Posted on Saturday, January 26, 2002 - 07:49 am:

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Jose: So they've actually tested a hopped up M2 engine with special intake/exahust and it passed the 80 dBc test? Did you just prove my point or what?

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Posted on Saturday, January 26, 2002 - 08:05 am:

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Ever hear of a "silent chain"? Many moto manufacturers use them for their cam drives. Swapping the primary's roller chain for a silent chain would go a LONG way to reducing mechanical noise, as would embedding oil passages in strategic places (try ringing a tuning fork that's immersed in oil). Really, it ain't so tough as you are making it out to be.

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Posted on Saturday, January 26, 2002 - 08:08 am:

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g9: Did you consider water-cooling the Blast engine?

Yeah. Absolutely. We considered it. But at the core physics level, it doesn't make as much sense. Because when you want to get rid of heat...the bigger the difference in temperature between two things, the faster the transfer of heat. Say you've got an engine that's gonna run at 180 degrees Centigrade, and you're running 100 degree water, you only have an 80 degree "delta t" (difference in temp) to get rid of heat. So you're gonna have to circulate tons of water past it to get that transition. Then when you've got that water heated up, now you take it out, you stick it in a radiator, and you expose it to 25 degree air. Again you don't have any delta t. Well if you run that 25 degree air right past your 180 degree cylinder, you're gonna get rid of more heat.

You know, during WW II they were building a lot of tank engines. They had battles going on in the desert. And they had water-cooling versus air-cooling back then. And they dropped all water-cooleds. Because you cannot get rid of the heat. They all went to air-cooled engines - the U.S., the Germans, everybody. An air-cooled engine gets rid of heat better when the temperature's high - a lot better. It's actually why the Volkswagen...became such a successful product - that, and the Citroen 2CV. That was air-cooled. That was the first car to cross the Sahara Desert - cause it was air-cooled! Nothing had ever been able to make it before.

Now, like you ran into, probably your timing's a little off or something like that, you get detonation. It's not an air-cooled situation, it's a matter of the timing's wrong. But you'd probably get that in your water-cooled and just wouldn't've heard it because of the water jacket....

The only thing we can't compete with as well is sound deadening - but man, from every other standpoint there's an advantage.

So we really couldn't find a reason to make it water-cooled. Everything said, make it air-cooled. Now, maybe under optimum situations, you design an engine for racing, to work at a certain temperature, to get the peak efficiency out of it, yeah...but for all-around-use engines? Air-cooleds are wonderful.

g9: Won't water-cooling and fuel injection eventually be needed to meet emissions limits?

The air-cooled engine seems to be fine. Again, the emissions tests are a true measure of what everyday life is like, the way the governments have set them up, so they measure start-up and all these kind of things...to get the vaporization of fuel to get clean burn, you need a warm combustion chamber. Particularly in cold start...we were gonna build a bike that people were gonna use for transportation, for jumping around the city. We expect a lot of short trips, and in fact most motorcycle use is for a lot of short trips. Air-cooled engines heat up almost instantly. Whereas in a water-cooled engine you've got to heat all that water up before the temperature stabilizes. The big deal is, the fuel dumps into the cylinder, is it truly vaporized yet or not - and oh by the way, I've got a choke on, so I'm dumping in extra fuel. An air-cooled motor just kills water-cooleds in the first bag of the three-bag test. The first bag is the start-up bag.

That bike right there, the Blast...our average emissions, and I'm just taking an average number - if you just take hydrocarbons, CO (carbon monoxide), and NOx (nitrogen oxides), the three key ingredients, averaged together, we're under 30% of the California standard. Less than 30%.

We'll probably do water-cooling, cause some customers want it, and there may be some advantages; but, to have to do it across the board? It's gonna be a long time before that has to happen.

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Posted on Saturday, January 26, 2002 - 10:18 pm:

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What dyno curves are avilable on this puppy?

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