Turns out this is little more interesting than originally thought. I pulled
the GM factory manuals for Chevrolet trucks from 1957 to 1961 to see how the
rockers were oiled. Here is a concise summary -- I refer you to the shop
manuals for the gritty details (where there are great schematics and pics).
1957
Lubrication of the rocker assembly is supplied by a drilled passage from the
rear camshaft bearing to a pipe located under the pushrod cover to a fitting
at the top of the cylinder block. The oil then flows through a vertical
passage drilled in the cylinder block and head to the rocker mechanism oil
connector pipe between the two hollow rocker shafts. A bleeder hole in each
rocker and supply pipe supplies oil to the valve stems and push rods.
1958
For 1958, oil to the rockers is now supplied by passages from both the front
and rear cam bearings through a horizontal drilled passage in the block,
then vertically up through the block and head, and into the rockers. No
pipe is used for rocker oiling in 1958 (other than the rocker oil connector
from top of head to rocker shaft). There's a bold warning in the manual not
to install early 1957 tappets in a 1958 block as 1958 tappets have an
annulus around the tappet that allows passage of oil to the rocker assembly.
1959
This is the year full pressure oiling was introduced to the rocker assembly
as stated in the manual. A 1/16" orifice located in the cylinder block has
been drilled to 11/32" diameter to control flow. The over flow end of the
rocker oil connecter has been closed to sustain oil pressure in the rocker
shaft. The oil grove annulus in each rocker arm has been decreased in depth
and relocated.
1960
1960 is similar to 1959.
1961
This is a supplement manual to the 1960 manual and it states: "A new valve
rocker shaft support, with a 1/8" horizontal slot located on the side of the
shaft bore towards the rockers, is installed on the cylinder head at the
front and rear positions. This new valve rocker shaft support, along with a
newly designed soil connector tube, improves the durability of the valve
train." That's all it states.
Note that the 57 to 61 factory manuals make no mention of a hollow head
bolt, nor do they differentiate between 235s or 261s. Note also I have not
disseminated information on hydraulic lifters.
Hope this helps.
Allen in Seattle
'50 3100
'55 M38A1
----- Original Message -----
From: "Allen Jones" <jonesal@u.washington.edu>
To: "Rob J." <rjjmsj@earthlink.net>
Sent: Monday, February 11, 2002 9:00 AM
Subject: Re: [oletrucks] 235 oiling ?
> Rob,
>
> I'll grab the '58 truck manual, find a scanner tonight, and email what you
> need. If I remember correctly, the oiling is supplied through a special,
> hollow head bolt in the center of the head (supplied through the block
> casting), and a fitted pipe from the top of the head to the center of the
> rocker arm assembly (similar to my '61)...to be verified with the '58
truck
> manual. Did you notice one of these bolts on assembly? It would have a
> hollow core with an exit hole an inch or three from the top. Can be
plugged
> sometimes making it hard to notice. Note that head and block would need
to
> be of the similar vintage for this set up. You may want to verify the
year
> of your block (embossed above the starter).
>
> Also, I couldn't find your head casting number on any of my lists...?
>
> Allen in Seattle
>
> ----- Original Message -----
> From: "Rob J." <rjjmsj@earthlink.net>
> To: "_Oletrucks" <oletrucks@autox.team.net>
> Sent: Sunday, February 10, 2002 11:02 AM
> Subject: Re: [oletrucks] 235 oiling ?
>
>
> > Allen,
> >
> > The number on the head is 3837161. I was told it is a 58 engine. I
> > currently have the external line, but would like to get rid of that if
> > possible. What I need to know, is how the oiling was supposed to have
> been
> > done originally.
> >
> > Hope this is enough info, if not let me know.
> >
> > Rob
> > ----- Original Message -----
> > From: Allen Jones
> > To: Rob J. ; _Oletrucks
> > Sent: Sunday, February 10, 2002 10:19 AM
> > Subject: Re: [oletrucks] 235 oiling ?
> >
> >
> > Hi Rob,
> >
> > What year truck are you working on (or what year are striving for
> > originality) and what is the casting number of the head you have?
This
> > information will help to better answer your question.
> >
> > Allen in Seattle
> > '50 3100
> >
> > ----- Original Message -----
> > From: "Rob J." <rjjmsj@earthlink.net>
> > To: "_Oletrucks" <oletrucks@autox.team.net>
> > Sent: Saturday, February 09, 2002 6:22 PM
> > Subject: Re: [oletrucks] 235 oiling ?
> >
> >
> > > I think I may have given the wrong idea of what I need. I already
> have
> > the
> > > modified external line from the "T" fitting the oil pressure guage
is
> > hooked
> > > into...the line from there runs around the block to the other side
and
> > > enters mid block near the top to provide oil to the rockers. What I
> am
> > > wanting, is a picture of the setup that is supposed to be in place
> > behind
> > > the lifter cover. All I have behind mine, is the plugged point (the
> > picture
> > > I put the link to, has arrows to show what is going on and what is,
I
> > think,
> > > missing)...ie. no line whatsoever...and what I'd like to do, is to
try
> > to
> > > eliminate the external line and do it the way it was intended to be
> > done...
> > >
> > > A couple of others have also offered advise on how to do the
external
> > line,
> > > so you aren't the only one who misunderstood what I wanted....so I'm
> > sure
> > it
> > > is my fault for not describing better.
> > >
> > > Anyway, what I need, is information on the way the engine was
> originally
> > > intended to provide oil to the rockers (my belief, is there is
> supposed
> > to
> > > be some type of a feed line behind the lifters cover, and THAT is
what
> I
> > > need information on).
> > >
> > > Rob
> > > ----- Original Message -----
> > > From: Mike Baggese
> > > To: _Oletrucks ; Rob J.
> > > Sent: Saturday, February 09, 2002 5:41 PM
> > > Subject: Re: [oletrucks] 235 oiling ?
> > >
> > >
> > > Rob,
> > >
> > > My digi camera is a el-cheeeeepo, and my '59 is put away with
> > low-light
> > > conditions, so I won't be able to take a pic that'd be worth
> wasting
> > > bandwidth to send you.
> > >
> > > I can take a look at it tomorrow and explain the routing for
> > you...not
> > > too difficult as I recall, the input to the oil filter is tee'ed
off
> > with
> > > 3/16th? copper tubing and routed up with the fuel line in front of
> the
> > > head, around to the side of the head.
> > >
> > > I'll do a re-check tomorrow and let you know for sure...need to
> fire
> > the
> > > old beast up anyways.
> > >
> > >
> > > > [Original Message]
> > > > From: Rob J. <rjjmsj@earthlink.net>
> > > > To: _Oletrucks <oletrucks@autox.team.net>
> > > > Date: 2/9/02 8:55:44 AM
> > > > Subject: Re: [oletrucks] 235 oiling ?
> > > >
> > > > Any chance you (or anyone else), can send me a digital picture
of
> > the
> > > setup?
> > > > rjjmsj@earthlink.net
> > > > ----- Original Message -----
> > > > From: Mike Baggese
> > > > To: _Oletrucks ; _Old-chevy-truck ; Rob J.
> > > > Sent: Saturday, February 09, 2002 12:00 AM
> > > > Subject: RE: [oletrucks] 235 oiling ?
> > > >
> > > >
> > > > My understanding is that it was a "mechanic mod" at first.
Then
> > > later,
> > > > either the dealers or the factory did the work.
> > > >
> > > > I have it on my '59 235, but it's not been done on a '55 or
> '56
> > 235
> > > I
> > > > have in the barn.
> > > >
> > > >
> > > >
> > > > > [Original Message]
> > > > > From: Rob J. <rjjmsj@earthlink.net>
> > > > > To: _Old-chevy-truck <old-chevy-truck@onelist.com>;
_Oletrucks
> > > > <oletrucks@autox.team.net>
> > > > > Date: 2/9/02 7:58:40 AM
> > > > > Subject: [oletrucks] 235 oiling ?
> > > > >
> > > > > I seem to recall from a previous thread, that there is
> supposed
> > to
> > > be
> > > an
> > > > > oiling line behind the tappet cover. I finally had a reason
> to
> > > remove
> > > > my
> > > > > cover, and took a picture (see link below). What I don't
> > recall,
> > is
> > > > whether
> > > > > or not this line was present in ALL 235 engines regardless
of
> > > whether
> > > or
> > > > not
> > > > > they were solid or hydraulic, or maybe only present in those
> > with
> > > solid
> > > > > lifters, but not hydraulics (and vice versa), or maybe only
in
> > > certain
> > > > > years. In the picture, the green arrow points to a plug in
> what
> > I
> > > > suspect
> > > > > is an oil gallery going to the rocker arms, but in my case,
is
> > > plugged
> > > > off
> > > > > and not being used. I would think that somewhere in the
> yellow
> > > > highlighted
> > > > > area, should be another plug, but in my case, there is
> nothing,
> > ie.
> > > not
> > > > > holes that I can see. I have had to route an external oil
> line
> > from
> > > the
> > > > > rear of the block on the opposite side, around the back of
the
> > > block,
> > > > and
> > > > > plumb it into the rocker arm oiling setup at the green
arrow.
> > While
> > > > this
> > > > > end-around approach has worked and gets good oil to the
> rockers,
> > as
> > > long
> > > > as
> > > > > I have the engine down and being worked on, I thought that
> maybe
> > I
> > > could
> > > > fix
> > > > > the lack of the oil line behind the cover. If anyone knows
> what
> > > should
> > > > be
> > > > > there, and whether or not I could maybe tap a line in by
> > drilling
> > > into
> > > > the
> > > > > yellow area and tapping the hole for a fitting, or knows of
> > anyway
> > > to
> > > > get
> > > > > rid of the external oil line, I would appreciate discussing
> this
> > > with
> > > > you.
> > > > >
> > > > >
> http://groups.yahoo.com/group/old-chevy-truck/files/Image07a.jpg
> > > > > oletrucks is devoted to Chevy and GM trucks built between
1941
> > and
> > > 1959
> > > >
> > > >
> > > > --- Mike
> > > > --- passnb4u@earthlink.net
> > > > --- EarthLink: The #1 provider of the Real Internet.
> > > > oletrucks is devoted to Chevy and GM trucks built between 1941
> and
> > > 1959
> > > > oletrucks is devoted to Chevy and GM trucks built between 1941
and
> > 1959
> > >
> > >
> > > --- Mike
> > > --- passnb4u@earthlink.net
> > > --- EarthLink: The #1 provider of the Real Internet.
> > > oletrucks is devoted to Chevy and GM trucks built between 1941 and
> 1959
> > oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
|
