Can This 1968 4.2L Jaguar Block Be Saved? 

Mine isn’t too bad but give me a mic & telescoping gauges or a soldering iron and I’m screwed 😂

00l

@@JAMSIONLINE wanted to be an architect as a younger man. Try bringing pen to paper on a bad day. Gave up idea if being a surgeon very early in life

@@JAMSIONLINE yeah! Soldering is also my weakness 🤣 even though mine isn't as bad as yours

Try not to let your difficulties interfere too much with what you want to do. I knew someone with the tremor who worked all his life as a tailor, right up into his 80's. He found ways around the problems it caused.

As he said. We’ve been recently rebuilding 4.2l that cracked like yours. We used top hat sleeves and it end up great.

@brandon kerley , and Krzysztol Pazdziora, Were they cast iron street blocks, or rare aluminum racing blocks? The one in this video is a rare aluminum racing block...A second look at the video reveals the magnetic 🧲 particle inspection being done on the block, with the liners removed... My mistake... It is a cast iron block... Thanks for the heads-up on this one ..

@@michaelmartinez1345 actually that is a cast iron block in the video, if it was an aluminum block they would of not been able to do the magniflux method

@@michaelmartinez1345 aluminium one, almost same case as aluminium rover v8 4.0 and 4.6 from discovery 2 and p38

But did you repair the cracks in the cast-iron block?

I agree with this as it would give the most longevity out of the repair and since the parent cylinders need bores because of taper anyway the machining time to clean up the extra braze would be minimal

Don’t know how that would work. Different metals, different coefficients of expansion. Brazing is a melding technique, not a welding technique. Creates a solution of metals. One would think thermal fatigue will occur quickly. Your experience obviously differs, and I’m not saying that you are wrong.

@@BoogWar01 yep you have no idea what youre talking about. Brazing is the way.

@@fuckingpippaman it is a newbie response based on lack of information. Happens all the time.

We had the same type of Crack brazed on an old ferguson tractor engine with wet sleeves it still holds.

That’s a nice deck bro

@Chris Hartley, if the pan rails on the lower side of the block are not parallel with the deck surface for the head, then how is the block fastened to the OEM milling machine bench for the initial deck surfacing, cylinder boring and fastener drilling and tapping? My guess is the oil pan rails were machined first, at the OEM, to provide a reliable set of sturdy surfaces to locate the block onto the milling bench, for several of the of the machining process's and operations to take place... And my guess is the machinists are aware of this... Just guessing though...

@@michaelmartinez1345 I'm not sure about engine boring machines. I'm only familiar with Bridgeport style mills. However, if the machine spindle isn't perfectly square with the table of the machine, the deck could be milled flat and the bores put in perpendicular to the deck. But the deck wouldn't be parallel to the pan rails, and the bores wouldn't be perpendicular to the pan rails. The spindle should be checked for squareness to the table by sweeping the table with a dial indicator.

@@michaelmartinez1345 Not all engines have a base "parallel" to the deck, V6 and V8 for instance, so that method could not possibly be used, the block must be clamped by some other method. On "parallel" base engines the same method is used simply because the engine is on an assembly line, they don't have time to waste setting things up perfectly parallel. The block is held in clamps and rotated as various machining operations take place, so although the surfaces should in theory be parallel there is no guarantee that they will be, particularly on older engines. On the more recent engines the mills and drills rotate around the block so the angles of surfaces are much more accurate relative to each other but they are still not machined with reference to another surface on the block, too time consuming.

@@jeeprenegade1985and Chris Hartley, I remember seeing large machines that held engine blocks on decks that rotate, but those deck surfaces were perpendicular to the machining heads... This way the blocks could be rotated to match the cutting tools... And yes, for high production purposes, v type blocks had numerous machine tooling equipment placed in positions to match the needs to work that block... But the pan rails were still used as a baseline to measure and position the pre-cut block with... Lots of engineering is involved with manufacturing and mass production of equipment like this... Definitely more than one way to do the job...

First I spent 30+ years in an engine manufacturing facility. Repairing and rebuilding machines and doing Tool Work. The way manufacturing lines are set up especially for engine blocks requires the first two surfaces to be machined are the deck and pan rail with the main bearing half rounds. These are located relative to casting features. The second operation would be to drill, ream and chamfer two locating holes in the pan rail. These are located relative to the main bearing half rounds and a casting feature. This feature is usually relative to the two center cylinders inside the coolant passages. All other features during the machining process are dimensioned from the pan rail and the two locating or main manufacturing holes. These holes are typically anywhere from .625/16mm to. 750/19mm in diameter.

this right here sounds like the "Correct" method of repair.

I was just wondering why welding wasn’t an option. I understand why its not for the avg home gamer. But the pros, with a rock and hard place situation like this have im sure come up with some. Probably not mig, but im fairly certain of some tig rod for casted metal. and ya ya i know heat affected brittle zone next to weld. But with proper heat up and cool down like he’s mentioned here with an oven, it dose a great job of negating those problems. 🤷🏻‍♂️. I understand the speciality of it. So im curious if some have specialized in it.

I was wondering the same thing. Why wasn't welding a option. I personally suck at welding but I've seen guys on RU-vid do some amazing things.

Dollar to return yield, you can throw all $ at it, in the end will work be worth yield. Only customer can quantify $s.

You don't need an oven or kiln, just a big tub of sand and two guys with weed burners. I saw a very large casting fixed that way.

Lani at Copper Gaskets probably has all the specs needed to cut them, it's pretty surprising just how much stuff he has for all sorts of obscure engines, plus, he offers various thicknesses from about 1/32" to 5/32" (forget exactly as I haven't bought any for a while)

@@1crazypj he did a very custom m110 Mercedes gasket for me several years back. Top quality.

Yeah I was going to reply with the same thing mate but you beat me to it. I have done this before successfully and if done here in combination with the top hat sleeves it would deal with those cracks growing

@WRXHEAD, Yes, I was thinking the same thing.. Literally an 'open' invitation for very bad corrosion to develop between the block and the sleeve...Luckily, on this engine, the corrosion btwn. The block and that sleeve that the machinist removed appeared to be minimal, probably because the correct anti-freeze concentration was maintained in this engine, and halted the corrosion... But as soon as the concentration of A/F gets below 25%, the corrosion becomes very bad, especially between dis-similar metals like aluminum and steel, or cast iron.... I imagine that after that type of corrosion takes place, coolant starts leaking into the crankcase, and then destroys the bearings of that engine... I don't know WHY Jaguar 🐆 did that, but I certainly don't like those slots, and would consider having them slightly beveled, welded shut, then machined flush with the adjacent surface... Do any other companies do this without using 'O' rings on the outsides of the liners, like the Diesels do?

They worked just fine in the 3.8 engine. When the factory took them to 4.2, they did it with an overbore and those blocks have the cracking issues..

@@TyphoonVstrom So the extra boring of the increased displacement of the cylinders meant the sleeves were too thin at the top of the cylinders, and then caused the sleeves to crack? I now understand an additional reason for the increased size of the step at the top of the cylinder block... To stop the cracking of the sleeve in that high pressure / highly stressed area... I did not notice a crack on the Aluminum casting... A mark of the Dye penetrant bleeding through the cracked liner, yes that is apparent... But I did not notice a specific crack of the Aluminum casting... Is this where the castings are also known to crack?

The Volkswagen Golf engine started out as a 1.5 with water between all cylinders, but the later 1.8 and 2.0 versions had solid metal between the two center cylinders

@@erik_dk842 , that is a good observation... I noticed that several engine manufacturers have done that , especially with their dry sleeve engines... The castings were 'siamesed' joined between the cylinders... I heard that some companies have done away with cast-iron sleeves in aluminum castings, by using the 'nikasil' plating process.. Some of these companies had reasonable success with this technique, while other manufacturers had problems with it... Jaguar 🐆 was one of the companies that had lots of problems with that process... Personally, I don't like major castings like engine blocks to be made in such a way that they can not be restored by machining cylinders to an oversize... And that is precisely the situation with the 'nikasil' process, no machining of any surface treated in this way can be done to restore the surface without replacing an ALUMINUM liner with std. sized pistons, which is also questionable if that can be done reliably.. A single life use of the treated pistons & rings and/or the cylinder liners is all that is practical with that process... My guess, is it could negatively affect the resale value of a vehicle, especially one that was originally sold as a high-end vehicle, like a Mercedes , BMW or even a Porsche... It appears that the use of low sulphur fuels, that is the ONLY type of fuels being sold in certain areas, negatively affects the cylinders and pistons that have been treated with the 'nikasil' process, that could cause the 'nikasil' coating to delaminate from the parent material, causing extensive internal engine damage... No thank you, I'm avoiding that situation like a potentially insane in-law ..

Just put the goddamn numbers on a good block

@@erik_dk842 aren't they part of the casting and not on a plate so it can't be removed and done that way to deter engine theft and prove tampering

​@@erik_dk842 considering these are rare and any good block would cost more than a salvage car or a car with small issues.. tampering with engine block serial numbers is a felony especially if youre gonna use it on the road..

P

Numbers matching block - difference could be thousands of dollars!

NOT doing it will cost more than saving a numbers matching 68 Jag

What @sideslip said. I came here to say exactly this (based on many years of professional experience building XK engines)

He sold himself to suppliers and is now their stooge.

I have done repairs like this and the lock and stitch repair is the best way to fix cracks like these in an iron block . They won't be able to do anything about the cracks between the coolant passages but that's alright. I have never heard of anything bad coming of coolant leaking into coolant.

That was my thought too, grind out the crack, weld it up, heat treat, and then machine it.

What will stop it from cracking again?

They can't crack any further now. They are down to the cooling passages

Yep and even if water does get up to the deck, that's what the head gasket is for. Top hat sleeves done right works perfectly on these.

it depends how often it will be driven

Laserwelding was coming to my mind, when I saw the video.

I wondered about good old Lock and Stitch!

They will even stamp the original number in them to keep the car "numbers" matching.

@@michaelau5159 Doesn't help if you want a 4.2? Unless you resleeve it?

@@JohnSmith-yv6eq bore spacing between 3.8 and 4.2 is different. 3.8 is slightly offset while 4.2 is evenly centred. I think the best thing for the engine in the video would be new Darton flanged sleeves. They even have coolant ridges to help with keeping the cylinders cool more evenly.

Would using a high nickel welding rod be better. It reduces the heat input to the block immencely. I performed a crack repair many years ago on an old 272 Ford Mercury engine which cracked between two bores. I drilled and tapped a small hole on the crack. The hole had a small lead in chamfer. I used a silver frost paint to coat the screw. This was then cut off and penned in place. Another hole was drilled and tapped which overlapped the first hole. The surface was ground flat after that. I was only a teenager at the time and we had very little access to tooling. Anyway the repair worked well. The engine was in my speed boat so as you would appreciate that motor got a hiding.

@@johnspathonis1078 ah metal stitching Did you use a regular bolt or a specific bolt designed for that purpose.

@@TheMadHatter626 we have used brass 1/8” pipe plugs in 6 cylinder Diesel engines. But that’s on the side of the crankcase and not the deck surface.

@@TheMadHatter626 Hi Wolfman. It was just mild steel 1/4" UNC screws. I was an engineering student in 3rd year of my course so I had next to no excess money. We scrounged as much second hand and free stuff where possible. The block performed a bit like mild steel so I suspect is may have been an early type of SG cast iron. The crack occurred from a blown headgasket between two cylinders. We were on a water skiing expedition a long way from home so it ran for a day or so with bad blowby. The head was a rightoff. I must admit it was entirely a self induced problem.

I like to ideal of using a good machine to drill hole to the bottom of the water jacket and then using a bolt of the right grade with some green loctite I called sleeves compound which I usually use to put the sleeves in re bore the home and maybe put a step sleeve in. And finish off by Decking the block.

O rings or loctite

Not to forget the Le Mans wins in 51 and 53 with the 3.4 C Type. It was the 53 C Type that won due to the disc brakes.

The XK 120 was a throw together. The MK7 was not ready for the show so they made the XK 120 from MK7 parts. It stole the show. I have worked on many here in Denver.

@@lookronjon I could wrong but the Mk5 & Mk7s were BIG HEAVY cars the XK120 were by comparison light sporty aerodynamic MK5 &7 were a bit of a tank, my grand mother years ago had a BRG XK150 chrome wire wheels green leather 3.4, my grand dad had a MK4 saloon red, chrome wire wheels leather BEAUTIFUL CARS ABSOLUTELY BEAUTIFUL, these days NOTHING even gets close not even late model Jags NO Thank you!!!!

I agree, Lee from barum engines will set you straight

Yess!!! That's the only way. If he isn't experienced with oxycetylene torch he should pass this part of the repair to someone else.