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I think that most of the mfgs do a decent job figuring out the rocker arm geometry. The problem is that they don't tell people what the assumptions are behind the designs. Some rocker arms are designed to be stock replacements, some as race parts, some for stock heads, etc.

I spent my own money years ago to buy one rocker arm from every mfg possible so I could do my own measurements. I gradually figured out which arms worked with which heads and what lift ranges but it was a bit of a painful process.

I used to sell these rocker sweep tools. They do a good job of providing an engine builder with an actual number for the sweep. Without an actual measurement you're just kind of guessing at the results of a geometry change.

I've looked at the system that the OP sells and it doesn't make any sense to me. Maybe it works, maybe it doesn't. I'm not going to buy one to test out. I'll let someone else do that job. I've tested enough parts over the years!



I'm sorry Andy, but I have to disagree. Rocker arm companies do a decent job of figuring out how to sell rocker arms. They, and one brand in particular, make a lot of money making their products based on the misconception that centering the roller on the tip of the valve is proper geometry. I call that taking advantage of an uninformed customer, not providing a quality product or service. ANY rocker arm can be corrected to have proper valve side geometry, and they could manufacture the rocker to have the proper adjuster angle when the valve side is correct, but they won't. If they did that, it wouldn't look right, and certainly wouldn't be right, when just bolted on the head. They also won't tell you they aren't right just bolted on because they know guys won't spend that kind of money for something that isn't right, so they give the illusion that it is. This annoys me to no end.

BTW, what would you consider the application to be for the RAS rockers, stock, performance, race? I have a set, and they need correction just like all the rest of the bolt-on rocker brands.

I have a rocker sweep tool similar to the one you show in your pic. With the RAS rockers on a factory iron head with stock length valves, and a cam lift of .560" (small street/strip solid) the shaft had to be raised considerably. Oh yeah, and the sweep measured with the tool went from .062" to .022". I'd call that progress.

Also, I use a minimum of five measurements and specs and four different math formulas to determine correct geometry. There is no guessing involved.

You wouldn't necessarily have to buy one of my kits. I'm always looking for unbiased independant shops to test, and possibly be a dealer for my products, but it sounds like that wouldn't be of interest to you. And that's ok, I've already seen the positive results firsthand and I wouldn't have invested a lot of my own money to manufacture them if I didn't feel they were worth it.

Mike Beachel

I didn't write the rules of math nor create the laws of physics, I am just bound by them.