- Hello, this is Davin Reckow with Hagerty,
and today, I'm gonna drill out the oil galleries
on a 389 Pontiac, and put in some pipe plugs.
What I have, I have the engine block
sitting up on a drill press,
and I'm gonna use the drill press
to tap out these two oil gallery holes.
You might say, why don't you just
put the factory plugs back in there?
Well, as you can see,
this motor's been rebuilt a couple times,
so it's not that this hole is wore out
and the plugs won't hold in there,
but a common upgrade is to tap these out,
and put a pipe plug in,
and never do this crimping function again,
and the pipe plug never moves, it seals up nice.
It's just a nice upgrade.
We're gonna start this project on the drill press,
but we're gonna finish it with hand tools.
Those hand tools are the tap,
the chamfer tool, which, we'll use,
actually, in the drill press,
a five-eighths wrench, which I'm gonna use
to drive the tap, a pair of dial calipers
to measure the depth of the cross hole
as it comes into here,
and then, last, the Allen driver to put our plug in.
Unlike a straight tap that has
a multitude of sizes and thread pitches,
tapered pipe taps are fairly limited
in your selections.
Here, I have approximately
a preexisting hole of about 552.
This is considered an eighth inch.
Obviously, too big.
Same thing for the quarter,
and then up to what I'm gonna use,
actually, is a three-eighths.
This is a half-inch here.
If this hole was a little bit too big for this tap,
then obviously, I would need to drill this out,
and then go to the half-inch pipe.
Now, there's a drill chart.
It'll tell you the exact dimension
that this hole needs to be for the pipe taps.
Here, it's starting the hole.
This is gonna be fine,
and I'm gonna verify that with my chart.
As you can see, I have this block
set up into a floor-standing drill press.
You could simply do this on the floor
with a hand t-bar and such,
but the drill press is a nice, stable way to do it.
I need to chamfer this back so,
when the tap starts, it has a nice, clean lead in
going into the hole.
I'm using Rapid Tap here around the edge of this hole.
Any time you're drilling,
depending on how much speeds and stuff like that,
but basically, to drill this through,
and make it a nice, clean chamfer
and not get a lot of chatter out of it,
you want to lubricate your tool that you're using.
Again, all I'm trying to do is clean up
the sharp edges from the punch marks.
It gives me enough lead in for my tap
to come in there cleanly and start.
Now, I only have a half-inch chuck on this drill press,
so I gotta be a little creative here
in how I'm gonna do this.
For starting purposes and such,
what I'm gonna do is actually use
a five-eighths 12-point socket.
Fits in here nice and tight.
With the adapter here that I have,
there's all kinds of ways to do this.
I'm gonna use the drill press
to modulate the speed.
Again, lube it up a lot.
Do not be cheap on the tap
'cause the last thing you want to do is break this off.
I got good lube up into the flutes,
cutting edges of the tap.
Again, what I'm going to do is,
I'm just gonna hold some pressure on it,
not a ton, but enough to keep up with the cutting,
and I'm just gonna toggle the on-off button.
Okay, that's as far as this is gonna get
by using the drill press,
but the key is, it's started.
Instead of trying to sit here and push into that,
and not getting a good cut starting off,
and then having it crooked and such,
in the drill press, it gives you a nice line,
a good, straight line into that hole.
Now, I'm gonna work the rest of it just by hand.
Like I said, I got a good start on it.
I'm gonna work it back and forth.
The idea is, you cut a little,
back it up, take the chips back out of your way.
You really feel the difference in the tap.
One thing you want to make sure is,
as you're tapping down, you don't put
your oil plug over the top of a cross feed,
or a feed to the main runner.
Here, I'm gonna shine a light from our main bearing.
It shows the oil path that I'm talking about
making sure we don't block.
We know the oil passage goes
from the front main up to your cross hole
that we're trying to block off.
What I'm gonna use is just a little piece of brake line
I can put up into the hole,
and this is just for some sanity.
I can measure down to that using calipers.
My guess was that it was about a half inch,
and I'm right, it's just a fuzz over half, 560.
We know that this cross hole comes into the main hole.
From the top deck down, that cross hole is 560.
Like I mentioned, you don't want this plug
to cover up the cross hole,
but knowing the thickness of this is only 413,
that gives me about 150 thousandths of clearance
if this surface is flush to this surface.
When it threads down in there,
if this is flush, and this is flush,
I know I'm not covering up that cross hole.
Quick note on pipe taps.
They are tapered, unlike a straight tap
or a straight thread that would be,
let's say, holding the mains down.
What that means is, as this fitting
is screwed into the thread,
there's a slight taper, and that taper
is what helps seal.
A normal thread is straight.
It doesn't create a seal,
but a pipe tap will create a seal.
For instance, if I measure the very top end of this,
which is how deep, it measures about 660.
The beginning of this is only at 640.
I got 20 thousandths of taper on this tap, roughly.
The point is, I need to run this tap
to right about that depth,
which is about half the depth
of the threaded portion, in order for this
to actually sit down deep enough.
If I'm not deep enough, it'll sit here.
Until I get way up here,
that's where I gotta be, to where it sits flush.
When you're using a tap, the key is patience,
just like when you're drilling,
patience with the drill bit.
Let the tool do the work.
If you overwork the tool, it'll break off,
and that comes into a whole nother repair issue.
Now, obviously, I'm gonna clean the motor very well
before I assemble it, so the chips
down in the oil path, at this point in time,
is not a big deal.
I gave that an extra half a turn,
make sure it was deep enough.
There.
It's just a fuzz above proud, it's fine.
It's not gonna go anywhere.
I'm not worried about covering up the cross hole.
My tap may have went across the face of that cross hole,
but that's not gonna affect oil flow.
We're gonna clean this block up spick and span,
get all the chips out it, get all the oil out of it,
and then it'll be ready for assembly.
Thanks for watching today.
Hopefully, you found it informative.
If you got any questions, leave them
in the comments section below.