Page 636 of High Performance Parts for American V-Twins 2008 by S&S Cycle

race components cylinder heads s&s® special application b1 cylinder heads for evolution® big twin engines 1986 03 sportster® models s&s special application b1 heads are intended for racing and radical street applications with high cfm requirements they are available for modified harley-davidson® evolution® big twin engines and 1986 03 sportster® models and are specifically designed for maximum structural integrity and heat dissipation for maximum versatility sa heads are available in three stages of completion unfinished semi-finished and fully machined due to the complex machining required to complete unfinished and semi-finished heads we recommend them only for professional engine builders with extensive machining capabilities fully machined sa heads require some finishing and final assembly all sa heads regardless of part number or options are shipped unassembled this allows the builder to finish them exactly as required special design features sa heads are cast from 356 aluminum alloy and heattreated to t6 specifications precise cnc machining insures dimensional accuracy the sa cylinder heads are designed for engines with a minimum cylinder bore of 4 and will accommodate cylinder bores up to 41/2 head bolt circles of 5.675 with 1/2 head bolts or 5.750 with 7/16 head bolts can be used s&s can match the industry s more common bolt patterns if requested at time of order other patterns can be machined if a print is provided head gasket surfaces feature sufficient material for machining to adjust compression ratio without compromising structural integrity both internal and external oil return passages are provided on finished sa heads heads include plugs for blocking off the external drains if not required the large sa intake port is located approximately .500 higher than stock which may cause interference problems with the top motor mount particularly in rubber-mount chassis the intake port utilizes a directional vane similar to the one used in the intake port of s&s super stock® heads the vane routes the incoming fuel-air mixture around the valve stem and guide to minimize turbulence and improve flow and cylinder fill with minimal finish porting of a fully machined sa head intake flow is typically 195 cfm at 10 water and 0.700 lift professional porting is recommended in order to achieve the full potential of these heads the unique design of the sa intake port requires the use of a special intake manifold and mounting hardware this manifold is not included in the head kit and must be ordered separately this manifold will be machined to customer specifications for manifold length and bore size port to port measurements must be supplied from mock-up or assembled engines see page 16-18 the exhaust port has also been relocated in sa heads requiring that a special exhaust system be fabricated to assist the builder exhaust pipe starter adapters are included with some fully machined head kits some builders weld pipes to the exhaust adapters while others attach them with heavy springs weld-on spring tabs for pipes are included with the adapters typical exhaust flow with minimal finish porting is 147 cfm at 10 water note sa cylinder heads add approximately .300 to engine height compared to stock heads causing interference problems in some chassis pushrods for engines with s&s sa cylinder heads must be .200 taller than they would be with stock heads but the pushrod cover keepers will be the same length as with stock heads note flow figures are based on measurements obtained with a superflow® 600 flow bench at the s&s research and development facility in viola wi 16-51 visit us at www.sscycle.com

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