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Re[2]: U20 head oil plug

To: "ROADSTER" <datsun-roadsters@autox.team.net>,
Subject: Re[2]: U20 head oil plug
From: Fred_Katz@ci.sf.ca.us
Date: Wed, 15 Sep 1999 11:54:46 -0700
Thanks for the input, I'm always running into things that the manual 
doesn't explain. I got responses direct to me. Whether the plug is in or 
not, the pressure is the same. That's why I was wondering whether a plug 
was needed or not. I found out from other folks that plugs were put in some 
late model U20 heads and shouldn't have been, and no thought was given to 
the fact that there's a chain tensioner dependent on oil from that galley. 
So, they had to drill a hole to allow oil to get to the tensioner. The plug 
is unnecessary, and I'm told, could allow debris to back up behind the tiny 
drilled hole and block oil flow to the tensioner.

The reason the pressure is the same, is that the drilled hole is no smaller 
than the hole going into the tensioner. The back of the tensioner (and 
gasket) block the oil galley hole. The net effect is that the pressure is 
dependent on the size of the hole in the tensioner, with or without the 
plug.

I recently rebuilt my oil pump, and spun it by hand to see if it works. There is
plenty of oil and oil pressure to take care of the cam, and the small amount 
going to the tensioner (because of the small tensioner hole) is not going to 
take away from the cam.

Fred - So.SF

>Subject: Re: U20 head oil plug
>Author:  "PATRICK P. CASTRONOVO" <slick@mohaveaz.com>
>Date:    9/15/99 9:29 AM
>
>I would think the small hole was there to oil the tensioner.  To leave the 
>plug out would do nothing for the tensioner, and would result in a lack of 
>oil pressure to your upper end, the cam.
     

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