10049801-Super Duty four port special aluminum cyl. head:
This version of Pontiac's Super Duty four 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 head's rocker cover rails are raised .300" and the exhaust ports are raised .600". The valv 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" exhaust valves. 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.:
10045437-Aluminum cylinder head
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, lightweight head gives you Pontiac and NASCAR quality with plenty of extra metal, and proven performance with totally redesigned, super free-flowing ports. Oversize ductile iron seats and phosphorus bronze guides are standard. Intake volume is 178cc. This head accepts standard four-cylinder intake port centerline manifolds.:
347056-Four Cylnder Performance Head:
This cast-iron performance head is designed to be used on 151ci or 153ci 4 cylinder engines.:
10031322-Cast-Iron head W/O EGR:
10031323-Cast-Iron head with EGR:
10093306-Cast Iron Super Duty Block
Pontiac Motorsports' four cylinderSuper Duty block is cast specially formulated grey iron with a tensile strength of over 47,000 psi. This premium material strengthens the casting and improves ring seal. The Super Duty block has rough-bored 3.750" diameter cylinders; the walls are siamesed to optimize coolant flow around the bores. The cylinder barrels are lengthened to accomodate long-stroke crankshafts. The two-bolt main bearing caps are installed with 1/2-13NC Grade eight bolts; the reinforced head bolt bosses are also tapped for 1/2" fasteners. This block has provisions for left or right-hand starter motors.:
TECHNICAL NOTE: This block uses five needle roller camshaft bearings. Bearings and camshafts are availible from aftermarket manufacturers.:
The picture above shows the comparison between the exhaust side of the SD-4 aluminum high port head(top). The SD-4 early iron head. The stock Fiero head and a stock Citation head.
The above picture shows a comparison of the intake side of four heads. The stock Citation Head(top), then the stock Fiero head. Under those is the early iron SD-4 head and the aluminum high port SD-4 head(bottom).
The above picture is a comparison of the combustion chambers of the stock Fiero head(top). And the early iron SD-4 head(middle) and the aluminum SD-4 high port head.