rival12

Hey HT,

I was having an issue with my Crankshaft Pulley, and decided to purchase an Unorthodox Racing set.

SAE
Crank Pulley 5.73 lbs to 1.00 lbs
Power Steering Pulley 0.88 lbs to 0.22 lbs
Alternator Pulley 0.71 lbs to 0.17 lbs

Metric
Crank Pulley 2600 Grams to 453 Grams
Power Steering Pulley 400 Grams to 100 Grams
Alternator Pulley 320 Grams to 75 Grams

Logic was originally that the one crank pulley alone from local Honda Dealership was nearly as much as all three from Unorthodox Racing.








I decided to take some pictures, and weigh all the pulleys for comparison.


Also used a Crankshaft Pulley Holder tool from Powerbuilt. Part # 648796

ian1006

Where did you buy the pulleys? Its also not a good idea to run a non dampened crank shaft pulley.

rival12

Not to be insensitive. The title does say Unorthodox Racing. Likelihood of it being from them.....quite high?

It's not a good idea to run a non-dampened crankshaft pulley? If you're going cite problems, then please back up with empirical proof. Hearsay is not appreciated.

Next, are you just saying this? any qualifications? personal experience? proof?

I'd rather have a 1.0lbs pulley, than a 5.7lbs pulley. There is risk of more vibration, sure, the same can be said for balance shaft removal.

some Honda pulleys are solid also http://www.inlinefour.com/ctrn1cranpul.html

not sure what the point of your post was.

Please enlighten me when you have a moment.

ian1006

Deleted

rival12

I was showing weight comparison.

extralargenog

iTrader: (1)

DO YOURSELF AND YOUR BOTTOM END A FAVOR AND THROW THAT THING IN THE GARBAGE. NOW. AND BUY AN OEM PULLEY.

The rotating assembly being balanced has NOTHING to do with the harmonics that are suppressed by the balance shafts.

Your logic is whack.

Or, beat up your bearings and enjoy the fail. Those pulleys are garbage, which is why you never EVER see ANYONE making power for any amount of time running them. A simple SEACCh will give yo all the "proof" you need.

But, youll run it anyways... Enjoy.

They are ****.


BTW, NO F or H pulleys are non dampened.

pcguy760

I just had my AC belt drive removed from the STOCK pulley and then had the machine shop balance it... I think thats a better route if you want to reduce some pulley weight lol.

extralargenog

iTrader: (1)

Do you seriously think MAYBE 16 OZ of rotating weight that close to center makes ANY difference in performance??? Youd make more just taking off the belt than all the **** you did to the pulley.

By the way, The AC runs off the ALT belt, not the PS belt

extralargenog

iTrader: (1)

Sell me your OEM pulley OP...

361 accord

thats a massive difference in weight and hella difference in moment of inertia----on paper and at what cost to the motor?



i'm going to argue both sides here, because i'm procrastinating fluid mechanics homework

"its unbalanced"
probably so, and to balance a 1lb pulley like that, it'd need spun up to like 50,000RPM on a hella precise machine---
get a few rock chips and some belt crap in the 1lb pulley and its going to explode the motor and kill everyone nearby

oem honda ones are really heavy for durability and balance-ability and is probably hella-balanced
and since its almost 6 pounds, when it gets old and rock chipped and corroded and gunky,it'll still be perfect




"its undampened"
"its a four-banger, running on exploding dinosaurs, how freakin smooth can that be? besides that's what a flywheel's good for, and the balance shafts"

big spinning **** is going to have some funny little frequencies which is unavoidable, but bolting on a solid metal pulley will perfectly transfer those frequencies(**maybe amplify some frequencies and reverberate 'n ****) to the belts and accesories
so now the belts all jiggly and its going to wear stuff out
At least, i think that's what's going on

extralargenog

iTrader: (1)

Your logic is flawed. You obviously dont understand what the issue is, nor the point of the balancer... Let alone WHY its necessary, and the solid POS is a joke detrimental to the bottom end

361 accord

I'm glad you know better, because i just bullshitted all of it just now, with no real basis



did you maybe mean dampener? the part on the crank pulley that looks like its made of two pieces with rubber jammed in it, because i know there is a harmonic balancer-but thats a different part

anyways then whats the point of it, and why is it necessary?


and what do you mean by "the solid POS is a joke detrimental to the bottom end" ?

pcguy760

No but its all gravy when you get it done for FREE!!!!

rival12

It's all bolted up. Feeling some nice throttle response, not a huge gain, but definitely noticeable. My Fuel efficiency has gone up also.

Extra, i did search, and there's nothing concrete to back what you're saying. Found some Dyno results on a different application.

http://www.driveaccord.net/forums/sh...ad.php?t=52533

Base Dyno with Catback
WHP- 211
WTQ-189

Dyno with Underdrive pulley installed and CBE
WHP-220
WTQ-209

extralargenog

iTrader: (1)

Theres plenty. I know of 3 personaly that have shaken bottom ends and repetitively broken pumps and ****ed up bearings. Maybe not on a stock POS motor, but ANYTHING making ANY power + those = HUGE bearing fail. PEriod.

If you cat figure out why... Well, thats about typical for ths subforum.

All Changed to stock pulley, Problem eliminated... I make 4 times the power you are making, surely if I thnought (knew) it was a good idea ID have one on my Pile of ****. I dont, Neither does ANYONE making power reliably.

rival12

Problem Eliminated? I've had Bearings go on the stock pulley, and pumps break. How do you know it's the Pulley? ....?

What kind of setup are you running?

extralargenog

iTrader: (1)

One that has never EVER not will ever see a UR prodict on it... One that has had thousands of cotinually beaten miles on it for years.

If you flail a bottom end / pump with an OEM pulley on it, either youre a retard, neglect it, or have a junk motor to start. Being as Ive run a junk motor making 300whp bone stock (F series) and not had an issue and multiple people (at that level and above) have f ed multiple bottom ends with that pulley, threw it in the garbage (and run OEM) and had not 1 more problem... you don't need to be a genius to figure out those pulleys are ****.


I have a brand new OEM pulley, make 750 at the wheels and beat the **** out of the motor to 9K. Try that with a UR pulley and see what ***** itself first.

If you seriously dont get it... I dont care, but the fact you dont is comical. Hey, at least its shiny


Rave on

GhostAccord

If you are that worried about removing weight from the external rotational mass. My suggestion would be to drop power steering and run an OEM single. The F20B, Euro R or S2K pulleys are all single belts that will fit the F/H series crank. (S2K with some slight mods) They are lighter than stock, they are balanced and also have that sweet little rubber band in them for any resonance issues.

chikin pickle

Do you know anything about engine mechanics? First, second, or third order vibrations? You obviously don't know what a balance shaft does. Cancels second order engine vibrations. Which are entirely unrelated to what the harmonic balancer pulley does.

A flywheel will not prevent these vibrations. In fact, the force from the flywheel resisting the motion of the crank is what causes it to deflect in the first place. Secondly, it is made of the same material as the crankshaft so the vibrations will travel through it unchanged.

Just for reference, big spinning inline six engines don't have any funny vibrations. They are perfectly mechanically balanced. You can make them the size of an apartment and put them in ships without funky vibrations.
No, you don't have to put it on a big machine and spin it up to 50,000 RPMs. You design it that way in a CAD system. and make it on a lath which is spinning it at probably 1000-1500 RPM depending on the material (It's impossible to make unbalanced things on a lathe). Then you drill the holes with a CNC machine, that places them equidistant accurate to 0.001" so that it is never unbalanced to begin with. but that's not here nor there.

Yes, four pounds is a large difference in weight but it is acting over a small distance and therefore would produce a very small change in the overall moment of interia of the entire rotating assembly (which includes the crank, all pistons, flywheel, clutch, transmission rotating assembly, driveshafts, brake rotors, hubs, bearings, and rims/tires).

The purpose of a harmonic balancer pulley is simple.

As your engine fires, the crankshaft deflects under this load ever so slightly. Think of winding a clock spring only it's your crankshaft. The more power your motor makes, the more it deflects. After the load is released, the crank return to its original form. So your crank acts like a torsion spring, winding and unwinding as the cylinders fire.

At certain RPMs the force of the engines power stroke occurs simultaneously with these vibrations. This resonates them and will generate enormous amounts of stress on the crankshaft. This leads to catastrophic engine failure.

This happens in EVERY ENGINE EVER MADE USING A METAL CRANKSHAFT.
It is simple physics, and EVERY ENGINE EVER MADE WITH A METAL CRANKSHAFT incorporates some kind of dampener to suppress this type of crankshaft vibration. The rubber element of the pulley absorbs and dampens these vibrations. It is necessary.

extralargenog

iTrader: (1)

TOO much tech for Honduh Tech... SHiNy is better cuz its hella JDM yo!

chikin pickle

Word.

Bwill9886

Check out extralargenog's sig (or search some threads, whatever).

I don't know him, but I do know enough from being on honda-tech a little while to know he's got quite a bit of knowledge about this subject.

Sometimes it's just better to leave what works alone. There are so many ways to make more power/improve efficiency, so why choose one that gives minimal gains with these kinds of risks?

This should be in every one of these threads about lightweight pulleys... at least in a shortened version. I've tried to explain some of this before, but this is much better.

Not that it would change a ton of minds, but at least then we could all say we told them so when they have problems/realize they wasted money.


With that said, I'm glad you seem to be enjoying your purchase OP. Hopefully you have no problems.

chikin pickle

Also I would like to add that these underdrive pulleys do not get their power gains by reducing weight like a flywheel. They get their power gains by making the pulley smaller, so the accessories produce less torque on the crank, not by reducing crank inertia.

extralargenog

iTrader: (1)

BINGO!

b18c4si

Confusing subject this , and another one that just seems largely open to debate, and personal interpretation, is there anyone that 100% knows the answer to this question ? some people say these pulleys ruin engines as they are not dampened, others say the rubber in the oem unit is not for harmonic distortion ? some say the lighter one places less strees with less mass on the crank with better balancing ?
Obviously short term it would improve the performance , how well are honda engines balanced ?
How about some actual facts? (not an opinion,hearsay or what you worked out in the pub after too many lagers))
Anybody done high miles using these pulleys and done so in a spirited way ?
Anybody ?