I have both a shaved B-series crank pulley and a CTR N1 crank pulley. I'm debating which to go with. Just wanna know from other's experiences. I know either one will be good and I know and have read the posts about the CTR N1's, but I just wanna see what others think is better. Thanks

PS = I'll have to get the shaved OEM balanced before installation.
And the CTR is a lil lighter than the shaved OEM pulley.

 

Oh ****, be prepared for a debate.

If you're that worried about it... Balance your CTR pulley. There is nothing wrong with the CTR pulley IMO, I use it, and I like it.

 

^Agreed.

Put in the CTR without doing anything and call it a day. Thanks.

I really dont care how many people come in here with their computer racing so called evidence. Do you understand how many cars have ran and ran hard throughout the years without dampeners. This place is really filled with alot of people very over worried about things that have little to no effect on the wear of their engine. For example.

You'll have a member or two that likely runs a oil filter with a card board end piece inside and some quaker state synthetic tell you how bad a CTR pulley is on your engine. Really, hes the one that should be concerned.

Fact of the matter is most people repeat what they've heard and hardly ever say what they have experienced. When making any modifications, use your common sense.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by thevanitygroup &raquo;</TD></TR><TR><TD CLASS="quote">Fact of the matter is most people repeat what they've heard and hardly ever say what they have experienced. When making any modifications, use your common sense.</TD></TR></TABLE>


Exactly!

there is more 'proof and documentation' on the internet that it dosen't affect your bearings or oil pump as some owners have documented rebuilds after a few amount of miles/km and everything is still fine.

I know a friend that runs one and had no problems, as well I am going to run it on my motor this upcomming weekend

 

I think a better question would be why would you run a N-1 over a shaved pulley?

(I did not bump this thread either)

 

a shaved one can be shaved incorrect/carelessly...?


Modified by xtrafastcivic at 9:31 AM 8/20/2006

 

While I do think the stock Honda pullies with the rubber damping ring are not optimized for a high-rpm, high performance motor I do think they they are better than nothing at all. I know its not the same thing, but take a look at a class like NHRA Pro Stock where everyone is very limited in the type of motor that they can use--1/100 of a second can be the difference between qualifying and going home. NONE of them run solid/lightweight pullies--they all run HEAVY fluid filled or elastomeric harmonic dampers. I am not saying that running a solid pulley will ruin your bearings nor do I have any conclusive proof--but why even take the chance? Is 2-3 hp worth a $5000-$7000 motor? There have also been dyno tests that show not only do the solid pulleys not add hp, but they actually LOST hp because of the crank harmonics that were transferred to the camshaft affecting valve motion. I used to run the Unorthodox single alternator race pulley and I will admit after putting it on the engine was much more eager to rev and just felt a little stronger--and I didn't have any problems with it, but you will NEVER see me run one again!!!

 

I suppose if you did it with a Dremel tool or something yeah

 

Also, some people may say that the early b16a motors had solid pullies and pretty much all of the d15 motors had solid pulley but there is a big difference in stresses between an 8000 rpm 160 hp motor and a 9500 rpm 240 hp motor.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by d16dcoe45 &raquo;</TD></TR><TR><TD CLASS="quote">Also, some people may say that the early b16a motors had solid pullies and pretty much all of the d15 motors had solid pulley but there is a big difference in stresses between an 8000 rpm 160 hp motor and a 9500 rpm 240 hp motor.....</TD></TR></TABLE> What are the differances? Harmonics, Twist loading, Oil shear, Oil volume and temperature? Can detonation play a role?

 

As I understand it, the force on the connecting rod and the crank becomes very high as the rpm gets up there. The effective weight of the rod it seems would go up tremendously. Also, bearing speed gets very high--which on a d-series (not the engine in question, I know) starts creating problems above 9000 rpm. I don't have any facts or figures to show you. I sense you are not asking for information--I feel like you already know this information and are asking me as a way to put me on the spot--you probably think I am spouting internet bs that I "heard" somewhere with no facts to back it up. So if you have the facts, why don't you share them?

 

the smaller the journal the less bearing speed. So a D15 is better. But the crank has less integrity because it is smaller and has a "whip effect". The larger the stroke, the more the torsional forces come into play. On a 95mm "Honda " motor I would use a harmonic " torsional" load suppressor pulley. Especially if it was a race motor that lived at "max" rev's all its life. Stroke "or loading" arms on the crank (think about that) and RPMs decide the crank flex. Balance and weight decide were it happens.
Most people lose bottom ends from to tight a clearence and detonation.Not the balancer.

 

I can understand people screwing up bottom ends with too tight clearances and the detonation--which is almost never blamed for bearing problems around here!! But as a question for you Don, if you were building a motor for an important customer or yourself--say it was a moderate rev b16 (you are saying 90-95+ strokes seems to warrent a dampener more than a short 77mm stroke)--say 9000 rpm maybe 185-195 hp at the wheels--would you consider running a solid CTR pulley or even an Unorthodox style no weight aluminum pulley? And why or why not?

 

Possibly because all the 1.6 Cosworth, Toyota, Honda Formuls Atlantic engines I have ever built or others have built did not have a harmonic balancer. Shift point was 10,000 RPM. Now if you have " louie's crank shop" knife edge your crank, all bet's are off. With or with out a balancer. Stroke " leverage arm" and rod length " multiplier" does give you the bend forces @ 90 degrees, toss in piston, rod weight, and the numbers get huge.200 grams off the rod and piston will increase the effective BHP range 900-1100 RPM. Peak may only be 5 more, but can be 12 more another 800 RPM up.

 

I would run the stock pulley, period, for almost any motor.

The problem with changing the pulley is how the new state of balance effects bearing loads and overall vibration. In many cases, a change in a few oz-in will take a rotor from an acceptable state of balance (nearly unlimited life) to very limited life.

 

unmodified stock crank pulley for me...cuz AC ownz

 

It's nice to stay cool, plus at the same time, not worrying about the pulley. I wish I could find a fluidamper that has ac and ps pulleys on it. If they do make one, I'd buy it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mar778c &raquo;</TD></TR><TR><TD CLASS="quote">I would run the stock pulley, period, for almost any motor.

The problem with changing the pulley is how the new state of balance effects bearing loads and overall vibration. In many cases, a change in a few oz-in will take a rotor from an acceptable state of balance (nearly unlimited life) to very limited life.</TD></TR></TABLE> So therefore, you should change the flywheel weight either? As it was designed to operate with the crank and front pulley?
What is a "state of balance" ? New Jersey?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote"> So therefore, you should change the flywheel weight either? As it was designed to operate with the crank and front pulley?
What is a "state of balance" ? New Jersey?</TD></TR></TABLE>

I just run ACT's flywheel, which is balanced from the factory.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DonF &raquo;</TD></TR><TR><TD CLASS="quote"> So therefore, you should change the flywheel weight either? As it was designed to operate with the crank and front pulley?
What is a "state of balance" ? New Jersey?</TD></TR></TABLE>

The flywheel and harmonic dampener are two different animals by design.
The flywheel is meant to have a very very high or very low frequency such that its response to unbalance is very low almost nil within the engines operating range. Thus changes in wieght will not make it have any thing other than a flat low response to unbalance.

The harmonic damper by design is not meant to have a flat a response to unbalance. It is designed to lower amplitudes of a specific response to unbalance. Changing the weight will typically ampilify the crank response to unbalance because of the change in damping characteristics. For instance, the original harmonic dampener was designed to reduce vibration levels at every 33 hz multiple. The modified dampener works at every 41.67 multiple. The crank was not modified thus it still responds as always. Mis-matched damping and crankc response produces short lifed engine.

Yeah, I guess new jersey is a state of balance.