Cycle News - Archive Issues - 1970's

Cycle News 1976 04 27

Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles

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Political lifeline Life or death for the twO· stroke: -~ -~ Is the jury still out? There is still a huge logjam of misconception to be cleared up before we come face to face with Federal and Californi a emission standards on motorcycles. That happens in 1978, when a graduated 5-14 gmfkm EPA standard and a blanket 10 gmJkm C.A.R.B. 'Aaugh! What did I do to deserve this?' standard on hydrocarbon emissions will force nearly every two stroke over 175cc off the street/road environment. 1980 will be worse. What 's it all mean? The technicalities One gross misconception, harbored by many who should know better, is that the whole problem will go away if we somehow come up with a perfectly smokeless two stroke oil. That may have been true several years ago when uns ophisticated legislators were writing laws against smoking vehicles. No more. The ru le-wr it ers are technicians, n ot politicans, and we're in deeper tr ouble than m any in the "trade" imagine . What the rule m ak ers are zeroing in on is n o t s mok e but reactive hydro car bons (RH C). A h ydrocarbon is any su bstance based on mol ecu lar chains of hydr ogen an d carbon. That in cludes sugar, lube oil, tar, gaso line, coo king gas, parts o f your body, p lastic ru bber , coal, tree sap, lipstick and bo oze, among lots o f other t hings. A reactive hydrocarbo n (usually a gas) is an y t hing that co mbines with oxides of nitrogen (NO x) and ozone in the at mosphere in the presence of sunlight to form photochemical smog. Ideally, when you bum gasoline (a hydrocarbon) and a trace of oil (another hydrocarbon) in an engine, you'd like to get water, carbon dioxide, and lots of hea t as end products, because chemically, that's what's supposed to happen with complete combustion. The booger is that nobody's perfect, and combustion is never complete in a real-life engine. In fact, we deliberately contribute to this by using fuel-rich mixtures for cooling. So we wind up with a fuel-air mix that does n o t contain enough oxygen to burn every bit of fuel . Therefore, what comes out the exhaust is hydrogen-carbon rich; i.e ., carbon monoxide and unburned hydrocarbons in various forms. The foregoing applies to all engines. What makes the two stroke unique (and t he refore vulnerab le) is that for effective scave nging at speed, a high- performance tw o stroke ch uffs about 25 pe rcent of its fuel -air charge o u t the exha ust port unburned before th e p o rt clo ses on t he upstr o ke. The more radical the port ti ming, the more is los t, although resonant expansion chambers are designed with the intent of packing at leas t some of the fuel-air charge back in when the engine is "on the pipe." Com b in e this unburned charge with what comes o u t the exhaust port after firing, and you've got a regular devil'. mix 'of hydrocarbons (more different chemical co mpo unds than anybody has bothered to count) . Nearly all of these compounds are colorless gases; so me are odorless and so me are n o t. The po in t is, even a smokeless oil (co ming out as an other colo rless gas) whe n mi xed with all the rest, would still regis ter on governme nt testing apparatus as a po llutant an d t he engine wo uld regist er about t he same HC output as ever. It's to o late for smo keless oil. So far, these are the techniques that will reduce two stro ke hydrocarbon emissions. 1. Lengthen the stro ke, in effect, giving the fuel-air charge more opportunity to bum completely. (Yamaha has done just that in making the RD400 out of the RD350) . 2) Lower the exhaust port. The milder the timing, again ,the more time there is for complete combustion and the less charge is lost. 3) Lean the mixture. To keep temperatures below seizure level, the heat output per stroke has to be reduced (by reducing fuel-air-charge, lowering compression, etc.] resulting in a radically detuned engine that will stay together under learn-bum conditions. 4) Provide a be t ter-controlled mixture with fuel injection. Expensive. 5) After-treat the exhaust, with catalytic converters, air injectors, afterburners, or some combination. 6) You can cheat a bit by gearing su pe r-tall for the gov ern ment tests and offering smaller co untershaft sprockets under- t he-counter to customers. And t hat's it. Under ermssio n controls, look for th e surviving two strokes to be slower-turning, slightly less thirsty , and more expensive than their pre-control counterparts. Performance will suffer dramatically . Ride on old TI0 long-stroke Suzuki or one of the old Sears Allstate twins and you 11 get an idea of what th e Brave New World will be like. What about us racers? For t he first few years, GP road racin g, Class lie" dirt track , motocross, trials and desert co mpetition will feel little effect, assuming t ha t exemptions for o ff-ro ad , co m petiti on and exhibition m achin ery can be main taine d. But p roduction ro ad racing, w hich is already a zo o in much of the co u ntry (with too many race clu bs pus hin g too many diffe r ent versio ns of "productio n"), w ill be utter ch ao s. Wit h four strokes and de-n utted two stro kes rep lacing p resen t stree t models, it's t he older machinery that will be m ost co mpetitive. (We already see this as t he effect of stringent noise limits takes hold) . And so me associations limit "production" to machinery no more than three years old. It's going to make rule-fmagling the mass-participation sport of the 1980's. Whoopee. Woods/enduro riders are really going to hurt. Here in California, where everybody trucks his off-road bikes a hundred miles a weekend in a gashog van as a m atter of habit, we tend to forget how the rest of the world lives. But at Dayto na, watching hordes of mud-splattered Montesa King Scorpions running aro und the streets before; during and after the Alligator Enduro, the tru th was brought home. In the eas t and midwest, the typical woods ri der still rides to t he w oods o n a carefully tricked-out street legal enduro bike; an d most states in the area are pre tt y forgiving of what's legal. All that will en d for m asses of people and ' the dealers who serv ice th em. When faced with the p rospect of 1) doing the usual in th e local mud with an emission-controlled legal bike that weig hs 100 pounds more than his o ld one or 2) going fo r a pure off-reader and a' $5000 Califo rnia van instead of that one $ 1400 legal enduro he was considering trading up on; the woods . rider we know today will m ost likely chuck it all. Finally, as factories see less and tess to be gained by main tain ing special families o f racing engi nes that th ey 're not allowed to sell in any form to t he highway -travelling public, pure t wo stroke racing/offroad e quip men t is go ing to become prohib itively expe nsive or n on-exi st ent . It migh t ta ke ten years co m pletely, bu t it's to happen inevitable , wi th proposed government co ntrols. Fingers in the dike The point we 'r e trying to make is that th e controls themselves are not inevitab le or foreordained, although our ti me is getting shorter with each passing ra ce we ekend. On the Fe deral level , the Presiden t's Council o n Wage and Price Stability has blasted the EPA's proposed . standards; and the agency itself is reh ash ing the economic impact of its actio ns as a result. The AMA an d the MIC are both in the thick of itt. In California, SB1324 is in the hopper to severely curb the power of th e state 's Air Resources Board to create arbitrary emission standards. Russ San fo rd o f M.O .R.E. is on to p of this one and urging everybody's su pp ort. The Federal and California issu es are i nter-related beca use there . are polit ically ambitious in dividual s in bo th C.A. R. B. and EPA wh o are en gaged in a game of on e-upmanship to show h ow "tough" they can be ' on pollution. Motorcycle emission co n tr ols are a p awn in that gam e. All this m eans that y o u racers an d off-re ad ers need to ge t yo ur heads out ,f y our perso nal trips long en o ugh to unders tand wh at 's happening and react. Even if y ou neve r ra ce AMA , even if yo u never cast a vote or write a le tter, y ou'd better co nsi der t ossing a- few bucks in t he directio n of t h ose who are fighting y our political battles for yo u, to ensure that y ou st ill have a game to pl ay . Lane Campbell

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