to me there's a HUGE difference between something that reduces some vibrations and something that can save a crank from breaking. Sure it's a damper in the broadest sense, but it's nothing like a harmonic damper which actively balances out the crank with counterweighting lest it can break without it.
BTW, nowhere in the FSM or nissan FAST program is the term harmonic balancer/damper used. We're splitting hairs now though, or at least we will be beyond this post, so i'll bow out.
11-03-2006, 06:01 AM
#42
Originally Posted by Pervis Anathema
My pop's '05 Camry has, IIRC, a DOHC 16V 2.4L ~160hp / 160tq 4 banger with VVTi. It would easily beat my old VG auto, especially up top. It also consistently averages 33mpg combined. 
11-03-2006, 06:02 AM
#43
Holy crap. I just realized I was talking about a 4th+ gen pulley in a 3rd gen forum. Sorry, guys...
But either way, 3rd gen pulleys are not harmonic balancers either, so I will continue.
Exactly. If the stock pulleys were balancers, those members' engines would have been ripped to shreds. Therefore, the stock pulley is not a balancer.
Case in point:
But either way, 3rd gen pulleys are not harmonic balancers either, so I will continue.
Originally Posted by MyGreenMax94
Many members have used underdrive pulleys on these cars with no vibration issues...
Case in point:
Originally Posted by CandiMan
As stated there's nothing to worry about so go ahaed and install it. For the many Maxima owners (3rd, 4th, 5th+ gens and myself included) who have been using an UDP for many years there's nothing to worry about. Of course there will always be exceptions to the normal (your Dodge article for example) but if UDP's were such a problem in the industry, the makers would stop making them because no one would be buying them regardless of which make/model you have.
Originally Posted by Matt93SE
I've had an ASP UDP on my Maxima for over 5 years and 70,000 miles.. Along with a Fidanza flywheel to lighten the other end for the last 40,000 miles. I've also got the same combination on my 240SX with no issues in the last year.
Both of these cars see/have seen heavy road course use.
Both of these cars see/have seen heavy road course use.
Originally Posted by MrGone
The problem normally comes from people installing the wrong harmonic balancer behind the UDP on small blocks, maxima's it's not a problem. (iirc, internally balanced vs. externally balanced)
I ran a UDP + Fidanza for over 2 years, only problem was it was too much fun to drive
I ran a UDP + Fidanza for over 2 years, only problem was it was too much fun to drive
In any case, this is VERY insightful, I didn't know our motors were internally balanced. That's kinda cool.
11-03-2006, 10:46 AM
#45
Actually, just because a few guys don't have problems and their engines haven't destroyed themselves doesn't really prove your point.
In fact, Matt and I have grenaded our engines. Probably not pulley related but then again, it could have contributed. One will never really know
In fact, Matt and I have grenaded our engines. Probably not pulley related but then again, it could have contributed. One will never really know
Originally Posted by d00df00d
Holy crap. I just realized I was talking about a 4th+ gen pulley in a 3rd gen forum. Sorry, guys...
But either way, 3rd gen pulleys are not harmonic balancers either, so I will continue.
Exactly. If the stock pulleys were balancers, those members' engines would have been ripped to shreds. Therefore, the stock pulley is not a balancer.
Case in point:
But either way, 3rd gen pulleys are not harmonic balancers either, so I will continue.
Exactly. If the stock pulleys were balancers, those members' engines would have been ripped to shreds. Therefore, the stock pulley is not a balancer.
Case in point:
11-03-2006, 12:01 PM
#46
Originally Posted by Jeff92se
Actually, just because a few guys don't have problems and their engines haven't destroyed themselves doesn't really prove your point.
And why aren't more people complaining about excess vibration with their solid, lightweight aftermarket pulleys?
11-03-2006, 12:09 PM
#47
Because that sample size is way too statisticly too low. You could run an engine on the same old oil for 70k and it might run fine. But that doesn't mean all engines will do this.
And remember, our engines DID fail. so you could make a case directly against yours also.
How do you know "excess" vibration that can be felt = amount that would do damage?
And remember, our engines DID fail. so you could make a case directly against yours also.
Originally Posted by d00df00d
Doesn't it? If the crank were unbalanced and you removed the balance weight, how could it go 70,000 miles without a problem?
And why aren't more people complaining about excess vibration with their solid, lightweight aftermarket pulleys?
And why aren't more people complaining about excess vibration with their solid, lightweight aftermarket pulleys?
11-03-2006, 05:23 PM
#48
Originally Posted by d00df00d
Doesn't it? If the crank were unbalanced and you removed the balance weight, how could it go 70,000 miles without a problem?
And why aren't more people complaining about excess vibration with their solid, lightweight aftermarket pulleys?
11-03-2006, 05:47 PM
#49
Originally Posted by nismology
It's balanced enough to not require a harmonic damper.
I've been into way more engines than most people on this forum have and I have yet to see an automobile engine that does not have counterweights. Having counterweights on the crankshaft does not make that engine balanced beyond the need of an external balancer. Jap engines are better balanced from the factory than most domestics and therefore are more forgiving when a balancer is removed. Canceling vibration from ancilary components is BS.
11-03-2006, 05:50 PM
#50
Originally Posted by nismology
Like i said before, our OEM pullies are there to reduce NVH, not to "balance" out the crank vibrations. How can it if there aren't any counterweights? Our cranks are internally balanced, and this is why you can get away with an UDP with no ill-effects. Haven't heard of a VG/VE/VQ crank breaking because of one yet. BTW, even some well built modern engines (ie LS1) require harmonic dampers. So new or old, some engines require them and some don't.
I don't know about you, but to me there's a HUGE difference between something that reduces some vibrations and something that can save a crank from breaking. Sure it's a damper in the broadest sense, but it's nothing like a harmonic damper which actively balances out the crank with counterweighting lest it can break without it.
BTW, nowhere in the FSM or nissan FAST program is the term harmonic balancer/damper used. We're splitting hairs now though, or at least we will be beyond this post, so i'll bow out.
I don't know about you, but to me there's a HUGE difference between something that reduces some vibrations and something that can save a crank from breaking. Sure it's a damper in the broadest sense, but it's nothing like a harmonic damper which actively balances out the crank with counterweighting lest it can break without it.
BTW, nowhere in the FSM or nissan FAST program is the term harmonic balancer/damper used. We're splitting hairs now though, or at least we will be beyond this post, so i'll bow out.
11-03-2006, 05:52 PM
#51
Originally Posted by d00df00d
Holy crap. I just realized I was talking about a 4th+ gen pulley in a 3rd gen forum. Sorry, guys...
But either way, 3rd gen pulleys are not harmonic balancers either, so I will continue.
Exactly. If the stock pulleys were balancers, those members' engines would have been ripped to shreds. Therefore, the stock pulley is not a balancer.
Case in point:
But either way, 3rd gen pulleys are not harmonic balancers either, so I will continue.
Exactly. If the stock pulleys were balancers, those members' engines would have been ripped to shreds. Therefore, the stock pulley is not a balancer.
Case in point:
11-03-2006, 05:56 PM
#52
Taken from Unorthodox racing's site:
4) "Is my crank pulley a harmonic/torsional/vibration damper or a harmonic balancer?"
People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term used loosely in the automotive industry. Technically, this type of device does not exist. The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the merging of the two terms. None of the applications we offer use a counterweight as part of the pulley, as these engines are all internally balanced.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that makes them look similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note in these applications, the elastomer is inadequate in size and durability to act as an effective torsional damper. If you look at the pulleys on some imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, the Nissan Altima, 1.8L Eclipse, 2.3L Fords, Chrysler 2.2L's, and 1.8L VW's, to mention a few. This is not to say with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most owners who have installed our pulleys notice the engine actually feels smoother. This is result of replacing the heavy crank pulley with our crank pulley. NVH is variable and unique to every car. NVH will increase with the installation of an aftermarket intake and/or exhaust, for example. Think of OEM intake systems in newer cars, they use baffles and resonators in the intake to quiet all the intake noise. Aftermarket intakes eliminate these resonators and create dramatic increases in engine noise from the throttle opening and closing. So to most tuners, certain types of NVH can make the driving experience more enjoyable.
The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement. This is not necessary in most modern engines because of the many advances in engine design and materials. Factors such as stroke length, displacement, inline, V configurations, piston dwell time, piston pin off-set, power output, etc., do determine when and how these harmonics and torsional movements occur.
Again, there is a lot of internet hearsay about crank pulleys. When engine problems occur, too often people are quick to blame the pulley first, rather than taking the time to look logically into why there was a problem. We hope that after reading this you will understand the crank pulleys better.
People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term used loosely in the automotive industry. Technically, this type of device does not exist. The "balancer" part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the merging of the two terms. None of the applications we offer use a counterweight as part of the pulley, as these engines are all internally balanced.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that makes them look similar to a harmonic damper. The elastomer in the OEM pulley serves as an isolator, which is there to suppress natural vibration and noise from the engine itself, the A/C compressor, P/S pump, and alternator. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to noticeable noise and vibration in the passenger compartment. It is important to note in these applications, the elastomer is inadequate in size and durability to act as an effective torsional damper. If you look at the pulleys on some imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, the Nissan Altima, 1.8L Eclipse, 2.3L Fords, Chrysler 2.2L's, and 1.8L VW's, to mention a few. This is not to say with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most owners who have installed our pulleys notice the engine actually feels smoother. This is result of replacing the heavy crank pulley with our crank pulley. NVH is variable and unique to every car. NVH will increase with the installation of an aftermarket intake and/or exhaust, for example. Think of OEM intake systems in newer cars, they use baffles and resonators in the intake to quiet all the intake noise. Aftermarket intakes eliminate these resonators and create dramatic increases in engine noise from the throttle opening and closing. So to most tuners, certain types of NVH can make the driving experience more enjoyable.
The purpose of a traditional harmonic damper is to protect against crank failure from torsional movement. This is not necessary in most modern engines because of the many advances in engine design and materials. Factors such as stroke length, displacement, inline, V configurations, piston dwell time, piston pin off-set, power output, etc., do determine when and how these harmonics and torsional movements occur.
Again, there is a lot of internet hearsay about crank pulleys. When engine problems occur, too often people are quick to blame the pulley first, rather than taking the time to look logically into why there was a problem. We hope that after reading this you will understand the crank pulleys better.
11-03-2006, 06:12 PM
#53
Originally Posted by nismology
Taken from Unorthodox racing's site:
They are trying to sell a product,so naturally they are going to tell you their product will not in any way harm you're engine....
Again i will say this...ALL 4cyl/v6/v8 engines will have some vibration from the crankshaft,even internally balanced ones...
11-03-2006, 06:14 PM
#54
Originally Posted by nismology
Taken from Unorthodox racing's site:
Automakers that mass produce cars and trucks are not going to the expense of balancing their engines so well that it eliminates the need for a harmonic balancer. Modern engines are better balanced than old 350s but they still are not perfect. A crank pully with a rubber concentric ring in the middle is there as a harmonic balancer or a vibration dampener or a torsional dampener; whatever you want to name it they do the same job. Manufacturers used to deal with NVH by using balance shafts and some still may do. Honda and others use specially designed engine mounts for the purpose of NVH.
11-03-2006, 07:43 PM
#55
Um, so... Someone mentioned 4 cylinders being 1/4 off. Are not some 4 cylinders (being "in-line") as with in-line 6 cylinders have two pistons which fire at the same time? Therefore doubling the power which would otherwise be produced by one cylinder firing, if even in a succession (as with V6/V8/etc)? Isn't this how 4 cylinders and inline 6 cylinders are able to ultimately be tuned to produce such un-godly horsepower numbers?
11-04-2006, 04:24 AM
#56
Member
Join Date: Mar 2005
Location: Georgetown, Ky
Posts: 66
Originally Posted by Chris Gregg
Um, so... Someone mentioned 4 cylinders being 1/4 off. Are not some 4 cylinders (being "in-line") as with in-line 6 cylinders have two pistons which fire at the same time? Therefore doubling the power which would otherwise be produced by one cylinder firing, if even in a succession (as with V6/V8/etc)? Isn't this how 4 cylinders and inline 6 cylinders are able to ultimately be tuned to produce such un-godly horsepower numbers?
It would be better to create a 2 cylinder engine with larger cylinders. The reason is few parts means less weight and friction. Also a V2 would only have 2 bearings, a striaght 2 would have 3. When looking V4, there is 3 bearings, and straight 4 would have 5.
Again friction is issue.
NOW.... if you change from 4 stroke to 2 stroke, you almost double the power! But that cost in other ways, normally life of the engine and air quility.
But a 2 stroke can also be quite useful, look at a Train Engine. These are normally V12 2 cycle engines producing 3200HP from 250 to 1000 rpms, running 11 L cylinder, so 132 Liter Engines! V12 cut the bearing count to 7 and almost 1/2 cylinders always in a power stroke (because a power stroke also has an exhuast portition). They are also built to run continously at full power/rpm. Try that with your Maxima.
11-04-2006, 10:20 AM
#57
Originally Posted by Grace_Imports
Where do you come up with OEM pullies canceling NVH? Wrong. They are there to cancel torsional vibrations from the crankshaft period. Jap engines are well balanced but not perfect.
Any rotating mass attached to the crankshaft will serve as a harmonic damper, but not a balancer.
A damper will help prevent vibration by evening out the movement of the crankshaft, even with the momentary torque peaks from firing pulses. A balancer is an offset mass that serves the same purpose as a counterweight on the crankshaft itself; similar end, different means.
Removing a damper won't cause problems if the engine's internal tolerances are right and it is operating correctly. Removing a balancer would be fatal.
11-04-2006, 10:28 AM
#58
Originally Posted by d00df00d
Removing a [b]damper[b] won't cause problems if the engine's internal tolerances are right and it is operating correctly. Removing a balancer would be fatal.
BTW, if you guys can't see the difference, i'm really wasting my time.
11-04-2006, 01:12 PM
#60
Senior Member
Join Date: Oct 2004
Location: Pretoria - South Africa
Posts: 1,205
That infernal lump of metal on the end of the crank ...................
If you see any rubber in it/its mounting, it cannot serve any engine/crank balancing purpose for obvious reasons ................ not at all.
If you see rubber it means the pulley mounted on that rubber is itself a perfectly balanced (relative to the axis it rotates around) chunk of metal (so that it doesn't affect the crank's rotating balance in any way) and its sole purpose is to limit the amount of varying torque transmitted to the nose of the crank by the ancillaries (eg AC kicking on/off) driven of that pulley - it achieves that by 2 methods:
1. The rubber taking up torque and flexing and delaying/smoothing out the torque application to the nose of the crank
2. The rotating mass of the pulley has momentum and therefore stored energy - any ancillary kicking in or requiring lumpy chunks of power will first have to kill off the energy stored in the rotating mass of the pulley before the ancillary can directly influence the cranks nose - its generally hoped that there is enough energy stored in the rotating mass of the pulley to cater for the power requirements of the ancillaries for the short time that the rubber mounting smoothes the application of the load to the actual crank, and that by the time the crank is actually driving the ancillaries, the crank should have experienced no or as little as possible varying torque on its nose
Well sure! - but lets compare apples with apples. If the Maxima also had bearings the same size as the train (ie something not much smaller than the actual hood surface area of the Maxima) and if the Maxima engine were also effectively stationary (250 to 1000 vs about 2000 to 6000) then it too would last longer - in the end you make more horsepower by burning more fuel ...................... there are effective ways of making enough power in each application totally dependant on the power delivery characteristics required and the calibration of the operator's ****-dyno 
If you see any rubber in it/its mounting, it cannot serve any engine/crank balancing purpose for obvious reasons ................ not at all.
If you see rubber it means the pulley mounted on that rubber is itself a perfectly balanced (relative to the axis it rotates around) chunk of metal (so that it doesn't affect the crank's rotating balance in any way) and its sole purpose is to limit the amount of varying torque transmitted to the nose of the crank by the ancillaries (eg AC kicking on/off) driven of that pulley - it achieves that by 2 methods:
1. The rubber taking up torque and flexing and delaying/smoothing out the torque application to the nose of the crank
2. The rotating mass of the pulley has momentum and therefore stored energy - any ancillary kicking in or requiring lumpy chunks of power will first have to kill off the energy stored in the rotating mass of the pulley before the ancillary can directly influence the cranks nose - its generally hoped that there is enough energy stored in the rotating mass of the pulley to cater for the power requirements of the ancillaries for the short time that the rubber mounting smoothes the application of the load to the actual crank, and that by the time the crank is actually driving the ancillaries, the crank should have experienced no or as little as possible varying torque on its nose
But a 2 stroke can also be quite useful, look at a Train Engine. These are normally V12 2 cycle engines producing 3200HP from 250 to 1000 rpms, running 11 L cylinder, so 132 Liter Engines! V12 cut the bearing count to 7 and almost 1/2 cylinders always in a power stroke (because a power stroke also has an exhuast portition). They are also built to run continously at full power/rpm. Try that with your Maxima.
11-04-2006, 03:37 PM
#61
Member
Join Date: Mar 2005
Location: Georgetown, Ky
Posts: 66
Originally Posted by LvR
Well sure! - but lets compare apples with apples. If the Maxima also had bearings the same size as the train (ie something not much smaller than the actual hood surface area of the Maxima) and if the Maxima engine were also effectively stationary (250 to 1000 vs about 2000 to 6000) then it too would last longer - in the end you make more horsepower by burning more fuel ...................... there are effective ways of making enough power in each application totally dependant on the power delivery characteristics required and the calibration of the operator's ****-dyno
The larger RPM range of the Maxima (or any car) helps mainly to lower the wieght of transmission by lowering the number of gears needed. This in turn lowers the HP needed to move the car.
It is all one big balancing act.
11-05-2006, 08:38 AM
#62
Why are we talking about trains? This is going to be meaningless to many people and confusing in how this relates to Maxima's. Train "engines" do nothing but turn the generators inside given they move on electric motors. The electric engine component alone typically only has about 1500-2000hp per locomotive. Stay focused people! Get back on topic! You guys have essentially killed this thread.
11-05-2006, 09:24 AM
#63
Senior Member
Join Date: Oct 2004
Location: Pretoria - South Africa
Posts: 1,205
This is going to be meaningless to many people and confusing in how this relates to Maxima's
Just explain to me how a thread with a title such as this here thread's relates to Maximas, and 3rd gens in particular, especially since a
is already present in the very first post with not single moan about that then?Anybody not able to think for himself and calmly reason with his peers deserve to be confused as many a post here has already demonstrated.
11-06-2006, 11:03 AM
#64
Originally Posted by LvR
Anybody not able to think for himself and calmly reason with his peers deserve to be confused as many a post here has already demonstrated.
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