A noob question, that I hope won't upset.

Looking into oil cap hole, on 4.2l XK motor in search of tappet hold down kit which I have read about, I can see oil pooled. Using my dipstick finger measurement, it is about 15mm deep.

From experience with various brands of engine, I know that some oil pooling is normal but have not seen so much before.
​​​​​​Having zero experience with XK motor, I seek assurance from forum's experienced that this is normal or do I have some sort of oil return restriction?

The head is clean and looks to have been worked on, which can be a good thing or a bad thing depending on the experience of the mechanic and how judicious he/she was with gasket sealant.

Oil pressure is good, as far as Smith's Gauge is concerned, 40psi at idle. Tappet noise is apparent, ticking not knocking. As this is the only XK I have heard running, I have nothing to compare it to.

Thank-you, everyone.

 

I changed the oil. When adding new oil, it drained from head at a reasonable rate. So I am guessing that the oil bath in cam gallery is normal for XK motor.

 

You have nailed it..

The XK oil drain back slots are on the topside of the camshafts, so, the area is quite full of oil when running, hence the leaks, oops.

 

Cheers Grant. Valuable information for an XK virgin.
A good design for cam lubrication, then, so long as you can keep the slippery stuff inside.
I have read that the XK motor was used in miltary tanks, in one variation. I can't get this fact out of my mind when working on her, especially when I changed the 44 gallon sized oil filter, today. Lol

 

I have actually seen an XK motor on an Alvis Scorpion light tank; being built in the old Holyhead Road Alvis Factory in Coventry. It was a low compression version, cams tuned for torque, and was painted pale green.
My lovely old ex-factory development car TD 21 was what enabled me to visit. Sadly a very good friend from those days, ex Alvis Cars test driver, is with us no more.
https://en.wikipedia.org/wiki/FV101_Scorpion#Engine

 

You certainly have some experience with these motors, then.
What an asset to the community.
Good on you, Greg. 8-)

 

The XK engine is a brilliant design, but gets very cross if overheated.

Most issues with the XK are typically confined to the cylinder head; the bottom end is usually 'bulletproof'.

The tappet 'hold down' is necessary for engines having emission controls and warmer thermostat requirements as the tappet buckets tend to rise up and are then struck by the rotating camshaft. Broken bits of the tappet bucket may find their way into the timing case and can cause catastrophic engine damage.

 

More valuable insight. Thank you.
I'm going through the cooling system now.

I spent 13 years working in auto cooling and A/C, so understand how important a good system is.

In all that time, we never worked on a Jaguar. Recored radiators for them, but never had one in the shop. Maybe the boss was turning them away.

 

Probaly turned them away, common pratice, then and now.

Make sure you get the correct length thermostat. Some books etc are WRONG.

Dayco dt18A, is what I use, 6 and 12, and that stabilises the system 100%.

Being in OZ, Dayco is a daily word, not so overseas I am told.

 

Dayco actually manufactured the stock we used to sell, as a National cooling system service franchise.
The thermostat that I pulled today, to do system flush, had a solid flange. No bleed nipple.
I always like to drill a bypass hole to allow air to bleed, also prevents thermal shock if in a very cold climate.
I'm going to do some research on alternative radiators and thermo fans. The Jaguar fan is a monster that cleared the leafs from my driveway with a few revs. Loud! Sucks a lot of air, which is a good thing but old school compared to modern fans and shrouds.
Australian Ford Falcon or Holden Commodore are likely candidates.
Link pipe and trans cooler setup has to go, too.
Car has an external trans cooler, so either a nice stainless pipe or a two pass radiator with top and bottom hoses on RHS.
FUN!

 

I have a stock, recorded radiator. AU Falcon twin electric fans.
Barely gets to 1/4 on temp gauge stuck in traffic in Qld summer. Did multiple trips from Brisbane to Armidale and hardly saw the temp gauge move.

 

EF and EL taxi pack fan assembly is what I used on 6 and 12 cars. Made by Bosch in Germany. NLA now, and the Chinese knockoffs are a waste of $$.

A guy in Scotland, XJS V12 (same car in that area), fitted the X Type Fan Pack, which he stated adapted easily, and cost him 15 UK Pound.

Others claim the X300 fan pack, dunno, I reckon they are too wide, but if they fitted them, they must be OK.

 

The stock radiators are a great unit. We used to sell cores regularly. They were used in custom cars.

​​​​​
I am only looking to the future, when she needs replacing, with the hybrid swap, although my cross pipe/trans cooler does need replacing now.

 

Great information, Grant. Thank you. Now I know what to keep an eye open for.

Most modern fan assemblies are very efficient. The blade design and integrated shroud assembly is the secret.

Hot rod boys used to fit 16" Davies Craig fans and wonder why they suffered overheating at slow speeds, not realising that the fan only sucked air through its swept area and not the whole radiator.

For best results the shroud needs to be the same size as the core and relatively well seated to promote air flow through the core only and not around the edges of the shroud

Claims of HP loss through viscous coupling are real enough, although very minor, and promoted the change over to electric fans.