Dual Port Series
“The patented Dual Port is our STREET PERFORMANCE/ECONOMY DESIGN. in the Mini’s, the primary section boosts the fuel mixture to nearly the “speed of sound”, about 3 times faster than normal velocity. This positively gives each cylinder a full fuel charge every time to smooth out the power stroke. When engine or driver demand cuts in the secondaries, a cold (over 30° colder) and dense mixture is sent down the secondary runner to be rammed into the combustion chamber by the sonic flow to the primary runner. This adds up to 15-30% more horsepower, quicker throttle response, extended RPM range, better gas mileage, Quicker starting, reduction to exhaust emissions.
The two barrel mini Dual Ports come standard (order “DP”) to accept the stock 2 stage carburetor. However, as an alternative, most can be drilled to accept the Holley 5200 series (order “DPH”) or the Weber 32/36 series (order “DPW”)”
“DPH” ACCESSORIES (HOLLEY 5200)
Some Mini Dual Ports (including Datsun. Toyota. Chevy Luv and Ford Courier), which have been drilled for the Holley 5200 carb will usually require a 1″ carb riser No. 6176 in order for the carb linkage to clear the manifold. Also available is a linkage accessory kit (No. 6230) for CABLE OPERATED
applications or CABLE CONVERSIONS when installing the “DPH” manifold. A Universal Foot Throttle Kit (No. 6244) completes the installation where a change of throttle linkage is desirable. The new Holley Datsun 5200 carbs also work very well with the Dual Port. In this case, order the “DPH” and substitute our No. 6176 in place of the Holley carb plates supplied with the carb. The linkage accessory kit is not necessary.
6176- 1″ Holley Carb Riser Recommended – See above
6230- Universal Cable Linkage Accessory Kit Recommended – See above
6232- 1″ Offset Riser (Used in place of No. 6176 on later Courier/ Mazda OHC Engines where cam cover is wider than cylinder head side surface)
6235- 1″ Offset Holley 5200 Carb Adapt. (Holley 5200 to stock DP base. Fits Courier, Datsun, Luv, Toyota, etc. with carb base measurement of 3-1 /8″ x 1-3/4 “. See Carb Conversion Chart on page 8.)
6244- Universal Foot Throttle Kit See above
“DPW” Accessories (Weber 32/36)
The Weber 32/36 will not usually require any accessories. A Weber riser plate (No. 6234) is included with the “DPW” to ensure
linkage clearance. Some minor linkage adjustments may be necessary and a Linkage Accessory Kit No. 6230 is available
6230- Universal Cable Linkage Accessory Kit. Available if cable conversion is necessary.
6232- 1″ Offset Riser (used in place of No. 6234 on late Courier/Mazda OHC engines where cam cover is wider than cylinder head side surface)
6234- Weber Riser Plate – Included with “DPW” Manifold (5/16″ for linkage clearance)
6236- 1″ Offset Weber 32/36 Carb Adapt. (Weber 32/36 to stock DP base. Fits Courier, Datsun, Luv, Toyota, etc. with carb base measurement of 3-1 /8″ x 1-3/4″. See Carb Conversion Chart on page 8.)
6244- Universal Foot Throttle Kit. Available if Cable Conversion is necessary.
EGR Valve Adapter
In order to meet Federal Emissions Standards, most 1973 and later vehicles use an EGR Valve to cut down emissions. This valve is bolted directly to the stock manifold on a special boss. Offenhauser engineers have been working on the problem of emissions tor some time and they attacked the EG R problem head-on. The result is a special adapter kit that can be used with ALL stock and high-performance manifolds. While some modifications are necessary on other brands of manifolds, all Offenhauser 3600, DUAL PORT 360°, Port-O-Sonic manifolds will be equipped at the factory with drilled and tapped holes to use the EG R Adapter Kit. Tests conducted at the Offenhauser plant as well as independent testing facilities have shown that the stock EGR valve will function as it is designed and that there is no change in engine operation when the stock EGR valve is installed according to directions, using the Offenhauser EGR Valve Adapter Kit.
1973-1975 Chevrolet LUV Using stock 2bbl only #6106