Driving Angry
The soul of an internal combustion-powered vehicle is the engine. It provides the power, but it’s the experience of that power that makes it special. High cylinder count engines tend to have the most exciting sound, particularly the V12. Ferrari V12s are known for a high-revving, spine-tingling scream. Aston Martin’s V12 has an angry roar. It’s a unique signature of this generation of Aston Martin.
The mighty AM08 V12 engine fills the engine bay of the DBS. (image credit: Author)
The V12 has been the crown jewel of engines for Aston Martin since the 1990s. It all started in 1994, at Ford’s Advanced Powertrain division. As Aston Martin was owned by Ford at the time as part of the Premiere Automotive Group (PAG), this gave Aston Martin access to Ford’s considerable engineering and technology resources.
An engineering team was assembled at Ford Advanced Powertrains division to begin work on the AML V12. The key team members were Don Nowland, Bernard Ibrahim, and Anthony Musci. Nowland was responsible for cylinder heads, ports, chambers, intake manifolds, throttles, valvetrain and cams. Ibrahim worked on throttles, exhaust manifolds, front-end accessory drive, front cover and electronic controls. Musci focused on the cylinder block, oil system and pump, cooling system and pump, pistons, rods, crankshaft, and also electronic controls.
The design goal was to build a unique V12 for Aston Martin, while leveraging many of Ford’s best resources. The engine would be designed to compete at the Le Mans 24 Hours; deliver very high torque from low RPM as well as high-revving power; would be scalable for power growth well beyond a “normal duty” Ford engine; and would only use a component from other Ford projects if it made sense and didn’t compromise the design.
The AML V12 design featured all-new block, cylinder head and crankshaft designs, using the piston assemblies and valve train components from the then-upcoming Ford Duratec V6 family. The use of some Duratec components may have contributed to the myth of the AML V12 being “two Duratec V6s welded together.”
Another contributing factor to the myth may have been an engine mock-up that was created back in 1992. ECS Roush was tasked by Ford to build a “quick package study” for a V12 design. They welded three sections of Ford's new 2.5-liter Duratec V6s together. It was simply to provide the package space required for a V12, not to be a running engine. The Advanced Powertrains division later transformed it into a display-quality concept engine, but was by no means functional. This mock-up was shown at the 1993 Geneva Motor Show, alongside the Aston Martin Lagonda Vignale concept car. Some in the press noticed that the display engine had visible weld lines, adding fuel to the rumors of “two V6s welded together.” According to Anthony Musci, there are “many technical reasons why that approach would never work successfully if creating a V12 from two 60-degree V6s.”
The AML V12 and Duratec V6 have quite a number of significant differences. The Duratec V6 is A319 cast aluminum with cast-in iron liners and a bed-plate bottom end. The AML V12 is A365-T6 aluminum, features a deep-skirt six-bolt main block, thin-wall press-in liners and directly mounts nearly all of its drive accessories. It features 3.0mm-larger main bearings, a bank-to-bank offset approximately 15mm less than the V6, and has a completely different casting design including a precision water jacket. Crankshaft design is unique, as a 60 degree V6 and V12 have vastly different design requirements. Cylinder heads differ as well: the Duratec V6s are A319 cast aluminum, the AML V12s are A365-T6 cast aluminum with unique combustion chambers, a higher compression ratio, a precision water jacket, and unique intake ports (one of the design features that significantly improved low-end torque while maintaining high-end power).
Musci said that the AML V12 design team borrowed the best ideas from muscle car engines as often as they did from newer state-of-the-art engines. “We really wanted to put together something completely new. No other V12 of comparable size, revs, etc., I am aware of has anywhere near the low and mid range torque of the AML V12. ”
Left: V12 engine blocks ready for assembly Right: A rack of new pistons is inspected before installation (image credit: Aston Martin Lagonda, Ltd.)
The final engine design is a 60 degree V12 configuration with quad overhead camshafts, and four valves per cylinder. Two Powertrain Control Modules (PCMs) are used to manage the engine. Each module manages six cylinders, which means it operates as if it were two separate inline-6 engines.
The AML V12 ran for the first time in September 1995. The first engine completed was taken by Ford to be used in the Indigo Concept Supercar. This version was unique in that it was dry-sumped, unlike the later production versions, and fitted with a “Ford V12” nameplate. Engine number two was installed in a DB7, which was the intended platform for the engine.
The first time the public got to see the AML V12 with proper Aston Martin badging was in “Project Vantage,” the prototype of the first-generation Vanquish shown at the North American International Auto Show (NAIAS) in January 1998, a year before the 1999 Geneva Motor Show reveal of the DB7 Vantage. The DB7 Vantage became the first production model to feature the AML V12.
Ford and Aston Martin partnered with Cosworth Technology to manufacture the AML V12s, until Aston Martin’s dedicated engine plant in Cologne, Germany came online in September 2004. Cosworth also worked closely with the Ford team on final tuning of the engine, in preparation for full production.
The AML V12 has evolved over the years, with a number of power, torque, fuel efficiency, and emissions upgrades. Each new version has the designation “AMxx,” where “xx” is the version number. For example, the original DB7 Vantage engine had the designation “AM02.” The DB9 had three different versions during its 12-year production run (AM04, AM09, and AM11). DBS had just one version, the AM08.
The AM08 design appears to have been most closely based on the DB9’s AM04, rather than the first-generation Vanquish’s AM03 or AM06 engines. Significant upgrades were made throughout, increasing power while reducing emissions to meet the ever more strict government regulations.
During the development of AM08, engineers benchmarked the Vanquish S manifold airflow, but due to styling constraints these couldn’t be used on DBS, as they wouldn’t fit under the hood of the new car. DB9’s intake manifolds weren’t able to meet the performance requirements for DBS, so a bespoke intake manifold and bridge assembly were created.
DB9 (AM04) intake manifold and bridge assembly compared with DBS (AM08). (image credit: Aston Martin Lagonda, Ltd.)
In addition to the intake manifold changes, the air boxes were modified to include a second “by-pass” intake port, which opens above 5,500 RPM to provide more top-end power. This translates to the world rushing at you through the windscreen unabated as the rev counter sweeps towards redline. The DB9’’s AM04 delivers peak power of 450 bhp at 5,750 RPM, while the DBS’s AM08 continues to pull hard up to a peak of 510 bhp at 6,500 RPM.
The AM08 cylinder head is a unique part for DBS. In addition to the changes made to the intake manifolds, the cylinder head intake tracks were re-profiled to improve airflow into the combustion chamber. Valves and camshafts were carried over from DB9’s AM04, but the valve guides and seats are unique to the AM08. Fuel injectors from Vanquish S (AM06) were carried over as well. The compression ratio was increased from 10.3:1 to 10.9:1 by creating an additional 0.5mm of skim on the cylinder head, and increasing the airflow.
A 65,000-mile AM08 V12 engine with cam covers removed for inspection. (image credit: Author)
The exhaust manifolds are very similar in size and shape to DB9, and also include the primary catalytic converters. For DBS, exhaust gas flow was significantly increased with a more open structure. The secondary catalytic converters are special high-flow design as well. To make sure that emissions were not increased by this change, the wash coat of the ceramic brick was upgraded to a more efficient blend. At launch, DBS had the cleanest-burning engine of any Aston Martin.
The AM08’s oil sump is an improved deeper design, lowering the oil level relative to the crankshaft. This reduces the amount of contact between the crankshaft and the oil. Excessive contact between the shaft and the oil can “whisk” it—aerating the oil — reducing power, and potentially causing engine damage.
The DBS also received an updated radiator and cooling fan package with greater airflow, thanks to an improved fan layout.
Final inspection of a V12 engine at the Cologne, Germany engine plant before being shipped to the factory in Gaydon, where it will installed as the raging heart of a new Aston Martin. (image credit: Aston Martin Lagonda, Ltd.)
While none of these changes are massive on their own, together they provide a big performance boost over the previous incarnations of the AML V12. You can feel it when you drive the DBS.
The era of the big internal combustion engines is coming to a close. With modern EVs, the instant torque of electric motors will press you back into your seat and hold you there, silently. It’s impressive, but it’s not the same experience as the roar and vibration you get from a big angry V12 at full song, and the engagement of changing your own gears on a proper three-pedal car. The DBS delivers this experience in a way few others cars do.
DBS V12 6-speed manual - one of the last truly engaging driver’s GT cars (image credit: Aston Martin Lagonda, Ltd.)
Acknowledgements:
AML V12 engine development history details are based on Anthony Musci’s excellent article, “The Origins of Aston Martin’s V12,” published in the Aston Martin Heritage Trust Magazine “ASTON,” issue #21 in December 2021, as well as several conversations between this author and Mr. Musci. Details of the later generation engines were generously provided by several sources with Aston Martin Lagonda, Ltd.