Warning: Never rely on mathematical numbers for valve lift as they will not provide correct numbers (see "I promise" in the next paragraph). To do this properly you must install the rocker arms on one side first with 0.100" lash. Rotate the engine clockwise slowly by hand, watching to see when the first valve that opens gets close to full opening, being sure that it does not bottom on the retainer or go to coil bind and start to flex the pushrod. If OK, go back to the adjusting position and remove all lash. Repeat the process. If OK, screw the adjusting screw in one full extra turn (about 0.050") and repeat the rotation to full lift again. The valve retainer should have clearance to the guide and the springs should not be at coil bind. Now, be sure to check every valve and then do the other side. Never rely on just checking one valve. I promise that our rocker arms will provide the advertised ratio you order or more. Our rocker arm ratio is calculated from the lift of a stock camshaft on a stock genuine VW head. When lift is added at the cam it will increase the ratio of our ratio rocker arms higher than the advertised ratio. The reason is that we have designed the geometry correctly for the added ratio. This is accomplished by relocating the rocker and machining it in such a way as to accelerate the ratio. The more the cam lift increases the more the ratio increases the valve lift rather than decrease it like "all" of our competitor's ratio rockers do. Make sure you do not buy too high of a ratio for your application. Warning: People trying to use our rockers on "Aftermarket" heads such as ARPM, Dynosoar, Super Flow, Autocraft, Street Eliminator etc. be forewarned, you may end up with our 1.45 rockers lifting the equivalent of a 1.6 or more. I have even seen heads so far off that they have 1.5 on one end of the head and 1.71 on the other end of the same head, or 1.54 on one head and 1.65 on the other head. Do not blame our rockers if you get weird lift readings like this from your aftermarket heads. Aftermarket head castings often vary. From time to time customers have told us that one end of our rocker shaft will hit the casting and requires simple grinding on the head to clear. Note: Berg ratio rockers clear stock valve covers on stock VW heads, as well as with our GB 890 cover connection on Superflow heads. |