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SC Intake Modifications & Porting How-To

The 1989-1995 SC Intake is called a single plane intake which allows
for higher RPM air flow. A few changes to this intake will prove to be
valuable when building a engine for 4,000 rpm - 6,500 rpm use. All 1989-1995
SC intakes are interchangeable.

To begin all SC intakes have incorporated inside the intake an Air
Divider or Air Splitter in the shape of a Triangle which splits the incoming
air and directs it to either side. This Air Divider was incorporated to
assist in lower RPM air movement. The Air Splitter takes up about 4sq inches
of intake volume. The Air Splitter is non structural part of the intake
which means removing it will not affect the intakes structural integrity.

Removing the lower intake splash plate. Carefully remove the rivets
from the intake. After the rivets are removed you will be able to see the
three round casting marks where the machining will occur. Any machine shop
should be able to mill the air divider out.

After the machinging of the Air Divider is completed a replacement
piece of aluminum must be welded back over the opening caused by the machining.

Reinstall the steel splash plate afterwards using the rivets.

Next area is the Intake opening which the Plenum bolts to. Here we
will gasket match the opening and increase the radius for better air flow.

Before you begin porting a few areas will be identified. First is
the right side opening of the intake plenum which blocks air from the #3
cylinder. Alot of material can be removed to improve the air flow to that
cylinder. Using the same technique for both sides. This will provide much
better air flow to the intake ports.

The easiest way to remove the material is with a long carbide tip
porting bit. Coming in from the intake port you can remove the material
much easier.

Pictured below is porting on the left side of the Intake Plenum port.
Move the corner back to provide better air flow to the #6 port.

Next we will do gasket matching to all the intake ports.

After all porting is done and the intake is cleaned up and ready
to be installed I have a few tips.

The first is the intake bolts are no longer available from Ford.
The intake bolts usually show signs of electrolysis and begin to thin around
the head of the bolt. I recommend replacing the bolts before installing
the intake. The OEM bolts are M8 x 55mm x1.25 pitch 9.8 grade bolts. Replacement
bolts can be purchased from McMaster Carr
these bolts are M8 x 55mm x 1.25 pitch Grade 10.9 bolts yellow zinc . I suggest adding
a USS 1/4" grade 8 yellow zinc washer to the bolt and some locktite to
the threads. The USS 1/4" washer fits tightly over the M8 bolt and will
provide better torque. The 1/4" washer part number is 98026A029 sold in
lot of 100 only. Part number 95327A581 is 10.9 grade for about $12 per
box of 25 bolts.

Another tip is replacement of the front and rear seals. If your Intake
Upper Gasket set came with cork instead of the OEM installed black rubber
gasket which is no longer available from Ford. Another alternative is these
molded front and rear seals from Ford. They are used on the 3.8L Winstar
and work very well on the SC intake.

MN12 Performance Inc

[email protected]
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