I an getting a lot of valve noise in my newly built engine. Specs are: Mild cam, new GX head stainless 3 angle valves, 1625cc over bore, lightened flywheel, twin SU carbs, fully balanced engine. Otherwise all stock. Valves are adjusted to .010 per haynes manual. I wonder if I need to change the guides to bronze. Any suggestions welcomed!

The manufacturer of your cam may specify a different clearance spec. You might check with them for their recommendations. It has something to do with the ramp of the cam profile.

Another idea is to adjust the clearance with engine fully hot (14 thou).

Oh, and make sure there is drag on the feeler guage. A loose fit can cause tapping noise.

I'll give it a try this weekend. I wonder if it has to do with seat material. I didn't change the seats or guides when I got the new GX head. Valves are stainless as well. They might transmit sound differently than the stock valves. I know my stainless exhaust on my Cooper S is a lot noisier than the stock system. Not exhaust note but rattle type noise. I can deal with the noise as long as I know there is no damage being done. Oil is still clear as new so I don't figure theres pieces of engine floating around in there!