Oil to the head comes through the rear main cam bearing. There is a hole at
the top and bottom of the bearing and there is a spiral groove in the rear cam
journal whose purpose apparently is to reduce the flow of oil to the head.
There is a hole in the head gasket to allow oil to flow though the pathway
from the cam bearing and into a corresponding hole in the head. Oil then comes
up through the rear rocker pedestal and down the shaft to the rockers etc. It
is a good idea when starting a new engine to make sure you see oil coming out
and lubing the top of the engine. I did this check and there is a long story
of what happened next that I wont bore you with again.
If this pathway is blocked it is easy to get great oil pressure and destroy
the rocker assembly in a few mins. Another good reason for lots of assembly
lube, it may be all that is protecting your engine for many seconds.
I don't know if it is possible to install the head gasket the wrong way around
to obscure that hole. If you have the block bored for spit cam bearings the
machinist needs to know to align the holes in the bearings with the holes in
the block.
I have a rocker arm that has been out of a car for years and it still has a
good coat of oil on it. The one in this picture looks like it is growing
barnacles and that as they say is a puzzlement.
Stan
-----Original Message-----
From: 6pack-bounces+stan.foster=hp.com@autox.team.net
[mailto:6pack-bounces+stan.foster=hp.com@autox.team.net] On Behalf Of Scott
Tilton
Sent: Monday, September 08, 2008 1:20 PM
To: Kendall Larsen
Cc: 6pack List
Subject: Re: [6pack] New Engine AUTOpsy
On Mon, Sep 8, 2008 at 5:46 AM, Kendall Larsen
<mailkendall@sbcglobal.net>wrote:
Here are some pathology pics of the damage. Cylinder 1 rod bearing spun.
http://picasaweb.google.com/kendalll/TR6Engine08#
Yeah - someone made a good point - the top end looks BONE DRY.
What's the reason for that?
was it somehow cleaned up before the picture was taken? (if so, I'd love to
know how)
Someone who knows more about the oiling paths than me might be able to
comment on whether or not it is possible that there are blockages in the
system that still allow for normal oil pressure readings even though little
/ no oil is getting out to where it needs to go.
Sorry to read / see your bad news.
Scott
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