Sunday, December 10, 2006

VW - Lubrication to the Right Side of the Engine

>I've taken my engine apart, (sniff) and noticed something I don't >understand. How does the right case half's lifters get lubrications? ...


Dear Mike (and the Group),

Pressurized oil reaches the right side of the engine via the #2 cam bearing web.

This is one of the weak links in the Type I design and part of the reason those nifty drop-in hydraulic lifters CB usta sell did not work -- the 'corner' lifters on the right side of the case were starved for oil. This is also why those nifty needle-bearing rocker-arms don't work as well as they should -- insufficient oil supply.

This is also why a lot of big-bore strokers last only a few minutes. In relieving the cam & #2 cam bearing web to clear the flanges of the stroker crank, the builder would often cut away a bit too much, causing a dramatic drop in oil pressure for the right-hand side of the engine.

Fortunately, it's pretty easy to fix :-)

See the #3 cam-bearing web? Notice the hole is NOT drilled all the way through?

On some crankcases (careful here, troops) you may be able to extend the oil passageway by drilling from the #3 cam bearing to the end of the valve lifter oil gallery, which must also be extended. This gives the right-hand side of the crankcase two sources of oil. But it doesn't work for all crankcase castings and there is a bit of tricky work involved even when there is enough metal for the drilling -- you have to get the angle just right or you've screwed the pooch.

You can make this modification work on an early crankcase... but you have to add a bit of metal down in the bottom of that hole you'll find just off the rear-ward end of the right-hand valve-lifter gallery. And anyone who can TIG down in the bottom of that hole deserves a Nobel. (BT, DT, got the Prize :-) (Hint: You can't use a regular torch.)

There are a couple of hi-tek tricks you can do to the heads to feed oil into a hollow rocker-shaft for the purpose of juicing needle rockers but it's not for the faint of heart. If you gotta turn eight grand for a couple of hours to get a champagne shampoo it might be worth looking into. Otherwise, stick with a properly applied coating of DFL-1 and clean oil.

-Bob Hoover

PS -- Opening up the right-hand crankcase half at the #1 cam-bearing web to the main oil gallery and ensuring 100% lubrication to the rockers (normal is only 8%) is the foundation of the so-called 'HVX' mods.

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