M50 Stripped Cap
When rebuilding your own vanos it's very easy to strip out the stock piston cap as it's made from a soft metal and requires a special socket due to the very shallow hex machined into the top. We've seen this countless times and unfortunately this part is not available from BMW separately! Our solution was to redesign our own replacement cap that uses a much more durable securing method.
Pro tip - Use a heat gun to heat up the aluminum piston housing before attempting to loosen the cap. This will make it much easier to loosen the cap and can help prevent the hex from stripping.
If you've damaged your cap trying to remove it or you want to upgrade your existing cap while rebuilding your own vanos then we have the best (and likely the only) solution on the market.
Our caps are CNC machined from high strength steel (vs. the soft metal on the original) and installs with a special pin tool for installation so it's virtually impossible to damage the cap even after repeated removal/install cycles.
We sell the cap as a kit that includes the special tool required for installation, and when you are done you can send the tool back for a $40 refund.