In preparation of final assembly of our race motor, I notice the oil hole in the bearing shell is considerably smaller than the oil feed hole. Is anybody enlarging the bearing hole, or do you want the increase in pressure at that point? If you do enlarge it, what is your technique? Thanks.
The main bearings. We've drilled out the main oil feeds as discussed here, but the feed hole is the bearing is considerably smaller. My concern is over oil distribution and the integrity of the bearing itself.
I would say no. The purpose of drilling the entire #1 feed hole is only to enlarge that portion which goes from the cam feed up to the main gallery of the lifter bank.
I Think Your Talking About All Of The Holes In The Main Saddles,there Is Some Documentation That Tells You To Drill These Holes To 23/64 But They Do Not Say Anything About The Bearing Holes Now Being Undersized, Good Question,now Do You Drill The Bearings To Match Or Not
I did, but I wouldn't call myself an expert on the subject. Seems that you wouldn't wan't to leave it small since you're trying to get as much oil to the mains and rods as you can, why would you leave a restriction? Oil for the rods comes from the mains. I've been wrong before, maybe one of the big dogs has something to say about this. Seems maybe if you were only oiling from the front you could leave the front ones small to save pressure for the back of the engine, but why not just run oil to the front and back since you did say this was a race engine. I used a dremel tool, be careful not to scratch the bearing surface. I also have an engine that I didn't do any thing to and it has worked unbelievably well.
thanks. That was my impression as well. My main concern becomes losing integrity in the bearing itself.
