You have a Harmonic balancer .... If you were to ballance the engine they will also balance the Balancer ... If you have the Unorthodox Pulley then they will balance that ... The Unorthodox Crank pulley replaces the stock Balancer , so even with a stock engine you can remove the balancer ....
The KA is internaly balanced very well ... The factory installs a Harmonic balancer to cut down on engine vibrations so the owner has a smooth car ... The UR Pulley is just a piece of aluminum so there is no Balancer at all ... I have over 140,000 Miles on My Altima and have the UR Pulley .and am very very hard on my engine !!!!! And have had no problems at all ......
I remember reading some place that the KA was "vibration prone" as so that is why there is an external balancer on the engine. The KA is internally balanced like just about everyother import engine The UR pulley is not a balancer, it acts just like every other pulley on the engine. I had the UR pulley on the engine i blew... never had any vibration problems with it and it was at 120K. I think that it is a comfort thing more than an engine damage issue when it comes to the balance in the crank pulley on the KA.
There is some controversy about the pulleys, as they are not equipped with the harmonic balancer that the stock pulley has. We feel the risk of removing the balancer on certain engines is not really a risk. Inline, four-cylinder engines for the most part have short, stiff crankshafts. These do not need a balancer as much, because of their high natural frequency. Engines with long, whip-like cranks, like inline six-cylinders, need balancers to prevent failure, but most four cylinders do fine without them.
Nissan four cylinders, with the exception of the vibration-prone KA24, can do fine without a balancer. We have had underdrive pulleys on many SR20 engines, some with more than 1,000 track miles, with no problem whatsoever. Nissan four cylinders are also internally balanced, which reduces the need for a harmonic balancer. Many cheaper engines, on the other hand, need to have a built-in imbalance on the pulley to make up for a lack of an internal counterweight. Like the SR20 engine, the GA16 engine actually felt smoother and revved more freely with the underdrive pulley installed.
For some of you too lazy to go to the Unorthdox site...
3) "Isn't my stock crank/eccentric pulley a balancer, harmonic/torsional, or vibrational damper?"
The factory pulleys on today's late model cars (from 1986 to Present and sometimes even earlier depending on the vehicle) serve two functions. First and most importantly they are designed to reduce or eliminate the audible noises herd in the cabin of the car that the accessories (alternator, air conditioning, power steering, and air pump) make when the engine is running. This fact exhibits the factory fanaticism about making the car quiet for the occupants (i.e. the use of resonators in the intake to quiet intake noise, all aftermarket intakes eliminate these resonators). It has nothing to do with engine function or longevity.
The second function of late model crank pulleys is torsional damping. Torsional damping is necessary due to the excessive diameter and weight of the factory crank pulleys. The design of our underdrive crank pulleys eliminates the need for any torsional damping for two reasons. One, the diameter of our crank pulleys is smaller than the original designs, in almost all cases smaller even than the rubber torsional ring, therefore effectively reducing the force the accessories have on the crankshaft. Second and most importantly is that our pulleys are significantly lighter than their OEM counterparts (anywhere from 3 to 11 lbs.). This weight loss dramatically reduces the stress exerted upon the rotating assembly by the excessively heavy factory crank pulley.
Our pulleys are so well balanced that when owners call us about how happy they are with the product they always mention their motor feeling smoother. Lastly is the misconception that the crank pulleys on these vehicles are harmonic dampers. A harmonic damper is a unit bolted to the crankshaft snout that is completely separate from the belt drive system. An engine that uses a harmonic damper has the accessory drive crank pulley bolted to it, they are separate pieces that are attached to each other. Balance shafts, which are used by several manufacturers, are specifically designed to eliminate harmonic vibrations. None of the vehicles we manufacture pulleys for have harmonic dampers in the traditional sense.
Owners who have engines that use balance shafts must understand that if they eliminate their balance shafts their engines must be balanced to 0 grams if they expect to have no long-term engine problems with or without the use of our crank pulleys. Our pulleys are made with 6061-T6 aluminum billet which is a very consistent material and the CNC machining process ensures that all our pulleys are perfectly true. This balance shaft elimination is rare and only happens on a few models that are modified for racing only (Eclipse/Talon/Laser/Galant VR4/Conquest TSI/Starion just to name a few).