Lightweight pulley wow

[White64Goat]

Enigmus, I've got a question for you. In your DIY writeup you said to give the crank bolt a good tug clockwise, yet your picture of the breaker bar has the arrow pointing counter-clockwise. So is the crank bolt a standard thread (lefty-loosie, righty-tighty) or is it a reverse thread bolt with righty being loosie?

[Silverdub]

It is standard and turn COUNTERclockwise. He seems to be as confused as my wife that still mixes up left and right

[Coheed]

Originally Posted by D1cker

Mine should be here on Monday, I was worried at first as most of the cars I've had, pulleys have caused issues with the oil pump, but the OEM pulley doesn't seem to have any harmonic balancing.

It's like a cheaper lightweight flywheel!

The OEM is a harmonic balancer. You can see the rubber ring separating the inside and outside parts of the pulley.

Most of the time you don't feel any difference in vibration. But rod bearing wear CAN be impacted due to 2nd wave harmonics. You can't feel them, but they impact the crank, and is the reason OEMs use a harmonic balancer in the first place.

I hate the OEM balancers, they seem to slip out of "time" and the timing marks wander off their marks with mileage and abuse. But everyone should know the advantages and disadvantages of using a solid one.

[Coheed]

Originally Posted by exmayol

Nice mod, great value. Whenever I get my BRZ this will be one of the first on my todo list. I've been running one on my RSX for at least 30K with no problems whatsoever.

K20 has internal balance shaft.

[White64Goat]

Here's a trick I learned while working for Pontiac. Since I don't have my BRZ yet I have no way of knowing if this will work because I don't know if or what type of under-pans there might be in the way, but on the older Pontiac V-8's you can take a 1/2" drive breaker bar with an air gun type deep well 6 point socket and place the socket on the crank bolt and turn the crank clockwise until the breaker bar rests against the floor, pull the coil wire and tap the engine over with the starter, loosens the crank bolt!

[Coheed]

Originally Posted by noAE86

rotating assembly is always balanced together,

crank pulley, crank pulley bolt & washer, crank pulley key, crank shaft, rods, pistons, piston rings, wrist pins, wrist pin clips, flywheel, flywheel bolts, clutch cover, clutch cover bolts,

its not the good old days of 2t 3t toyota engines that you can slap together and turn key,
in the past with my high strung engines, we would mark every item to know exactly where it assembled back together down to the clips, + or - grams was the tolerance, and this made for a fantastically smooth revving engine,

given this day and age every factory has high tech assembly plants, there might be 5-10 grams differences between parts but if the numbers are any higher, the result is a fuel injected vibrator,

The rotating assembly of the engine is balanced independently of the clutch/flywheel/harmonic balancer. Individual components are balanced separately to a zero tolerance. Engines these days are not "externally" balanced with the flywheel/damper.

[Coheed]

Originally Posted by sportsguy83

We are not talking about those holes, the ones we are talking about are on the face of the pulley, and they have no thread for a bolt.

There is no need for thread for a bolt because a jaw puller will remove it without damage, as opposed to the factory pulley. The outer ring of the factory pulley can be pulled of from the inner piece because the only thing holding it together is the rubber damping ring. Bolts are there for removal of the factory unit, as you know. But just in case other's are wondering, a 2-3 jaw puller will pull the aftermarket unit off rather easily.

The other holes are balance holes, because this factory pulley is cast it requires balancing.

[Captain Snooze]

Originally Posted by Coheed

Individual components are balanced separately to a fine tolerance.

fixed

[Coheed]

Originally Posted by Captain Snooze

fixed

No, I meant zero. You would literally have to spin the harmonic balancer to speeds that would cause it to separate before you saw even an ounce of variance from zero.

So for all intents and purposes, it's a zero tolerance. I'm sure you could nitpick fractions of an ounce at 9000rpm, but that's pointless.

[Enigmus]

Originally Posted by White64Goat

Enigmus, I've got a question for you. In your DIY writeup you said to give the crank bolt a good tug clockwise, yet your picture of the breaker bar has the arrow pointing counter-clockwise. So is the crank bolt a standard thread (lefty-loosie, righty-tighty) or is it a reverse thread bolt with righty being loosie?

Originally Posted by Silverdub

It is standard and turn COUNTERclockwise. He seems to be as confused as my wife that still mixes up left and right

oops I fixed it. Wasn't thinking straight at 1am and wanted to finish it so I could get some shut eye. thanks for pointing it out!

[Sportsguy83]

Originally Posted by Coheed

There is no need for thread for a bolt because a jaw puller will remove it without damage, as opposed to the factory pulley. The outer ring of the factory pulley can be pulled of from the inner piece because the only thing holding it together is the rubber damping ring. Bolts are there for removal of the factory unit, as you know. But just in case other's are wondering, a 2-3 jaw puller will pull the aftermarket unit off rather easily.

The other holes are balance holes, because this factory pulley is cast it requires balancing.

Thanks for the info I didn't know all of that. But regarding my post, I was referring specifically at the balancing holes. :happy0180:

[Captain Snooze]

Originally Posted by Coheed

No, I meant zero. You would literally have to spin the harmonic balancer to speeds that would cause it to separate before you saw even an ounce of variance from zero.

So for all intents and purposes, it's a zero tolerance. I'm sure you could nitpick fractions of an ounce at 9000rpm, but that's pointless.

Even your statement is contradictory: "No, I meant zero" and "I'm sure you could nitpick fractions of an ounce".

So.... If the device to weigh the items was accurate down to 0.001 grams that leaves an error of margin of +/- 0.0005. Which is not zero. I agree the tolerance are so fine as to not to matter but they are not zero.
Please forgive me; I am a pedant.

[Coheed]

Originally Posted by Captain Snooze

Even your statement is contradictory: "No, I meant zero" and "I'm sure you could nitpick fractions of an ounce".

So.... If the device to weigh the items was accurate down to 0.001 grams that leaves an error of margin of +/- 0.0005. Which is not zero. I agree the tolerance are so fine as to not to matter but they are not zero.
Please forgive me; I am a pedant.

Right. Nitpicking. :P

We could go as far as to measure the number of quarks and bosons that make up the pulley, but it's pointless right? Measured in grams, it should balance out. Of course, after a few thousand miles that could change things.

[PERRIN_Jeff]

Originally Posted by OrbitalEllipses

Weren't misfires caused by lightweight flyhweels used in conjunction with lightweight pulleys?

From my experience with the WRX/STI, this did happen sometimes, but mainly older cars. Keep in mind, these were misfire codes, not actual misfires. Meaning the car ran perfectly fine, but Check Engine Lights popped up. The good thing is, this is an item we can tune out of the map!

Originally Posted by Coheed

The OEM is a harmonic balancer. You can see the rubber ring separating the inside and outside parts of the pulley.

Most of the time you don't feel any difference in vibration. But rod bearing wear CAN be impacted due to 2nd wave harmonics. You can't feel them, but they impact the crank, and is the reason OEMs use a harmonic balancer in the first place.

I hate the OEM balancers, they seem to slip out of "time" and the timing marks wander off their marks with mileage and abuse. But everyone should know the advantages and disadvantages of using a solid one.

My only correction to your statements is they are not Balancers, but rather Dampeners. They are dampeners that are balanced on them selves, but that is it.

Originally Posted by White64Goat

Here's a trick I learned while working for Pontiac. Since I don't have my BRZ yet I have no way of knowing if this will work because I don't know if or what type of under-pans there might be in the way, but on the older Pontiac V-8's you can take a 1/2" drive breaker bar with an air gun type deep well 6 point socket and place the socket on the crank bolt and turn the crank clockwise until the breaker bar rests against the floor, pull the coil wire and tap the engine over with the starter, loosens the crank bolt!

We always joke about just starting the engine with the wrench on the crank and seeing what would happen. Not that I would recommend this at all!