Cause of blown motors?

[Poodles]

Originally Posted by stugray

I disagree. Not only is the multiple part assembly clearly more than just a simple pulley, but mine has a hole drilled into it along the perimeter.

I can only assume that the hole was drilled to balance the rotating mass.

When pros build these engines, they have the rotating mass balanced.
This rotating mass includes the pulley and all rotating parts.

If you change one part, you invalidate the balancing.

Did the factory balance each of these engines as a complete rotating mass?
I have never had a definitive answer to that question...

Most modern engines are zero balanced, meaning that each part is individually balanced and not balanced as a unit. Older stuff sometimes have external counterweights, and any built motor is usually zero balanced then balanced as an assembly for good measure.

Originally Posted by steve99

Two thing that seem implausible

1. An OEM manufacturer would install a part that is not needed or install a part that is more complex and hence more expensive than it needs to be.

2. You have a rotating crankshaft that weighs many Kilograms with a flywheel bolted to it at one end with clutch and pressure plate and people are replacing the pully/balancer on it. You replace this to save probably less than 5% of the total rotating mass of the crankshaft flywheel clutch pressure plate assemblies, and this rotating mass is close to the axis of rotation. What difference does it make ??

Unless it smaller diameter and under-driving alternator/air cond/water-pump ect which will probably have other undesirable effects in stop start traffic, maybe fine on a track

Bingo. Saving a small amount on each part is a huge difference in mass production. I also love people putting one piece driveshafts on cars like this, they really need to learn what a driveshaft critical speed is and realize why the OEM's run multi piece shafts.


If you want to lose rotational mass, use a light weight flywheel and clutch assembly. Then again, the heavy flywheel is nice for drivability, and it's a nice big heat sink as anyone that's ever welded a clutch disk to the steel insert in an aluminum flywheel will know...

Originally Posted by stugray

You just dismiss a fact because I used the word "assume" in my sentence.
I will rephrase that for you: My stock harmonic balancer has a hole drilled around the perimeter. Therefore, one can safely state that the factory performed some kind of balancing or there is no reason for that hole to be there.

And as for the "Subaru has stated blah blah, blah pulley......" THIS IS CLEARLY a "he said, she said" situation.
NOTE: If you search for "John J. Mergen" you will find dozens of quotes from him about this pulley issue, but almost all of them differ from the others in some way. I have never seen a post from the very person who received this email. It has reached birther status in the blogosphere...

I have read almost every thread about pulleys and every time it comes up: Someone's step-brother's cousin once saw an email from someone who might have been a technical person at Subaru that stated that the pulley is not a balancing pulley.

We have a number of facts (and common sense) that say otherwise.
1 - the Stock pulley on my subauru BRZ is a complex cast/machined/mulit-piece assembly. And NOT just a simple pulley.
2 - Apparently Subaru likes to waste money and engineering costs to make a complex fabricated heavier part and include it on our cars for apparently no reason whatsoever.
3 - Armchair automotive engineers know better how these engines work
4 - Experience building racing boxer engines counts for zero because of above "armchair automotive engineers" SOME of which dont know what end of a crescent wrench is adjustable....

Who has more money into these cars, Subaru/Toyota or Perrin? In essence, it's "above my pay grade."

Originally Posted by suaveflooder

I understand, and honestly, you have been beyond respectful, which says a lot about you. I agree on not arguing over semantics. There really are some great responses on different forums that goes over this. It's been a debate for a long time.

I actually held off for a long time on the pulley because I kept thinking, "well what if." The more I read, and the more opinions I got (even from engine builders) was that the pulley is fine. Although, some of the guys metioned not to put both a lightweight flywheel and pulley on together as it does create said vibration. Jury is still out for me on that one, but I'll keep reading as information continues to come out.



lol, this is not a "he said, she said" idea, this is information from subaru. The "he said, she said" principle doesn't really come into effect in this case. Why not call the guy from above? I left his name on there.

Curious, is this the "complex" part you are referring to? Just took these from the pulley that came off of my car





Some more more "He said she said" for you. This one from FT86 speedfactory

Good information



So maybe this heavy pulley is "dampened" for the same reason perrin said in the quote from post #11. Perhaps it's not as "complex" as you think

Keep in mind who's trying to sell you stuff... Also, good luck going after said person that sold you stuff if it does cause damage. This has been the norm in the car scene forever (and most recently FA20club showed how easy this is to get away with). It's a sad reality, but I'll take the opinions of engineers that made the car. In essence the part res ipsa loquitur.

Originally Posted by suaveflooder

Lol, okay then. Sounds like you and I are finished here. I give you information from the company who DESIGNED and BUILT the car, and two BIG companies that know a hell of a lot these cars than you and I both and you give me, "I assume." That's fine, man. Have a good night


Sent from my iPhone using Tapatalk

First part is still up for question. Much like getting any low level tech's answer through customer service, it's not dependable.


Second part, come on, they're making and selling the parts, of course they're going to talk it up. Watch any infomercial and see how marketing works in action. It's not really dishonest, you just have to know that they're really there to make money and sell you something.

[suaveflooder]

Originally Posted by Poodles

Keep in mind who's trying to sell you stuff... Also, good luck going after said person that sold you stuff if it does cause damage. This has been the norm in the car scene forever (and most recently FA20club showed how easy this is to get away with). It's a sad reality, but I'll take the opinions of engineers that made the car. In essence the part res ipsa loquitur.




First part is still up for question. Much like getting any low level tech's answer through customer service, it's not dependable.


Second part, come on, they're making and selling the parts, of course they're going to talk it up. Watch any infomercial and see how marketing works in action. It's not really dishonest, you just have to know that they're really there to make money and sell you something.

I thought about this as well. Truthfully, what allowed me to relax a bit is that they were all "singing the same tune" so to speak.

Perrin:

The argument that the reduced weight and removal of the rubber ring will destroy the front main bearing is wrong! The rubber ring between the two halves of the stock pulley is to make up for mfr. differences. Two cheap cast pieces pressed together with rubber allows for additional slop in both. If Subaru chose to install a pulley like ours would add significant cost to the engine and is not cost effective for a production piece. The rubber ring is NOT a harmonic balancer! You should go to your car and let it idle. Raise the hood and note how the belts will track side to side and up and down. This is a result of the much less than precise pulley found from the factory. This causes undue stress and wear not only on the pulleys but on the belts and accessories as well. Installation of our pulley will result in smooth, true, and long lasting belt wear and accessory lifespan is increased. Plus, throttle response, HP and torque are all increased dramatically for such an inexpensive painless part.

Crank bearings, and rod bearings are much more prone to premature wearout from increasing boost than from installation of a precision made billet pulley. This should not be a concern.

Ft86 Speed Factory:

An opinion often expressed is "if the manufacturer put it there, it must be there for a reason". However, if you look at it from the car manufacturer's point of view, casting pulleys from steel is very cheap and easy, because they can be produced in large numbers and there is no waste (as opposed to machining them from billet). But because the resulting pulley weighs significantly more than one made from aluminium alloy, it requires dampening.

Manufacturers will always build cars (even high performance cars) to suit the widest possible selection of driving scenarios and drivers, which means there are always compromises. The weight of the flywheel and pulley also affect how fast the revs drop between gear shifts, and a production car is designed to only allow the revs to drop fast enough for average shifts. If you hurry the shift the revs will be too high for the next gear, resulting in a sharp jerk as the momentum of the engine transmits through the drivetrain. Reducing the engines' inertia with a lightweight pulley kit allows faster and smoother shifting.

Subaru:

"Thank you for your patience as I checked with our Technical Services Department regarding your message below. They advised that the crank pulley is a pulley and nothing else. It is not used as a harmonic damper/balancer.

Thanks for the opportunity to be of assistance. If you need any future assistance, please feel free to contact us again."

Best wishes,

John J. Mergen
Customer Service Department
Subaru of America, Inc.

Now why not add in another person. This is from Unorthodox Racing's website

Dampers: Facts Not Fantasy

Much of the science behind dampers is based on theories in books, applied in a vacuum, not actual real world facts. Most people buy a damper because they herd they needed one or out of a fear of the unknown. The problem is people don't know why they do or don't need a damper. There is no mystery here, just cold hard facts based on real world use and need. So lets get started.

First what is a damper? The most basic definition comes from Websters, which says; a damper is a dulling or deadening influence. Now that's pretty simplistic but its a great start. A damper is designed to absorb motion and frequency (harmonics) created by the crankshaft and the rotating assembly (rods, cams, etc). The most important aspect/element of a damper is how it's mounted to the crankshaft. A damper must be interference fit to the crankshaft snout. This means the damper must be heated up to be pressed onto the crankshaft snout, making a fit so tight its like the parts were made from one piece of metal. Without being interference fit a damper cannot function according to the most basic law of physics, "every action must have an equal and opposite reaction." Without interference fit a damper moves on the crankshaft snout and loses all of its ability to counteract crankshaft torsional movement.

The purpose of a damper is to protect the crankshaft from cracking due to excessive torsional movement and harmonic frequencies. A damper has no effect on bearing wear, it is the engines balance and build tolerances that control bearing wear. Dampers are not necessary in most modern engines because of the many advances in engine design but more importantly the quality of the materials and machining tolerances. Factors such as shorter stroke lengths, short piston TDC dwell time, no piston pin off-sets, forged crankshafts and engines that are balanced to blue printing specs or better (Honda engines are 0 gram balanced). Another important factor is the actual tune of the engine, especially when modified. Poor tuning leads to detonation which is an engine killer and no damper can stop this damage.

Now that these important facts are out in the open you need to figure out if your engine does or doesn't need a damper. If your factory crank pulley is not interference fit onto the crankshaft you do not need a damper. A great example of this is the 4G63 engine (1990+ Eclipse, Evo, Laser & Taon) which has its crank pulley mounted to the engine with four small M8 bolts. The 420A SOHC/DOHC crank pulley (Chrysler Neon, etc.) is interference fit but not because it needs a damper but because there is no key or dowel pin to hold the pulley from spinning on the crankshaft. Still confused? If you unbolt your crank pulley and it slides off the crankshaft you do not need a damper. There are a few engines where the crank pulley is sometimes slightly tight (VG30DE & DETT) but these engine also do not need a damper.

Now lets cover some damper terminology mis-understandings. The term "Harmonic Balancer" is often used but is incorrect. This type of device does not exist but was created by putting two terms together. The words are harmonic damper and engine balancer. A harmonic damper is just a fancy name for a damper. The term engine balancer is for engines that are externally balanced and have a counterweight cast into or bolted to the crank pulley or damper. The proper way to describe the incorrect term above is Harmonic Damper or Damper with or without external balance weight.


Now many people will still have lingering confusion even after all the facts above. This is ok as we are changing people's understanding through real facts not urban myths and legends that have persisted for too long. As discussed above many of the pulleys on import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley making them look similar to a damper. The elastomer in the OEM pulley serves as an isolator, suppressing noise from the engine accessories; the A/C compressor, P/S pump, and alternator. This noise is what car manufacturers call NVH (Noise Vibration & Harshness) which they want to keep out of the passenger compartment. Its the same reason OEM's use of dual mass flywheels to quiet transmission noise and freewheeling alternator pulleys to quiet even more alternator noise.

Many earlier generation crank pulleys on domestic & import engines have no rubber at all. We have samples of many of these from Acura/Honda B & D Series engines, 2.4L Altima, 1.8L Eclipse, 2.3L Fords, 2.2L Chrysler's, and 1.8L VW's just to mention a few. Some people will now worry that because we remove the NVH damper they will start to hear more engine accessory noise. The type and amount of NVH is unique to every car. As an example NVH will increase with aftermarket intakes or exhausts. OEM intake and exhaust systems use baffles and resonators to quiet intake and exhaust noise. Aftermarket systems eliminate these baffles and resonators to increase HP but they also increase noise from the throttle opening and from the additional size of the freer flowing exhaust. To most people the increase of in NVH makes for a sportier driving experience not to mention more HP.

For engines that need dampers UR will finally be offering the most innovative new damper technology in 20 years. The Ultra Damper will be in a class by itself offering unmatched damping capability from idle to redline. Even more amazing is the Ultra Damper will be ligther than the factory damper and any other damper currently available. Once again UR is leading the industry in advanced light weight solutions helping increase engine efficiency, saving you the consumer money on fuel and maintenance costs.

Add this information with hundreds of thousands of people running lightweight cranks for hundreds and thousands of miles, I'm pretty comfortable running a lightweight pulley The more information I'm reading, the more I get that subaru does not use harmonic dampener or balancer, it's just a crank pulley.

[Boxer486]

A drilled see thru hole is usually for alignment. Dimples are for balancing.

[Fear]

Just read this whole thread and i figured it out ....


The answer is yes.

Have a nice day

[s2d4]

Originally Posted by Fear

Just read this whole thread and i figured it out ....


The answer is yes.

Have a nice day

you must be FAER.

[Fear]

Originally Posted by s2d4

you must be FAER.

You spelled it wrong...

Honestly though I think our crank pulley is a shared part with other platforms... So both arguments have merits .. Hence the "yes" answer

[billwot]

Originally Posted by FirestormFRS

No! The factory does not balance every engine that comes down the line. Mass production engines get whichever pulley is the next one in the box. The hole you see on the outside of the pulley is to balance the pulley itself. Kinda like balancing a tire.
The tolerances are extremely tight on the crank balance and the pulley, but that's about it as far as balance goes.

[Poodles]

Originally Posted by suaveflooder

I thought about this as well. Truthfully, what allowed me to relax a bit is that they were all "singing the same tune" so to speak.

Perrin:

That's a bunch of crap... They're a small shop making parts and don't even understand the concepts behind the part. Hell, the part isn't SFI rated so this is all pointless anyway.


Of course if you want info from someone who does make SFI rated pulleys and knows what they're there for, look no further than ATI: http://www.atiracing.com/products/da...mper_dinan.htm


I'd say Dinan is far FAR larger than these three people you've linked are together.


Also of note, the higher your output, the larger the damper has to be to handle it. This is why some of the Supra guys run custom ATI dampers (and guess what motors haven't blown...)

Originally Posted by suaveflooder

Ft86 Speed Factory:

Complete BS as aluminum can be cut extremely fast and on a cylindrical piece like this (that is ALSO machined steel) it would be cheaper for the OEM's to use them. Not a single one of them does. A single step process vs a multiple part process will always be cheaper, so they honestly have no idea what they're talking about. Hell, look at the cost of one of their pulleys vs a real damper from ATI...

Originally Posted by suaveflooder

Subaru:

Still hearsay and I'm still not convinced it's real. I'm inclined to believe it's fake simply because anything like that would have passed their legal department on the way and had a disclaimer about how it could potentially hinder warranty claims on the engine/drivetrain.

Originally Posted by suaveflooder

Now why not add in another person. This is from Unorthodox Racing's website

Oh this is comedy gold. Unorthodox's pulleys have been well known in the car scene for causing failures (oil pumps, front main bearings, etc), but I'll at least humor what you highlighted.


- First part is false as if the pulleys DID move, they hammer the hell out of the keyway in the crank. They're a press fit, that's why they require pullers to remove.


- Wrong again, it's flexing of the crankshaft that would damage bearings (and has been shown over and over with their products). Forged cranks have no effect on this other than they will flex more before breaking.


- Part about bolt on pulleys is false as well as there is still a part that is a press fit on the crank after they are removed. Miata is like this, and guess who have oil pump failures from Unorthodox's pulleys?


- Wrong and wrong...and wrong. It's there to damp the big huge pulsing thing under the hood called an internal combustion engine. The accessories don't have pulses at all, and even if they did, they're attached solidly to the motor and attached to the crank with a rubber belt. Dual mass flywheels are used for more than that (yes it does help with gear clash in the transmission), and freewheeling alternators are for economy.

Originally Posted by suaveflooder

Add this information with hundreds of thousands of people running lightweight cranks for hundreds and thousands of miles, I'm pretty comfortable running a lightweight pulley The more information I'm reading, the more I get that subaru does not use harmonic dampener or balancer, it's just a crank pulley.

Hundreds of thousands? You're wildly overestimating how many of these things are in the wild. It's ok, you can be happy about your car going hundreds or even thousands of miles, I'd prefer mine to go hundreds of thousands of miles. People have had failures is less time than the average person changes their oil...


So the pulley that Subaru doesn't look like all the other cars on the road that run harmonic dampers?

[suaveflooder]

Originally Posted by Poodles

That's a bunch of crap... They're a small shop making parts and don't even understand the concepts behind the part. Hell, the part isn't SFI rated so this is all pointless anyway.


Of course if you want info from someone who does make SFI rated pulleys and knows what they're there for, look no further than ATI: http://www.atiracing.com/products/da...mper_dinan.htm


I'd say Dinan is far FAR larger than these three people you've linked are together.


Also of note, the higher your output, the larger the damper has to be to handle it. This is why some of the Supra guys run custom ATI dampers (and guess what motors haven't blown...)




Complete BS as aluminum can be cut extremely fast and on a cylindrical piece like this (that is ALSO machined steel) it would be cheaper for the OEM's to use them. Not a single one of them does. A single step process vs a multiple part process will always be cheaper, so they honestly have no idea what they're talking about. Hell, look at the cost of one of their pulleys vs a real damper from ATI...





Still hearsay and I'm still not convinced it's real. I'm inclined to believe it's fake simply because anything like that would have passed their legal department on the way and had a disclaimer about how it could potentially hinder warranty claims on the engine/drivetrain.




Oh this is comedy gold. Unorthodox's pulleys have been well known in the car scene for causing failures (oil pumps, front main bearings, etc), but I'll at least humor what you highlighted.


- First part is false as if the pulleys DID move, they hammer the hell out of the keyway in the crank. They're a press fit, that's why they require pullers to remove.


- Wrong again, it's flexing of the crankshaft that would damage bearings (and has been shown over and over with their products). Forged cranks have no effect on this other than they will flex more before breaking.


- Part about bolt on pulleys is false as well as there is still a part that is a press fit on the crank after they are removed. Miata is like this, and guess who have oil pump failures from Unorthodox's pulleys?


- Wrong and wrong...and wrong. It's there to damp the big huge pulsing thing under the hood called an internal combustion engine. The accessories don't have pulses at all, and even if they did, they're attached solidly to the motor and attached to the crank with a rubber belt. Dual mass flywheels are used for more than that (yes it does help with gear clash in the transmission), and freewheeling alternators are for economy.





Hundreds of thousands? You're wildly overestimating how many of these things are in the wild. It's ok, you can be happy about your car going hundreds or even thousands of miles, I'd prefer mine to go hundreds of thousands of miles. People have had failures is less time than the average person changes their oil...


So the pulley that Subaru doesn't look like all the other cars on the road that run harmonic dampers?

Alright, man. I'm assuming all you want to hear is that "you win?" Works for me. This is not an arguement that is worth continuing with. Honestly. Your entire arguement assumes we have a harmonic balancer. Mine does not. The article you posted from ATI is for cars with harmic balancers/dampeners. Since I don't think our cars have them, the article doesn't pertain to our cars. (And I've been apart of enough M3 forums, as well as owned one, to know about the lovely reliablily of the M3, including E9X's having STOCK engines with rod bearing failure) So, I won't change my mind, and you sound like a stubborn enough ass to not have yours change either, so we are now going no where. I will continue to run my pulley, with no issues, and you will continue running your stock one…with no issues. Lol. The irony is that neither one will prove us right. Although, imagine what's going to happen when that rubber in the stock pulley starts to go and that pulley splits.

Did Subaru choose to use a harmonic balancer? No. I know for certain that there is no counterbalance in the crank pulley, as I have mounted my stock pulley on a spindle with Hall sensors to dispel that very same myth. The weight of the stock pulley is very well balanced.

I think you are confusing "balance" with "opposed firing architecture". Since the boxer motor cylinders are acting within the same plane but in opposite directions, you eliminate a lot of the loading problems requiring a "balanced rotating assembly" in a v engine configuration. Essentially the boxer throughout its firing order is creating equal but opposite loads on the crank shaft (in precisely opposing directions), while in a v, the forces are applied to the crankshaft 60deg (example) from one another. If your rotating assembly is not perfectly balanced you have x and y components of force to do something with. This is where the HB comes in as well as main bearing design, rod design, counter balancers, crankshaft inertia etc. Also why V engines are more prone to bend or "throw rods" in catastrophic failure modes.

Oh great. Another harmonic balancer question/debate.

I had a very long debate with mike-tracy about this.

His argument was:
- the SAE technical papers on the Boxer motor states that it uses a harmonic balancer.
--> "A double mass harmonic balancer is adopted to disperse the torsional
and bending vibration up to the 7500 rpm of maximum operating speed."
--> http://www.surrealmirage.com/subaru/files/SAE_boxer.pdf
--> http://img.photobucket.com/albums/v201/ ... za/pg4.jpg
--> Based on EJ20G I believe
- ATI & fluidampr make crank damper that are Fluid filled or Elastomer


My argument:
- Not a damper, only a thin rubber strip to soften the effects of the the a/c clutch and other accesories connected to it.
- Short crankshaft.
- Balanced motor by design
- 100,000 Lightweight, underdrive, overdrive crank pulleys made with no one reporting engine failure.
---> I personally have these on a handful of various EJ-series motors with no issues 100,000+ km on all of them.
- Subaru of America (SoA) response below
---->
"Thank you for your patience as I checked with our Technical Services Department regarding your message below. They advised that the crank pulley is a pulley and nothing else. It is not used as a harmonic damper/balancer.

Thanks for the opportunity to be of assistance. If you need any future assistance, please feel free to contact us again."

Best wishes,

John J. Mergen
Customer Service Department
Subaru of America, Inc.
----


As anothernord explained having the LW flywheel and crank can throw a code but this is unrelated to vibration.

Blah... stupid topic with no real factual answers
-Chuck

I agree with the others who have states that the crank pulley is NOT a harmonic balancer. In fact, I asked 2 subaru dealerships around here the same question, and they told me it was NOT a harmonic balancer. I've been running a lightweight crankpulley for ages and never had ANY trouble with my car. I also run a lightweight flywheel at the same time with no trouble.

Subarus do not have harmonic balancers. Like someone mentioned earlier, they are horizontally opposed engines, meaning they are as balanced as can be. The stock pulley is heavy, with rubber in the middle to eliminate vibration, and to help stabilize the crankshaft, as is the flywheel. However, many people with these cars replaced both the crank pulley, and the flywheel, and didn't see any adverse events happening.

Boxer engines that are properly configured do not have vibration modes that can be solved by any kind of balancer. The rubber in the crank pulley is actually to protect the accessories.

BAC is 100% correct that this is not a harmonic balancer.

The one thing I would add is that I have heard and read that the purpose is mainly to reduce NVH.

Took my stock one out years ago, but confirmed with an engine builder that it wasn't necessary first.

The purpose of the rubber in the pulley is to insulate the accessories from the impulse of the non-uniform rotation of the crank. The crank does not have a constant angular velocity, and v-belts tend not to damp these changes. The rubber in the pulley absorbs this impulse, and provides a relatively constant (or significantly damped) angular velocity to the alternator, PS pump, and A/C. This extends their life, and improves their efficiency.

As I understand it, harmonic balancer is a shock mounted crankshaft pulley that compensates for the stresses caused by the (unequal) angle(s) at which power strokes exert force on the crankshaft. One angle in an inline or slant, two in a 'V' configuration. Since the flat four power strokes are inherently 180 degrees apart the crankshaft sees equal opposing forces which eliminates the need for the harmonic balancer. A smooth running boxer looks motionless at idle because of the great balance, probably could pass the old Duesenberg nickel standing on edge trick.

The harmonic isn't needed with the EA81 because of the opposed nature of the cylinders - when one side fires, the forces are transfered directly across to the opposing cylinder

Perhaps the answer to the issue that challenges you lies in the economic cost...after all, it is not a satisfactory answer to say that Subaru did not install a stereo to save weight. THey did not give us a stereo so that they could price the car in a certain targeted price range. Making small modifications to gain only slight performance enhancement is not usually something they consider when first releasing a new car. My guess is that when the competition adds some HP to their car, Subaru will go looking for those smaller modifications that might be more costily buy yield more HP

According to the tech guys at SOA the boxer engine balances itself WITHOUT the aid of ANY form of dampener.

The pistons counter-balance the engine.
This is also helped by the fact that the crank uses 5 main bearings just like most other engines do except that our crank is about 1/2 the size of thiers so its able to withstand around 10 tons of preasure at any given point.

The main reason for a dampener is to help prevent crank walk and since the engine does not have to fight gravity in its running cycle there is no crank walk and hence no need for a dampening system.

btw,,ive had 3 lightnend pulleys on 3 different Subarus and NEVER had a problem.

Bottom line: I did these mods when the car had 13,000 miles. The car has 98,000 and has had no problems and the subaru dealership installed the crank pulley for me and said himself that it is not a harmonic dampener. Just a big ass heavy pulley.

Go for it.

The subaru flat 4 is internally balanced and the pulley is not a harmonic balancer. If it were the weight would not be uniformly distributed on the pulley - think about it, how is adding a perfectly balanced weight to the end of the crank balancing out anything?

Flat type engines (Subaru boxers and Porsche flat 6s) don't need harmonic dampers due to the design characteristics of the motor. In a "V" type or Inline type all the forces are going in a 1 or multiple direction(s) with no counter force. In a Flat type engine every force has a counter force ie. piston 1 counteracts piston 2, piston 3 counteracts piston 4, and vice versa. This is why Flat type engines are so smooth and also why they don't need a harmonic damper, which is why they never come with them from the factory.

FYI, Subarus don't come with harmonic dampers, they just have a pulley. They have rubber in them to make them cheaper to make over a solid steel pully.

This is why solid lightweight aluminum pulleys are so popular, they have no adverse affects on our engines.

If a horizontally opposed engine benefits from a damper, whether it be fluid or elastomer, there is a larger issue at play and the damper is like putting a bandage over a wound. It will hide the main problem but the main problem will still be there. Most likely it's the rotating components not being balanced and causing uneven vibrations/harmonics. Which is usually a sign of excessive wear and a rebuild/freshening-up is in order.

This isn't always the case though, sometimes a simple fix is just masking a larger problem, and sometimes the simple fix was the needed fix. But when it comes to excessive vibrations and harmonics in a horizontally opposed engine there normally is a larger issue the needs to be addressed as the design of the engine creates equal opposing forces that cancel each other out. If they aren't equal, or close to, something is wrong.

Fact: It was in an email reply made by Subaru Of America that stated, and was quoted above, saying that it is only a pulley, not a harmonic balancer of any sort.

The person has emailed SoA to ask what properties and function the pulley had, and the responder talked with the engineering department, to my understanding and recollection.

This information and the entire message is viewable on RS25 and NASIOC IIRC. I've read it and the whole thread.

Those short-crank subarus did not require any sort of harmonic balancer to protect the crank from harmonics and cracks.

[stugray]

Originally Posted by suaveflooder

Your entire arguement assumes we have a harmonic balancer. Mine does not. .

Funny. That is the entire discussion that we just cannot agree on:
"what is the definition of a harmonic balancer"

MY stock BRZ has a harmonic balancer from the factory.

It looks like this:


Perhaps yours does not.

[Apoc]

Originally Posted by Poodles

That's a bunch of crap... They're a small shop making parts and don't even understand the concepts behind the part. Hell, the part isn't SFI rated so this is all pointless anyway

Why is SFI Rating important for us if these cars aren't intended to be raced competitively and don't need to comply with safety rules of race sanctioning organizations? There are only 9 SFI certified manufacturers for harmonic dampers mostly for drag racing and I don't imagine Subaru crank pulleys are one of their target markets. The only part I've ever seen here that is SFI rated is the ATI damper you linked. Should we avoid all non SFI parts?? or are you just talking about if we drag race competitively with our weak little underdampened subarus

"About SFI Foundation
The primary users of SFI standards, or specifications (specs), are equipment manufacturers whose products are tested and self-certified to the appropriate procedures. SFI Specs are included as part of the rules of race sanctioning organizations. Ultimately, the consumer benefits from the SFI program because it establishes recognized levels of performance or quality for a given product which results in a safer racing environment"

[suaveflooder]

Originally Posted by stugray

Funny. That is the entire discussion that we just cannot agree on:
"what is the definition of a harmonic balancer"

MY stock BRZ has a harmonic balancer from the factory.

It looks like this:


Perhaps yours does not.

And that's the entirety of the argument, which is why it's going nowhere.

One thought, rubber makes it harmonic balancer. Harmonic balancer balances the engine. Cool

Other thought, rubber decreases NVH from the crank shaft. Cool.

Yet another thought, rubber helps balance the pulley itself (due to weight, this is important otherwise it could actually create a vibration). Double cool.

Quotes one and two cover this above. The pulley is blanced from the factory, so it doesn't sound like a harmonic balancer/damper (whatever poodle wants to call it).

Because the crank is short, forged and has opposing pistons, it shouldn't need a harmonic balancer/damper like a V-engine.

I can tell you this, looking through subaru forums looking for this information has given me some interesting insite to this "damper", or "pulley" whatever you want to call it. When the stock rubber wears out, it JACKS up your crank! Here's one from a mercedes owner on one of the threads I came across, but this was common on subaru engines as well when the stock rubber failed.

Personally, I had a Mercedes E430 V8 whose harmonic balancer came apart one day and destroyed the whole front of the engine in the process. It cost over $4000 to repair the damage.

And subaru

based on experience before buying the lightweight pulleys. I found that the stock 2-piece can develop rust over time and break into two pieces anytime causing catastrophic failure. they weigh 5 times of a lightweight pulley and 'does not act as a harmonic damper found on for example traditional V8 engine dampers. The elastomer portion of the pulley helps dampen some noise from the engine accessories (ie. alternator, PS pump, and A/C compressor) but in our experience, the increase in this noise is in-perceivable.'(paragraph excerpt from Grimmspeed site) one of the good reasons to go with the Grimmspeed lightweight crank pulley from Seven automotive during timing belt installation. no problems and engine revs more freely. If fluid motor mounts can leak, I can imagine the fliud damper being relative to it.

I'm going to go ahead and bow out of this argument now and agree to disagree. Of course I will read poodles response where he shamelessly bashes me and gives me information based on a completely different engine….again, but it really is going in circles now, and I'm about to get my car back tomorrow, so I will not give two shits about any of this

[Poodles]

Originally Posted by Apoc

Why is SFI Rating important for us if these cars aren't intended to be raced competitively and don't need to comply with safety rules of race sanctioning organizations? There are only 9 SFI certified manufacturers for harmonic dampers mostly for drag racing and I don't imagine Subaru crank pulleys are one of their target markets. The only part I've ever seen here that is SFI rated is the ATI damper you linked. Should we avoid all non SFI parts?? or are you just talking about if we drag race competitively with our weak little underdampened subarus

"About SFI Foundation
The primary users of SFI standards, or specifications (specs), are equipment manufacturers whose products are tested and self-certified to the appropriate procedures. SFI Specs are included as part of the rules of race sanctioning organizations. Ultimately, the consumer benefits from the SFI program because it establishes recognized levels of performance or quality for a given product which results in a safer racing environment"

Because these people put their money were their mouth is. Just about anyone with a good CNC machine can make a crank pulley...

Originally Posted by suaveflooder

And that's the entirety of the argument, which is why it's going nowhere.

One thought, rubber makes it harmonic balancer. Harmonic balancer balances the engine. Cool

Other thought, rubber decreases NVH from the crank shaft. Cool.

Yet another thought, rubber helps balance the pulley itself (due to weight, this is important otherwise it could actually create a vibration). Double cool.

Quotes one and two cover this above. The pulley is blanced from the factory, so it doesn't sound like a harmonic balancer/damper (whatever poodle wants to call it).

Because the crank is short, forged and has opposing pistons, it shouldn't need a harmonic balancer/damper like a V-engine.

I can tell you this, looking through subaru forums looking for this information has given me some interesting insite to this "damper", or "pulley" whatever you want to call it. When the stock rubber wears out, it JACKS up your crank! Here's one from a mercedes owner on one of the threads I came across, but this was common on subaru engines as well when the stock rubber failed.



And subaru

I'm going to go ahead and bow out of this argument now and agree to disagree. Of course I will read poodles response where he shamelessly bashes me and gives me information based on a completely different engine….again, but it really is going in circles now, and I'm about to get my car back tomorrow, so I will not give two shits about any of this

You're missing the point. It's NOT a balancer, it's there to damp the torsional harmonics on the crankshaft. You're confusing the terms and their applications.


Also, a large V8 is going to have a more substantial damper because of it's inherent vibration issues. Just because a flat-4 has a smaller one doesn't mean it's still not doing it's job.


Coming from inline-6 motors (which are considered "perfect" in balance and the only engines that equal it are V12's and flat-4's), the damper is smaller, but it is still a damper and still quite necessary as tolerances are never perfect in a motor.

[industrial]

Originally Posted by stugray

Yes that pulley is exactly like mine.
Note that the pulley is made from at least three pieces:
An inner cast & machined part, a rubber middle section, and a machined outer part.

If it really does not matter, WHY did the engineers put that part (that is clearly more expensive to manufacture than a solid aluminum machined pulley) on instead of a solid pulley.

And note how you have two holes machined into the edge of the pulley.
My engine came back from the balancer with holes exactly like that in the pulley and the perimeter of the flywheel.
Why do you suppose those are there on a factory pulley?

WHY??? - CUZ RACECAR?

You do realize that subaru has been using almost the same part on all their cars for years right? That one below is from my 2002 Forester. This isn't some custom engineered part just for the BRZ. Sometimes car markers do things for people called "bean-counters". I'm not sure I understand that this part is more expensive than a machined aluminum part. You aren't thinking about economics of scale. It maybe cheaper to buy 100 machined aluminum pulleys. It's definitely cheaper to buy 100,000 cast iron pulleys which can be used on a wide variety of vehicles, many of whom may have NVH issues with a solid pulley.