underdrive pulley & lightened flywheel

[jyt747]

Would there be any problem with getting an ASP underdrive pulley while having a lightened flywheel? My friend said that there may be a problem because the flywheel doesn't have the mass to keep everthing in harmony with the pulley. Thanks in advance for your help.

[West]

Everything would be just fine. I had both on my old 91 240SX.

[BlankFlip]

west, did u ever dyno that s13?

[jyt747]

Thanks for the info, West. BTW, sorry to hear about your car. So who's the lucky person who got it?

[whateverjames]

the pulley and flywheel should work fine. i have my power steering belt and mechanical fan removed, and i have the JUN flywheel, and everything seems to be fine. i'll be buying the ASP pulley.

i had a dream a few nights ago that i bought west's car. (even though i had no intentions of buying it!) i remember it costed $36,000 and he only accepted paypay. and for some reason i didn't care because i had $36,000 to spend.    strange.    i never did get to drive the 240sx in the dream though.

[Nismos14]

LoL james freaky dream $36g's! LoL

[vancouvers14]

from what i've heard, you can't do both mods

[BlankFlip]

both mods and still be able to leave everything the way it is right? so u can just get the pulley n flywheel n put 'em on?

[jyt747]

Vancouvers... Why wouldn't you be able to have both mods? West had both on his car and it was fine. Does anybody else have any input? AND what the #### kind of dream is that james?! <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>

[WhiteS14]

If the stock crankpulley has a harmonic dampener - usually a rubber insert sandwiched between 2 pieces of the crank pulley, there can be some longterm adverse effects to the crank bearings.

The purpose of a harmonic balancer is to control harmonic vibration, not to balance an engine. &nbsp;Each time a cylinder fires the resulting combustion creates a tremendous amount of pressure, which becomes the force applied to the crankshaft. Each combustion is like a hammer blow to the top of the piston. It hits with enough force to cause the crankshaft not only to turn, but to twist as well. This twisting, along with the accompanying rebound (when the crank rebounds back in the opposite direction), is known as torsional vibration. This explains the broken parts that result in the absence of a good damper. &nbsp;Is a 5hp gain worth rebuilding the motor?

I'm still new to Nissan's, so I'm not aware of their design. &nbsp;Please excuse my ignorance if I'm wrong. &nbsp;Just want to share what I know.

[drift freaq]

from what i've heard, you can't do both mods
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thats ludicrous . The lightened flywheel is balanced when its made the pulley is balanced when its made . It will work fine. If people want to get nitpicky then yes having everything balanced on your bottom end at once is better . It will not hurt your engine though if the parts are bolted on afterwards . I would go with the ASP pulley they seem to put more thought into their pulleys as far as the relation the original pulley had to the engine i.e. balance. Its also a lot cheaper than the Unorthodox . Which used to be the same price until Unorthodox got big and jacked the price up.

[WhiteS14]

Will an underdrive pulley from a Nissan KA21 pickup fit the KA24?

[vancouvers14]

afaik, the lightened flywheel has to be balanced with the crank. &nbsp;i dont think its just balanced all on its own. &nbsp;

can anyone confirm?

[sykikchimp]

WhiteS14 is correct about the Harmonic balancer. &nbsp;It is actually a seperate peice, not part of the pully, ASP &amp; UR pulleys do not come with this Balancer and you can't attach it (or maybe you can, but I believe it would take some custom fab work.) &nbsp;Theoretically it should cause long term effects. &nbsp; &nbsp;But I still have not read about anyone having those problems. &nbsp;Some people have had for more than 3 years..

Of course if they blew their engine, they might not realize it was due to the Pully, because they would probably be &quot;Racing&quot; the engine.. (just thinking about the Tuner mentality.. we love to drive hard <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'> .. &nbsp;)

Also just a note.. &nbsp;you should probably replace the front crank seal while your there. &nbsp;I've heard of it leaking after the install and the pully slinging oil all over the engine.

[drift freaq]

whiteS14 writes...
afaik, the lightened flywheel has to be balanced with the crank. i dont think its just balanced all on its own.
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err true be not true. Ideally yes,but you can stick an aftermarket aluminum flywheel thats balanced on your engine with no ill effect.
Plus I am getting a flywheel lightened right now by top end performance and they are balancing it. If you take metal off in large amounts it does have to be rebalanced.

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In answer to sykikchimp
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On nissans the so called &nbsp;harmonic balancer is actually part of the stock pulley. That is In NIssans eyes according to their service manuals.
Now , Unorthodox racing says its not neccessary. ASP says they took it into consideration. I called and asked them :biggrin:

[ca18guy]

Nissan engines do not have a harmonic balancer. They have a damper. Think of it as a pulley with tiny rubber inserts to &quot;absorb&quot; harmonics it does'nt balance anything and is not &quot;balanced&quot;.

(Edited by ca18guy at 2:41 pm on Jan. 10, 2002)

[sykikchimp]

yeah.. &nbsp;I know its a damper.. &nbsp;I was refering to it as a balancer to work with the laymen.. &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'> &nbsp;

Drift - Very cool. &nbsp;I didn't know that. &nbsp;and its the first I've heard about them. &nbsp;I think UR is crazy saying its not necessary. &nbsp;Sure, maybe not necessary for racing apps, but for those of us who actually would like to drive our cars for &nbsp;Several years, I believe it does increase engine life. &nbsp;If it wasn't necessary why would Nissan put it on the engine.
Maybe thats why the ASP pully is a little heavier than the UR pulley.. &nbsp;?? &nbsp;

[jyt747]

Thanks for everybody's help. Does anybody have any first hand, long term experience on this besides West? Thanks again everybody.