RULE 55 – SPORTSMAN ENTRY (SE) CLASS SE (Sportsman Entry) is an entry level class intended to promote a fun, affordable class with a maximum speed of 85 mph using only GM or Ford cast iron small block and cast iron heads derived from passenger or truck model vehicles sold in North America (on road vehicles only), and abiding by inboard runabout and safety rules.
55.1 General Rules 55.1.1 A prop shaft release is recommended but not required until Jan. 2016.
55.1.2 Maximum speed of 85 mph is allowed.
126.96.36.199 Starts may be either clock start or flag start. For flag start lane selection shall be by draw.
188.8.131.52 A GPS may be run in a heat of racing to determine speeds that may require the use of a restrictor plate.
184.108.40.206 Because this is a speed limited class, there shall be no competition or kilo records kept.
55.1.3 Minimum length of an SE hull is 16 feet.
55.1.4 Minimum width of a SE hull is 72 inches.
55.1.5 Hulls under these minimums which competed in an older racing class are to be grandfathered. Contact the Class Chairman for confirmation.
55.1.6 Minimum weight, including driver and safety equipment shall be 1850 pounds weighed immediately after a heat of racing, after draining the hull of water.
55.1.7 If a hull with a safety capsule participates, it must start and race from the outside.
55.1.8 SE boats are to run with only two-bladed propellers.
55.2 Hull Configuration
55.2.1 The hull must conform to the flatbottom hull requirements as specified in the Technical Manual for the Inspection of Racing Runabouts. Non-current hulls which do not conform to these specifications may be exempted by petition to the Class Chairman.
55.2.2 All fins shall be mounted between the chines on the underside of the hull.
55.3.1 General Notes
220.127.116.11 No titanium engine parts are allowed. 55.3.2 Block Assembly. Any GM cast iron small block or Ford cast iron Windsor small block engine block designed for general automotive or truck use may be used.
55.3.3 Bore and Stroke.. Maximum Bore x Stroke is 4.065” x 3.500”
55.3.4 Crankshaft. Any aftermarket crankshaft may be used.
18.104.22.168 Only flat top pistons with valve relief(s) are permitted.
22.214.171.124 Any aftermarket pistons may be used..
55.3.6 Connecting Rods. Any aftermarket steel connecting rods may be used.
55.3.7 Cylinder Heads. 126.96.36.199 Only stock GM or Ford Windsor cylinder heads with in-line valves.may be used.
188.8.131.52 No porting, polishing, or grinding is permitted in ports or combustion chambers.
184.108.40.206 Heads shall have a maximum intake runner volume of 170 cc
220.127.116.11 Combustion chamber volume using compressed gaskets and deck height shall meet the following values:
Compressed Gasket and Deck Height in Inches
Minimum Volume in cc’s 0.100” 56 cc (GM 305 Head only)
55.3.8 Camshaft and Valve Train
18.104.22.168.1 Only flat tappet camshaft and lifters may be used. 22.214.171.124.2 Either hydraulic or mechanical lifters with a maximum diameter of 0.843” for GM or 0.876" for Ford may be used. 126.96.36.199.3 Maximum lift, measured at the valve, shall not exceed 0.450” (lift is to be inspected @zero lash)..
188.8.131.52 Timing Chain. Use of any chain set or gear drive of dual idler design only is permitted.
184.108.40.206 Valves. 220.127.116.11.1 All steel or stainless steel valves with a minimum valve stem diameter of 11/32” with a minimum 0.340/0.341 stem diameter 18.104.22.168.2 Maximum diameter of intake valve is 1.945” for GM .GM 305 heads and Ford heads 1.845". 22.214.171.124.3 Maximum diameter of exhaust valve is 1.505” for GM and 1.545" for Ford.
126.96.36.199 Valve Springs. Valve springs shall have a maximum diameter of 1.260” for GM and 1.445" for Ford.. 188.8.131.52 Rocker Arms. 184.108.40.206.1 Roller type rocker arms with a maximum ratio of 1.52 for GM or 1.60 for Ford may be used.(Lift at cam x 1.5 for GM or 1.60 for Fords helps determine legal rocker ratios) may be used. 220.127.116.11.2 Studs and/or guide plates with 5/16” pushrods may be used. 18.104.22.168 Adjusting Nut.. Any adjusting nut, posi loc, strut girdle may be used. No shaft type rocker assy
55.3.9 Intake System
22.214.171.124 Intake Manifold.
126.96.36.199.1 Any production style as cast/as produced iron or aluminum intake manifold may be used
188.8.131.52.2 Sheetmetal or tunnel ram style intake manifolds are expressly prohibited.
184.108.40.206 Other Intake System
220.127.116.11.1 A carburetor spacer is required; it shall have a minimum thickness of 0.500” (including gaskets) and a maximum thickness of 2.25” (including gaskets. The spacer may be wedge shaped, if desired, providing it fits within the above envelope. A restrictor plate, if required, shall be in addition to this thickness.
18.104.22.168.2 The intake manifold may be matched or blended to the carburetor spacer.
22.214.171.124.3 Use of any intake scoop, velocity stack, and/or air cleaner is permitted.
55.3.10 Fuel System
126.96.36.199.1 Carburetor is to be a Holley #4776. Only the following dimensions are to be inspected.
188.8.131.52.2 Maximum venturi diameters:
Primary/Secondary = 1.265”/1.3275”
184.108.40.206.3 Maximum throttle plate bore is 1.5675”
220.127.116.11 Fuel and Fuel System
18.104.22.168.1 Any pump gas may be used, including E85. See Rule 40.18.12
22.214.171.124.2 Any fuel pump is permitted
126.96.36.199 Ignition system may be either points-type system or HEI system
188.8.131.52 Electronic ignition systems are not permitted. Pertronix distributor points conversions may be used.
184.108.40.206 Any plug wires may be used. 220.127.116.11 Firing order is to be 18436572 for GM and 13726548 for Ford.
18.104.22.168 Any manifold or steel header with a collecter of the standard straight style may be used
22.214.171.124 No multi-step or 180 degree systems may be used, single step permitted.
55.3.13 Lubrication System.
126.96.36.199 A wet sump system with the oil pump mounted in the stock location is required.
188.8.131.52 Any oil pan is permitted
184.108.40.206 Accusump systems are permitted
55.3.14 Other Specifications
220.127.116.11.Any gasket may be used.
18.104.22.168 Vacuum pumps are not allowed.
22.214.171.124 Use of a heavy duty/SFI flexplate or aluminum flywheel is recommended.
55.4 Class Chairman.
55.4.1 The Class Chairman is Paul Grichar. He may be contacted at [email protected]
55.4.2 Vice Chair is Dave Weber who may be contacted at [email protected]
55.4.3 The class shall be directed by the Class Chairman and Vice-Chairman through 31 October 2016.
55.4.4 Rule change proposals for this class shall be submitted to the Class Chairman.