1963 Jaguar MkII 3.4

Falling Inline – The Story of the Jaguar XK Straight-Six

Jaguar. A legendary name in both performance and luxury. Just the name is enough to conjure images of elegant, long-legged coupes and saloons powered by the now infamous XK straight-six engine. But, what is the story behind this incredible powerhouse which lived 1000 different lives?

Debuting in 1949, the XK straight-six came with a sizeable 3.4-litre displacement, it was the brainchild of four very important icons in the Jaguar world. Sir William Lyons, William Heynes, Walter Hassan and Claude Bailey. The introduction of this engine however stretches back nearly a decade before. During World War II when the company still went under the name SS Cars, the team were actively seeking and developing replacements for its engine lineup so, during its wartime efforts they worked on the new powerplants for its post-war cars. Jaguar had begun to produce and develop the engine just after the nightmares of war had begun to subside at the end of the 1940s. The cornerstone of these engines was to be higher output, higher quality and higher style, thus the XK Inline-Six was born.

The XK engines first saw service in 1947 with the 3.2-litre units (XJ 6 Cylinder) but during testing of the engines, it was found they severely lacked low-end torque, so the blocks were bored out to 3.4 litres (XK 6 Cylinder) and were destined to be the beating heart of one of the most beautiful cars ever made, the XK120 which broke cover at the 1948 London Motor Show. This would then see the engines fitted to the upcoming MkVII’s and countless other models over its production run.

The cast-iron engine blocks were not the lightest but were highly durable. The construction techniques developed for this engine would push other manufacturers to refine and develop new and improved engines to try and match the level that Jaguar was achieving. Jaguar fitted special vibration dampers to the crankshaft of the engine to absorb and limit the number of frequencies travelling through the crankshaft and ultimately the XK’s split case engine design.

In 1951, Jaguar began work on developing the idea of a smaller displacement but still useable version of XK straight-six. The results for the 2-litre engine were mixed and by 1954 the engine had grown to become a 2.4-litre unit. The engine itself was actually shorted than the bigger displacement engines but remained under the same name and architecture. These engines would be put forward to power the upcoming stylish and sleek saloon, the MkI. The road engines were entirely carburetted until 1978 (the first year of road engines being fuel injected for the US market) but would use a combination of two or three SU’s. Webers or Zenith carburettors except for the MkII 240 which had a set of downdraught Solex units.

From this, all the subsequent Jaguar XK straight-sixes were laid out. Short block engines would make up the smaller displacements such as the 2.4 and 2.8-litre engines and the longer, more torquey powerplants would go anywhere from 3.4 to 4.2 litres by the end of its production. Jaguar officially retired the XK 6-cylinder in 1992 replaced by the newly developed AJ6 platform it used alongside the faithful XK until the AJ6 was then also retired in 1996.

During this incredible engines lifetime, it would see all manner of changes and applications. From racing to agricultural work. Le Mans to Leicester and beyond. This incredible piece of not only industrial design but of engineering excellence and durability should be remembered and revered for the legend it surely is.

Long live the XK Straight-Six.

Coming Back Together – The Rebuilt Straight-Six is Back for the 1963 Jaguar MkII 3.4

The straight-six for the 1963 Jaguar MkII is back and is in the car. Some of you may remember from it’s last update, some damage was found on inspection of the internals of the engine so it was sent away for a rebuild.

The engine has been gone through thoroughly to ensure all is ok before it went back into the car. Paul, one of our in-house restoration technicians, has fitted the glorious 3.4 litre straight-six back into the front of the stunning white MkII.

The accessories will be refit into the car and testing will begin by our in-house technicians to ensure the engine and the issues noted have been rectified.

Starting From Scratch – Diagnosing an Oil Leak on the 1963 Jaguar MkII 3.4

Our in-house engine builder at Bridge Classic Cars, Ady, has been working at trying to get to the bottom of the oil leak with the 1963 Jaguar MkII 3.4.

At idle, the engine would behave itself perfectly. Not a spot of oil but any higher in the revs and it would begin to leak. Ady has spent countless hours hanging over the engine bay of the MkII trying to get to the root cause of the issue. He believes he has found the cause.

Upon inspection for the oil leak, Ady has found the bores in several cylinders to be heavily scored.

With some of the pistons, the rings have too much play in them and allow a lot of the cylinder head pressure to escape past the rings, down the cylinder and into the crankcase. With this added pressure, it begins to push the oil out to any opening that may have a weakness.

The rear main seal on the MkII 3.4’s is a split seal design. Meaning at the bottom engine they are cut to allow them to be slipped into place during installation. This, with the added crankcase pressure, has been pushing the oil from the crankcase through the rear seal and out. So a combination of pistons slop, ring movement and too much crankcase pressure have been causing the leak we have been searching for.

The only remedy for this in Ady’s experience, is a full engine rebuild with new parts including a rebore to clean up the cylinder walls.

Keep an eye on the Bridge Classic Cars blog for more updates on the MkII 3.4.

Finding the Source – Investigating an Oil Leak on the 1963 Jaguar MkII 3.4

This 1963 Jaguar MkII 3.4 is back in the Bridge Classic Cars workshop after its recent overhaul to investigate an oil leak from underneath this impressive tourer.

Our workshop manager John and in-house engine builder are on hand to look into the issue and will advise on the next steps to take to resolve the issue.

Keep an eye out on the Bridge Classic Cars news page for more

A Tell-Tale Heart – Engine Refit on a 1963 Jaguar MkII 3.4

The Jaguar straight-six. A staple of British motoring since its first outing in 1949 and continued in production well into the 20th century. This particular engine was lovingly refreshed by our in-house engine builder Ady along with some other sympathetic restoration work completed by our highly skilled technicians here at Bridge Classic Cars to make sure this Mk2 3.4 was one of the best out there.

The level of detail put into this engine by us here at Bridge Classic Cars matches the rest of the care and attention lavished on this fine example of this era of Coventry Jaguar. With so much attention given to the build-up of the long block, the install had to be given the same respect.

After a full engine bay respray, it was important to install the engine slowly and methodically. Gently easing the glorious straight-six into its age-old home. Like a well-tailored suit, the engine slipped perfectly into position where it could be checked that it would not interfere with any other componentry and it sat just right for all to behold when the long, elegant bonnet was opened for its tell-tale heart to be on display for all to proudly see.

Jaguar MkII – Replacing O’Rings

Ady has carefully removed the o’ring from our Jaguar MkII oil pump to replace with new.

The parts are all here on the shelf and we’ll start the rebuild of the engine very soon.

Paint prep for the Jaguar Mk II engine.

Lydia has been taking the flaking paint off the engine block for the 1963 Jaguar Mk II 3.4. It’s going to get re-painted, so a smooth surface is required. The block was cleaned several times first to get grease and dirt off. She used an air gun, to begin with, to blow off as much as possible, then a mini air sander for the worst bits that were on a flat surface, and sanded the curved flaking areas by hand. Once all the sanding was done, the engine block got blown again with an air gun to remove debris and then cleaned over a few times. Lydia finally masked up any areas that aren’t getting painted. It’s now ready to go in the spray booth!

Engine bay re-spray for the Jaguar!

The 1963 Jaguar MK II has been in the paint shop recently.

All the original paint and underseal was stripped from the engine bay of the car. It was then cleaned to remove any excess residues that would get in the way of the new paint. All the wires were masked up to prevent any paint from spraying onto them. Paper was then stuffed into any gaps. The final bit of prep was to cover the rest of the car in plastic sheeting. The engine bay was then finally ready for the new paint to be applied.

Stripping the Jaguar MkII engine bay

Work continues on our 1963 Jaguar MkII. Paul has stripped the engine bay of key components, clean up in preparation for refit. The refit will commence once the engine bay is prepared and painted by our paint shop.

Jaguar 3.4 MkII Balancing Act

Ady has been balancing the carbs on our 1963 Jaguar MkII to improve the running and overall performance of the car.