Lightweight Aluminum Crank Pulleys

[jirkipi]

Crank Pulley1.jpg

Crank Pulley2.jpg
Hi guys,
I have 5 6061 T6 Aluminum Stock Diameter Crank Pulleys left for the Audi 80/90/CQ/S2....2.3L 7A/NG/NF engines. Let me know if anyone is interested (jirkipi@rogers.com). BTW they weigh under 3lbs. compared to the 10+lbs. stock unit. They are yet to be anodized, so let me know what colour you would like. The price is $292.11CDN each.
Here are some pictures of what they will look like anodized in clear, red, and black...

Thanks,

Paul

[caterpillar]

alupulleys

arent they some sort of vibrationpulleys they should take up the vibbs from the cranck
they looked nice

[volcano rs]

do these affect the balance of the crank in any way ?. being so light .

[SteveH]

The front pulley is used as a harmonic balancer for the crank assembly. To be used these pulleys would require machining and balancing of the crank assembly.
Something to think about if your undertaking a rebuild..

[jirkipi]

Yes, they are called 'harmonic balancers'. These pulleys do not disrupt anything in terms of the crank. The flywheel takes up pretty much all of the vibration, not the crank pulley!!!

[robo]

Yes, they are called 'harmonic balancers'. These pulleys do not disrupt anything in terms of the crank. The flywheel takes up pretty much all of the vibration, not the crank pulley!!!

If you sure I defo want one.
cheers

[jirkipi]

The crank does not need to be machined for these to work properly! I have had one on my A4 1.8T for well over 300,000Km. with no ill effects whatsoever! There is A LOT of debate in regards to LW crank pulleys and the crank, but I can tell from first hand experience that they do not affect the reliability of an engine the least bit. Your telling me that in order to be able to run a LW flywheel that your crank has to be machined & balanced. I don't think so!
These are not underdriven crank pulleys, and do not underdrive the accesories at all. You save over 70% with the weight reduction at the crank. In fact it will increase the life of all accesories (PS / A/C / Alternator), and give back some of the HP lost at the crank.

[SteveH]

That may be the case with a 4cyl motor, but not with the 5cyl. The front pulley on the 5cyl motor is part of the balancing for the crank assembly, that is a fact. Just because you've noticed no ill affects doesn't mean it's ok. The same is also true for the flywheel. I'm not saying the pulley isn't a nice looking and well made item, but I wouldn't just bolt it to the front of my motor without getting it re-balanced.

[SteveH]

BTW...how do you bolt these onto the nose of the crank? From the pic there is a small raised section in the centre, around which the bolts for the rear toothed pulley must sit. This doesn't appear to leave much land for the main crank bolt to sit on.

[jirkipi]

The 1.8T and the 2.3L both have 'harmonic balancers' built into the crank pulley, in fact most cars do! Your comment about me not noticing any ill effects really baffles me... If something doesn't belong on a car, especially on or inside the engine, wouldn't you start noticing some kind of wear, sounds or vibrations in the engine. The A4 has been run very very hard with the LW crank pulley all it's life (300,000Km.....and still going strong).
I don't mean to sound harsh or anything like that at all! But, it seems to me that you've heard some sort of horror story in the past where someone put a LW pulley on their car and it blew up or something along that line.
The pulley is made very well. It could have been much lighter, but I didn't want to disrupt the balance between strength and weight. Everything bolts up exactly the same with the LW crank pulley as it does with the stock piece. Everything was kept stock except the design of the front and the weight ofcourse.
The 4 hex bolts that screw onto the toothed pulley bolt up exactly the same as the stock piece. The hole for the main 'big' bolt that screws inside the toothed pulley & crank is the exact same as the stock unit as well. The picture may be a little deceiving, but all the measurements reamined the same.

[Jeffer]

I'm with Steve on this one. The stock S2 crank is balanced with the harmonic damper.
When the pully is replaced by a lightweight one, then balancing is needed. A thing that is missing in your pulley is a cranck locking notch.

[AnLe]

Is CDN=CAD? How much postage would be to Finland?

I would not change bottom parts without balancing, but other than that I cant see no harm in this mod.

[SteveH]

These lightened pulleys are a good mod if you're looking to loose weight from the rotating components. I've seen a few originals that have been machined to loose weight and a few aftermarket items. All offer weight loss, however, something like this alloy version is much lighter than an OE item that's been machined. There are two issues that need to be addressed when changing the front pulley/harmonic balancer..

1) Balancing of the rotating assembly. Choose to ignore this if you like.
2) Provision for locking the engine to remove/replace the item.

On the few OE items I've seen that have been machined to loose weight, the lobe on the inner surface of the harmonic balancer has been removed. This lobe provides a locking point for the crank locking tool and is an offset weight that is part of the harmonic balancing for the crank. This results in the two points I've mentioned above needing to be addressed. On the cars I know of, changes to the front pulley have been done at the same time as balancing the crank. I personally, would always address crank balancing when making any changes to any part of the crank assembly. There is no way that the affect of the lobe being removed by either machining or replacement of the pulley is insignificant. Take a look at an OE pulley, they are all drilled on the front face to fine tune the balance..

[S2 Ant]

I can see why they would need to be balanced, but would the effect of the other belts not consitute a problem with this tho?

For instance, a fairly tight alternator belt and a slack aircon belt is going to be pulling the pulley toward one side.

Would this not cause the balance issue to still have problems? Fair enough its balanced in its own right but these belts must then throw things out due to the tension and direction they run?

[AnLe]

I see it that alternator or similar auxilary tension is just static and to one direction, thus 7000rpm rotating mis balanced crank has it all around the crank 7000 times in minute.

Same way that 100gram lighter rods means hunreds of kilos saved in rotating mass.