Why an all steel pulley when most people tell you that you want something lightweight? That is because most people simply do not know the truth about what is needed to provide greater engine life and spread their ignorance with hype and sales talk or maybe they want your engine to fail prematurely. Let's take a look at some good common sense.
First, the stock engine when never turned over 4400 RPM with its stock flywheel has little need for this device or our Equalizer pulley. They are unable to generate the conditions that this eliminates. In the early 60's, we started to lighten the flywheel and/or increase the performance and RPM range of the engines and either of these changes pounded the cases out. We then developed proper counterweighting techniques and it stopped this problem. For years, people have tried (unsuccessfully) to copy our exclusive procedures to do this. This completely cured that problem, however, as the power, RPM and acceleration rates increased more new problems were encountered.
We had completely cured the new problems with our race engine by installing our Equalizer pulley in the early 70's, however, did not realize it until my 138 HP bus showed the #1 main working in the case at the 135,000 mile inspection. Now, many would say, "So what, that engine obviously should show such wear at that mileage, especially with that HP and the use it had been subjected to." Personally, I felt it was a problem that should be addressed so I could go 200,000 plus miles without this, especially when no other signs of wear were there and I knew immediately what was causing the wear.
The light pulley allows the nodes (vibration like a guitar string) to travel up the crank from the pulley end to the flywheel end of the crankshaft. Naturally, the flywheel stops this node at that point transferring it into the case. By adding the extra weight to the pulley end with our heavy pulley it stops this from occurring, no longer being sent to the flywheel end.
So why more than one weight? Another good question. I found that different acceleration rates and RPMs required different weights and diameters of pulleys. Naturally, the all out race engine would use the original Berg power pulley size Equalizers. All stock VW engines with lightened flywheels and/or higher performance up to 6000 RPM, and engines that require full cooling must use the stock size pulleys. Engines that are turned over 6000 from time to time must have at least the Achiever and if often in the 5500 to 6500 our Equalizer would be extremely smart. If you have any doubts - get the Equalizer. We can assist you in the selection of our Achiever or Equalizer at the time you make your purchase. All Berg pulleys are dynamically balanced. Both use the stock pulley bolt/washer or our new GB 435S bolt and Belleville washers and come with copyrighted Berg instructions and NEW higher torque specifications.
Another factor is belt groove wear. Berg steel pulleys will provide up to 10 times longer life as compared to an aluminum pulley.