I've started the Hoover mods to the case, lifters and rockers. If you've never read through Bob Hoover's blogs, you might want to take a look. Brilliant work and observations from a guy who converted VW type 1 engines for aircraft use in Alaska. Here's a link to the HVX "Hoover mod" oiling post: https://bobhooversblog.blogspo...007/05/hvx-mods.html
Lots of folks have taken the mods and clarified things, created video instructions, etc, but I enjoyed going to the original source and getting a feel for the guy who came up with them. He passed away from cancer in 2010 and the last 18 months worth of blog posts have updates on his fight with the disease in addition to a wide ranging set of observations on how to build engines and planes that won't kill you. An amazing guy.
In any event, my 12" long 7/32" drill bit arrived and I slowly and carefully extended the right side cam oil gallery and then did the treacherous plunge drill down to intersect the new gallery extension without breaching either the internal or external case walls (phew!). Not hard at all, just a little nerve racking. One absolute key is to go slow and frequently pull the drill back to clear the magnesium dust and chips so they don't think about igniting. I did not use any cooling liquid, I just was very patient. The bonus was a big pile of magnesium dust and chips that made a serious fire display when ignited outside with a propane torch.
Next I'll be finishing up the various case, lifters and rocker arm tweeks that allow the new oil gallery to cool and lube the right head adequately. Then drilling and taping for the replacement NPT gallery plugs and a thorough cleaning of the oil galleries and other engine parts before the final air blow out and securing the new gallery plugs. There's a great link for gallery plug steps and comments on the #4 bearing restriction plug question (many different opinions on how to handle this plug that restricts the amount of oil that gets to the #4 bearing in an attempt to prevent oil leakage from the front pulley as the bearing wears). I'm inclined to drill a 3mm hole in a plug to limit the oil flow even though the #4 bearing itself has only a 2mm hole. @ALB, I saw you commenting on this 15 years ago on samba or shoptalkforums, any thoughts these days? Also any thoughts about best approach for rockers and rocker shafts mods to take advantage of the new oil flow?
Here the gallery plug link I thought brought a lot of info together: https://www.shoptalkforums.com...hp?f=34&t=132558
You'll see a little discussion about whether Bugpack or EMPI plug kits are better. I think this is now moot since the Bugpack plugs are also now EMPI labeled and appear to come in the same sizes. General wisdom seems to favor aluminum plugs secured with Loktite blue.
Mike