Why yes , I did. LOL

 

one of our founding fathers wrote that "the government should be afraid of the people"

it is time to restore the fear to our government

scott

 

Mini DOES have a 4 tiered ownership....
MINI ONE....not sold in north america...
just-a
S
JCW.

 

i still ride my 1974 bmw r60/6, my very first new vehicle ... it also has over 120,000 miles on it

both of my bikes have been in all 48 of the lower states, mexico and canada

scott

 

I meant with changing engine displacement. Not just having one like they do now.

 

http://www.autoguide.com/auto-news/2...injection.html
One possibility is that different 3-cylinder engines will be used in different models, with varying displacements. A model like the standard Cooper would get a 1.3-liter, while the Cooper S a larger 1.5-liter.

 

Never said they did. You can have 1 liter V12's or 10 liter singles. But, in general, there is a "sweet spot" with respect to cylinder displacement around 400-600cc per cylinder for gas engines that most engines tend to gravitate to. It's the reason you see engines go to six-cyls around 2.6L and eight-cyls around 4.0L. You can certainly build a 2.0L triple but giving it acceptable running characteristics and having it rev high enough to make decent power is difficult, and at this displacement, a 4-cyl is typically a better compromise.

In the case of the huge Triumph 3-cyl you mention, that's in a motorcycle cruiser application where huge lumpy engines are desirable. By most conventional measures (specific power output, vibration characteristics, driveability, etc.) its actually a pretty crappy engine, but it is unique and the bike sells because of it. As well, Triumph's signature engine is a triple, so they tend to try and use it everywhere.

Again, the move to triples is not because they're "better" overall than a four per se. They're just a better engineering compromise as we continue the trend towards making more power from smaller displacement engines. They're becoming a better overall choice with respect to cost of production, packaging, fuel efficiency, etc. in the displacement range of 1.0-1.5L compared to a four.

- Mark

 

I have never heard the 500cc rule before. The sweetest V8's were 5.0 Chevys and Fords. Jag 6's of 3.8 and 4.2 were great. The sweetest Twins I ever raced were 350cc's. None of these fit the category. As for Triumphs Rocket III, The two that I have ridden were smooth as silk. Nothing like a Harley or other cruiser.

 

We're talking about cost-effective engine configurations in modern mass-produced automobiles, not nostalgic waxing about what engines we've liked in motorcycles and antique cars. I have a 1000cc CBX six-cylinder (167cc per cylinder) which is a wonderful, charismatic, intoxicating powerplant for a bike, but that's got nothing to do with BMW putting triples in the next generation of smog-controlled, cost-contained, fuel-efficiency-is-everything automobiles.

- Mark

 

No, it doesn't. It does have a lot to do with your 500cc rule though. I was just wondering where that came from?

 

wow... you're pretty misinformed

one would argue most modern engine technologies were born of, or refined in, WWI and WWII warplane engines, but that would be for another post... "modern" direct injection for instance

motorcycle engine technology has its own merits but does not "lead the way" in engine design, and definitely not in engine management design.

the technologies you quote, hemi/multivalve/dohc, ohv, did not come from motorcycles at all. if you still want to persist, please find some sources. don't just compare your motorcycle knowledge to an old school pushrod V-8 and assume automobile engine design never progressed until the magic motorcycle came along.

 

the reasoning was what the original poster said. Mister honda wanted to prove he could make a 4stroke race against 2 strokes, and in order to do so he would need to increase the RPM's since, amongst other issues, he's missing a power stroke vs 2 strokes.

lighter reciprocating weight was everything. when you're asking a piston to switch directions that many times per second it needs to be light weight. you can achieve that by making the cylinders and pistons smaller, and increasing the number of cylinders to still get the displacement needed.

horsepower and torque are more related than you think. your gutless bikes had no low end torque but once the engine was spinning faster they were making more "work" with the available torque and thus HP came up by increasing the RPM's.

 

Boy this keeps getting better.

 

Here is a good article from MotorTrend
America's Low-Displacement Engines

A Look at Everything with the Displacement of a Cola Bottle - or Less



Read more: http://www.motortrend.com/features/c...#ixzz2HuOvJmZD
http://www.motortrend.com/features/c...s/viewall.html

 

It's not a rule, but the centroid of what piston displacements tend towards when engine designers weigh all the tradeoffs. Going bigger than 700cc or so results in engines with non-optimal combustion chambers, low rev ceilings, heavy crankshafts, and vibration issues that require more/bigger balance shafts to get acceptable vibration characteristics. Going smaller than 350cc or so results in engines that are costly and less fuel efficient. Most of today's engines are in that sweet spot of 400-600 cc per piston.

You can note that there are essentially no single cylinder motorcycles produced bigger than 700cc or so. (Suzuki had a 800cc briefly.)

A lot has to do with the physics of combustion - it takes a certain amount of time for a flame front to progress across a combustion chamber, and big pistons are more challenging from a detonation standpoint.

- Mark

 

All of this is true, except that lower reciprocating weight isn't everything and neither is higher horsepower from ever higher revs. If Honda's designs for 250's were superior to the much lower reving 2 strokes, they would have won more races, after all's said and done a four stroke doing 20k rpm's is doing more power strokes than a two stoke doing 8K.

 

which is why large displacement motors work better with longer strokes.

 

Aircraft piston engines technology never has translated well to cars. Their design parameters are very different. Look up "prop law".
I was wrong about the first hemi, 4 valve being a 1921 British Bike engine, apparently it's older than that, I will look up my book on Motorcycle technology in the aft. for your references. :-)


HISTORY: Multi-valve engines started life in 1912 on a Peugeot GP racing car. It was then briefly used by the pre-war Bentley and Bugatti . However, mass production on road cars came as late as 1970 - Triumph Donomite Sprint (1973), Chevrolet Cosworth Vega (1975), Lotus Esprit (1976), Abarth (1976) and BMW (1979) were the earliest adopters.

 

I guess you should of posted the rest of the facts like "Hemispherical cylinder heads have been used since at least 1901;[2] they were used by the Belgian car maker Pipe in 1905[3] and the 1907 Fiat 130 HP Grand Prix racer.[4]"

 

Yes, modern government mandates by publicly elected officials, they are shrinking the historically giant European DNA cars to nothing...

 

 

Everywhere I look on line I get a different set of "facts". My original comments were from an old set of Motorcycle books from the 1960's. Regardless of the origins and history, I still see no reason why a Three cylinder modern engine will be necessarily a guaranteed drawback.

 

Let's see what happens after it is out.

 

How about the 1908 Simplex racer that used a 10 liter 4-cylinder, 610 cubic-inch engine with large 5.75-inch diameter pistons and 55hp. WOW.