Hi all.
My late pre HE (1981)XJS seems to be a mixture of both metric and imperial threads and fasteners, but when it comes to the engine, can anyone advise if the engine is the same or exclusively imperial? I'm doing a major cooling system overhaul & I need to replace the core plugs on the both coolant rail front and rear housings & I want to ensure I request the correct items.
Thanks in advance.
Scott.

 

Strange people the English ! Milk & beer comes in Pints , petrol comes in Litres but we work out our economy in Miles per gallon . The Brits reckon a pint is 20 fl.oz & the USA says its 16 Fl.oz. By my way of thinking it takes longer to get drunk in the USA , drinking pints , than the UK. Back to the Jag ! sorry I have no idea . But I do have a Metric socket set & an Imp socket set ...yep that's being English & living in Europe......

 

The engine itself is a mixture.

The head studs are 7/16" diameter. The threads into the block are UNC, and the top threads are UNF.

The bolts that hold the tappet blocks to the top of the heads are Metric.

The core plugs, I forget, but there is a book somewhere in the shed with the notes I made when I rebuilt the HE, and when I find it I will have the answer.

 

If I remember correctly, many parts on my 1989 XJ-S had metric threads (like the studs at the front of the engine for the valve covers). The bolts that hold the air con compressor in place are metric too... Oddly... Unless mine is just simply been bodged

 

I know my front suspension is all English except the ABS sensor bolt is metric. The car is mostly English with some metric thrown in there.

 

Not engine related but the stud for front bumper on euro models is 3/8 unf one end and 10mm metric on the other. There would be a reason, wouldn't there?

 

Unlike you sensible people in the USA, the Uk went metric in the 1970s. The XJS, being a 1960s design was originally imperial. But gradually, as parts suppliers etc etc metricated, the XJS became a horrible mix of the two. SO, for instance, the flexibles to the front brakes on my car are metric at the caliper end and imperial at the solid pipe end!

Then the caliper to hub/upright bolts are metric fine thread (they look like they are UNF but they are not!). Engine a mix, etc etc etc. The firewall battery studs are Whitworth! All part of the joys of the car.

Greg

 

Found the book.

I didnt put the sizes in, how dumb.

I will keep looking.

I have the Jaguar part numbers for them if that is of use to you.

 

Gordon Bennett!!! With such an eclectic mix, its no wonder I'm going potty trying to source replacement fasteners & core plugs etc. I hoped the engine might have been one or t'other but even that is a mixture.
At least I got my nice stainless coolant rail tubes right. 19.05mm o.d. Or was that 3/4"? I've got a headache. A James Boag will fix that. (beer for non Aussies).
Evenin' all! (for anyone that remembers Dixon of Dock Green)