So I knew that the problem with the oil tube interference with a rod bolt was a common problem. When I had my 8N engine apart I looked and sure enough a notch had been worn in the tube. Was not too bad and I put a hose clamp over it just in case it contacted again. Turns out that was a good idea.
I had carefully bent the tube a bit too make sure I had clearance, and I had measured the clearance to the pan but obviously not accurately enough.
After I got the engine back together I had a noticeable knock. Very hard to isolate, but I could feel it with a finger on the side of the block or if I grabbed the governor housing.
Hard to imagine that was just the tube hitting, but I removed the oil drain plug and while holding the pickup and cranking the motor I could feel a [u:4be182bccc]very slight [/u:4be182bccc]movement once per rotation.
Trimmed about 1/8" off the pickup shroud and it shifted down just enough to clear the rod bolt. Now smooth and quiet.
So, my point is if you bend the pickup to clear the rod bolt, just make absolutely certain that the pan does not push it back up to where it interferes.
I had carefully bent the tube a bit too make sure I had clearance, and I had measured the clearance to the pan but obviously not accurately enough.
After I got the engine back together I had a noticeable knock. Very hard to isolate, but I could feel it with a finger on the side of the block or if I grabbed the governor housing.
Hard to imagine that was just the tube hitting, but I removed the oil drain plug and while holding the pickup and cranking the motor I could feel a [u:4be182bccc]very slight [/u:4be182bccc]movement once per rotation.
Trimmed about 1/8" off the pickup shroud and it shifted down just enough to clear the rod bolt. Now smooth and quiet.
So, my point is if you bend the pickup to clear the rod bolt, just make absolutely certain that the pan does not push it back up to where it interferes.