Jaguar XK Engine Cylinder Head (SP)

The Jaguar XK engine was produced in various iterations from 1949 to 1992, with several different cylinder head designs used throughout the years. One of the most popular high-performance cylinder heads for the XK engine is the "SP" (Straight port) head, which was developed by Jaguar in the 1950s for racing and high-performance applications.

The SP head features larger valves, revised port shapes, and a more efficient combustion chamber design compared to the standard XK head. These improvements allow for increased airflow and better engine breathing, resulting in improved power and torque output. Additionally, the SP head is typically lighter than the standard head, which can also contribute to improved performance.

The SP head is a relatively rare and sought-after component, as classic Jaguar specialists at P&K Thornton we have reconditioned hundreds of XK engines over the years and have used the same experience and expertise to recondition this XK SP Head for improved performance and reliability. A list of some of the work carried out on this cylinder head are below:

  • Chemical clean

  • Lead-free seats inlet

  • Lead-free seats ex

  • Fast Road Head Port Wor

  • Fit bronze valve guides

  • Cut all 12 seats

  • Skim face flat

  • CC balance 

  • Bore Tappet guides 1.4"

  • Machine Cam Clearance

  • Pressure test

  • Polish Front

And a list of new parts fitted:

  • Inlet valve competition spec 

  • Ex valve competition spec

  • Tappet followers 

  • Performance high lifts cams

  • Double competition valve springs

If you are interested in this XK SP head and would like to benefit from the full performance of it we can also offer the following for you:

  • Suitable air intake manifold

  • Suitable 2” carburettors

  • Suitable side air filters

  • Polished cam covers

  • Polished front engine breather

  • Bottom end engine rebuild


The full list of compatible engine models are listed below:

Year Model Engine Size Cylinder Head Size

56 - 59 MK8 3.4L B

57 - 59 MK 1 3.4L B

57 - 61 XK 150 3.4L A then B

58 - 61 XK 150S 3.4L SP

58 - 61 MK 9 3.8L B

59 - 61 XK 150 3.8L B

59 - 61 XK 150S 3.8L SP

59 - 66 MK 2 3.4L B

59 - 66 MK 2 3.8L B

59 - 67 MK 2 2.4L B

61- - 72 E Type 3.8L SP (Straight port)

61- - 72 E Type 4.2L SP

61 - 63 E Type LW 3.8L SP

61 - 64 MK 10 3.8L SP

63 - 68 S Type 3.4L B

63 - 68 S Type 3.8L B

64 - 66 MK 10 4.2L SP

66 - 68 420 4.2L SP

66 - 70 420 G 4.2 L SP

67 - 68 340 3.4L SP

67 - 68 340 3.8L SP

67 - 69 240 2.4L SP

68 - 73 XJ 4.2L SP

For prices please feel free to get in touch +44 (0)115 9262266

PerformanceAlficinaJaguar XK Engine, Jaguar XK, Jaguar XK Cylinder Head, XK Cylinder Head SP