Air-cooled horsepower. Ducati vs. BMW vs. Guzzi

[Travman]

BMW has a version of their twin the R1200 S that is rated at something like 122 hp (130 in their HP2 Sport).  Moto Guzzi's Griso engine is rated at 110 hp.   I think the latest 1100 Monster is rated at 95hp.  What is the difference?  I know the others have about 100 more cc's.  What else?  Is it the number of valves, 2V vs. 4V?  Even Buell's twin is rated at 103 hp.  I'm sure the Monster is lighter, but it would be nice to say Ducati has the most powerful production air-cooled twins. 

P.S.  I know these aren't real world from the rear wheel horsepower.  I simply used whatever the manufacturer claims. 

[woodyracing]

yeah 4V vs 2V is a major factor

[krolik]

Though its tubular steel perimiter frame lends it an unusual silhouette, the 2009 Griso's most distinctive feature is its new 8-valve, 90 degree twin engine. The transversely mounted powerplant boasts 563 new components, including new heads and pistons that help it achieve a compression ratio of 11.1:1. Horsepower has been boosted to 110 (at 7,500 rpm), and torque is 79.7 ft-lbs at 6,400 rpmâ€"pretty impressive for an air-cooled engine.

The new 1170cc engine descends from the big R1200GS update. The R1100S never got the 1150 engine and for this reason the R1200S is miles better than the old R1100S. The new horsepower has been achieved by extensive modifications to the cylinder heads in particular. R1200S also features new high load resistant conrods, modified camshafts, harder valve springs and new pistons. Compression rate is increased to a staggering 12.5:1 and is mainly responsible for the torqey feel despite of the high revving (8.800rpm) air/oil-cooled engine. Maximum torque is now 112Nm @ 6.800rpm. An engine like this can probably be tuned to around 135-140 bhp in race trim, so the 122bhp in the standard bike with air/oil cooling is pretty good. It feels good too, especially with full throttle opening the engine pulls like an ox from 7.000 rpm. It really is noticeable and evidence BMW has increased the rev ceiling to make the new R1200S as sporty as a Boxer can be. BMW has followed the US army motto; “Be all you can be”. R1200S is all that.

DUCATI MONSTER 1100   DUCATI MONSTER 1100 S
Type    L-Twin cylinder, 2 valve per cylinder Desmodromic, air cooled   
Displacement    1078cc   
Bore x Stroke     98x71.5mm / 98x71.5mm
Compression Ratio    10.7:1   
Power*    95  hp @ 7.500 rpm   
Torque*    75,9lb-ft @ 6.000 rpm   
Fuel Injection    Siemens electronic fuel injection, 45mm throttle body   

Well the Griso and the R1200 have 4 valve heads and higher compression ratios, thus more HP.  ALthough the Ducati 1100 engine is pretty close to the Griso in torque.

[Speeddog]

Moto Guzzi 1200 and BMW R1200 should make more torque than the Duc 1100, just because they're bigger, *and* due to the 4-valve heads.

Honestly, I'd much rather have the lighter weight of the Duc, if I had to choose.

[Triple J]

So why doesn't Ducati make their air-cooled engines 4-valvers?

[The Don]

So why doesn't Ducati make their air-cooled engines 4-valvers?

No idea, but do we really need four valve engines? what are the pro's and con's? I love the torquey feeling of my two valve.
Don

[woodyracing]

cooling would be an issue, if you look at the BMW and the Guzzi the heads are sticking out into open air.  A large capacity, high performance, 4Valve engine is going to run hotter.  With a Ducati L-twin configuration the cooling wouldn't be efficient enough.  It would have to be radically de-tuned to keep the temperature manageable (say, maybe two fewer valves per cylinder would do it!)

[wheezer]

They are probably concerned that increasing the HP in the air-cooled bikes would cannibalize sales of the more expensive (higher profit margin) liquid-cooled bikes.

Why spend the money to develop higher horsepower air-cooled motors when they have a perfectly good alternative sitting on the shelf? Don't get me wrong, I prefer simplicity and less cluttered appearance of the air-cooled motors ( I have an S2R1K), but it doesn't make sense from a business perspective.

Perhaps a case can be made now that there are no new liquid-cooled Monsters, but if the next Multistrada is truly moving to a 1098 engine then there is one less reason to do so.

[fastrt6dakota]

Let's at least compare apples to apples (or at least Washington Apples to Granny Smiths).

BMW HP2 Sport:
1170cc 4-Valve V-Twin (air-cooled)
133+hp
MSRP $25,375

Moto Guzzi Griso 1100:
1064cc 2-Valve V-Twin (air cooled)
88.1CV (Roughly 88hp)
MSRP: $13,490

Buell XB12R:
1203cc 2-Valve V-Twin (air/fan/oil-cooled)
103hp
MSRP: $9,999

Ducati Monster 1100
1100cc 2-Valve V-Twin (air/oil-cooled)
95hp
MSRP: $10,549

While the Ducati has the 2nd lowest HP rating, it also has the 2nd lowest MSRP of those bikes. It's also in a crowd that includes 2 "sport" class bikes, as opposed to "standards". If you want to include Ducati "sport" style bikes, let's include the upcoming bread winner.

Ducati Streetfighter
1098cc 4-Valve V-Twin (Liquid-cooled)
155hp
MSRP: $(est)$16,549

STILL lower priced than the BMW, with more power to boot.

You can't just assess motorcycles based on price, engine size, and power rating. There are lots of factors that make up the whole riding experience. Shaft driver vs chain, 90 degree twin vs 45 degree twin, standard vs sport... this list goes on.

Short of riding each one of them and making an objective observation, you'd be hard pressed to find the "better" bike based just on the tech specs and MSRP.

[Big Troubled Bear]

I think ducati claims that the 696 engine is the highest HP to capacity rating in it`s class ie. 2 cylinder, 2 valve aircooled engine

[vw151]

Given more money the ducati L-twin can make loads more power.  NCR has bikes powered by a disgustingly worked over 1000ds motor making 130hp at the crank but it's been fitted with high comp pistons and displacement has been  upped to 1080cc.  It also has titanium internals and lightened everything. Of course the engine work alone costs more than a typical air cooled ducati.  Hell, NCR's titanium exhaust is probably $5k or more.  Of course their bikes also weigh in under 300lbs in many cases.  Freaking sick.    It really is a matter of how serious they want to get about developing the motor.  My 1000ds was making 78 rwhp and is rated at 95hp at the crank.  Now it makes 88rwhp and all I did was add an exhaust, rapid bike and open air box.    The BMW HP2 comes with akrapovic exhaust and tune, forged pistons and 4 valve heads  plus bigger displacement.  Well.....  you get the picture.  there is a reason some of the bikes are much more expensive. In the case of the HP2, it pretty much comes pre-modified with all the cool bells in whistles you'd have to spend thousands on to get your ducati motor near it's spec.   I also agree, if there is a water cooled alternative why would they sell a similar horsepower air cooled motor that is probably less reliable to boot.    Couple that with the fact that ducatis are usually way lighter than BMWs and guzzis and the argument can continue. 

BTW,  check out this sweet pic of an HP2.  Those bikes are sick looking.



And here is a picture of a bad assed $120k NCR race bike powered by a 1080 kitted 1000ds making about 130hp.  If I remember right this bike weighs 299lbs. I think the titanium frame only weighs 11lbs.   HOLY SHIT!!!!

[Statler]

I think the weights of the actual motors would be interesting to see.

[mitt]

Also, I wouldn't exactly call the bmw R motor air cooled any more.  It is oil cooled, and it is a significant amount of oil, not just a splash.

mitt

[vw151]

Also, I wouldn't exactly call the bmw R motor air cooled any more.  It is oil cooled, and it is a significant amount of oil, not just a splash.

mitt

Sounds very porsche-911-esque.   It was "air cooled"  but took 9 quarts of oil and had an "oil cooler"  in the front of the car.    Hey, there is more than one way to skin a cat right. 

[Travman]

Thanks for the information guys.  It would be relevant to see how much each of the engines weigh.  The 1100 DS looks like it would weigth significantly less than the BMW, Guzzi, & Buell.

I do think it would be cool to see a 4V, higher compression, higher hp & torque, 1200cc version of the current engine (perferably with no drawbacks).  It will never happen, but I'd still like to see it.