The misconceptions and myths behind crank pulleys and dampers
06-08-2005, 11:30 AM
#1
Thread Starter
The misconceptions and myths behind crank pulleys and dampers
For years I had the idea that dampers were a necessity burned into my head. The thought that our honda engines required a damper to control and or absorb torsional vibrations was something I was told and convinced of this by some of the big name and well known engine builders out there. Who was I to argue?
Something that I didnt take into consideration, a lot of these guys I was learning from have V8 backgrounds where dampers are an absolute requirement. Recently, I decided to look into this theory. I called ATI, Fluiamper and Unorthodox Racing and talked to each company a little about the benefits of each respective product. Each company was very informative and extremely helpful with any questions I had regarding their products.
Previous to my research on this topic, I had heard of the horrors of oil pump and bearing failure with underdrive crank pulleys. I searched web board archives for claims of these occurances and came up with something that suprised me. Each person who posted about potential oil pump or bearing failure due to the use of underdrive crank pulleys had never owned or run one themselves. In most cases, they didnt personally know anyone who had either. They were simply repeating what they had been accustom to hearing. Thats exactly what i had done as well. It kind of resembles the theory, or thought in which Columbus ended once and for all hundreds of years ago. "The world is square." Everyone believed the world was square at one time simply because highly respective individuals had said it was, claiming that if you went too far in one direction that you would fall off of the planet. This became an unwritten fact. Although it had never been proven, it became a common thought, therefor it was passed on from person to person. Well, a guy by the name of Christopher Columbus came along and ended all of that square nonsense. Hopefully with a few projects, tests and follow ups we can do the same with the myth of Honda inline four cylinders and harmonic dampers.
Everyone who has run or used an underdrive crank pulley has nothing but good things to say about them. Ive found some who have been running them for as long as 5 years with no problems what so ever.
The more I looked into it, the more interested I became in this subject. So much in fact, that I have aquired a complete set of underdrive pulleys from Unorthodox Racing to use in a project Article I am working on.
Here is a piece of information taken from the Unorthodox website for everyone to look over:
<FONT COLOR="red"><U>In regards to cranks and dampers:</U>
People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term that is 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 that we offer utilize a counterweight as part of the pulley as these engines are internally balanced.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that looks 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 that in these applications, this elastomer is somewhat inadequate in size, as well as life span, to act as an effective torsional damper. If you look at the pulleys on some of the imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, Nissan, and 1.8L VW's, to mention a few. This is not to say that with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most who have installed and driven a vehicle with our pulleys will notice the engine actually feels smoother. This is a natural result of replacing the heavy steel crank pulley with a CNC-machined aluminum 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. Also, a true damper is pressed on to the front of the crank, not just bolted on as with most of the application we are all familiar with. Dampers are not necessary on most modern engines because of the many advances in engine design and materials. One of the main factors is that motors have switched over to OHC cams. Other factors such as stroke, displacement, inline, V configurations, power output, etc., do determine when and how these harmonics and torsional movements occur.
<U>In regards to oil pump failures</U>:
Urban myths have been floating around about Honda oil pumps failing by using an Unorthodox Racing crank pulley/s. The real fact is that these OEM pumps have been failing with AND WITHOUT the use of our pulleys and before our crank pulley/s were available on the market. Also note that these failures are few and far in between.
The Acura/Honda oil pumps are excellent units, but there are a number of reasons for the failures that do occur.
Most of the oil pump failures have been in Acura/Honda B series 1.6/1.8L applications. The Mazda 1.6/1.8L applications have seen a few failures, as well as the new Ford Focus ZETEC in race vehicles. Again, note that on all these applications the oil pump failures have occurred on engines not using our pulley, using the stock crank pulley.
These pump failures can be linked to the following causes. These causes may act individually or in combination to cause the actual failures:
- The gears used in many pumps including those in the Honda B series engines and Mazda Miata engines are of a low-cost powdered metal composition. The factory uses this metal because of its acceptable cost-to-strength ratio. The problem is, these parts are not always deburred properly from the factory and when pushed to their limits can and do fail.
- Many times additional stress is added to the oil pump by using oil thicker than what is specified by the manufacturer. The oil pump and bearing clearances were not designed from the factory to push oil of higher viscosities. This extra stress on the gears, combined with the above mentioned poor deburring process, can attribute to oil pump failure or engine failure
- Another contributing factor to oil pump failures is the weak cast backing plate of the B16/B18 oil pumps. Simple inspection shows that when compared to an H22 oil pump, a screw is not present in a critical location of the plate in the B series pumps. Compound this with the use of a higher viscosity motor oil and poorly deburred pump components and you have the ingredients for an oil pump failure.
- This issue, specific to the Mazda 1.6/1.8L engines, involves the flex of the crankshaft and the lower half of the engine due to the additional stress of a forced induction system (such as a turbo or supercharger). The additional stress produced by forced induction causes flexing of both the block and the crankshaft between the front main bearing and the oil pump. This can also contribute to oil pump failure. Early Miatas were notorious for having crankshaft problems and later models suffered from problems as power is increased significantly.
- Lastly, any failure inside a motor, related to aging components or a poor engine rebuild, can cause the oil pump to fail. ANY particles passing through an oil pump design such as that used in the Honda B series engines will cause damage or failure.
Remember that oil pump failures happen regularly on engines using a factory crank pulley. To help combat these failures, a few steps should be taken to help prolong the life of your oil pump and engine:
- Unless building a race motor with race clearances in mind, you should always use an oil viscosity matching, or as close to the factory recommendations as possible.
- If using a factory oil pump, always have your oil pump components deburred properly. It is recommended you have a competent engine rebuilder handle this
- For those who run dedicated / extreme race vehicles we recommend using an external wet or dry sump oiling system. These systems are designed for the heavy abuse a race engine receives on the track. Remember, the stock oiling systems were designed for factory horsepower levels and can only handle a certain amount of power increase over that level
- Lastly and most obvious, have a competent, trusted machine or performance shop rebuild your precious motor. It only takes one simple mistake to turn a costly engine rebuild into a doorstop</FONT>
Something that I didnt take into consideration, a lot of these guys I was learning from have V8 backgrounds where dampers are an absolute requirement. Recently, I decided to look into this theory. I called ATI, Fluiamper and Unorthodox Racing and talked to each company a little about the benefits of each respective product. Each company was very informative and extremely helpful with any questions I had regarding their products.
Previous to my research on this topic, I had heard of the horrors of oil pump and bearing failure with underdrive crank pulleys. I searched web board archives for claims of these occurances and came up with something that suprised me. Each person who posted about potential oil pump or bearing failure due to the use of underdrive crank pulleys had never owned or run one themselves. In most cases, they didnt personally know anyone who had either. They were simply repeating what they had been accustom to hearing. Thats exactly what i had done as well. It kind of resembles the theory, or thought in which Columbus ended once and for all hundreds of years ago. "The world is square." Everyone believed the world was square at one time simply because highly respective individuals had said it was, claiming that if you went too far in one direction that you would fall off of the planet. This became an unwritten fact. Although it had never been proven, it became a common thought, therefor it was passed on from person to person. Well, a guy by the name of Christopher Columbus came along and ended all of that square nonsense. Hopefully with a few projects, tests and follow ups we can do the same with the myth of Honda inline four cylinders and harmonic dampers.
Everyone who has run or used an underdrive crank pulley has nothing but good things to say about them. Ive found some who have been running them for as long as 5 years with no problems what so ever.
The more I looked into it, the more interested I became in this subject. So much in fact, that I have aquired a complete set of underdrive pulleys from Unorthodox Racing to use in a project Article I am working on.
Here is a piece of information taken from the Unorthodox website for everyone to look over:
<FONT COLOR="red"><U>In regards to cranks and dampers:</U>
People are getting their crank pulleys confused with the harmonic dampers found on some V6 / V8 engines. "Harmonic Balancer" is a term that is 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 that we offer utilize a counterweight as part of the pulley as these engines are internally balanced.
The pulleys on most of the new import and smaller domestic engines have an elastomer (rubber ring) incorporated into the pulley that looks 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 that in these applications, this elastomer is somewhat inadequate in size, as well as life span, to act as an effective torsional damper. If you look at the pulleys on some of the imports there is no rubber to be found at all. We have samples of these, mostly from Acura/Honda, Nissan, and 1.8L VW's, to mention a few. This is not to say that with our pulleys you will hear a ton of noise or feel more vibration from your engine compartment. Most who have installed and driven a vehicle with our pulleys will notice the engine actually feels smoother. This is a natural result of replacing the heavy steel crank pulley with a CNC-machined aluminum 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. Also, a true damper is pressed on to the front of the crank, not just bolted on as with most of the application we are all familiar with. Dampers are not necessary on most modern engines because of the many advances in engine design and materials. One of the main factors is that motors have switched over to OHC cams. Other factors such as stroke, displacement, inline, V configurations, power output, etc., do determine when and how these harmonics and torsional movements occur.
<U>In regards to oil pump failures</U>:
Urban myths have been floating around about Honda oil pumps failing by using an Unorthodox Racing crank pulley/s. The real fact is that these OEM pumps have been failing with AND WITHOUT the use of our pulleys and before our crank pulley/s were available on the market. Also note that these failures are few and far in between.
The Acura/Honda oil pumps are excellent units, but there are a number of reasons for the failures that do occur.
Most of the oil pump failures have been in Acura/Honda B series 1.6/1.8L applications. The Mazda 1.6/1.8L applications have seen a few failures, as well as the new Ford Focus ZETEC in race vehicles. Again, note that on all these applications the oil pump failures have occurred on engines not using our pulley, using the stock crank pulley.
These pump failures can be linked to the following causes. These causes may act individually or in combination to cause the actual failures:
- The gears used in many pumps including those in the Honda B series engines and Mazda Miata engines are of a low-cost powdered metal composition. The factory uses this metal because of its acceptable cost-to-strength ratio. The problem is, these parts are not always deburred properly from the factory and when pushed to their limits can and do fail.
- Many times additional stress is added to the oil pump by using oil thicker than what is specified by the manufacturer. The oil pump and bearing clearances were not designed from the factory to push oil of higher viscosities. This extra stress on the gears, combined with the above mentioned poor deburring process, can attribute to oil pump failure or engine failure
- Another contributing factor to oil pump failures is the weak cast backing plate of the B16/B18 oil pumps. Simple inspection shows that when compared to an H22 oil pump, a screw is not present in a critical location of the plate in the B series pumps. Compound this with the use of a higher viscosity motor oil and poorly deburred pump components and you have the ingredients for an oil pump failure.
- This issue, specific to the Mazda 1.6/1.8L engines, involves the flex of the crankshaft and the lower half of the engine due to the additional stress of a forced induction system (such as a turbo or supercharger). The additional stress produced by forced induction causes flexing of both the block and the crankshaft between the front main bearing and the oil pump. This can also contribute to oil pump failure. Early Miatas were notorious for having crankshaft problems and later models suffered from problems as power is increased significantly.
- Lastly, any failure inside a motor, related to aging components or a poor engine rebuild, can cause the oil pump to fail. ANY particles passing through an oil pump design such as that used in the Honda B series engines will cause damage or failure.
Remember that oil pump failures happen regularly on engines using a factory crank pulley. To help combat these failures, a few steps should be taken to help prolong the life of your oil pump and engine:
- Unless building a race motor with race clearances in mind, you should always use an oil viscosity matching, or as close to the factory recommendations as possible.
- If using a factory oil pump, always have your oil pump components deburred properly. It is recommended you have a competent engine rebuilder handle this
- For those who run dedicated / extreme race vehicles we recommend using an external wet or dry sump oiling system. These systems are designed for the heavy abuse a race engine receives on the track. Remember, the stock oiling systems were designed for factory horsepower levels and can only handle a certain amount of power increase over that level
- Lastly and most obvious, have a competent, trusted machine or performance shop rebuild your precious motor. It only takes one simple mistake to turn a costly engine rebuild into a doorstop</FONT>
06-08-2005, 11:33 AM
#2
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Re: The misconceptions and myths behind crank pulleys and dampers (Innovation)
I had a UR crank pulley for 2 weeks until it made my engine fly out of the car, roll into a ditch and explode. 
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JK, it's been fine for about 2 years now.
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JK, it's been fine for about 2 years now.
06-08-2005, 11:40 AM
#3
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Re: The misconceptions and myths behind crank pulleys and dampers (Hawkze_2.3)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Hawkze_2.3 »</TD></TR><TR><TD CLASS="quote">I had a UR crank pulley for 2 weeks until it made my engine fly out of the car, roll into a ditch and explode.
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JK, it's been fine for about 2 years now.</TD></TR></TABLE>
More than 1 yr
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JK, it's been fine for about 2 years now.</TD></TR></TABLE>
More than 1 yr
06-08-2005, 12:41 PM
#7
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i guess i will be on the list soon to ...
now is there a big difference betwen the UR and the lower cost units...i mean as long as its balanced and of good stregth right?
now is there a big difference betwen the UR and the lower cost units...i mean as long as its balanced and of good stregth right?
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06-08-2005, 12:52 PM
#8
Thread Starter
Re: (machine4321)
UR is the only way to go IMO, theres a lot more to it then just machining a chunk of aluminum...
UR is the best of the best when it comes to underdrive pulleys, quality is second to none
Ill post pics of my set in an hour or so
UR is the best of the best when it comes to underdrive pulleys, quality is second to none
Ill post pics of my set in an hour or so
06-08-2005, 12:55 PM
#9
great write up, its nice to see that someone can write it in a manner hta tis logical easy to read and well thought out.
I have been using the UR ultra-r pulley for around 2 years now and have not had an issue yet. the fact that it weighs somehitng like 13oz is nice since i only need the alternator spinning enough to keep the engine rtunning.
I have been using the UR ultra-r pulley for around 2 years now and have not had an issue yet. the fact that it weighs somehitng like 13oz is nice since i only need the alternator spinning enough to keep the engine rtunning.
06-08-2005, 01:50 PM
#12
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Re: (JohnEVolution)
does the UR pulley retain the same diameter as the stock pulley for the alternator belt? Not to claim the world is flat or anything (since I don't own one), but I've heard plenty of stories about alternators not working as efficiently due to a decrease in circumference of the pulley. This is not something I can trace specifically to UR, but a problem i've seen from lightened pullies in general. Great write up though
06-08-2005, 02:05 PM
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Re: (IHateJDM)
so you called a couple companies and they told you that their product was cool to use?
This is where i get my hesitation from.
http://www.ntpog.org/reviews/u...shtml
note: larry and the rest of the endyn crew are not the most loved source on HT or even the most reliable. however NTPOG isnt too bad of a source. take this information as you see fit. its your engine.
This is where i get my hesitation from.
http://www.ntpog.org/reviews/u...shtml
note: larry and the rest of the endyn crew are not the most loved source on HT or even the most reliable. however NTPOG isnt too bad of a source. take this information as you see fit. its your engine.
06-08-2005, 02:37 PM
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Re: (Shakes)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Shakes »</TD></TR><TR><TD CLASS="quote">so you called a couple companies and they told you that their product was cool to use?
This is where i get my hesitation from.
http://www.ntpog.org/reviews/u...shtml
note: larry and the rest of the endyn crew are not the most loved source on HT or even the most reliable. however NTPOG isnt too bad of a source. take this information as you see fit. its your engine.</TD></TR></TABLE>
That doesn't mean that it's the pulley. It could have been a badly built engine.
This is where i get my hesitation from.
http://www.ntpog.org/reviews/u...shtml
note: larry and the rest of the endyn crew are not the most loved source on HT or even the most reliable. however NTPOG isnt too bad of a source. take this information as you see fit. its your engine.</TD></TR></TABLE>
That doesn't mean that it's the pulley. It could have been a badly built engine.
06-08-2005, 02:38 PM
#15
Thread Starter
Re: (Shakes)
Well, that is part of what Im doing with this project. Im going to do a few things differently and go against the grain a little bit. Im just going to keep sailing, hopefully I wont fall off the earth 
06-08-2005, 02:47 PM
#16
Thread Starter
Re: (Innovation)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NTPOG »</TD></TR><TR><TD CLASS="quote">I gave Top Speed a call (his supplier), and I found out that they don't carry Unorthodox. However, Anthony told me that they carry a knock off that is CNC machined from the same type of aluminum</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Innovation »</TD></TR><TR><TD CLASS="quote">UR is the only way to go IMO, theres a lot more to it then just machining a chunk of aluminum</TD></TR></TABLE>
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Innovation »</TD></TR><TR><TD CLASS="quote">UR is the only way to go IMO, theres a lot more to it then just machining a chunk of aluminum</TD></TR></TABLE>
06-08-2005, 03:12 PM
#17
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you can also add me to the list... ive had the UR pulleys for well over 5 years. the car is still pulling 13 second quarter miles on a stock block...
06-08-2005, 03:14 PM
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Re: (Innovation)
A few years ago I made myself an aluminum P/S pulley in machine shop and I was too afraid to install it because of horror stories. However, I noticed that the stock pulley doesn't have any rubber on it. The original post makes sense to me, however I won't go installing an aftermarket crank pulley.
Now, if only I could find that P/S pulley I made!
Dan
Now, if only I could find that P/S pulley I made!
Dan
06-08-2005, 04:08 PM
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Re: (Shakes)
There is a difference between a lightened and a lightened <U>underdrive</U> pulley. A lightened pulley is supposed be exactly the same as oem except for weight, being usually made of aluminum. The underdrive version is still made of the same material, but slows the speed of the accessories by changing the pulley diameter, so you gain power because the "gearing" of the accessories is lower (kinda like gears on a bike, easier to turn=more available power because less work being done). The downside is signifigant if you run things like a system. At low rpm (about 1,100 and less) you'll be straining your battery and alternator because it is not spinning fast enough to compensate for the cars usage. You are also at a very very slight chance of electrical damage due to a worn out regulator from the slow to fast enough speed, causing unstable voltage, but like I said, pretty slim chance of that. My recommendation is to go with a regular lightened pulley to get the benefits of less inertia, without the possability of potential problems. I will choose reliability over 2 hp any day. That's just me though. Obviously, the same applies to p/s and alt. pulleys
06-10-2005, 07:26 AM
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Hi,
I'm Brian from Unorthodox Racing.
I believe that Innovation invited me to Honda-tech previously.
As far as the underdriving goes we only underdrive about 15-20%. We do not rely on underdriving for our gains because most of our gains come from the weight loss.
When we prototype our pulleys we install the pulley on the car, then we turn on every single accessory that can possibly be on at the same time (ie. Power windows, seats, AC, defroster, radio, headlights wipers etc.)
And we make sure that voltage does not drop below 12 volts.
It's easier for us to make our product right, then to make our customer's unhappy.
If underdrive really bothers you we do have available Lightened Stock Diameter pulleys.
I don't post here regularly but I will try to keep an eye out. If you guys do have any questions please feel free to contact me.
Brian C.
Unorthodox Racing
11 Brandywine Dr.
Deer Park, NY 11729
631-586-9525 X-17
BrianC@unorthodoxracing.com
I'm Brian from Unorthodox Racing.
I believe that Innovation invited me to Honda-tech previously.
As far as the underdriving goes we only underdrive about 15-20%. We do not rely on underdriving for our gains because most of our gains come from the weight loss.
When we prototype our pulleys we install the pulley on the car, then we turn on every single accessory that can possibly be on at the same time (ie. Power windows, seats, AC, defroster, radio, headlights wipers etc.)
And we make sure that voltage does not drop below 12 volts.
It's easier for us to make our product right, then to make our customer's unhappy.
If underdrive really bothers you we do have available Lightened Stock Diameter pulleys.
I don't post here regularly but I will try to keep an eye out. If you guys do have any questions please feel free to contact me.
Brian C.
Unorthodox Racing
11 Brandywine Dr.
Deer Park, NY 11729
631-586-9525 X-17
BrianC@unorthodoxracing.com
06-10-2005, 10:14 AM
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Re: (chigga311)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by chigga311 »</TD></TR><TR><TD CLASS="quote">Hi,
I'm Brian from Unorthodox Racing.
I believe that Innovation invited me to Honda-tech previously.
</TD></TR></TABLE>
Brian,
I have an UR power steering pulley on my car. there is a section on it about 15mm long on the edge where you can see it was broken off of the mold or what not. now i have not seen anything noticable with my PS, however thats not nearly as delicate as the crank is. the person i bought this pulley from said all of them in his set had that same marking.
wouldnt that throw the weight off a couple of grams? in crank terms that is significant.
i will post a pic of it when i get home.
I'm Brian from Unorthodox Racing.
I believe that Innovation invited me to Honda-tech previously.
</TD></TR></TABLE>
Brian,
I have an UR power steering pulley on my car. there is a section on it about 15mm long on the edge where you can see it was broken off of the mold or what not. now i have not seen anything noticable with my PS, however thats not nearly as delicate as the crank is. the person i bought this pulley from said all of them in his set had that same marking.
wouldnt that throw the weight off a couple of grams? in crank terms that is significant.
i will post a pic of it when i get home.
06-10-2005, 10:35 AM
#23
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Re: (Shakes)
Im one of the people that had oil pump failure, do
to having a UR pulley instead of a dampner. Im not trying to bash ur
pulleys.Cause my friend has been running one for years now and had
no problems. I think ur pulleys are not ment for reving really high due to
the vibration and thats when you need a dampner.
to having a UR pulley instead of a dampner. Im not trying to bash ur
pulleys.Cause my friend has been running one for years now and had
no problems. I think ur pulleys are not ment for reving really high due to
the vibration and thats when you need a dampner.
