Hi All

I'm James from New Zealand and i'm picking up on my fathers stalled out xj coupe project. He's 65 now and its sat in the corner at a panel shop for almost 20 years.
My experience i suppose you would say is in Turbo EFI , fabrication , machining , welding, and computer aided design . My current occupation is building Big open single seater formula style cars for Rodin Cars.

The Goal for this coupe is that the XK 4.2 is staying and it has to look great, sound great and have reasonable performance ( think 95 x300 4.0 performance ) to help with this a rare S2 overdrive manual gearbox has been sourced but the engine upon teardown had a few issues despite its low 102,000 km.

Engine Block
With the mini cracks between the cylinder bores it will need a dry sleeve kit fitted ( i have those ) and of course bored honed to a new set of Mahle 9:1 pistons.

I'd like to hear from any member who has had this process done for their engine and any associated issues. If done correctly i would expect the ductile iron liners to last many moons and now have any sealing or "liners dropping" issues. My experience is only with modern engines and ive never had one sleeved before.

Replacement Cylinder head studs
I see a lot of options for oe style head studs in the back of the Jaguar magazines and on SNG Barret website . Being a long stud 4.2 right into the water jacket is there a preference on which studs to use ? Does a particualr brand have a better corrosion resistance or a special coating ?

9:1 compression pistons & Triple Carb SU Conversion

On SNG Barret the Mahle 9:1 pistons look to be the highest compression off the shelf option in a quality piston, my thoughts were is with the bump in compression and fitting Triple SU carbs this would give me the most reasonable bang for buck performance , sound and reliability. I'm hoping this would get us close to good honest 200hp at the crank . I'm sure some of you out there have fitted triples into your Series 2.

If anybody can chime in i would really appreciate it.

Ignition Systems.
My last question is ignition systems, as an EFI turbo person Carbs are a stretch for me. But they are in fitting with the period correct nature of the car. But points ignition in my view is not suitable. Have any of you fettlers done an Electronic distributor or full computerized ignition system retrofit ?

 

Off the shelf electronic ignition kits suitable for Jaguar XK engines exist and are not too dear. Ask ken Jenkins at ukjag AT hotmail DOT com.he can pre map it for you and send you the ready to fit 123 Tune system (dizzy, HT leads, coil, plugs).
https://123ignition.com/

 

Series 3 Dist and AB14 amp, drop n, wire up, drive off. Plenty of S3 rusting away across the ditch I would think.

Stepped liners, done a few over the years. Very time consuming to machine and fit. Machyine one hole, fit said liner, machine 2nmd, keying that into the 1st, and so on down the line.

Balance the whole thing, well worth the time and expense, transforms that long stroke sucker.

I only use OE head studs, and keep the coolant up to snuff, no issues, ever.

Mahle be my choice as well, Hastings rings.

Triples, always thought about it, but the brake booster was just in the way for my liking. HS8 spec would be the best in my opinion.

 

Stepped liners, (also known as "top hat" or "lipped" liners are the only way to provide a cure for the block cracking between the bores, as the lips cover the cracks and thus stop head gasket failure. They are expensive to do because the old liners have to be machined out first and then grooves machined around the bores to take the lips. I don't think they can be pressed out, but I may be wrong.
The block deck has to be faced-off once all the liners are in place, so make sure your workshop has the front timing cover to bolt on as the top of this forms part of the surface for the head gasket and thus needs facing off too.

 

Forgot.

S3 Inlet valves, bigger than teh S2, and allows more and better breathing.

 

Why not use the series 3 cylinder head and fuel injection manifold? Add an after market ecu that can also control the ignition.

 

This is great thanks for the replies team

I will start newest first,

Peter2442 - i would of preferred an S3 head but the Series 2 head has already been tested machined, valves done ect. so best to use it and carry on. I was dead set on EFI until i watched YouTube for about 5 days while off work sick and i want to try the SU's and keep some of the mechanical magic of carbs and linkages. The discussion i had with my dad was - if we did EFI it will be an XJR6 engine.

Fraser Mitchell - Great info i knew they needed to be stepped, but i absolutely would of forgotten about sending in the timing cover. We actually inherited the liners with a donor car many years ago. I have contacted some machine shops to ask of their XK engine experience.

Grant Francis - Good to hear it that regulars OE studs are the best option , that's a great tip on the S3 Dist & Amp I will be sure to look out for one. I already have a box of hastings rings that came with the liners. I actually have pistons too but only 8:1 so they are getting re purchase

Greg in Frace - that 123 Ignition Unit looks excellent, I really like the 16 advance curves offered.

Thankyou all so much, if anybody has other engine rebuild XK wisdom they wish to share please keep posting it.

 

My block was cracked, but I managed to buy an uncracked block, a rare beast indeed, as 7/10 7L blocks crack and 8/10 8L blocks.
When inserting the new head studs, be aware that some are slightly longer than the others. The longer ones are placed where the engine lifting brackets fix onto the head studs. YOu also need to make sure the tapped holes are totally clear because if the studs don't go fully home, you can end up thinking you have clamped the head down, but you haven't because the stud had reached the limit in the domed and chromed head nuts. I actually had a tool made up that allowed me to clean up the threads all the way down by brazing a long T-piece to a plug tap. I also vacumed out each stud hole too. I also replaced all the core plugs and cleaned the coolant passages out. The amount of crud that accumulates in the rear of the block is amazing.
As mine was a Series 3 crank with the hardened journals it didn't need grinding, but I got the chap who sold me the block to remove the sludge traps in the crankshaft and clean them out. They are the worst aspect of the crank and totally unnecessary, as there is a filter in the system !!

 

I was hoping to get the block into a commercial dishwasher that still uses solvents or acids to give it a really good clean up with the core plugs removed. A trick we do at work is use an Earls Race engine preheater unit and fit a filter inline and keep filtering and dumping until it clears up.

can you post a picture and length of your thread tapping tool ? An un cracked block is really rare , but the block i have is the correct one for the car so best to use what ive got considering there isn't much choice.

what would you consider the best documentation for the series 2 XK rebuild procedures ? I don't have any manuals or specifications and some guidance on the preffered document would be very helpful.

 

A small thing, often neglected.

Behind the chain hydraulic tensioner, INSIDE the oil gallery is a SMALL conical filter mesh. Many claim :it is not there", but with a very fine wire hook, household fuse wire is good, and carefully prodding and pulling there it is. It is a MUST on these engines, or that tensioner will fail to tension, and chain rattles will be your friend.

 

Hi Frazer. I must disagree about the crank plugs. I found lots of crud in my crank that could have ruined my rebuild. Also, the factory manual states to remove the plugs and clean.'
Picture here, I hope:
An Image from the Jag-lovers Photo Album
Rob

 

I would recommend you consider sourcing a serviceable S3 block and have it remanufactured instead of the expense of sleeving the original. The S3 block has additional circulation between the #3 and #4 cylinders. Even after sleeving, you could end up with a split in the deck.

 

Er, my post said that I had the sludge traps in the crankshaft cleaned out, and that it was the worst aspect of the car. They are unnecessary as there is a filter before the oil curculates in the gallery, and anything that gets past this is too small to worry about. Of ocurse the engine design goes back to the 40s when engine filtration may not have been so good, but no changes were ever made over the decades since 1948 to remove this needless feature.
Have a read here. Roger Bywater was a n engine development engineer at Jaguar in the 70s
http://www.jagweb.com/aj6eng/xk-engine/index.php

 

I made extension for tap from 14" 1/4 socket extension and with tap forced into 9/32 socket. Had to make sure socket and tap did not fall off inside engine (Supper glue gel) The welded rod/T handle, would be safer.
To clean holes and get rid of any fluids in hole I used 5/16" brass tube with slots cut in one end to allow airflow, hooked up to shop vacuum cleaner with tubing and a cut-up small funnel duct taped to the shop vac hose.

 

Ah, I see now what you mean. I thought all cranks had plugs?
Rob

 

For your ignition options: “ that's a great tip on the S3 Dist & Amp I will be sure to look out for one. I already have a box of Hastings rings that came with the liners. I actually have pistons too but only 8:1 so they are getting re purchase..... The 123 Ignition Unit looks excellent; I really like the 16 advance curves offered.”

- I went with the S3 Dist and Amp.. See the thread for details: https://www.jaguarforums.com/forum/x...epairs-210475/
- The123 ignition is a new Distributor, but most of the optional curves are for racing and high rpm. curve 0, 1 or 3 are ok for Long Stroke XK engine
- Pertronix D171618 is a new Distributor with a matching coil is a good option for carbureted Jaguar 4.2 engine
If you go with high compression pistons and high octane fuel, the D171618 is the curve you want, you will have to retard the The S3 distributor to 13-14 degrees static
Rgds
David

 

That graph is very helpfull, the s1 distributor is fairly aggressive on its advance in comparison.

can any members contribute their experience with 9:1 engines ?

Is the hemi head so fussy that the higher compression is even an advantage?

The more I’ve searched and googled it seems a lot of xk owners are wary of 9:1 engines.

When I first wrote this topic 9:1 seemed clear cut as it was offered by jaguar but I keep reading that static timing needs to be reduced and these engines seem to suffer pre ignition quite easily .

 

NAH.

Firstly none of mine were ever driven docile enough to build up carbon, pre-ignition fodder.

The MK X 3.8 was a mongrel after a long hard run, but I simply walked away and let it sort itself out.
The 3.4 S type, NO.
A few of the S2 4.2 hinted at it, but a change from the HEAVY flywheel, to the S3 Flexplate sorted that.

You want to go manual, so no issues that I can see.

High idle is problematic, but again a manual can negate that, with the ability to stall the engine if need be.

There was an Anti Run On valve on the S2 cars, and the wiring for that on a RHD car is under the battery tray. PITA system, but it did work, had Lucas reliability stamped all over it.

Our S2 Daimler went 9:1 when I rebuilt it, and a S3 flex plate, BW66, S3 Dist system, twin HS8 SU carbs, balanced engine etc etc. NEVER an issue.

 

Forgot, it happens.

Fussy, never had a Fussy Jag engine. MANY, that were set up and fiddled by fools, but when put back as designed, SWEET as.

Too many people over think these engines, it its just how it is. They try to establish WHY it does this or that, who cares, it does what it does, and does that very well for a very long time.

Fiddle less drive more, works for me.

Daughters S2 4.2 had a rebuilt engine, by HER, she broke it not me, that was 13 years ago, she be 18 at the time. Still storms down the road, and she is the same one who asked "if I put a dent in the floor under the accelerator pedal will the car go any faster", FACT. FUSSY not in this household.

 

I had a bad case of engine pre-ignition (pinking) on my 8:1 XJ6 many years ago. It was in the last days of leaded "super" petrol - supposed to be around 97 RON but I think most of the super had gone out of it by then. The engine though only having 65,000 miles was consuming huge amounts of oil. My diagnosis was that the valve stem seals were totally stuffed, passing enough oil to reduce the octane level of the petrol. After fitting new stem seals (and reducing static advance to 8 degrees from 10), no more problems. I am of the view that a newly rebuilt engine with 9:1 pistons could run well on todays 98 RON petrol especially with the right distributor.