Raptor S/A Limited Considerations
Seeing one’s name in print, other than in the police report section for a traffic violation in a local newspaper, runs the risk of causing a fat head development problem. Upon experiencing this predicament, one may be able to better understand why politicians act they way they do at times. If you folks detect a similar attitude developing on this writers personality, please forward your objections A.S.A.P. to Hooked-up so an attitude adjustment secession may commence.
This month the question came up as to what and why do we run a S/A Limited engine in the R.C.C.C.A. cage kart series. Two years ago, before RCCCA, Briggs WKA stock engines were used. With pushing over 410 lbs around, the machine didn't perform much better than a fast rookie. This was like restrictor plate racing without a restrictor. We had problems keeping interest and entries fell off.
Last fall, Dave Turner built an experimental engine for Jeff Hosington. Tom Bell also built one on his own, and they proved to be the bang for the buck we were looking for. During the winter, Dyno Cams was contacted to came up with a 107 SS ground with a .290 max left. Griffith Specialties supplied a .750" bore S/A (stock appearing) Briggs carburetor. Other than the bore and throttle plate, WKA stock carb tech rules apply. Here is a carburetor for under $100 that actually works well right out of the box. Other modifications include high performance valve spring kits and adopting the Limited Modified tech on the head and deck pop-up. Stock length after market connecting rods was also permitted. Did you know Rix makes great rod and billet lifter sets? Check it out at http://www.rixkartengines.com. Better yet, order a bunch! Is this a sales pitch or what? This statement is probably due to the reality of the first paragraph being experienced.
Critics (folks sort of standing back with a wait and see what breaks attitude) said the carburetor would break and be a constant problem. Well, we do listen to advice, so every engine built included an over the shroud brace kit from A.P.S. We have experienced some very rough track conditions, almost like a plowed field at times. As of September not one carburetor has broken. They are easy to adjust and alcohol doesn't load the crankcase when pacing around for those long restarts.
Cross your fingers on this one, but not one engine has blown. They will top out around 8,000 RPM and produce about 11 HP. With performance being livened up quite a bit behind the wheel, very close, throw the blanket over, style racing has become commonplace. Entries are up and new folks joined the ranks as the season progressed. Through these efforts, a bulletproof engine that's easy to build, tune and gives great performance has been realized. Maybe the powers that be should take a look at this combination.
The junior class runs an unrestricted WKA stock engine. With the additional weight of the cage kart, the unrestricted rule has provided enough performance to make things interesting vs traditional junior power plants. Competition is close; entries have been up and with newcomers throughout the season. Parents seem to value the additional protection provided by the cage kart design.
Traveling as a group from track to track has promoted a family oriented atmosphere between karters in this series. Remembering back many years ago, one of the original objectives of major karting associations was to promote fun and enjoyment for the whole family. If something breaks, other competitors offer whatever assistance is necessary to correct the problem before the next heat race or feature begins. Folks being helped often beat the helper. Based on past experiences this is not as commonplace in karting today as it should be.
Next month we will take a whack at camshaft terms and attempt to discuss crossover, overlap, scavenging and how to check, tech, record and analyze for potential performance considerations. Your comments are welcome, good or bad, and thanks for listening. Rick at Rix.