I Finally got my engine back from the machine shop after 2+ years. Unfortunately the gentleman that was going to help me with assembly passed away in a motorcycle accident during this time, so I am on my own as far as assembly goes. Are there any step by step guides out there for re-assembly? I bought a book detailing the rebuilding of the engine, IRS, and Carbs that was done in the 80's (British, yellow cover) however it is not giving me the detail I need. Thanks...

 

There are workshop manuals, of course, and hard-copies can be searched for on the internet. Only trouble is these are based on brand-new engines. What I suspect you're after is a book with all the "hidden knowledge", held in mechanics and enthusiasts heads and not always written down.

So, what are you after, info on rebuilding an XK engine or more than that ? What detail is the book missing ? I've rebuilt two XK engines and rebuilt a Mark 2 from a bare shell in the 80s so have been where you are today. It was easier then as a lot of the experts were still around, but are now dead. Knowledge does disappear over time, unfortunately.

 

I have the workshop manuals. What I'm looking for is the the nuances of rebuilding that engine. I already had the shop machine the rear so that I can put a modern seal in it. I've heard about using a later model oil pump for more flow. I plan on using a new aluminum radiator to deal with the Texas heat. Most of my upgrades were going towards drivability and reliability. I've never put together an engine before, but its all of the little things. The order of it. You don't know what you don't know kids of things. I can always dump it back off to the machine shop, however that doesn't teach me anything. I'm sure with someone sitting over my shoulder it would go quick, but on my own..... I don't want to turn it into a catastrophe...

 

All you can do is pick up an E-Type manual and follow the book. Jag XK engines have been pretty much the same since 1948. Look up technical bulletins and these will have Jaguar updated parts listed. XKs has a bunch of downloads for free. SNG Barrett can help and so does Terry's . Not a hard engine, keep area clean, follow specs. and have a good torque wrench.

 

Well first question is - is it a 3.8 or a 4.2 ?

I rebuilt a 1967 2.4 which is a short block engine, then much later a 1980 4.2 long-stud engine. One thing I found was to look carefully where aluminium is in close proximity to steel or iron. Where the coolant inlet to the block runs through the timing cover, look closely where the edge of the aluminium timing cover butts up to the block. Corrosion can be such as to make a passage through from coolant into the timing chest. Mine was nearly there so I got it repaired.

Other thing is to make sure the sludge trap plugs are removed and the sludge cleaned out. It is amazing how these traps fill up and you wonder how much oil is getting to the bearings ! When replacing with new plugs, make sure they are staked using a punch on the edge. The plugs can be very difficult to remove, BTW.

3.8 engines can suffer cracking of the block near the cylinder liners. Liners were put in because boring out to 3.8 from the 3.4 original left too little metal there. Essentially, every engine after the 3.4 was a spatchcock basically, the long stud engines being particularly bad in this respect. The engines were made on used machine tools from inception in 1948 !! Jaguar spent quite a lot of cash on the V12 tooling, only to see it all set to nought by the fuel crisis in the 70s. Only years later in the mid-80s did they develop the AJ6 and AJ16 engines, which should have been the top priority in the late 60s.

For an old engine, it is well worth taking out the core plugs and flushing out the coolant passages that collect a lot of crud over the years especially at the rear of the block where there isn't much circulation. It doesn't harm cleaning out the oil gallery too, but don't use pipe cleaners !

Hopefully, others will give advice based on their own experiences.

 

Fraser's advice is very good but I wonder if you fully follow the meaning.


I think the sludge trap plugs means the plugs in the crankshaft which are hexagon socket plugs. If the engine has just been machined by your engine shop, it is most important to make sure everywhere inside is clean and free from machining swarf/grindings. This applies to the block, head and crankshaft - all oil and waterways.


As sad, you need good tools, particularly a torque wrench. If you go a bit at a time and ask questions on here if you run into unsure areas, you can expect to get help, sooner or later

 

I also agree with the thrust of advice given by Fraser except for two areas and the second is really only of emphasis . . .

• replace all head studs secured into upper face of engine block - research the issues, more prevalent on later 4.2s but these are not immune to stretched. softened or corroded studs;
• replacing all core plugs (Welsh plugs) is just as mandatory as the crank sludge trap plugs and for reasons given by Fraser.

But, let me backtrack a bit . . . your reticence of the factory workshop manuals is not well founded. Save one or two modern fundamentals that were not available using technology from 50+ years ago, these manuals really are the bibles of how to do it properly. So, humour me. I have been asked often over the past 50 years to set out my 10 Golden Rules for a perfect XK engine re-build. Here goes . . .

Rule #1 is to adopt a systematic approach by breaking down what may seem complex, into a succession of small, repetitive tasks.

Rule #2 is to ensure sufficient bench and workspace and adopt absolute cleanliness at all times.

Rule #3 you have started on - no compromises when it comes to cooling, lubrication and timing systems. You mention a few items critical to reliable E-Type function in warm to hot climates - having spent much of my years in 40-50C climates, stock is not good enough. Your new, improved radiator is a too often overlooked mandatory item - but add new water and oil pumps. I'm not kidding here . . . you might succeed with a re-milled oil pump, but if not, you have a lot of work to do on a brand new engine to correct it later.

Rule #4 is all about engine bottom end & drive-train assembly. Measure all piston ring gaps at top, mid & bottom of stroke. Being new replacements never means that gaps are correct. File to spec. Once piston & rings for cyl#1 are done, clean any filings away, oil & assemble, then wrap in clean paper (not rag) and number. Use Plastigage and tension all caps to check all bearing clearances as you fit crank into journals, but never rotate crank until caps are removed. Use dial gauge to set end float at centre bearing coz 5thou is not to be fooled with . . . we aimed for 3thou. Double check that all numbered caps match. Repeat for rods. Oil all bearings as you assemble. Ensure that conrod cannot foul crank as you compress rings and fit each piston. Ensure each piston's "F" mark faces front. Immediately fit the big end cap.

Rule $5 is about timing gear. Assemble oil pump & distributor drive with care - the slot for latter is offset, so set it up now for #1 TDC so that rotor will point accordingly. Check timing gear sprockets for wear and replace as necessary. Don't bother checking t/chains, guides and tensioner . . . just replace with new. With timing case and sump fitted (see comments below on silastic), it's time to secure top chain and wrap top of engine to keep it spotless.

Rule #6 is all about gaskets . . . or modern practice lack thereof. Plenty of fiery debate to be had but my hard earned throws anything made of cork in the bin. Hot oil and cork, over time, start leaking . . . and re-tightening only accelerates the problem. Modern liquid formula solutions, if used correctly, are damn near infallible and really oil tight engines are assured. Next into the bin goes all copper or brass washers fitted to unions on lubrication and fuel lines . . . but only after securing new replacements.

Rule #7 is about what hangs off the back of the engine. With re-faced and balanced flywheel, don't skimp on new clutch and release bearing. Manual trans can last a lifetime, which is good coz unless you really want to test your boundaries, rebuilding an all synchro full of needle rollers, shift rods and little interlock detent ***** and springs is best left to others. This is unfortunate because I cut my teeth on the earlier Moss boxes where re-building was a given. Even though I have now done many, I started with one. If you have a go, follow the workshop manual. There are no secrets; no shortcuts; no expensive special tools . . . but heaps of self satisfaction and pride in tackling a challenge most avoid, thus never learn.

Rule #8 is to take time out to make 3 special tools that will last you a lifetime - the first you need now and that's a dummy shaft for centreing the clutch to flywheel - literally a 5minute job on a lathe. Real smarty pants will take 10minutes and turn out 3 or 4. The other two tools are the camshaft indexing plate and a top t/chain tensioner. Diagrams and dimensions of all these are in the manuals.

Rule #9 is to assemble the clutch and tranny to the engine block . . . along with the starter motor, but nothing else . . . then follow the established procedure for refitting into vehicle. New engine and transmission mounts are mandatory, as are careful and sensible safety precautions to ensure nothing slips. This will ensure no unforeseen scrape down some beautifully painted body panel. Never placing yourself under a raised engine or vehicle during this step, will ensure that you never suffer crush injuries or broken bones.

Rule #10 is to assemble, measure, check then repeat . . . all the head and its associated valves, cams, etc. All this area is well documented but perhaps not so, the repetition necessary to ensure perfect valve/seat lapping and adjustment of clearances. Major tip here is not to compromise on getting them perfect . . . if it isn't spot on, do it again until it is. The competition fraternity found good reason to open out Jaguar's specs of 5thou / 8thou to (usually) 8thou / 10thou, but only under hard race conditions.

There is no Rule #11 . . . all the systems and bits that hang off the XK engine to deliver the optimal fuel.air and ignition are well documented. Perhaps if there were a Rule #11, it would be to stay calm, enjoy your JD or Shiraz or frothy suds after a good day's work while you plan out the next. Enjoy . . .

Ken

 

Thanks guys for the info. I am excited about this project. I'm even shopping for a new torque wrench b/c I don't think my harbor freight one will cut it. I plan on picking the engine up Friday and getting it mounted. I have a friend loaning me a diesel engine stand which I guess is much stronger than the single one that I have. I have room in my garage to rebuild the engine, but I have been worried about the dust / cobwebs / etc... that seem to infiltrate. Most likely I will have everything in either bins, or heavy garbage bags when not being assembled. Like I said, I've never rebuilt an engine, but it's always got to be someone's first time, right? Thanks and I'll keep you up to date.

 

How's it going Stancey?


I must say, engine building is something I enjoy most. My last one was a 0.5c.i. model helicopter engine and the one before that was a 373c.i. Chrysler V8 which had supposedly been restored - but was done by a cowboy who did not flush the crank so it ran the bearings (all of 'em) within 200 miles and also installed 4 big end caps the wrong way around etc. etc.!!


Once I had finished with it, it ran lovely ........ if I say so myself


So if you have the manual, take your time and most importantly - keep it all clean. You will finish with a fine engine.


Jerry

 

So, this is where I'm at so far. Engine wiped down, cleaned, etc... painted with a gloss black engine block paint. I'm surprised about how straightforward the Jag manual is so far. The journey begins... I feel like I want to rub down the cylinders again because when I was trying to blow air around to get lint off, I was getting a bunch of scale from the water holes blowing around. Not smart on my part.....I'll keep everyone posted with pics as I slowly churn through it...