Jaguar is offering a few cool performance-oriented models nowadays, but it's also building limited-series continuation cars. As of 2020, the Jaguar Classic workshop rolled out three continuation series for the iconic XK SS, E-Type Lightweight, and the Le Mans-winning D-Type.

But Jaguar Classic is now also offering a continuation series of its inline-six XK engine in a 3.8-liter format. The XK mill was first introduced back in 1949, but it remained in production for more than four decades, until 1992. However, the 3.8-liter variant was short-lived. First used in the XK 150 in 1958, it was discontinued in 1968, when it was replaced by a larger, 4.2-liter version. This continuation engine is the perfect choice if you're restoring an old Jaguar, but it's decidedly expensive.

The continuation 3.8-liter XK engine fits in various models

Initially offered with a 3.4-liter inline-six, the XK 150 was upgraded to the 3.8-liter version in 1958. The SE model came with 220 horsepower on tap, but Jaguar also offered an S variant with 265 horses. These cars were built through 1960.

The same engine was featured in the elegant Jaguar Mark IX from 1959 to 1961 and then in its replacement, the Mark X, from 1961 to 1964. The Mark 2 sedan also offered it from 1959 to 1967 and it was also included in its more luxurious version, the S-Type, from 1963 to 1964. Finally, the 3.8-liter inline-six powered early versions of the Jaguar E-Type, from 1961 to 1964. These cars came with 265 horsepower and 240 pound-feet of torque on tap.

The continuation 3.8-liter XK engine is very expensive

Bringing old technology back to life is expensive. Just like Jaguar's continuation cars are more expensive than modern sports cars, this old XK engine requires a fat wallet. That's almost $18,000 as of September 2020, which is more than an entry-level Chevrolet Sonic ($16,720) and just slightly more affordable than the all-new Trailblazer ($19,000).

But dropping this continuation engine into your classic Jaguar will actually cost you more. That's because it doesn't come with pistons, connecting rods, a crankshaft, and a cylinder head. Sourcing these parts will increase overall cost to more than $20,000, a sticker that would probably get you a Jeep Compass or Renegade, both priced below the $23,000 mark in base trim.

Granted, finding a used block will be cheaper, but the continuation block is built to original specifications and comes with a one-year warranty. If you send the company proof of vehicle ownership, it will even come with the serial number from the engine you replace.

Needless to say, Jaguar likely won't sell to many of these engines, but enthusiasts who value originality will be happy to have this option.