4age crank pulley, OE or Alloy ?

[Q-Authority]

This is probably pointless, but I can't help myself, lol.

The 4ag crank pulleys do not have harmonic balancers, repeat, do not have harmonic balancers. The small rubber insert, in the 4age pulleys, is merely there to reduce engine vibration noise, and to reduce vibrations from being transmitted to the drive belt accessories. A harmonic balancer is an entirely different beast. Engines such as the 4ag do not need harmonic balancers.

People have run solid 4ag pulleys for ages now, and it is only a relatively small number who have reported issues with their engines. Because of the abuse most of these engines will probably have been put through, and the ocassional lack of mechanical expertise of the owners, there is no way to determine if solid pulleys have ever had anything to do with any of their issues. From most of the posts I have read regarding problems, virtually no one has ever throroughly researched their problem, and the pulleys are often blamed for an absolute plethora of issues.

As for the Endeavor pulleys, yes they are solid two-piece pulleys, and are very well made. The only very minor issue I have is that they have made the flange, of the front (A/C) section that sits against the face of the rear section (S/C, wp, alt), a bit wider than preferred, and it thus creates a small offset of about 1mm, which is not on the oem pulley, or others such as the HKS. I'm not sure that it will really make any difference, but I would prefer that there was no offset, just for piece of mind. That being said though, I really like having a steel center, so there is less worry about keyway or crank fit wear, and the oversize pulley I had them make still weighs considerably less than an oem pulley.

Because the cost to manufacture a pulley with a rubber isolator is so expensive, it is rather unlikely that anyone will ever bother, so I wouldn't get your hopes up. Manufacturers did so in the past because they could sell such a large number of them. I still think HKS could sell a lot of them, at least for a limited time, but they can't be talked into it.

If I had a choice I would prefer a pulley with a rubber isolator, just to reduce a bit of noise, which is a prime goal of mine. But when it comes down to using a 20 some year old pulley, just how much vibration reduction do you think these things still have in them? They're probably all just a bit on the stiff and dried out side by now I would think. However, I do have both an Endeavor 4agz pulley, and an HKS 4agz pulley, which I will compare at a future date, just to see if there really is any difference between the two in this regard.

Oh, and by the way, an HKS has a working diameter of 155mm, not 157mm, as most report. It's overall flange diameter is 157mm, but the belt surface diameter is only 155mm. I had Endeavor make my custom 4agz pulley before I got my hands on the HKS one, and had asked them to make it with a 155mm diameter based on the belt surface, not the flange, just in case their flanges were a little oversized, and might hit the timing pointer. So as it turns out, I now have two identical sized pulleys for comparison. Endeavor was quite happy to build the custom pulley to my specs, and did so in a very timely manner, so my hats off to them for great customer service. Sorry for the run on!

[RT40Corona4AGTE]

very interesting read, thanks for contributing!

[Casey-G]

I looked at my OEM gze pulley and if i were to turn it down it to fit it would remove the rubber.. its probably becuase the gze has a larger diameter?

Im thinking now ill just get my gilmer crank pulley balanced

[RT40Corona4AGTE]

i concur!

[allencr]

This is probably pointless, but I can't help myself, lol.

The 4ag crank pulleys do not have harmonic balancers, repeat, do not have harmonic balancers. The small rubber insert, in the 4age pulleys, is merely there to reduce engine vibration noise, and to reduce vibrations from being transmitted to the drive belt accessories. A harmonic balancer is an entirely different beast. Engines such as the 4ag do not need harmonic balancers.

Is it your point that it can't be a harmonic balancer if its outer ring is also driving a belt, but would be one if it weren't trying to do 2 things at once?
So could we say that it is 1/2 of a harmonic balancer on a 4AG, not something entirely different?
Thanks.
**
**
http://www.bhjdynamics.com/index.php...roducts_id=158

[Q-Authority]

Is it your point that it can't be a harmonic balancer if its outer ring is also driving a belt, but would be one if it weren't trying to do 2 things at once?
So could we say that it is 1/2 of a harmonic balancer on a 4AG, not something entirely different?
Thanks.
**
**
http://www.bhjdynamics.com/index.php...roducts_id=158

No I wasn't really implying anything like that. Harmonic balancers are just a completely different beast, significantly more complicated, and designed quite differently than the rubber isolator on our pulleys. The isolators we have simply cannot handle the complexities that a harmonic balancer can. I suppose I'll have to try and put together some sort of brief description of what a harmonic balancer really does, and how they are generally designed, in order to save and use for disussions like this, but a brief search on the subject should show you that they are indeed quite different. Unfortunately, they are complex enough that I don't usually carry a complete enough description of their design and function in my head, beyond somewhat simple terms. Sort of like quantum physics. I thoroughly enjoy reading up on the stuff, and can follow along a decently written article without any problem, but just don't ask me to give a detailed description of super symmetry a week later, without having to look it up again. My small brain just has too much else going on.

As for the product you linked, that looks like it may have harmonic balancer capabilities, but I'd have to know what is going on inside that steel inertia ring they have on there, which is a critical piece of their design. A normal 4ag pulley has nothing like that on it, nor do they really need one. Perhaps that one becomes more useful when really pushing the design limits of the engine.

[Talasas]

No I wasn't really implying anything like that. Harmonic balancers are just a completely different beast, significantly more complicated, and designed quite differently than the rubber isolator on our pulleys. The isolators we have simply cannot handle the complexities that a harmonic balancer can. I suppose I'll have to try and put together some sort of brief description of what a harmonic balancer really does, and how they are generally designed, in order to save and use for disussions like this, but a brief search on the subject should show you that they are indeed quite different. Unfortunately, they are complex enough that I don't usually carry a complete enough description of their design and function in my head, beyond somewhat simple terms. Sort of like quantum physics. I thoroughly enjoy reading up on the stuff, and can follow along a decently written article without any problem, but just don't ask me to give a detailed description of super symmetry a week later, without having to look it up again. My small brain just has too much else going on.

As for the product you linked, that looks like it may have harmonic balancer capabilities, but I'd have to know what is going on inside that steel inertia ring they have on there, which is a critical piece of their design. A normal 4ag pulley has nothing like that on it, nor do they really need one. Perhaps that one becomes more useful when really pushing the design limits of the engine.

It would explain why the stock pulley on my 4AGE has rubber showing on one side and completely solid metal on the front. I could never figure out how the hell it worked with rubber only inserted into a groove.

[Bazda]

Interesting.

With the stock pulley the rubber isolator you can see from both sides of the pulley.
Well on a fwd 4age. Duno about the single row rwd items.

Im getting my stock pulley modded by pressing out the inside and then pressing back in a billet steel section just so I know the key way is safe. Seen it done to a few race cars here, (on the 2zzge's).

[JP]

ATI have a bit of harmonic damper info on their site:
http://www.atiracing.com/products/dampers/101/index.htm
http://www.atiracing.com/products/da...mper_dinan.htm

[Q-Authority]

Im getting my stock pulley modded by pressing out the inside and then pressing back in a billet steel section just so I know the key way is safe. Seen it done to a few race cars here, (on the 2zzge's).

That is a very good idea. More people should have that done when their keyways start showing wear, but few do, or even think about it. Worn keyways and possibly slightly worn crank fittings, are probably two of the main reasons why solid aluminum pulleys fail. It would probably help if more companies used a higher grade aluminum for their pulleys, like Nevo did, but everyone is so conscious about costs, and sale prices, and the average buyer these days seems more than willing to just buy the cheapest thing they can find.

ATI have a bit of harmonic damper info on their site:
http://www.atiracing.com/products/dampers/101/index.htm
http://www.atiracing.com/products/da...mper_dinan.htm

Good links. The first one shows what I generally think of as a rather complex harmonic balancer, and would represent what you might find as an aftermarket item. It's built to handle far greater forces that a typical pulley damper.

The second link shows what I would consider nothing more than a damper, and is pretty much nothing more than what comes on the oem pulleys. You'll notice that they tend to stick with the term 'damper', and not 'harmonic balancer', which is probably a safer advertising term, as it really does not imply the same thing.

Lastly, when a couple of more brain cells woke up I realized that I probably overestimated what was going on with the item shown on the following link: http://www.bhjdynamics.com/index.php...roducts_id=158
The steel inertia ring is probably nothing more than a solid heavier piece used to counter the lighter weight of the inner section, to help maintain a slightly smoother idle, and why oem pulleys generally use cheaper heavy materials to start with. Otherwise that pulley just looks like it uses a rubber dampner, so not a lot going on in that dept.

[Bazda]

Only reason why I change the inside to a solid billet steel item is because one has let go on my car in the past.
I used to also run an alloy pulley made of air craft spec grade alloy 7000 series. So tougher than the normal 6061 grade that is generally used for most items on the market.

Also remember there are fluid dampers as well which have silicone in them. Meant to work better than the rubber ones.

[dangdang]

Silicone has excellent damping properties which is why a lot of high end euro cars have silicone fluid filled suspension bushes.

What is the composition of the Ross balancers? And how does that composition differ so greatly from just the OE "damper"? Obviously the Ross are not silicone filled but surely the inside workings are not so secret that they are broken down into just trademarked names for explanations.

[Bazda]

I have no idea what the Ross ones have in them. I should ask them.
Maybe get a silicone one off a Euro car and modify it to fit could be the best idea