2 questions

[60sRacer]

Just for looks, I put aluminum washers on all 6 of the cam cover bolts. With a highly polished aluminum casting and chromed bolts, the rough die-cut of the washers just looked low grade. Been like this for 20 years with no other problems.

On the half-moon washers (they are there to permit line boring of the cam journals) - they are rubber (not silicone) and do harden with age and exposure to air (especially the ozone of local smog) and heat, so should be replaced occasionally. When new they are slightly proud of the mating surface and themselves crush to form a nice seal.

I've never had a problem with the half-moon's sealing, except when one fell out unnoticed during a valve adjustment. That was messy! The real leak problem is the hardening of the cam cover gasket, and it slipping out of place. I use a gasket sealant to fasten the gasket to ONE side (the valve cover) of the installation, moderately tighten it in place clean and dry while the sealant hardens. Keeping it stuck to the cover makes it easy to scrape off when needing replacement.

Robert

[Alfacliff]

the origional post is about a newer Alfa, with vvt. it would have the two bolts in front.
cliff

[the_sicilian]

guys ive installed and been running the blue-silicone revision for those rear valvecover plugs. theyre a bit odd in installation in that they totally overlap the sides of the rear wall, but have worked flawlessly. even under Mobil1 synthetic (i like to clean out the engine every year with a round of 15w50 synthetic ) theres no leakage down the rear at all. definitely highly recommend them. (maybe because its one of the few times im satisfied with IAP)