| 00347056 |
Pontiac 4 Cylinder performance cast-iron head, designed to be used on 151ci or 153ci engines. |
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| 10045437 |
Pontiac 4 Cylinder 2.5 Special Head for Super Duty Four. This 2.5 special aluminum cylinder head is a
race winning design for the four-cylinder Pontiac aluminum “Super Duty” that’s proven itself in IMSA road racing and
Competition Eliminator Series. This rugged, light weight head gives you Pontiac and NASCAR quality with plenty of
extra metal, and proven performance with totally redesigned, super-free flowing ports. Oversized ductile iron seats and
phosphorus bronze guides are standard. Intake volume is 178cc. This head accepts standard four-cylinder intake port
centerline manifolds. |
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| 10049801 |
Pontiac 4 cylinder Super Duty Aluminum. This version of Pontiac’s Super Duty four-cylinder aluminum cylinder head’s
are designed for maximum-effort competition engines. The intake runners and water jackets are raised .670” to improve
flow. In the Special High Port casting, the two center intake ports are moved .800” closer together to straighten the
path to the valves. Both heads’ rocker cover rails are raised .300”, and the exhaust ports are raised .600”. The valve
centerlines are relocated to unshroud the valves, and the rocker stud holes are moved to match the new valve
locations. The valve seats will accept 1.94-2.08” intake valves and 1.60-1.625” exhausts. The combustion chamber
volume is 67cc.
Technical Notes: Valve guides are supplied but not installed. A template is provided for redrilling headers to fit
the revised exhaust flange bolt pattern. An intake manifold must be fabricated to fit the High Port Special’s port
spacing. |
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| 10048649 |
60° V6 Aluminum Head. Production “Generation II” V6/60° transverse-mounted engines have aluminum cylinder heads with
splayed intake and exhaust valves. This canted valve design enhances cylinder breathing by unshrouding the valves at
maximum lift. The high-velocity intake runners and heart-shaped combustion chambers promote swirl in the cylinders for
efficient combustion. Spark plugs are centrally located in the chambers.
Technical Notes: Aluminum cylinder heads are recommended for Midget racing classes and other applications where
lightweight engines are preferred. Aluminum V6/60° heads are machined for 1.72” diameter intake valves and 1.42”
exhaust valves. |
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| 10134359 |
90° V6 18° Aluminum Head. This new family of aluminum cylinder heads for competition Chevrolet small-block 90° V6
engines offer a significant improvement over conventional Chevrolet designs. They feature an 18° valve angle vs. the
older 23° angle design with 43cc chambers. They also feature relocated valve centerlines, shallow combustion chambers,
centrally located spark plugs and high-flow exhaust ports. All heads with date codes of 9-1-97 have .080” added to the
head face for 9.1:1 compression ratio. The relocation of valve centerlines (.275” toward the intake manifold)
minimizes shrouding at high lift. It also allows the installation of larger valves (up to 2.20” dia. intake valves in
some applications). These changes produce a substantial improvement in total airflow potential. Raised intake runners
maintain the runner/port relationship with the revised 18° valve angle. This low-port version has excellent flow at
low valve lifts due to their tall short-side radiuses and deep valve bowls. The shallow wedge-shaped combustion
chambers allow builders to achieve high compression ratios with small piston domes. Spark plugs are .350” closer to
the center bore than previous designs which improves flame travel across the chamber and reduces spark advance
requirements. High-flow exhaust ports are .450” higher and .240” wider at exhaust manifold flange than previously.
This minimizes turbulence in the runner and provides a smooth transition from the valve bowl to the header pipe for
increased exhaust flow.
Technical Notes: These heads are recommended for maximum effort competition engines. They are sold without valve
seats and valve guides. Valves with .300” longer-than-stock stems are recommended for low-port V6/90° 180 heads;
.400” longer -than -stock valves are recommended for high-port 18° heads. Aftermarket shaft-mounted rocker-arm
assemblies and pushrods are required. Piston domes and valve pockets must be matched to the revised combustion chamber
design. Aftermarket head bolts with small diameter heads are recommended to provide wrench clearance with large
diameter valve springs. A two-piece Bow-Tie cross-ram intake manifold (P/N 10051125-6) is recommended for Chevrolet
V6/90° engines equipped with the 180 cylinder heads that require a four-barrel intake. |
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| 10134394 |
90° V6 Splayed Valve Bow Tie Cylinder Head. The splayed-valve Bow Tie cylinder head with 45cc chambers represents a
radical change from conventional V6/90° cylinder head designs. GM engineers adopted the big-block Chevrolet V8’s
free-breathing valve layout to the Chevrolet V6. The intake and exhaust valve are inclined in two axis relative to
the cylinder bore centerline. This compound valve angle moves the valve head away from the cylinder wall as the valve
opens. This design minimizes valve shrouding and promotes airflow at high lift.
Technical Notes: This cylinder head uses rocker arm mounting bar P/N 10134395, intake manifold gasket P/N 10185004
and rocker cover gasket P/N 10185008. Also required are aftermarket manifolds, valvetrain components and build your
own valve covers. |
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| 10218168 |
60° V6 Gen III Cylinder Head. These Gen III cylinder heads are used on late model V6/60° engines for improved
performance. They feature an increase of 0.040” in intake valve diameter and a reshaped port for a flow improvement
of 16.7% at 0.450” of valve lift. The exhaust port has been reshaped into a “D” port configuration for a flow
improvement of 31.7% at 0.450” of valve lift. |
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| 12480009 |
90° V6 18° Aluminum Cylinder Head, NASCAR. This 18° aluminum cylinder head is identical to P/N 10134359 except for
the new design intake port for the NASCAR Daytona Dash Series. This head will have casting P/N 12480009. |
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| 24502523 |
90° V6 18° Head, CNC Machined. These race-prepared aluminum heads are based on the familiar 18° Bow Tie V6/90°
casting P/N 10134359. Their intake runners, combustion chambers and exhaust ports are already modified for maximum
performance using CNC machinery. The 18° design offers improved airflow and more efficient combustion. The CNC
cylinder head’s port volumes and cross-sectional areas are configured for 4.5-liter (274ci) competition V6s with
4.100-inch and larger cylinder bores. New CNC porting programs were written specifically for the V6/90° cylinder head.
The V6 head’s intake runners differ significantly from small-block V8 versions in both size and position. The roofs of
the V6 head’s intake ports are 3 inches above the deck surface. This lower runner entrance (compared to a high-port V8
head) required a different treatment to maximize airflow. The recommended intake and exhaust valve diameters are
2.150” and 1.625”. Overall valve length should be 5.250” (.200-inch shorter than valves for high-port V8 heads). This
head casting has been updated to accommodate CNC porting techniques and to make it more “racer friendly.” Material was
added to the floors and roofs of the intake runners, and the water jackets were revised to increase the thickness of
the port walls. The head bolt holes adjacent to the intake ports’ “long walls” are drilled for 3/8” fasteners; stepped
head studs are available from aftermarket sources to fit the block’s 7/16” head bolt threads. The angle of the V6
head’s rocker cover rail was also changed from 17° to 14°. Bosses were added to the upper rail to reposition the
hold-down bolts for the rocker cover. This revision eliminates interference between the rocker cover and the rocker
arms for the two end cylinders. These heads are designed to use aftermarket shaft-mounted rocker arms. The intake
rockers for the end cylinders (1,2,5,6) should be offset .550”; rockers for the center cylinders (3,4) should be
offset .650”. Roller lifters with .150” offset are recommended to provide pushrod clearance. Three angle valve seats
are installed in the modified combustion chambers. Their 48cc chamber volume accommodates the 9.5:1 compression ratio
required in several racing series that use V6 engines. Intake valve seats are of ductile iron, 2.250” OD x .312” deep.
Exhaust valve seats are of beryllium-copper, 1.680” OD x .312” deep. Back angle is 12° intake / 25° exhaust. Overall
length is 5.250”. Valve guides are bronze, 11/32” ID. Valve springs are 1.550” diameter cups. Spark plugs have a
.0709” reach tapered seat, 5/8” hex (“S” series); 3/4” reach gasketed seat, 5/8” hex head (“C” series). Recommended
components are P/N 10051125 - Bow Tie intake manifold base; P/N 10051126 - Bow Tie intake manifold top; and
P/N 10134325 - intake manifold gasket.
Technical Notes: Use with rocker cover P/N 12480057 only, and rocker cover gasket P/N 24502557. |
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| 25500030 |
Buick V6 Stage II Aluminum Head. The aluminum Stage II cylinder head is a light alloy head with rectangular intake
ports and square exhaust ports. 100 valve angles, unfinished seats for 2.02” diameter intake valves and 1.60” exhaust
valves are installed. This uses 3/4” tapered seat spark plugs. Comes without valve guides installed.
Technical Notes: Stage II aluminum heads use the six bolt pattern found on Stage II blocks which require longer studs
and are available from aftermarket sources. Requires rocker cover P/N 25500122, rocker cover gasket P/N 25500175,
intake gasket P/N 25500173, exhaust gasket P/N 25500174, and intake P/N 25500029 or P/N 25500170. |
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