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Re: More oil

Subject: Re: More oil
Date: Tue, 29 Jun 2004 23:26:33 EDT
In a message dated 6/26/2004 9:37:08 PM Eastern Daylight Time, writes:

Putting  in a freshly reground crank today I note that again, the rod journal 
supply holes are poorly aligned with the supply groove in the main  bearings 
I dutifully chamfer the holes to provide maximum  coverage.

I find your wording rather confusing, main, rod, etc... 
I think I know what you're trying to say, however.
Anyway, the way I remember it is the oil gets pumped into the block oil  
galleries. Amongst other destinations, they come to a hole in each main  
area which is aligned to the hole in each main bearing.  The  main bearings are 
fixed in location, the hole is always aligned.
The oil flows thru the hole in the main bearing and fills the continuous  
(360 degree)groove and what doesn't leak past the crank/bearing surface  
continues into the hole in the crank.  From there it goes to the adjacent  rod 
bearing(s) and lubricates that area.
I don't think there is any significance of BDC alignment, but I could be  
Enlarging/aligning the main bearing hole may be of help, but the flow  is 
limited by how much oil makes it by the main bearings to the sump and the rod  
bearings to the sump.  Maximizing the potential flow by  enlarging/aligning the 
holes is not a bad idea.
"cross drilling" the oil holes in the crank to enlarge these galleries is a  
method to increase flow to the rods.  Drilling the galleries in the block  
ditto.  (kinda like the external rocker feed to the head).
I haven't checked, but I would expect that the comp prep manuals deal  with 
Does this make any sence?


74 Spitfire, 71 Stag
"Reality... it's  not what you think"
Clark W. Nicholls 
_www.cwnicholls.com_ (  
fax: 419-844-7564  (yes, 419 provided free by
phone:  413-243-3433

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