Really cool valve adjustment system Options

[mepstein]

Now snapgap.us is selling valve adjustment kits for VW/type 4 engines. Check out their products. Really cool stuff. I’m not affiliated in any way.

[djway]

What is the weight difference between the adjuster assembly versus the steel nut?

[SNAPGAP]

What is the weight difference between the adjuster assembly versus the steel nut?

The OEM jam nut weighs 2.7 g. The SNAPGAP collar, shim and cap head screw total 6.1 g. In developing SNAPGAP, I read a lot of articles about the impact of increased weight on valve train components. I am sure others with more knowledge than I can provide additional or more technical input. However, this is what I have taken away from my reading. Most of the articles concern the desire to reduce weight in valve train components in drag racing engines where a premium is placed on reducing moment of inertia on push rod engines where the rockers are directly opposed to gravity so as to achieve higher RPMs faster. Those engine builders are trying to balance the strength of components at 10,000 RPM vs. weight of rockers, valves and valve springs and push rod components vs. cost of titanium materials and so on. One article noted that at 5000 RPM additional valve train weight makes no meaningful difference.

I could not find any information on the 911 set up where the shaft mounted rocker arm ends are not directly fighting gravity.

In my personal experience driving my SC with and without SNAPGAP, I have not noticed any reduction in power or ramp up -- but I may be biased. Rather, my engine seems smooth, powerful and quiet -- no ticking.

I explored and had prototypes made of high strength aluminum (1/2 weight of steel) as an alternative to steel for the collars but at this point have concluded that because the expansion rate of aluminum is 2x that of steel, there is too much risk of the collar expanding and loosening around the adjustment screw. If I were convinced that eliminating the additional weight would make a meaningful difference, I would explore other lightweight materials such as Titanium -- but the cost may be prohibitive.

Hope that is useful information.

Brad