Jaguar XJ6 Engine (Series 3)

It was during one of those idle mid-pandemic flick-throughs of Faeces Book marketplace that I saw it -- a Jaguar XJ6 motor for sale, unceremoniously dumped in a paddock up in the Perth hills. I went and looked at it, paid about $100 too much, loaded it onto the trailer and so the next project was born.

Why on earth take a risk like this? Because I just can't help myself, basically... a DOHC motor, straight 6 (my favourite engine configuration... so smooth and can be wound out to ballistic RPM), and looks like it wouldn't be out of place powering a Spitfire. And also, having sold the mighty Bismarck, I have been left with a boat-shaped hole in my life. So maybe I can rescue some old engine-less boat and power it with this? Brilliant!

Got it home and parked it on the workshop floor. First thing I found out was that the motor was locked SOLID -- and no amount of prying, hammering, levering or soaking the pistons in a variety of lubricants would get it turning.

So it was time to invest in a hydraulic engine lift and an engine stand; clearly the head was going to have to be pulled off before anything else could happen. But first I drained the sump and was greeted by a stream of water followed by a chocolate milkshake that was maybe also crunchy. From here on I knew that things could only get worse!

The head simply did NOT want to budge. I had read that these can be pigs to remove, as the studs go straight through the water jacket and can get rusted in solid. So I ended up welding together a jig to mechanically raise the head by pushing off the engine studs.

After 4 (or was it 6? 8?) hours of wrestling, cycles of heat from the propane blowtorch, and more tension applied to the alloy head than I really want to know about, FINALLY a small gap opened up along the head gasket. It was moving! Another hour or so of jiggery-pokery and the cylinder head was at last dangling in the air. I left it to hang there for a few days, like a pirate's corpse in a gibbet, just so I could fist-pump every time I walked past the darn thing.

Upon examination you could see what a terrible time this thing had suffered. It had obviously been through a major, MAJOR overheating episode. Some of the camshaft bearings had started to melt. A couple of the valve springs had de-tempered in the heat. I didn't know it was possible to roast an engine to this extreme... but apparently it is.

The next question was why it had copped such a roasting. It was when I pulled off the water pump that finally the scenario clicked together in my brain: the rear of the water pump, which is incorporated into the alloy front plate of the engine, had rotted through and allowed the coolant to directly enter the engine. With the coolant now pissing into the engine, the motor then overheated and the nut holding the steering wheel had just kept on driving until everything seized up solid. Then, not satisfied with that, they decided to try to start the motor again, holding the key on 'start' until the copper blocks on the commutator of the starter motor just melted away. Some people...

Next step was to get the pistons unseized. For this I had a block of hardwood turned up on the lathe by my brother-in-law, complete with a dish scalloped out of the end so that contact would be made only with the perimeter of the piston and not the dome. This block was plonked in one of the pots where the piston was about half-way down the bore... and then I reached for the 6lb sledge hammer and smacked it a beauty. Faced with this unstoppable force, the piston was no longer an immovable object. The motor was turning at last!

Then it was time to pull the pistons and the crankshaft out and inspect the bores, the bearings, the rest. The bores were still within tolerance after a hone, and displayed no major pits or scratches. And thankfully the pistons were still serviceable. One or two of the main bearings were also showing signs of melting, so they all got replaced along with the big-end bearings. A new set of piston rings was ordered as well, a new set of valve springs, a fresh set of camshaft bearings, and an engine gasket kit too. A new starter motor and alternator also helped chomp more holes in my non-defined budget (which is the poor man's version of the unlimited budget.)

There was also the question of fueling. I just couldn't face the old EFI system... the plethora of sensors and switches and wires and injectors was a nightmare worthy of Alice Cooper. So I hit on a plan: I took everything off the intake plenum, blanked off all the holes in it one way or the other, flipped it upside down, bolted it back onto the motor, and cut a square hole in the top to accept a mounting plate... and bolted on a Frankenstein of a Holley 500cfm carburetor that my brother had cobbled together from his vast collection of stuff. Sorted!

Other odds and ends were taken care of... a replacement alloy front engine plate was found on eBay. Then I reconditioned the water pump, re-shimmed the valve buckets, had 2 cracks in the head welded up, and had it skimmed flat as well. Now there were a few other things that I probably could have/ should have done... but where do you stop with something like this? At some point the hip pocket has had enough pain and it's time to take your chances. Which, in this case, I think are pretty good.

Fresh oil and oil filter were done before anything else. Then I fitted up a radiator, fuel can, electric fuel pump, some basic gauges (volts, water temp, oil pressure), and fired it up. With no muffler and just the original cast iron manifolds this thing indeed sounded like a Spitfire on the runway! Ran it up to temperature and everything was excellent.

So now I just have to find a boat. Stay tuned!

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