Tools: center punch, wrench to turn tap, drill, 3/8 NPT tap, 37/64 tap bit, and a couple of smaller
bits to work your way up to.
Materials: 3/8 NPT heater hose fitting, Teflon
paste, WD40
The thought of drilling a hole into your engine
block if you have never done it before doesn't
sound that appealing eh? For the ultra paranoid you can practice drill and tapping on piece of scrap
aluminum first to get an idea of what it's
like. The block is actually pretty soft and easy to drill
into though and once you are done you'll be
suprised at how easy it ended up being.
Here you can see the boss (circular area to
the left of the front torque mount) that Nissan cast into
the block for the DET applications.
To get enough room down there to fit a drill you'll need to
pull the AIV, oil seperator, exh. manifold,
fans, radiator, and front mount. The oil pans need to be
dropped too so you can properly clean all
the shavings and make sure you know when to stop
drilling.
These are the main tools for performing the surgery.
Use a center punch to mark where you will drill
the pilot hole. Then drill with a bit half the size
of the bit used for the tapping hole.
I recommend a 3/8 NPT tap, it is big enough for your oil return
and if you were to screw up you can try a
1/2 NPT. When you drill be sure to lubricate the bit
with WD40. Be prepared for a ton of
fluffy shavings. MAKE SURE YOU MAINTAIN THE
PROPER DRILLING ANGLE! I didn't need
a right angle drill or attachment to get in there.
I had the shank on my final bit ground down
some for free at a machine shop and found a drill stubby
enough ($30 Skil @ Home Depot) to fit in there.
The picture below shows looking from under
the car with the oil pans removed and how
far you need to drill through, roughly 1.5 inches.
The hole as viewed from the inside. Note the paper stuffed around the crank to deflect the shavings.
Drill too far and you hit the crank girdle DOH!.
Here I am well into tapping threads into the
hole. Note the combination wrench
used to turn the tap. When you tap,
try and keep it angled properly in the hole,
it works its way in eventually. When
cutting threads, for every degree of rotation
CW, rotate it CCW half that amount to break
up the chips. As you get deeper it
will be harder to tap. You will need
to pull the tap out and clear out the shavings.
WD40 is used to lube while tapping and to
clean out the shavings. Five or so good
threads should be enough.
To finish off we have the fitting screwed into
the block. Use teflon paste to make sure the seal is tight.
Doublecheck by feel the internal side of the block is free of shavings.
Here I tapped my SE-R while changing out the rod bearings. No turbo but at least its tapped and
plugged if I decide to have two boosted SRs.
