| Author | Message | ||
     Trac95ker |
This is interesting. http://thekneeslider.com/archives/2007/07/12/desmo harley-italian-american-v-twin-completed/ | ||
| Djkaplan |
An interesting exercise, but the RPM capability of the top end is totally wasted on the that bottom end. | ||
| Ft_bstrd |
Nice machine work. | ||
| Spiderman |
Actually the rev limiting factor of any H-D has been the push-rod top end... | ||
| Djkaplan |
Look further ahead than just what's in front of you. "Actually the rev limiting factor of any H-D has been the push-rod top end..." So what's the limiting factor after that? | ||
| Anonymous |
Actually the rev limiting factor on most H-D's is the bottom end. Putting desmo valve train on is absurd functionally. Nice machining, cool conversation piece, but no performance value. With it's short stroke and large crankpin and bearings, the XBRR spins over 9000 rpm with valve springs. | ||
| M1combat |
"Actually the rev limiting factor of any H-D has been the push-rod top end..." Not so much. Maybe the big twins with their multi angled pushrods but the XL valve train isn't too bad. Sure those heads will move that limit up, but I think they'll run into the limits of the lower end before they'll run into the limits of those heads or original "type" of valve train. | ||
| Barker |
Somebody enlighten me. With modern springs/metals, why would any one need a desmo system? R6 does 17k rpm (+/- 1k) with valve springs. | ||
| Natexlh1000 |
I suppose the thing to do next would be to de-stroke it like in a XB9 engine? | ||
| Ducxl |
With modern springs/metals, why would any one need a desmo system? In MotoGP at least,the winningest bikes' have "positive valve" actuation.AKA Ducati Desmodromics and..i believe pneumatics. Valve springs generate harmonics up high...They float | ||
| Trac95ker |
I wouldn't say Ducati won Moto GP because of their engine, it was more like the tires. | ||
| Rocketman |
Unless we know the flow rates for a good flowed Buell / HD head, like say the XB heads, and the comparable flow rates for flowed Ducati air heads, we pretty much can't judge anything other than the piston speed as the limiting factor in either choice. Aren't I the smart arse, lol. Still, it does look different, and don't we Buellers praise 'Dare to be Different' anony? Or yet again do we lambaste something non Buell because this is a Buell forum? Sad. Rocket | ||
| Buellerandy |
You would've been a smart arse if you gave a metal analysis along with your piston speed theory  Which (piston speed) I would believe could be a limiting factor. Andy | ||
| Ulynut |
you'll need a pretty tall frame to fit that thing | ||
| Rocketman |
You would've been a smart arse if you gave a metal analysis..... Andy, can you name these two metals?   Rocket | ||
| Buellerandy |
well, seeing as how I'm by no means a rock jock, I'd think the first was pyrite (if thats even a form of ore/metal) and the 2nd being gold? Let me know my score. Other obvious possibilities being brass, but I'm sure you'll let me know how wrong I am | ||
| Guell |
top i have no idea, the bottom looks like a liver. | ||
| Diablobrian |
you're correct Andy. Iron pyrite and gold | ||
| Rocketman |
Let me know my score. Other obvious possibilities being brass, but I'm sure you'll let me know how wrong I am No actually, you're absolutely bang on right. Goodness knows how you managed it, but I can assume you're just as good a metal analysis as I am. Now about those piston speeds Andy. What were you saying.......................... Rocket | ||
| Buellerandy |
Hey Rocket, I was saying I could probably agree with the piston speed issue you were talking about. Did you feel I was being condescending? | ||
| Djkaplan |
I remember in the late 70's when all the moto-pundits sounded the death knell for demsmodromic valvetrains. The championship was tire strategy game, but it's the 21st century and a desmo engine scratched it's way to the top... with a reputation for big power, no less. | ||
| Mr_grumpy |
Personally I think it's time somebody took another look at the Wankel rotary engine. Material technology & electronic control systems have come on so much in the last few years, I'm sure somebody could do something with it. | ||
| Djkaplan |
Mazda is still in the Wankel engine business! | ||
| Mr_grumpy |
I've since found this. http://www.nova-racing.com/nova_gb/index.htm Looks like it could be fun, strapped into a lightweight frame. | ||
| Rocketman |
Not at all Andy. I thought you were enjoying the banter just as much as I.  Rocket | ||
| Mr_grumpy |
Rocket, I've told you before, stop playing with that phaser & give it back to that nice Mr Spock with the pointy ears, & Scotty has been looking for that ring everywhere, he can't put the dilithium crystals in without it! | ||
| Strato9r |
........so THAT is what you were doing, burning up your fuse up there, alone...(!) | ||
| Diablobrian |
48 hp from that little nova rotary. I assume at the "crank/output shaft" | ||
| Deadduck |
and there is this one, not quite a wankel http://www.regtech.com/ | ||
| Skully |
With modern springs/metals, why would any one need a desmo system? Horsepower is a function of, among other things, RPM and Ducati is spinning their MotoGP bike well past 19,000. I do not know what the limit of valve spring technology is. | ||
| Strato9r |
I really admire the fact that the guy did it at all. It sure looks cool, and now it's got me wondering what kind of wacky top end I could graft onto a set of Blast cases that I scored recently. Any crazy ideas, kiddies?! |
