Unorthodox Racing Lightened Pulleys - Squeeling When Cold...

[SpawnedX]

Ok, so I put on Unorthodox Crank, Water Pump and Alternator pulleys (I have eliminated AC and PS from my car). I can hear a little extra crank rotation noise, which is pretty normal for lightened and under-drive pulleys. I am using the stock belt, and have tightened the adjuster all the way up and it has good tension, definitely not loose and I don't think it is tight, I would say just right.

When it is really cold outside I get what sounds like a rubbing or squeaking noise from what seems like the crank pulley area, soon as it warms up it is gone, but it goes away gradually throughout the temperature range. Belt is in good shape.

Anyone had a similar experience/resolution? It shows no sign of rubbing anywhere. I am also wondering, since noise travels, would a too lose alternator pulley do this only under heavier load?

I should probably define heavier load, the battery is pretty much dead, so when I get the car running even turning the radio on will cause her to die, so the alternator is doing all the work.

 

[SpawnedX]

It would be a coincidence if the battery wasn't dead prior to the pulleys being installed, which it was. I love assumptions.

A damper is need because metal flexes. A crankshaft flexes. This can cause a horrible frequency of vibration that can eventually cause bearing wear or crank splitting. Think of sound breaking glass, same concept. Now take the same glass and fill it with rubber, the rubber will absorb the vibration and cancel it with heat.

The glass needs to be filled with rubber. Now take that same glass burn out 4 holes in a circular pattern and clamp a rubber filled donut object on that glass. Hit it with sound then, doesn't save that glass. Same as that damper won't save your crankshaft since it is bolted a sprocket that is not dampered, that sits on the crankshaft.

 

[tkelly27]

Torsional Characteristics of Piston Engine Output, by EPI Inc.
Crankshaft Torsional Absorbers, by EPI Inc.

Is that really a guy from Unorthodox? I know one company I won't be purchasing from... balance shafts in a discussion about crank harmonics, shame. Balance shafts counteract the second order vibrations caused by having 2 pistons going one speed and 2 other pistons going another speed. They do nothing to absorb or dissipate torsional crank harmonics. Zero. Before anyone believes this B.S. your crankshaft will see the forces caused by this no matter what, it's only your butt that will notice a difference.

I am interested in the claim that if it is not pressed onto the crank snout it can't be a harmonic damper. It's obviously able to transmit the torsional force to the accessory belts, I'm unclear how it is incapable of transmitting a torsional damping force.

IT'S NOT AN INTERNAL BALANCE ISSUE! You can say that until you are blue in the face, but you've still got harmonics inherent to your engine design. It's the torsional spike due to one piston firing while the rest is not. This puts a twist into the crank which acts as a spring. Without any damping (or even with some? It's been a while since my vibrations class) this can go into a harmonic frequency giving you huge crank twists that will eventually break it.

http://en.wikipedia.org/wiki/Torsion_spring#Torsional_harmonic_oscillators

 

[SpawnedX]

I refute your claim of huge crank twists. I am not saying it does not cause crank twists, but quite simply simple physics say for each action there is an equal and opposite reaction. Under this same theory, if one piston is moving down faster, the others are moving up faster, causing a counter-reaction when that piston fires sooner than it would have, if their was not another piston increasing the speed of your 4 strokes.

According to your theories, it would be the journal closest to the pulley that would suffer the most stress as the harmonics do not have as far of a travel to be dissipated. Where-as the journals that are being shown to break are flywheel side, where there is plenty of distance to dissipate harmonics.

Dampering probably works, to an extent, but it seems illogical as to why we damper a small pulley and not the flywheel as well. Specifically related to the fact that this is most definitely NOT a balance issue. There is also no way to be positive on the direction of a harmonic vibration, how do we know it is not traveling towards the flywheel?

However, I feel that using Unorthodox or any company that makes dampers for a profit an unreliable source of scientific information. Do you really expect them to tell you "nope our product doesn't actually work and is far less significant then you think?"

It's pure science when we discuss motors, we know for a fact that a V8 will have more engine vibration and many more pulses being sent to the crank due to 8 firing sequences, yet some of them are undampered.

There are way too many inconsistencies with so called "facts."

One major inconsistency is the fact that it supposedly is preventing crank twist, by dissipating vibration, however the crank is still twisting, the vibration is just being dampened. If a crank is going to snap, it is more likely to occur before it springs back on itself causing said vibrations. The actual act of it snapping is more likely to come from one large jolt up front, like say detonation. I think a lot of these snapped crankshaft owners want someone to blame other than pure bad luck and/or bad tuning.

 

[blackrosenova40]

You work for Unorthodox?? Lmao

I actually am using there adjustable cam gears, now im starting to regret it.

I am a diesel technician and I have not seen a single damper that is press fit on the crank. I think I am gonna start telling customers they don't need them because they are useless as they are not press fit on the crank snout.

Id be out of a job within a day or two.

It would be a coincidence if the battery wasn't dead prior to the pulleys being installed, which it was. I love assumptions.



The glass needs to be filled with rubber. Now take that same glass burn out 4 holes in a circular pattern and clamp a rubber filled donut object on that glass. Hit it with sound then, doesn't save that glass. Same as that damper won't save your crankshaft since it is bolted a sprocket that is not dampered, that sits on the crankshaft.

 

[SpawnedX]

It has nothing to do with being press-fit, it has to do with the fact that the pulley doesn't truly sit on the snout with a single bolt holding it in, such as on the 420A, because it is sitting on the snout in that instance, it is far more likely that the twist will be dissipated into the rubber insert.

In gist what I am saying is the vibration is being transferred to the 4 bolts, then the 4 bolts transfer it to the pulley, and then as it travels into the pulley whatever is left is dissipated by the insert. I am quite literally saying this system would work better if our sprocket was dampered.

 

[tkelly27]

http://www.epi-eng.com/images/Engine/engine_technology_piston_motion_g1.gif
that's what causes the second order vibrations that the balance shafts counteract. You can refute it without doing the math, but it doesn't change the fact that your car will vibrate without balance shafts no matter what you do.

Up to two degrees of crankshaft deflection. I can't find the reference, but it's much in the same way that you would pull on a spring attached to a weight. You put a force on the spring, and it moves, then the weight moves. The crankshaft, damper, flywheel, etc. act as the weight, and the crank throw acts as the spring. We are positive on the direction of the twist in the crankshaft, if you are looking at the front of the engine it is in the clockwise direction.

The issue of a harmonic is that it oscillates and goes both directions. Springs don't dissipate harmonics very well. Drive without dampers if you don't believe me. Bouncing back and forth along the crank isn't going to do diddly to a harmonic. I didn't give any theories as to where the crankshaft would fail. When you initiate a twist on journal 1 the whole back end of the crankshaft has to catch up, and when you initiate a twist in 4 the whole front end has to catch up. Who know how the dynamic works out in that at the harmonic frequency.

Where would you want to dampen the flywheel? It gets hot and could easily melt the rubber. What do you mean transfered towards the flywheel? It's all in reference to the crank and really doesn't matter.

You know what else is weird? The harmonics from driving are transfered from the tire, to the wheel, to 5 bolts and lug nuts, to the wheel hub, to the bearing, to the steering knuckle, through two bolts, then to the spring and shock absorber. It's not doing any real damping either I guess. It would be far more effective if you welded your damper to the wheel.

Even if the bolts were bending, that is just another part of the spring that is the crankshaft and the way it transmits its force to the damper.

 

[SpawnedX]

I never said the motor would not vibrate more without the balance shafts, so I don't know why you keep referencing that.

What I am saying is, the crank is in essence broken into 4 parts, 1 and 2 pistons when firing will tend to twist and throw a vibration towards one end of the crank, but 3 and 4 will vibrate in the opposite direction. So, basically it would seem that only half the time that damper is doing anything useful, and since it seems most are snapping flywheel side, it would seem we would benefit from a damper there as well.

As far as the snout issue, what is being referred to as interference style snout, is that there is a third component between the crank and the pulley, the bolts holding it to the sprocket, rather than the pulley sits on the snout and has a larger center bolt to hold it into place. So vibration goes to the bolts then the pulley, lessening it's true ability to damper.

For any application which operates at high power and a relatively constant speed for long periods (unlike a race engine which typically cycles up and down quite rapidly and only has to live a few hours), it is critical that the major orders of crankshaft torsional vibration be attenuated.

Because I bet a lot of people have actually done this to their platforms. This is kind of like saying, hey stupid, your stocker is useless.

Many of the automotive 4-cylinder engines don’t require such an absorber, primarily because of their inherently higher stiffness-to-mass ratios. However, several automotive manufacturers have initially omitted a torsional absorber from early engine runs, only to find that crankshaft life was unacceptably short. The Nissan folks discovered this with the early 240-Z engines, which didn’t have an absorber, and therefore lasted only about 100 hours in automotive (i.e. VERY LIGHT DUTY) service.

This is like a double-edge sword. It hints that they may not be needed, but some early runnings on some motors did need them, and then hints that this may have caused some manufacturers' to use them just as a precaution.

 

[tkelly27]

I reference it because the pistons do not go the same speed on the up stroke as the down stroke. They also do not put the same force on the crank through all 4 strokes.

You're totally missing this. All cylinders fire independently of each other. When cylinder 1 fires, no other cylinders are firing, so there is a huge force only on the #1 journal of the crank. Even while rotating, the inertia of the rotating parts it's trying to spin faster resists the rotation of the crank. Due to this there is a twist in the crank. This will continue until there is no longer a force on the crank. There is NOTHING to balance this twist in the crankshaft. As this twist and untwist us going up and down the length of the crank the next cylinder fires, and on and on.

At most RPM's the twist forward and resulting spring back that travels down the crank is so muddled up with the other pulses that no harmonic can develop.

At a certain RPM the twist and untwist coming up and down the crank will match the firing of one or more pistons such that the energy put into it will add up. It's like a swing set. If you push in time it will escalate. This goes until the crank fails or you get out of that RPM range.

It doesn't matter where the damper is either. We want to dampen the torsional pulses and they all get to either end of the crank. Also, the one pictured broke on the #2 journal.

As far as the snout issue, it's totally stupid. Again, do you think your tires, wheels, bearings, etc. lessen the effectiveness of your suspension dampers? Those are all just extra springs, the vibration doesn't die or change in them.

 

[SpawnedX]

There is some controversy about the pulleys, as they are not equipped with the harmonic balancer that the stock pulley has. We feel the risk of removing the balancer on certain engines is not really a risk. Inline, four-cylinder engines for the most part have short, stiff crankshafts. These do not need a balancer as much, because of their high natural frequency. Engines with long, whip-like cranks, like inline six-cylinders, need balancers to prevent failure, but most four cylinders do fine without them.

What I am pointing out, and you can find it in your own articles, is that your information is based on the engine sitting at certain critical RPM ranges for some time. Because our cranks are so short, they have said high natural frequency, meaning the harmonics have to be at higher natural frequency to snap it. The question is, does anyone know what these RPM ranges are. Say you are daily driver Bill, and you usually cruise in 5th at 65 or 3,XXX RPMs, once and awhile you bring her to 8K for some highway fun.

Let's say these critical ranges are 1500, 4500, 7500 for the sake of its 5 freaking AM and I want to use whole numbers. The crank is most likely to snap at these ranges. These are all acceleration ranges and peak RPM ranges, never which you are probably at for very long periods of times. Reducing your risk factor a lot.

I think the only real way to solve if this is a huge risk or not is to know those ranges.

It also points out that cars prone to failure are usually cars that sit at high RPMs rather than go through a range of RPMs, like stock cars.

I am not denying that there is a risk, but I am saying maybe this risk is being made out to be larger and greater than it truly is. Then again, anytime you run 20+ lbs of boost you are taking a risk.

There still is no concrete proof that those DSM crankshafts snapped because they were undampened and you can't provide any. However, for each 1 you show me a picture of, I can find 5 guys who have used them for 50K miles no issues.

 

[tkelly27]

There is also cyclical fatigue. The crank is designed with a fatigue limit for repeated usage in mind. If you go through a harmonic that causes it to exceed that even for an instant, every time you go through that RPM you will be adding a cycle. That's a big if, but for 5hp, it's not even a question for me.

It's a bad way to gain an insignificant amount of power with an increased risk of engine damage.

Instead of finding 5 people that it worked for, find someone who cracked a stock crank in half while using a proper damper. The 4g crank can hold 1000hp or more. When detonation occurs the rod, piston, or head gasket will fail before the crank breaks. It doesn't add up when people with 300hp daily drivers are snapping cranks after installing an undamped pulley.

I still want Shawn from unorthodox to come here at tell me how 4 bolts and a dowel pin can not transfer torsional vibration when it most clearly transmits a torque to the alternator, water pump, etc. Explain it to me, I'm an open mind ready to be changed.

 

[unorthodox]

I still want Shawn from unorthodox to come here at tell me how 4 bolts and a dowel pin can not transfer torsional vibration when it most clearly transmits a torque to the alternator, water pump, etc. Explain it to me, I'm an open mind ready to be changed.

Simple physics. In order for all the torsional motions and frequencies created from the engines operation a damper must be one with the crankshaft. Simply stated previously that means the damper must be interference fit to the said crankshaft. If the damper is not interference fit it will move on the snout. Any movement not in phase with the cranks motion cannot be countered or absorbed. To be especially clear the dampers hub/housing/inner section must be interference fit. The inertia weight must be free.

Every action has an equal and opposite reaction. Simple law of physics.

The equal and opposite reaction/absorbsion cannot happen if the connection is not interference (in essence the two parts must be one).

Respectfully,
Shawn

 

[Oldsid]

No offense, but when does the bad information cycle stop on this site.

1. Our cars do not have harmonic BALANCERS.

2. Our engine is balanced internally, the cranks included, this is why we have balance shafts. To balance the engine internally, which is why a lot of these people always forget that they removed the shaft and put on lightweight pulleys and had issues, the same issues they would have with the OEM crank pulley.

Before I purchased these, I did ton of research on it, including wading through the crap.

Unorthodox Racing

Once again this post is in no way shape or form towards snowboarder, I have no idea his level of involvement in technical knowledge. He could have read the same misconceptions and trusted them on face value. I just want to clear the air for people who did not buy pulleys for this reason alone.

It may be the belt, this I agree.

All reciprocating engine do have a harmonic balancer. The harmoninc balancer is not for balancing of weight umbalance from the cranckshaft and any rotating mass but it is to dampen torsional vibrations.
Sowboarder is right; in our 4G63 engine, it is an integral part of the crank pulley (Mitsubishi Crank Pulley (1992-1994 Eclipse) : JNZ Tuning. Check this link for an OEM "dampened pulley".

 

[SpawnedX]

All reciprocating engine do have a harmonic balancer. The harmoninc balancer is not for balancing of weight umbalance from the cranckshaft and any rotating mass but it is to dampen torsional vibrations.
Sowboarder is right; in our 4G63 engine, it is an integral part of the crank pulley (Mitsubishi Crank Pulley (1992-1994 Eclipse) : JNZ Tuning. Check this link for an OEM "dampened pulley".

I'm just curious if you read what you post. Please learn the difference between absorber, damper and balancer.

We DO NOT have harmonic balancers, most cars no longer do, since most engines are internally balanced now.

 

[dsmspickdad]

Well that was interesting! Charge your battery, have that alt checked out! DSM's have a reputation for weak alt's. Return to the OEM pulley and properly adjust the belts. Good Luck!

 

[Ceddy]

This thread is so full of fail.

If you are just getting into DSMs and read this thread, your first lesson should be don't believe everything you read on the internet. And take into account peoples ulterior motives, EG trying to sell you something.

No one hear is is a mechanical or metallurgical engineer, and their theorys amount to zilch. If you want modify your engine trust what has be proven to work over the last 15+ years, or go to your local tuner/shop and find out what they have on their high power 4G63 motor.

OEM cranks are not weak, they have been taken past 1000HP, and many prefer them over aftermarket ones.

Balance Shafts have nothing to do with engine performance/safety. They are there for driver comfort.

The OEM Harmonic Dampener is there for a reason, if it had no use we would have got a much cheaper solid pulley.

Our cars already have problems with a weak alternator, and need all the fluid flow they can get. Putting on undersized pulleys isn't going to help this.


If you want to try a non-dampened/undersized pulley go ahead, but don't give people who are just getting started bad advise that could cause thousands in damage, because you have a unproven theory.

 

[donniekak]

Wow i don't know where to start here.
First off, two having to be as one for an equal and opposite is more of a poem than physical reality. Hang 5 bearings together, pull one back and let it go, watch the energy being transfered to ONLY the last bearing through the others. They are definetly not one, but transfer the equal energy of the ball impacting through the group, and propelling the last.
Now to the damper.
The stock pulley is a poor torsional damper, it's not heavy enough. What it is, is a harmonic damper. Take a stock 4g63 crank, suspend it from a small piece of rope around the flywheel mating surface. This simulates the crank floating on the oil wedge in the bearings. Strike one of the counterweights with a small metal object, not hard. Hear it, the crank rings like a bell. Bolt up the cam gear and stock pulley to specs and do the same, hear it, thud. The damper has dampened the harmonic ring of the forged steel. This is very important. The constant ringing of running a crank without a harmonic damper can cause damage. Not will, but can. Ask Ray Pampena, and others in the 3000gt community. An engine pushed to the very limit of the crank, WILL hold together better with a damper. The 6g72 is a good example because they make massive torque. People were breaking stock forged cranks at 7-800 ft/lbs. Most were running an aftermarket pulley. The cars making 1,000+ ft/lbs are all on the stock pulley.

 

[Oldsid]

I'm just curious if you read what you post. Please learn the difference between absorber, damper and balancer.

We DO NOT have harmonic balancers, most cars no longer do, since most engines are internally balanced now.

I do read what I post very carefully. Whether you call a part an absorber, a damper or a "harmonic" balancer is a matter of semantic in this case; the function of the part is what is important. It is true that in this case, there is no seperate "harmonic balancer" because it is integral with the OEM pulley as shown in the part link.
So there is a device, whatever you want to call it, to absorb, dampen..etc the torsional vibrations and not the imbalances of any rotating part. That's the function of the cranckshaft counter weights and the balance shafts.
The cranckshaft may fail if it operates in its resonant torsional frequency without some sort of a damping device and that is exactly what you may be doing by using a simple pulley.
Check out Ceddy's post pictures at the beginning of this thread and you will see what torsionnal vibrations can cause. If you want to have your cranckshaft to end up like that, suit yourself.

 

[goodbuds]

wow.. this was intense i just bought an unorthodox pulley, what am i gonna do uuse it for a fishing weight??

 

[hubz91talontsi]

Should have read this thread before you bought it =X

 

[goodbuds]

its ok i ll just sell it on ebay..hahaha