Thanks for all the input, guys. I've been reading the information and considering the group wisdom and slowly getting my head wrapped around how this works. Forgive my slowness -- the VW engine is new to me. Heck, the tools are new to me. You guys have been working on these engines since before dirt was invented. You were probably the kids hanging out behind the auto shop smoking cigarettes while I was trying to keep from flunking English, watching Shrimpenstein on TV, and trying to feel up the neighborhood girls.
Here's what I've learned so far. Probably full of holes and assumptions and misunderstandings, so corrections and amplifications are invited.
This is certainly Engine 101 to most RAMVA-ites.
As I understand it, you plug up the existing exit hole in the oil pump. The oil has to have someplace to go, so a new pump cover with an exit opening is mounted. We're talking pressure, so the oil line needs good fittings and strong hose that won't blow off. AN type fittings seem to be accepted. Aircooled.net offers blue hose, Gene Berg provides braided stainless steel covered Teflon hose. Steel-braid-covered Neoprene is also used. The exit hose from the pump cover goes to a high-pressure screw-on filter which is mounted somewhere handy. With my foresight I'll probably mount it right where it makes getting to the #3 spark plug impossible.
New oil pumps are available, too, with their exits already blocked. I'm not certain why there are so many sizes and choice of materials (steel vs aluminum). Need to do more reading on this.
On single relief cases, the return (filtered) oil goes to a place on the engine case that has been drilled and tapped to take a similar fitting. This is done to an existing plug on the driver's side of the pulley. Gene Berg sells the tools, as do others, for this work. It does not seem to be too difficult, but the process of drilling and tapping with forced air providing positive pressure in the case to blow chips out looks all kind of messy and fraught with possible blunders. Berg sez, "It is possible to drill and tap the case together without getting any shavings in the case. To receive our exclusive copyrighted instruction at the time you buy a full flow kit from us request part number "INSD/T" and we will provide it for free." Otherwise, buy the instruction book -- fair enough.
For dual-relief cases, there is a second option: Aircooled has a "slick adapter" that provides return. You unscrew a big ol' plug under the engine case and screw in the adaptor.
But John writes, "the engine oil goes thru the oil cooler all the time. This results in slower warmup times, and we remind you to have your engine's thermostat and flaps operational and adjusted to get the engine temp up above 170 degrees [F, or 77C] as quickly as possible to reduce engine wear from oil that's too cool! This is not as good as the proper method of full-flow which is to drill and tap the case, but it is an option," and ". . .you should be aware that oil temp sensors in the rear relief plug are not able to be used."
"How the engine works" at
But, here in SoCal, when the Santa Ana winds are blowing hot, dry air off the inland valleys in September, and temperatures are over 100F (38C), and the Wonderbus is hauling kids down the highway, I can't help but wonder if I should expand my oil considerations by adding more than just a good filter system, but also a temp sender, and additional cooling -- done right.
So tapping that case seems to be the best way to go.