This 3.4-liter inline-six is being reconditioned before it is reunited with a left-hand drive 1955 Mark VII M. An interesting example equipped with a factory sunroof and a 4-speed manual gearbox. The engine showed signs of previously being overhauled but hadn’t run for over four decades.
Here is the bare cylinder block with all oil and cooling plugs removed. It is fresh from the hot tank. Photo courtesy of the talented machine shop.
Really no need to redesign your 50 year old packaging when its this good.
Measuring the ring end gaps. Piston ring gap is critical.
The Hepolite pistons had little to no wear and passed a close inspection. So, we gave them a new lease on life.
Here is a simple piston pin puller. The 1/2″ felt ensures the piston doesn’t get marred-up while the pin is being drawn out of the press-fit in the piston and into the aluminum tube. Works great.
This internal passageway in the connecting rod delivers pressurized oil from the crank to the piston pin. A pipe cleaner, brake clean, and compressed air work well to remove decades of gunk.
The crank was magna-fluxed to ensure no cracks or other damage was hiding. Fortunately, the journals were within spec, so it only required micro-polishing before being reinstalled with new standard size bearings.
Short pieces of hose over the rod studs help protect the cylinders and crank journals during assembly.
A few thousandths off of the mating surface brought the head back into spec. New guides and valves were installed. Photo courtesy of the machinist.
The DOHC XK cylinder head dates back to the late-1940 and came in many iterations. In 1955, the factory painted B-type heads Duck Egg green (and, later just light blue). Camshaft installation and valve clearance are being finalized here on the workbench.
Confirming any timing marks before the cylinder head is reunited with the block. For whatever reason, Jaguar (counterintuitively) uses the front most cylinder as #6, and the cylinder closest to the firewall as #1. The camshaft drive unit is assembled prior to the cylinder head on the XK engine, and each camshaft sprocket uses a splined hub to properly set the cam timing. The entire camshaft drive on these early XK engines is different compared to other DOHC engines from the period. Unfortunately, I had to put the camera down.