I always hear of people preaching against them stating that they can and do cause premature bearing failure, but thats usually from people who have never ran one or dont have any experience with them. The people who have run them have pretty much all had nothing but good things to say about them.

If you have first hand experience (good or bad) with aluminum underdrive crank pulleys chime and and post about your experience.

 

Ehh, I could see why as aluminum doesn't have the harmonic dampening characteristics that steel does..,But don't take my word on it, there may be another reason..

 

i would also like to hear more about this, i have a UR underdrive pulley on my crvtec that im about to put in.....i posted about it and got flamed "its gonna **** your bearings up".......i asked the same question but got no one that actually had a problem....currently i dont have any first hand experience, but next week i will.....the more i thought about it a few things came to mind.

1) Not everyone ballances there entire rotating assembly, which would make it a few grams off just like they claim the pulley is....

2) Lots of people use random 10mm bolts on there pressure plate to flywheel (different weight bolts)

3) Ive seen a lot of "cheepo-shaved flywheels and im sure they are off by some ammount...

4) Wouldnt your alternator belt and other belts put a different pressure on your crank??? maybe not though...

i just dont think that small *** ammount would make a difference......i think people have a bearing fail because they spin a motor to 8-9k and are looking for a place to put blame other than themselves

more info would be awsome!

 

The answer you are looking for won't be given here.

To determine the answer you would need to test the engine with and with out the UD and that being the only thing changed. Plus you've have to have access to vibration measuring equipment and use it on an engine dyno ( to minimize the effect of additional rotating parts). Just because the rotating parts are balanced doesn't mean a damper pulley wouldn't be helpful.

Also, if a part doesn't give a person immediate hp gains they will be less likely to put down the cash for a dampener. Face it, most are more interested in peak numbers than engine life.

 

Modified by hybrid_vtec at 11:50 PM 5/25/2005

 

yup. my friend's USDM ITR motor had a UR pulley. spun rod bearings #1 and #4.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SkRiBLaH &raquo;</TD></TR><TR><TD CLASS="quote">yup. my friend's USDM ITR motor had a UR pulley. spun rod bearings #1 and #4.</TD></TR></TABLE>

I wonder how many people's "friends" have spun #1 and #4 without the UD pulley?

 

maybe your friend is a bit rev happy?

 

good timming on this thread..im in the market for one cuase my f20b is only a single rung pulley and i want p/s back

i have the balance shafts disconected and the harmonics b/s has been on my mind ...

imean do we really have any proff at all these are related .....

2point6 has been runnign a light weight pulley for as long as i can remember ..hes has had zero probles and thats on a stroked motor and hes still revving as high as most h22 will ...

tuff call but id rather have my mototr last then the few hp it might get me ....

 

I dont have *much* experience with the pulley, but I will share what I do have.

I flew halfway accross the country to pick up an Integra with a B18C1 in it (fresh build). I drove it 900 miles home, and then had 2 race weekends on the motor. Both weekends combined the motor was over 7k RPM for probably 3 to 4 hours. I was revving it as high as 9.5k on stock GSR valvetrain. After the 2nd race, I broke the motor down for a rebuild. The honda main bearings were absolutely flawless. No scratches/gouges whatsoever.

I completely rebuilt the motor using the standard ACL bearings. They all measured within spec. I decided to put the UD pulley back on, after seeing the internals.

By no means was this "test" over an extended period of time, but I can tell you that my #1 and #4 bearings were not about to go.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by machine4321 &raquo;</TD></TR><TR><TD CLASS="quote">good timming on this thread..im in the market for one cuase my f20b is only a single rung pulley and i want p/s back

i have the balance shafts disconected and the harmonics b/s has been on my mind ...

imean do we really have any proff at all these are related .....

2point6 has been runnign a light weight pulley for as long as i can remember ..hes has had zero probles and thats on a stroked motor and hes still revving as high as most h22 will ...

tuff call but id rather have my mototr last then the few hp it might get me ....

</TD></TR></TABLE>

thats the way I feel, but I also believe that if you balance everything and counter weight parts to properly run the pulley then you should have no problems at all. I am surprised no one has tested these theories yet. I think that it should be tested several cars with them and severals without them in both daily driving conditions and closed course conditions. All cars installed with fresh bearings, and driven a certain number of miles in the same conditions; and then torn apart at the end to determine the facts from the myths. These theories may be true, but also may not cause such an impact as some think. What I am saying is, it may cause premature bearing wear, but at what rate?

 

Everyone thats claimed to have had one for a number of years have all had B series motors. Im curious what the affects would be when running a UD crank pulley on a H series motor with the balance shafts removed.

Anyone used one on a H series motor?

 

I was bout ta get a pully for my new ls/vtec but iuuno if im gonna get one now after reading this thread. Any more input?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JdM DA InTeGrA &raquo;</TD></TR><TR><TD CLASS="quote">I was bout ta get a pully for my new ls/vtec but iuuno if im gonna get one now after reading this thread. Any more input?</TD></TR></TABLE>

There are a lot of debates on this subject. Do a search for CTR Crank Pulley!

 

It would be nice if someone from Unorthodox would chime in, I know they browse some of the popular web boards...

Lets see if they find their way over to this thread

 

I emailed brian @ Unorthodox. Hopefully he will be replying with some info. Its possible they have already done tests on other motors.

 

I've had one on my LS for a LONG time....2, almost 3 years. No problems. I jsut went LS V-tec, same bottom end (nothing touched, no balancing, nothing)so we'll see if it continues to do well but it seems like an urban legend to me that crank pulleyts TotTLAy **** uP Ur enGINe yO!

 

This is a good thread. I don't have any experience with an UD pulley, but enough knowledagble people have made it clear to me that they are not good.

Let's get some good info going on this thread.

 

After going back and reading some of the archived threads on this subject, it seems the only people saying negative things about UD pulleys are those who arent or have never ran them.

The people who are running them or have run them have nothing but good things to say about them. Some have even reported usage periods spanning as far as 4-5 years.

::shrugs::

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Innovation &raquo;</TD></TR><TR><TD CLASS="quote">Everyone thats claimed to have had one for a number of years have all had B series motors. Im curious what the affects would be when running a UD crank pulley on a H series motor with the balance shafts removed.

Anyone used one on a H series motor?</TD></TR></TABLE>

The H22 still has pistons and rods going up and down, and spark plugs firing just like the B series engine.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">

The H22 still has pistons and rods going up and down, and spark plugs firing just like the B series engine.</TD></TR></TABLE>

B series engines dont have balance shafts.

Removing the balance shafts in conjunction with a UD crank pulley was the basis of that post.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Innovation &raquo;</TD></TR><TR><TD CLASS="quote">

B series engines dont have balance shafts.

Removing the balance shafts in conjunction with a UD crank pulley was the basis of that post. </TD></TR></TABLE>

You are missing the point

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Slimm-rw- &raquo;</TD></TR><TR><TD CLASS="quote">I've had one on my LS for a LONG time....2, almost 3 years. No problems. I jsut went LS V-tec, same bottom end (nothing touched, no balancing, nothing)so we'll see if it continues to do well but it seems like an urban legend to me that crank pulleyts TotTLAy **** uP Ur enGINe yO! </TD></TR></TABLE>

BTW, I put it on at abotu 190k, and its now at 205k

 

I put a UR pulley on my ZC, and about 4K miles later I got a pretty severe knock coming from the motor. I have yet to tear the motor apart though. I also overheated the motor severely so that may be the cause too, I don't know.

 

People are getting the pulleys confused with the harmonic dampers found on 90 degree V8 and V6 engines. Harmonic balancer is a term that is used loosely in the automotive industry. This does not exist on most modern motor. The balancer part comes from engines that are externally balanced and have a counterweight cast into the damper, hence the melding 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 rubber in the OEM pulley serves as an isolator, which is there for noise suppression from the A/C compressor & P/S pump cycling on and off and the groan of the alternator when under a heavy load. This is what the manufacturers call NVH (Noise Vibration & Harshness) when referring to passenger compartment noticeable noise and vibration. If you look at some of the pulleys on older imports there is no rubber to be found. We have samples of mostly Honda, An Altima, 1.8L Eclipse, 2.3L Ford, Chrysler 2.2L, 1.8L VW and a few others all with no rubber. The purpose of a traditional harmonic damper is to keep the crankshaft from cracking which is not necessary on your engine. You have probably heard stories about bearing and oil pump failures. Any abnormal bearing wear is due to a lubricating issue, The most common examples are using the wrong weight of oil, a faulty head gasket or poor engine assembly practices. Using too heavy of an oil can shatter certain types of oil pump gears. Most of the time oil pump failure is caused by something being sucked up into the pump. Also the Honda factory pump is not deburred enough for extreme race use and can break under the excessive stress. There are companies in Japan that have been producing upgraded pump gears for more than 10 years now. The fact of the matter is the pulleys have been out there running for over 5 years and there have been no failures attributed to the pulleys. There is a lot of internet hearsay about the pulleys, too often people are too quick to blame the pulley first rather than looking into why there was a problem and then go and post it on a message board. You really have nothing to worry about. If you would like to read more info on the subject, visit the FAQ section on our web site(www.UnorthodoxRacing.com) or you can contact me directly at (631)-586-9525 Ext. 17.

Brian C.