I guess I'm not the only one who flubs it up every once in a while. At least the initial run of engine went great with virtually no leaks. I did have a bolt on the oil pump cover that needed to be tightened. There was a small drip there after about 10 minutes, but that was a pump that I did not rebuild.

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com

did a similar thing about a week ago. using a small mains operated pistol drill I turned over the pump and was pleased to see a steady flow from the overflow tubes.
turned my attention to the pressure gauge, great 50 psi. where the heck was all that blue smoke coming from???
now I need a new drill !!
stuey  

I have done the same thing on several different brands of engine over the years.Messy,but not hardly fatal! As you say,its good to have visual evidence of oil pressure

This was so stupid late last night I just have to laugh at myself and fill you in...I came home last night about 9:30 pm - I don't usually have 14 hour days but in my line of work you have be flexible. When I walk out to the shop after changing clothes my wife quips, "I don't know how you do it." (referring to maintaining this "go-go-go" ethic on the car late at night and all)
When I get out to the shop my plan is to mount the distributor in the 292 that is on the stand, make sure the initial time is right, etc. Well if you have been following my blog then you know that I have thoroughly cleaned up that engine, put in a new gerotor oil pump, reinstalled the oil filter mount, new oil pan gasket, etc. So I keep telling myself, "Don't button this thing all up until you prim that pump and make sure we've got oil to the rockers." (you guys with Y blocks know the drill here) So I walk around the engine twice and make sure everything is ready going through a list in my mind about what gaskets I have installed and all of that. I got my cordless drill and 1/4" socket extension ready to turn that pump counterclockwise and get it all primed.   
I get it all connected, take a final look see, and hit the trigger. After about 10 seconds I feel the drill motor start to load up and I know that we've got oil in the pump! Yippee. So I turn the drill a little faster and think to myself, "Let's see what she's got!" Another 5 seconds and I here this ubiquitous "squirting" sound coming from the opposite of the engine and it takes another split second for me to say, "Jessup, you idiot!"
That's right, we had excellent oil pressure and she was throwing out an oil slick about 8 feet long OUT THE FITTING ON THE OIL GALLEY where I had an oil pressure gauge connected when the engine was in the car! 
I just looked at it, hung my head, and laughed a little and thought about what my wife said before I walked out. "Well, I know how I do it --- not too well!" I reckon I need a little more sleep at night. How did I miss that. At any rate, you can see that we have excellent oil pressure and oil to both sides so after a little cleanup on aisle 292 we are good to go.
Note to self - do a better job with your "button up list" before you throw your liquid through the motor!

Daniel Jessup

Lancaster, California

aka "The Hot Rod Reverend"
check out the 1955 Ford Fairlane build at www.hotrodreverend.com