TECHNICAL ANALYSIS: Ducati 1299 Panigale

Our European Editor dissects and analyzes the new Ducati 1299 Panigale engine.

2015 Ducati 1299 Panigale S studio side view

At the EICMA show last fall, one of the technical highlights for me was how Ducati extracted an extra 100cc of displacement from the Panigale V twin. While the supercharged Kawasaki H2 and H2Rs certainly were impressive, I believe Ducati's increase in displacement to 1299cc actually was a harder path toward more power. This was confirmed during a discussion I had with the young and brilliant Dr. Marco Sairu, who is the boss of Ducati's Engine Project Department Management. We were standing in front of a display showing internal parts of the new 1299cc "Monster Panigale."

Here, supported by the technical analysis of Dr. Sairu, I will detail the philosophical approach to the radical over-boring that has created the 1299 Panigale. I will start from the beginning, and I apologize if I return to concepts that I have already expressed in my previous story about the Ducati 1299 Panigale when it was unveiled at EICMA.

2015 Ducati 1299 Panigale S action shot

Over-boring an engine that already sports a very big bore is unusual. But in this case, it follows within the basic parameters of the whole Panigale project, in which the dimensions of the engine are tightly interfaced to those of the whole bike. The engine is the basic element of the frame structure, and its dimensions are a non-negotiable factor, at least until Ducati decides that it’s time to completely re-design the whole bike.

As we know, the Ducati Panigale 1199 was conceived around the most radically over-square bore and stroke measurements ever adopted on a road worthy twin-cylinder motorcycle engine: a 112mm bore and a 60.8mm stroke. Therefore, it was only natural to expect that any increase in displacement would come from lengthening the stroke, a proven way to gain torque and flexibility. But this stroking procedure was not possible on the Panigale because the engine was conceived as a racing engine, extreme in every conceptual detail, with outer measurement that were as tight as possible to keep the L-shape 90-degree V-Twin compact enough to fit in a chassis with a short (agile) wheelbase and correctly biased front weight distribution.

2015 Ducati 1299 Panigale S studio rear shot

This explains why the 1199 engine has 110.1mm conrods, which translates to a not-too-generous 1.8:1 rod-to-stroke ratio, given the wild bore size and the engine’s ability to rev well past 11,000. But this was vital to make the engine as compact as possible. To keep overall dimensions the same as on the 1199, stroking would have meant further shortening the rods. This would have caused a massive increase of secondary imbalance, plus more high-frequency vibrations, piston side thrust, and friction. By no means is this a technically refined solution. And let’s not forget that the Ducati 1199 already was the strongest twin-cylinder engine to ever power a street-legal motorcycle.

Dr. Sairu, however, confirmed that the public demanded more flexibility and a better power delivery at lower rpm, in the best tradition of Ducati’s V-twins. With the stroking option rejected, Dr. Sairu and his team took on the over-boring challenge. With the bore increasing from 112mm to 116, the most significant move is an appropriate increase in valve size to keep overall efficiency at the same level reached with the smaller version. But in this case, that principle of efficiency was sidelined and Sairu’s technical team focused on optimizing fluid dynamics to obtain the best possible cylinder filling over the broadest possible range of revs using the 1199’s 46.8mm inlet and 38.2mm exhaust valves. Valve lift is also unchanged, with 16mm inlet, 14.3mm exhaust. The result? A massive increase of torque starting at low rpm, and a solid horsepower increase with only a marginal loss of less than 300 rpm at the top end. It’s a terrific result that translates to significantly improved tractability and torque at all rpm. Just what the ultimate Ducati V-twin demands.

Ducati 1299 Panigale engine

A) The new Ducati 1299 Panigale V-twin is visually identified by the extended ribbing on all covers. This reduces resonance to help the bike meet the more stringent noise pollution standards in a number of European countries. The general look is cleaner and very purposeful. The complete engine weighs a claimed 135.6 lb., only 2.2 lb. more than the standard 1199 unit, which is no longer in production. (Only the race-ready 1199 R is in production.)

Ducati 1299 Panigale dyno chart

B) The comparison between the 1199 and the 1299 torque/power curves tells all. As expected, the 1299 makes massive torque, peaking at 106 pound-feet (144Nm) at 8,750 rpm. The strongest increase is between 5,000 and 6,000 rpm. Despite its "worsened" valve size to bore ratio, the 1299 puts out more torque than the 1199 from 4,000 to 11,000 rpm, thanks to good volumetric (and thermodynamic) efficiency.

Ducati 1299 Panigale engine

1) The bore increase from 112 to 116 millimeters is immediately perceivable in this image of the two pistons. Despite its larger diameter, the 1299 piston weighs only 480 grams (16.9 ounces), which is only 0.35 ounces more than the 1199's piston. Rings are the same thicknesses: 1.2mm, 1.2mm, and 2.5mm.

Ducati 1299 Panigale engine

2) This top view shows that the 1299 piston goes to a flat-top configuration with a 12.6:1 compression ratio. This translates into a faster and more complete combustion, thus better thermodynamic efficiency.

Ducati 1299 Panigale engine
Ducati 1299 Panigale engine

3 & 4) In the 1299 piston, the squish area logically larger, given the unchanged size of the valves. It's also continuous all around the periphery of the piston crown, maintaining a minimum thickness of 2-3 millimeters even at the thinnest points, around the valve pockets. This helps to contain combustion "inside" the combustion chamber while the piston dwells at TDC, preventing the gases from leaking downward and into the ring crevices where combustion is impossible and unburned carbon accumulatates.

Ducati 1299 Panigale engine

5) Here is the most significant difference between the 1199 and the 1299. In order to accommodate the larger pistons inside the standard cylinder casting (and keep the cooling fluid chamber unchanged around the cylinder barrel), the 1199 aluminum cylinder barrels have given way to steel cylinder barrels sporting the same outer diameter as the 1199's but a much larger bore. The 1199 barrels weigh 570 grams (20.1 ounces). The 1299's weigh 1,130 grams (39.9 ounces). That's almost double.

Ducati 1299 Panigale engine

6) The 1299's steel barrels receive the same Nikasil bore plating as used in the 1199. This help Ducati keep tightest possible piston-to-barrel fit, which reduces noise. The new steel barrels proved geometrically very stable with no sign of distortion at the end of long stress test that also confirmed the cooling is appropriate.

Ducati 1299 Panigale engine

7) To stand the much higher peak loads generated by the larger displacement, the 1299 received completely new rods (left). They are made of a high-tensile steel alloy, heat-treated and shot-peened. Most important, they have wider heads (24.2mm versus 22.95) to accommodate larger bearings and withstand the higher loads. They also have their heads crack-fractured in liquid nitrogen, for a more accurate coupling.

Ducati 1299 Panigale engine

8) The 1199 (left) and 1299 crankhafts. The diameters of the main end journals (50mm) and the crank journals (45mm) are identical. The 1299 crank needs inserts to compensate for the amount of steel removed from the counterweights.

Ducati 1299 Panigale engine

9) The wider rod heads and bearings adopted on the 1299 meant that the journal of the crankthrow should be widened accordingly. The 1299 crankshaft weighs 5,365 grams (189.2 onces), or 200 grams (7.1 ounces) more than the 1199's crank.

Ducati 1299 Panigale engine

10) The counterweights of the 1299 crankshaft are extensively machined to clear the larger skirts of the new pistons. That is why steel inserts are added after machining for accurate balancing.

Ducati 1299 Panigale engine

11) Head covers are ribbed for reduced noise. The short pipe protruding upward from the lower half is part of the secondary air supply system that improves the smoothness of the throttle response and the quality of the combustion at the lower rpm. The system has an electronically controlled main valve at the airbox, and this short inlet pipe ends at a reed valve to control flow to the short runner ending in one of the exhaust ports. This prevents back draft.

Ducati 1299 Panigale engine

12) The valves are the same as on the standard 1199: titanium 46.8mm inlets, and 38.2mm exhausts. Combustion chamber retains the basic design, but with a slightly enhanced contour to take advantage of the wider squish area.

Dyno chart.
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Studio side view.
Studio rear view.
Action shot.