about to drill....

[robertf03]

I just got my 401 back from the machine shop and am getting ready to assemble it.

So far all of the oil bypass writeups I've seen only show pictures, not exact measurements. I'll admit it, I'm timid as hell about drilling into my block. Do I need exact measurements, or is going by the picture and getting the hole "close enough" going to work?

This is the oil bypass going from the front of the block to the lifter oil gallery.

Thanks,
Robert

[tufcj]

The biggest thing is getting the new hole centered in the existing passage. Pull the plugs at both ends, eyeball carefully so you are centered. When you install the fittings, be sure that you don't screw them in too deep. If they're too deep, you partially block the passage and do more harm than good.

You really should have drilled before it went to the shop, that way their tank would have removed most of the shavings. You're going to create a lot of metal shavings, so take a lot of time to clean ALL of the oil passages, otherwise you'll just put metal thru your brand new bearings.

Bob
tufcj