Re: [ihc] Re: 345 Oil drain holes clogged?

[Steven Stegmann <steve.stegmann@xxxxxxxxxxxxx>]

I noticed that when the heads are installed on the
block, the oil drain passages from the valve cover
area to the valley are *horizontal*.  They don't look
that way with the head sitting on the work bench. 
That's what causes so much oil to sit under the valve
covers, horizontal drain passages don't promote fast
drainback.  This pooling also increases the likellhood
of valve cover gasket leakage.

The valve guides are designed to let oil into them. 
Then with the IH "seals", which are really just
O-rings snapped onto the valve stem, you get the
famous puff on start up.  That's intentional, not a
problem.

Your problem might be rings.  Famous test for rings is
to find a nice long hill on the highway and coast down
with your foot off the gas at 60-70 mph for a long as
you can, then stomp the gas.  If you get a huge cloud
this way it is the rings.  Careful, I've had some
engines that would almost bury the car behind when I
did this.

Steve
--- Tom Mandera <tsm1@domain.elided> wrote:

> Jim Grammer wrote:
> 
> > Cleaning the drain back holes is somewhat
> complicated by the fact that head
> > bolts run through them :(
> > 
> > I've seen the edges of the holes rounded(Mandera),
> don't know if the actual
> > bore was increased. Tom?
> 
> I didn't take any steps to actually increase the
> holes, I just 
> "chamfered" the holes to promote better oil drain
> back.  If the holes 
> were increased, it wasn't my intent.
> 
> Of course, when you're rebuilding, you'll usually be
> smart enough to 
> change the oil regularly afterwards, and avoid the
> "12,000 miles beyond 
> needing an oil change" coked up goo you find, thanks
> to the PO.
> 
> On my 392, I chamfered the drainbacks, but also
> Glyptal painted the 
> valley so it would not retain oil (get it back to
> the pan faster), and 
> then polished the con-rods so they'd shed oil
> better, too.. all to get 
> the oil back into the pan ASAP, since the 392 lives
> at 3500rpm.