My take on the oiling system crossover tube for the small block
As you can tell I'm a rookie but next attempt I will be using a 9/32 bit or smaller to start the hole straight.
Then I will step up a size.
Take it slow, double and triple check.
I also bought a few grinding stones to smooth the surface at the hole entrance so I can have an easier time starting the drill.
Just gonna de-bur it a little.
I flat out was in a hurry and went straight to the 5/16" bit which is taking out a lot of meat all at once.
My bad.
As Duane said very well, we started the hole straight into the bearing web surface to get a small 'divot' started not more than about .100" deep, and then with
light pressure, slowly angled the drill to the correct angle to match the passage. And we stopped and looked every very short distance as we got each hole started, like every 1/8" of depth, to make sure the drill was following the hole. If it gets off early on, the process is toast and you aren't going to get it back on track.
We were successful with this technique with the 5/16" drill but you may well do better with the smaller drill first. Know that in some materials, a
small hole size increase can be a problem as the drill will tend to grab and jump. Try this on the trashed block first; drill a 1" deep hole with the 9/32" drill and the try following on with the 5/16" drill to see how it behaves.
Pull out frequently to allow the chips to clear from the area near the drill's cutting edges; this will greatly lower the drilling pressure needed. And, IIRC we drilled pretty much dry for cast iron; I think we put in a few drop of kerosene or ATF to help keep the shaft of the drill rotating smoothly. And low drill speed! It has to be at least a few hundred RPM or so to prevent chattering and 'grabbing' in the iron so 400-500 seems to be good.
Hope it all works out 100%! We're all pullin' for ya!
