TOPIC:

4 in the top 6. Wonder Boy, and, Mr. Attitude fell off. The Savage Pampas strikes again.

On to Austin.

Yes, was not a good day for HRC: as an unbiased fan you expect the GOAT and Vinales to be up there every week, but interesting to see how the season is developing.
Was pleased for Zarco - pretty sure he is the real deal.
Looking forward to the Circuit of the Americas

And, Wonder Boy's brother fell off in the Moto2 race as well. Looks like it runs in the family.

So what kind of rev's are they pulling on those RC213V's to get to 180 KW's of power? That's 240 Hp/litre. Ouch !! And we're barely getting 100 Hp.liter on the KZ13's. Too bad we didn;t have a 71mm bore with a 62mm stroke and 4 valves a cylinder to work with.

Organization has an 18,800 RPM LIMIT, has for years. It is NOT hard to make 300 + horsepower, problem is, getting it stuck to the ground, especially when we run these things as speedboats.

The ONLY reason I would do a 4 valve head is to better fill the combustion chambers. Most people have NO idea on how a head works, nor ports, they go bonkers when some flow hero genius posts AIR flow numbers well past the Twilight Zone, then spin around lie a Whirling Dervish, when the whole mess has made it impossible to get the air/fuel mix into the right areas.

If we look at car heads, and yes, they are relevant to what we have, case in point, Buick Nail Head. Very nice inlet port, goes upwards. Intake valves in those heads have a "tulip" at their seat areas. Most genius head guru's grind that tulip right off, "to increase air flow into the chamber". Well, two things wrong with that, heads do not flow ONLY AIR, they wet flow a fuel/air mixture into the chamber. Wet flow is considerably different than dry air flow, in that dry air changes direction faster than wet flow mixtures.

The other thing the head destroyers are completely off the end of, that tulip actually turns the mixture up and aims it into the correct areas of the chamber, so, when it is whacked off, in the name of "ain't we great, we increased the living daylights out of the wrong kind of flow, but, we aimed it so badly, it don't run better at all".

Then, think about all this.....some head porters will cut, test, cut, test, cut, test, then finish their hacking.....at the last flow test, the one they LOST flow efficiency at, Congratulations, you have that "last grind after the best reading" port job.

It has gotten considerably better within the Japanese manufacturers, and Ducati, well, not so much Ducati, only because some of us cross worked at the different places as riders moved about, but, the design software for all this stuff is so well done, we can see the after effects on the computer, before a porting tool ever hits precious aluminum.


some of us have moved, and are now back to the good places we were years ago. Honda, Yamaha....then Ducati, and back to Yamaha (thank heaven, and the stars). Not even being a former World Champion, or, three (Rossi, Hayden, Lorenzo), can make a silk purse out of an Italian sow's ear, when the people behind the machines refuse to listen.

Good old harry weslake started all that off on his singles i think the early 70,s
your dead write of course regarding every one being an expert on that issue, what i have found over the years is different engine configurations valve arrangements can often need a differing line of thought when it comes to porting, valve shape, piston shape.
just increasing by half volume the airbox on a Ducati 996 can make a difference in performance, the 2 valves get a lot more punch driving out of corners mid revs if you D shape the exhaust, i have no experience in weather or not that would work on 4 valves
longer valve overlap made good headways around 94 i think in increasing combustion performance, something Ducati was well into back then
a crowed in Perth did a test on a standard CBR954 ? think it was, trying every different after market muffler on a Dyno
only 2 improved the performance above the standard, the rest was equal or lowerd HP. yet all are sold by company's who advertise as strap on performance.
when i was building my one off with Brook Henry(ex Vee Two) a lot of stuff i had learnt when racing 4/stroke multi,s was completely obsolete and had no place in Vee Twin design.
but the understanding of how the pump(engine ) works changes over time as does our understanding of history.
its all swings and roundabouts with engines and their builders some one will make headway with a issue that eventually everyone else will cotton onto, then they other guy will try something different the others all catch onto
also remembering more HP does not always equate to a higher speed at the rear wheel
eg the big bang NSR500 we tapped it at Suzuka to work that out, Hondas oval piston NSR500, and 5 cyllinder, Yamaha,s cross plan crank, kawasaki inline twin, Ducatis Desmodromic valve system, that they neither was the first to invent or use.
give it a few more years and everything we are at now with 4/strokes will be irrelevant! it will all end up electric Sad to say
formulae one has already seen the light and have a E series running
enjoy it all while you can guys while it lasts
Dion

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