Hi Walter, how are you? I was thinking of giving you a call on this one, but this works just as well
I don't -think- Porsche published a tech bulletin about notching both sides of the connecting rods in 914-4 engines, it's a fact. VW came with a similar bulletin about 12 years later I think. I have the original Porsche bulletin in my archive (twice) but as you know it's somewhat hard to get to
The VW version of the bulletin also covers a change in P&C clearance and the elimination of the paper and alloy gaskets on the cylinders for all later model Baywindows and all type 4 powered Vanagons. I think they even came with a spacer to restore CR. The notches -three per conn. rod side- are needed for additional piston cooling, according to the bulletins of both Porsche and Volkswagen.
As far as the distributor drive and original mechanical fuel pump (which we are not using) are concerned: I am only saying that there -could/might- be problems in a dry sump set-up, lubrication problems obviously. I just don't believe that the addition of a dry sump pump and a tank is a complete and well thought out way of doing this, there must be more to the story. If no additional modifications are required then I would like to learn about that as well. There seem to be plenty of mods required in non VW engines that are converted to dry sump and we have very little room to do so (not easy to alter crank case dimensions, not easy to install additional oilers for pistons and cam lobes), but that does not automatically mean we can get away with it. One solution might be to modify the scavenge pick up so there will be more oil in the sump at all times.
The temperature difference between stock type 1 configuration VS Gene Berg additional sump, both running approx. same amount of oil, gave me higher temps in a few rough field tests, again, no accurate data, just an observation, this translates very easily to a dry sump set up, not a conclusion, just something to think about.
So far the only advantages of dry sumping I can think about is the constant supply of oil under -severe- driving conditions (if the tank is narrow/high enough), and the additional oil quantity. Assuming we will go for true full flow filtering and and external cooler, there are realy no other benefits (ok, windage issues perhaps, but that is of little importance in this case).
Overthinking the issue, yeah, you may be right on that one, but see, this is not a low budget project, it deserves the right attention and it is not my engine, I have to be more than just sure. This engine needs to be torquey, ultra reliable and will stay in that Bus pretty much forever, it's not a test bed.
Cheers,
Brian
www.karrera.net