MK II Alloy sump

(Timothy M Fox) #1

Greetings all,

Are all XK sumps the same or are their variations? My car is a 1961 3.4 MKII and is presently fitted with a pressed steel sump. Is there any advantage in fitting an alloy sump? I have access to a spare alloy sump from a 3.8L MKII motor, hence the question.



(Tigger) #2

I write from a stance of general ignorance, but on the upside, more informed bods fly in to correct me so hopefully this will assist you. We have a 3.4 with ally sump - main difference apart from rigidity of structure is that the ally sump incorporates a ‘catch cup’ such that the oil flung out from the rear main seal is collected and dribbles backs to the sump. The thread of the sump plug on ally sump is of course notoriously weak so we have made use of an airplane style drainer so as not to overuse the sump plug thread

(Timothy M Fox) #3

Thank you very much for the message. Would you mind posting a photo of the drain plug you have used and where you purchased it?

I’m still keen to know if there are any structural differences (dimensions) between sumps on different XK engined models?



(Ian) #4

Far as I know the Alloy sump is just the same , just the oil pick up from the pump is diffrent , in shape !
Your need the Alloy spacers that go under the Anti roll bar retaining plate , and 4 longer bolts !

If it’s a XJ6 sump your need 2 spacers a side , or 1 1 inch a side

(Tigger) #5


Cannot do a picture right now, but pretty sure I bought it from ‘Cool Cat Corp’ – it is a fitting that replaces the sump plug and has a push/twist bayonet action to open/shut. As fitted to light aircraft engines I think.

(Timothy M Fox) #6

Thank you for the name of the supplier which was Cool Cat Corp.




(Timothy M Fox) #7

Thank you for the information, Ian.

In the MKII Parts Catalogue the alloy sumps are the same for the 3.4 & 3.8 L


(Timothy M Fox) #8

I forgot to mention that Cool Cat Corp also make a sump plug repair fitting, just in case someone has stripped theirs! This is from their website.

“Stripped your oil pan? Don’t despair, here is a simple fix. Our magnetic plug is self tapping and oversized for a quick, permanent fix. The magnet will trap small particles of steel and iron before they can damage your oil pump. Will it save you a rebuild? Maybe, maybe not…but it sure can’t hurt!”


(Paul Wigton) #9

Almost all FLAPS (friendly local auto parts stores) carry oversized repair plugs.

(Tigger) #10

Not in Ukadia they don’t. Guess it is mainly the colonials stripping their threads.

(Robin O'Connor) #11

This is one way to maintain the intergrity of the sump threads.
I replaced the stripped threads by tapping oversize and then a brass fitting locktited in place then a brass plug to seal.

(Timothy M Fox) #12

Given metal fatigue, I might be a sensible precaution to be proactive rather than reactive? I will be fitting a threaded plug repair fitting to the sump so that the next owner will have trouble free servicing.

Timothy Fox