cvt

No hard feelings dude...this is a forum, it's all in good fun.

gtracing

iTrader: (3)

no worries man, this is what the internet's for!

MSCA

iTrader: (3)

Well, I hate to bring an old thread back to life, but since this thread was linked from another more recent thread, I thought I'd chime in and tell you that gtracing is right on the mark with almost everything he said.

First of all, the factory crank pulley is most definitely a dampener. Anyone who begs to differ...just take a look at the factory crank pulley and explain to me why it has rubber in it. If it wasn't a dampener, it would NOT have rubber in it.

Next, you guys can argue all day over reported (or lack of reported) problems after installing an aftermarket lightweight crank pulley. At the same time you have to realize that you're argument is nothing but a fallacy if you think that nobody reporting problems means that it's never happened.

Removing the dampener from a crankshaft pulley doesn't usually have any immediate effects. You can probably get away with it for quite some time before problems develop. But if you wait long enough, problems are VERY LIKELY to develop. And it actually has nothing to do with how well the engine is balanced. gtracing has a good understanding of the issues, but even he might not understand that the dampener is to "dampen" the irregular rotation of the crankshaft. BTW, the crank dampener is also known as a harmonic balancer.

Anyway, the point is that the crankshaft moves in response to the pistons being forced down during combustion. Since there are gaps between each spark plug firing, the rotation of the crankshaft isn't exactly smooth. The dampener reduces (or absorbs) these torsional vibrations. So THAT is the main purpose of the crankshaft dampener. BTW, I'm not aware of one single internal combustion engine that doesn't use a dampener on the crankshaft pulley. If you guys know of one, please let me know. Like I said, I don't know of one...I'm not saying they aren't out there though.

MSCA

iTrader: (3)

The red dot is on rubber...and there's metal on either side. Any halfway decent mechanic can tell you that this is in fact a dampener built into the crank pulley.

TheLocNar

iTrader: (5)

Sure, it's a "harmonic dampener"... but the verdict is still out if that actually does anything to help. It's basically a thick rubber band.

MSCA

iTrader: (3)

Research and learn. That's all I can say to anyone who doubts what I'm telling them.

In the meantime, I'll say this-- OF COURSE it helps. It would be easier and cheaper for the engine designers to just install a solid metal pulley like they did for every other component on the engine. But they obviously felt it was necessary to install a dampener into the crank pulley, so that should tell you something, shouldn't it? If not, there's nothing more I can do to help you other than to tell you to do your own research on crank dampeners and why they are important.

TheLocNar

iTrader: (5)

The engineers also thought it necessary to make this engine run hot.

I'm not doubting you, or saying in any way that you don't know what you're talking about. Please don't get me wrong.

But from what I can tell, the jury is still out on this. And Sam hasn't had any problems in over a year, from what I recall.

Any failures could be traced back to a bad installation as well... not properly seating the pulley etc.

I had a stock diameter, lightweight UR pulley on my 2004 Maxima... there was a dampener on the OEM pulley. The car ran fine for 5+ years with it on.

MSCA

iTrader: (3)

Like I said, the negative effects are mostly long term. I learned the hard way with an older car that I used to own. You might have been lucky if you ran your Maxima more than five years without a crank dampener. On my car, the crank journals were shot after three years...but I put fair amount of miles on the car during those three years.

Anyway, once your crank journals are shot, you need a full engine rebuild or you need to replace the engine entirely. Like I said, I learned the hard way.

MSCA

iTrader: (3)

Here...read at least the "Crankshaft Deflection" section found here:

Fluidampr Harmonic Fluid Dampers Made in U.S.A.

It might even convince you why you should be using a better dampener than the OEM unit.

Fezzik

iTrader: (6)

Ok well just to tell you all. i had one on a car for 10 years from UR and it was an under drive pulley as well. I had it on my 2000 max and it was an auto. That was a beeoch to remove. I then took the timing ring off and put it on my 2k2 6 speed max. That was so much easier cause you could just have the person push in the clutch and apply the brakes.
Now I have the UR UDP on the max for 8 years (86k miles) and there was no detrimental effects so far. Everything is running fine and no probs. Did it make a difference. It did for me since it was underdriven. but Not HUGE. but faster revs for sure.
Just thought i'd toss out my 0.02 cents and experience on them.

TheLocNar

iTrader: (5)

Like a... let me guess... Fluidampr? lol

Team Punisher

Had it on 2 Maximas and 3 GS. I belive it's worth the MONEY. In fact gave the 06 to my son who at 33yrs old still takes care of it like he was 20. The car has about 60,000 miles on it and was driven in a cross crounty rally very HARD. So thats 5 of them i've had and well over 150,000 miles combined. And no problems.