WKA's Pit Board presented by AMB i.t. - 06.23.2008 *** WKA Briggs & Stratton Animal Engine Tech 06.23.2008 -- Since the Briggs Animal engine was first introduced into WKA competition, it has been the Association's intent to keep...
WKA's Pit Board presented by AMB i.t. - 06.23.2008
WKA Briggs & Stratton Animal Engine Tech
06.23.2008 -- Since the Briggs Animal engine was first introduced into WKA competition, it has been the Association's intent to keep these engines as close to factory specifications and parts as possible.
Recent post-race technical inspections have revealed several areas where some creative engine builders have taking liberties with these specifications to achieve an unfair advantage for their customers. The purpose of this communication is to make our competitors and their engine builders aware of some of the areas we have discovered, how we plan to address them, and when any new specifications and procedures will be implemented.
1. Valve Springs: WKA Technical Manual Section 704.18 VALVE SPRINGS states: "Stock Briggs & Stratton valve springs and keepers are mandatory. Springs must remain unaltered as supplied by factory." WKA 4-cycle Technical Inspectors will be comparing competitors' springs to stock Briggs & Stratton springs. The competitors' springs must be identical in wire diameter, number of coils, and uncompressed height.
2. Valve Spring Retainers and Keepers: In addition to the rule stated above, WKA Technical Manual Section 704.19 VALVE SPRING RETAINERS states that the retainers must be, "Stock as from the factory." New specifications for keepers and retainers are being developed and will be announced shortly.
Because of the number of non-conforming valve train components in the field, the new tech procedures and specifications will begin effective December 26, 2008. And remember to check the Tech Updates for other changes that have already been announced for the Animal valve train and are effective December 26, 2008.
3. Carburetor: WKA Technical Manual Section 704.4 CARBURETOR states: "PZ Model 22 Carburetor only. Must be stock as from the factory except any parts that are inside the float bowl or that can be removed through the float bowl are non-tech items." Some of our competitors are removing the main nozzle through the float bowl and modifying it. This is a legal modification. However, when they replace the nozzle, they are moving the tip up as much higher into the venturi. This is not a legal modification. When reinstalled, the main nozzle must extend into the venturi as was intended from the factory.
4. Rings: WKA Technical Manual Section 704.35 RINGS states: "Three rings are MANDATORY. Compression, or top ring, chamfer or O must face up, and must remain as manufactured. Scraper Ring must be installed with inside chamfer down and O up. Stock oil ring must be installed as from factory. Rings must be self supporting in the cylinder bore of the engine being teched. Ends of ring must remain flat. Excessive end gapping of rings not allowed. Rings must conform to all listed factory specifications and be of stock configuration. Known, standards for piston/ring configurations are Briggs & Stratton factory approved parts. No machining of rings allowed. Exception; lapping and end gapping allowed. Rings must be in one piece when removed from block." The competitors' rings will be compared to stock Briggs & Stratton rings. They must meet the specifications above and be identical to the stock rings. The top ring must be a chrome ring. Technical inspection of the rings as described is in effect now.
The carburetor and ring provisions described above are currently being included in post race tech.
And a final note: The deviation from stock valve springs was based on an opinion offered in error by a WKA Technical Inspector at an event almost three years ago. It is critical that all competitors and engine builders understand that WKA Technical Inspectors do not have the authority to approve new or different parts from those described in the current Technical Manual and Tech Updates. The only exception is that a Race Director or Head Tech Inspector can approve a part for one event, but that part must be submitted to WKA for approval at future events. This procedure is described in the 2008 WKA Technical Manual Page 8, Section 117.2 FIELD APPROVAL OF PARTS.