Underdrive Pullies?

[Redline240]

I know that both Unorthadox Racing and ASP make underdrive pullies for the KA but does either one use a harmonic balancer? From what i've read this can kill you engine over time, especialy in high hp applications. So does anyone know for sure if either of these units use one, or of another company that makes one that does?

Redline

[:: orion ::]

It's not needed...the 240SX OEM pulley doesn't have one, and KAs don't fail for +200k.

...and really, for an engine that doesn't go over 7000rpm, it's not that important.

And before someone says that the stock pulley has a harmonic dampener...it doesn't. It has a metal and rubber ring that helps to avoid NVH when the A/C compressor turns on, it has no dampening properties.

Later - Brian

[deviousKA]

Removing that ring secured by rubber you can loose 2-3lbs off the pulley. I have been running an oem ka pulley with that removed for over a year.

[SSS]

Just to ease my mind before i set off drawing up a new KA pulley, has anyone got a pic of a stock 240SX KA24E crank pulley? I have a stock fwd KA24E pulley laying here, but it seems to have a harmonic balancer.

[tonynalli]

you have gotting to be kidding me thinking that you dont need the balancer. do yall even know what they do, the company didnt put them there just because it would add wieght. its a weighted thick metal piece that turns with the rotation of the engine, to counter balance the vibrations caused each time the gas and air mixtures explode when ignited by the spark plugs. you will destroy your engine if you remove it. would you rather loose a few pounds right now or have to rebuild your engine in a few thousand miles?

[lovemysan2]

The KA is internally balanced. There is no harmonic balancer. There is a small rubber ring bolted into the crank pulley which can be removed. Its simply there to absorb some of the vibrations of the accessories.

And yes if we were talking domestic V8 you could not run without the balancer. Most japanese engines are internally balanced.

Devious does it really weigh 2lbs?

[deviousKA]

NO, like orion said the rubber mounted weight was integrated for the a/c only, and is mounted seperately on the power steering portion of the pulley (completely removable btw but you loose power steering). The actual crank pulley itself is balanced seperately, same as the flywheel. As long as the pulley is balanced in and of itself no problems will occur.

Take a look at nissan motorsports, unorthidox, asp etc... They have no "harmonic" damping properties at all, and cause no ill effects.

Actually, there is more of chance of out of balance with the stock setup. The outermost portion of the part where that rubber mounted weight is located (heavy), is mounted with 6 8mm bolts. This part has a lot of room to walk around and can easily cause out of balance if not centered 100%.

[deviousKA]

Yes it weighs 2/3lbs, solid part. I drilled about 50 small holes through the rubber, then got the rubber warm with a torch and twisted the part off in a vice.

[Calesta]

you have gotting to be kidding me thinking that you dont need the balancer. do yall even know what they do, the company didnt put them there just because it would add wieght. its a weighted thick metal piece that turns with the rotation of the engine, to counter balance the vibrations caused each time the gas and air mixtures explode when ignited by the spark plugs. you will destroy your engine if you remove it. would you rather loose a few pounds right now or have to rebuild your engine in a few thousand miles?

No kidding. Harmonic balancers are used to smooth out the power pulses, not to make sure that the rotating assembly is balanced. The two types of "balancing" are completely different. Maybe the harmonic balancer should be called a "power smoother" instead of a balancer.... it would be more accurate. You need a harmonic balancer to make sure your engine lives a long life. You can remove it to recover some of your rotational losses, but you lose engine life as well.

[DGA]

No kidding. Harmonic balancers are used to smooth out the power pulses, not to make sure that the rotating assembly is balanced. The two types of "balancing" are completely different. Maybe the harmonic balancer should be called a "power smoother" instead of a balancer.... it would be more accurate. You need a harmonic balancer to make sure your engine lives a long life. You can remove it to recover some of your rotational losses, but you lose engine life as well.

Your flywheel is used for the same thing. Smoothing out the power pulses at idle.

[Calesta]

Yes it is... and realistically, you need one (flywheel and balancer) at each end of your crankshaft.

[DGA]

Not entirely true. I know that Honda engines do not have an external balancer, just a crankshaft pulley, just like KA24DE does. Engines can be internall balanced.

I also have a vintage Chevy truck with a small block in it, and they are not internally balanced from the factory, thus needing an external harmonic balancer. You can remove the harmonic balancer if you get an internall assembly that is fully couterweighted and balanced. Guy I worked with had a '67 Camaro with a 327 in it, that he could hold at 12,000 rpm. He ran a harmonic balancer just due to the rev happy nature of that engine. It all depends on what you got spinning in that block.

[Redline240]

Good info here. Has anyone had any negative experences with one? Or reviews on the one you run. Any differences between the ones offered?

Redline

[:: orion ::]

you have gotting to be kidding me thinking that you dont need the balancer...

Tony -

It's Brian (from INTMO)...

The OEM crank pulley doesn't have a harmonic balancer...if it did, you'd be (somewhat) correct. But Nissan only added a rubber ring to reduce the harshness and shock when you turn on the A/C, like I said above...

None of the aftermarket aluminum pulleys have this or any type of dampener...and I know of no one who's ever had an issue, even with lightened flywheel and pulley combo...

Later

[Calesta]

Not entirely true. I know that Honda engines do not have an external balancer, just a crankshaft pulley, just like KA24DE does. Engines can be internall balanced.

That's strange. Every single unmodified Honda engine I've worked on had a harmonic balancer.

[Redline240]

2jz's use them too...many have blown due to aftermarked balancers...

Redline

[DGA]

The 1.5L DX in '89-'91 just has a pulley. It is not a hamonic balancer. I believe that its the same for the D16Z engines, that came in '92 and up SIs. I also think that the JDM B16As do not have a harmonic balancer. Do not quote me on the last one, its been a little while since we had one.

The factory manual for the KA24DE refers to the part as a crankshaft pulley, so does the manual for the S14 SR20DET. I could not find any more info on the pulley itself. I will double check the Honda motor at home for the same thing.

[keepingthe240]

All small block and big block chevies are internally balanced but the 400 s/b and the 454 big block. Give me a run down on the 327...a 302 chevy might hold 12k. 327 can't rev that high..283 can. oh yea.

Not entirely true. I know that Honda engines do not have an external balancer, just a crankshaft pulley, just like KA24DE does. Engines can be internall balanced.

I also have a vintage Chevy truck with a small block in it, and they are not internally balanced from the factory, thus needing an external harmonic balancer. You can remove the harmonic balancer if you get an internall assembly that is fully couterweighted and balanced. Guy I worked with had a '67 Camaro with a 327 in it, that he could hold at 12,000 rpm. He ran a harmonic balancer just due to the rev happy nature of that engine. It all depends on what you got spinning in that block.

[DGA]

Um, yes a 327 can rev 12K. Seen it with my own eyes. With enought money one can get almost anything.

Also what do you call that thing on the nose of the crank on a 262, 265, 283, 302, 305, 307, 327, 350 and 400? Its a harmonic balancer. I have a '69 Chevy with a 307 in it, and it has a harmonic balancer. Here is an example of one. http://www.jegs.com/cgi-bin/nc...r=361

[keepingthe240]

lol....repeat...All v8 chevies except a 400 small block and a 454 big block is internally balanced. Look at the web site....call jegs!!!Internal Balance 265, 283, 305, 307, 327, and 350. Also 90° V6, 200 & 229 C.I.D. Chevy 400 Small Block..External Balance with CounterweightChevy Big Block 454..External Balance with CounterweightInternal Balance ..396, 427 and 454 C.I.D.

Wow...never knew some 454's where internally balanced!! Must be the newer one are are internally balanced

Your comment that chevies are not internally balanced from the factory was wrong... but 2 of them are not..400 and 454ci I'm fully well aware that a v8 chevy can run 12k... but the guy might be running a 283 crank (302ci) or one boat load of an exotic crank.

[keepingthe240]

You guy might be running a 350 block and a 283 crank(331ci) Yo...can you see if you can put a roller rocker on a kade??

[dubstyles240]

this thread should have been locked after orions first post.

[DGA]

Yeah I know, I put my own foot in my mouth on that one. Man I could have sworn, that they were not internally balanced. So the only point of the harmonic balancer on those things is to smooth out the vibrations of a V style engine?

KADE is a cam on bucket design. No rockers. I am positive on this one.

[DGA]

I am not sure what crank he ran. He had it built by some place here in Portland, OR. He said that his bottom end was guaranteed for life.

[Asleep Altima]

my 350 needs a harmonic balancer. there is no way in hell would i run a solid pulley on there. ive spoken to honda guys and they have had more problems with lightened crank pulleys than any nissan guys ive ever talked to. i had one for over a year and had no problems and felt no difference when i returned to stock.

[keepingthe240]

Yeah I know, I put my own foot in my mouth on that one. Man I could have sworn, that they were not internally balanced. So the only point of the harmonic balancer on those things is to smooth out the vibrations of a V style engine?

KADE is a cam on bucket design. No rockers. I am positive on this one.

Yeah...the ka24 does have rocker arms. Your talking about the ca18 and the umm...z32

[Qballc]

SO what you all are saying is that if i get a lightened flywheel for my KA24e then i dont have to get the crankshaft and everything rebalanced??

[TrunkMonkey]

Yeah...the ka24 does have rocker arms. Your talking about the ca18 and the umm...z32

the ka24e (sohc) has rocker arms.

the ka24de (dohc) does not.

-demetrius

[TrunkMonkey]

SO what you all are saying is that if i get a lightened flywheel for my KA24e then i dont have to get the crankshaft and everything rebalanced??

no, you don't.

-demetrius

[Qballc]

SWEET!!