Tag Archives: 1963 e-type

December 2009 – Reason for coolant leak discovered

This one is for Derek, my eldest of sons, kind and level-headed. —Also more reasonable than I am, probably. It has been a great blessing to have the children Arlene and I have raised, and we both know that our lives together have been a matter of luck and work, however mixed. We count our blessings, and the first among all of them are our children.

It moves on its own, at last

I was talking with one of my colleagues at work, and he recalled when he started working with me — it seemed long ago, four or five years — and this old car was still in the garage. Actually, long in the garage, being putzed with and pampered and fixed and prodded. But it’s right on the edge of moving out to a new life on the road. Or at least that’s what I hope.

It seemed interminable, this long wait for the car to move. Here, too, there was an interruption, since my fix of the coolant leak was in fact no fix at all. But after Aaron returned from NASCAR Technical Institute in November and his tools started to pile up in the messy garage, there was in fact little choice but to get cracking on the last bits — the clutch hydraulics and the setting to rights of the brakes. Since Aaron came home, brake bleeding was not the chore it was before, but we discovered that the front brake master cylinder needed some fettling, since the play of the piston was not sufficient. I had a spacer for the master cylinder (from an old XJ or early S-type, I believe), and we installed it on the front master cylinder, which is fitted topmost on the pedal assembly. Works great now. Remember, this is due to the non-original Wilwood master cylinder conversion.

The clutch hydraulics were simple. And Aaron pushed a little by pushing the old car out into the elements so that he could fit his tool cabinets into the garage. I was not pleased that the car was under a tarp outside, but we got it done in part because I wanted to get the thing moving and back into the garage.

All was installed, and so coolant and oil went into the engine. It fired up great, and it moved on its own the forty-some feet into the garage (which by now had been cleaned). We ran the engine a few times thereafter, basically checking out the movement of coolant, the operation of the thermostat, the idle, and the like. It looked good.

I figured it was all downhill from there. It wasn’t. The coolant leak revisited the car, like some unwelcomed haunt.

Aaron called me one afternoon and told me that coolant was again in the oil, so the shade-tree mechanic “fix” wasn’t working. He had removed the oil pan enough to be able to locate the area of the leak, pressurized the cooling system, and discovered that the inlet from the water pump through the timing chain cover was leaking somewhere. A dribble of coolant was coming down the left side of the timing chain cover and into the oil pan. There was little to do but take the cover off.

It took only a few moments of looking at the inlets on the 3.8 and 4.2 liter timing chain covers to understand where things had gone awry.

Another difference between the 1963 3.8 liter and the 1979 4.2 liter XK engines

I’ve done some comparisons of the two engines that we’ve taken apart for this car: the differences of the cylinder heads and the blocks. I missed a rather important difference in the timing chain covers, though, and that was what came back to bite us. The 4.2 liter engine eventually had a better water pump installed and the passage through the cover into the block was slightly bigger and shaped to allow better flow of coolant. It was the difference of the inlets and the areas where the inlet passages were mated that made all the trouble.

Why not use the 4.2 liter engine cover? I didn’t have a water pump to fit. The XJ6 water pump I had would not clear the front of the engine bay, since it went forward beyond the “picture frame.” I couldn’t locate a new water pump either, since everywhere I looked, the water pumps were available only with core exchange or were “R&R” serviced.

A quick glance at the images that compare the 3.8 and 4.2 liter cover inlets shows the true source of the leakage problem. When you compare the two inlets (note the grey area to show the overlap), you can see that the curved sections end up severely narrowing the “kiss” of the cover to the block. And in fact the shape of the coolant inlet on the 4.2 liter engine block is even more pronounced than the cover’s inlet. Although it’s a little fuzzy, the photograph of the block inlet has “points” rather than curves at the upper and lower edges. If you look carfully, you might be able to see the place where the old 3.8 timing change cover (mis)matched the block inlet. I would bet that the leakage we saw came from the lower edge of the inlet, and that it arose only well after we had run the engine for a while, making it possible for the low pressure hot water to push the RTV out of the way.

Now the question was what to do. Obviously, the option of fitting the 4.2 cover would have been best, and I even toyed with the option of arranging a remote electric water pump. The prospect of begging for a 4.2 water pump was wholly unappealling, but was an option (and in fact still is an option now). The last option was to alter the 3.8 cover so that it would at least provide a more ample mating surface to the 4.2 block, in effect following the squared outlines of the 4.2 inlet. This was the option that we chose. The real debate was how to go about making the alteration. The initial approach was to build up the surface by welding aluminum and then machine the surface flat. I was very near pulling the trigger on that option, but the very real possibility of warping or distorting the cover made me hesitate. We could well end up with an unusable part, and we were throwing ourselves on the mercy of welding shops that would make no guarantees. The alloy of the cover was also an issue, I suppose. Lord knows how close a match the built-up metal would need to be.

Of course, there wouldn’t have been a debate without another option, and that was J-B Weld, I’m afraid. Now, I know that the stuff is broadly ridiculed, but I suspect that it’s also used more than people will admit. I’ve used it as an adhesive and filler on knobs and decorative parts of things. The bad reputation comes from people who use it idiotically, and I think that the J-B Weld marketing doesn’t help — engine blocks being “mended,” testmaments that the stuff is “better than baling wire” for farm implement repair, and the like. (As an aside, I have to hand it to the J-B Weld marketing people since they pitch their product to those who will actually buy the stuff — that is, the people who wander around Lowes and farm supply stores. They’re not pitching their product to machinists or welders.)

The stuff is tough, and J-B Weld claims a tensile strength of 3960 psi, adhesion of 1800 psi, flex strength of 7320 psi, tensile lap shear of 1040 psi, and shrinkage of 0.0%. It can handle temperatures up to about 600° F. These measures are of course less than aluminum, but they’re certainly within the range required for an area of little stress and reasonably low temperatures like where we needed to make changes. My main concern — and the crux of the debate — was adhesion. A J-B Weld alteration might hold up, but if a failure occurred it would probably be when a chunk would let loose from the filled area. A chunk falling into the oil pan or timing chain would be quite enough to ruin an engine in no time. The question of using J-B Weld has to do with where one draws the line between good use and idiocy. The application on the timing chain cover would not be stress bearing, though the area would experience temperature changes. As is the case with most adhesives (all of them?), surface preparation is the key to good adhesion.

No surprise here, I guess, about which way we went. The probability of immediate damage from welding and hypothetical (and, I think, remotely likely) failure of a J-B Weld application tipped the decision in favor of J-B Weld. Since the timing chain cover was out and easily cleaned, I went at it with all sorts of cleaners. I roughed up the area to be covered with coarse sandpaper and then scored the surface with a sharp probe tip. A final cleanup of residues and oil was all it took before I set up a dam made of masking tape. Then it was a matter of putting the J-B Weld into place. Twenty-four hours later, I brought the epoxy bumps down flush with the cover, and it was done.

By now, we have removed the cylinder head twice in search of coolant leaks. The oil pan was dropped once. The timing chain cover came off once. I sure hope this is the final chapter on this issue. It is interesting (at least to me) to reflect on the process of fixing up the old car. It is a mixture of physical grunt work, much cussing, posing hypotheses, scratching them off or confirming them with observation or test. This episode with coolant leakage was in fact as much an intellectual exercise as it was mechanical work on the car. The fact that it occurred shows the importance of documentation and keen observation, since had I just looked carefully at the differences in timing chain covers the issue would have been resolved the first time. Much oil and antifreeze would have been spared. And, more importantly, I’d be doing something more close to the finish line for this car.

On my birthday, by the way, I got a convertible top frame that David Boger located. It needs a little work, but I think the pieces I have at hand might do the trick of mending. I can hardly wait until I can put that on, toss in some seats, and drive the car around!

June 2007 – The block — 1963 E-type v. 1979 XJ6

You know you’re not in 1963 anymore when you see that drain swirl logo of British Leyland in relief on the block. It’s enough to make you think twice about your angle grinder and whether you’re enough of an artist to rub off the metal smudge. Of course, in October 1978, when this new engine of mine was cast, British Leyland — or “BL” — was the colossus astride nearly all of British automobile manufacture. At that time, Jaguar has been in the BL fold for a decade, and the conglomerate included nearly all of Britain’s formerly independent marques: Jaguar, Daimler, Lanchester, Mini, Riley, MG, Morris, Wolseley, Austin, Vanden Plas, Rover, Land Rover, Alvis, Standard, and Triumph. In the early 1980s, BL’s long-troubled history led to its unravelling. Jaguar was spun off and became independent with a stock offering in 1984. The remnants of British Leyland changed its name in 1986 to “Rover Group,” which of course has had its own history of disintegration. (At least it now is much more international, I guess, since BMW bought Rover and perhaps thought better of it. MG Rover is now Chinese rather than British.)

It hardly needs mentioning that Ford took up Jaguar eventually, spent a lot of money, and now appears to be setting the company up for the vacuum cleaners of private-equity investors.

At any rate, the logo of liquid(ity) going down the drain is on the right side of this engine block. However, the familiar “JAGUAR 4.2 LITRE” marks sit more centrally and more prominently smack in the middle on that side. That label is where it should be and where its like had been all along.

The left side has as its distinguishing characteristic the oil dipstick fitting. That feature is so undistinguished that I haven’t spent the time worrying whether it is the same as the 3.8, though I believe it will be prudent to use the XJ6 dipstick at first, just to make sure that the oil levels are correctly measured.

Differences of timing covers and water pump impellers

I was told that the timing cover was a drop in, but I was actually hoping that the water pump was instead. There are differences, beginning in 1969, of the capacity of the pump’s innards and the size of the water pump impeller. Also, the semicircular cutout for the crankshaft end was a bit wider — oddly, I thought. We actually checked the crank for signs of wear and checked for free play. But the more glaring difference was the water pump void.

Timing chain covers, E-type and XJ6. The E-type is on the left, and the XJ6 is on the right. Although the two covers are hole-identical and have identical studs, the main differences are in the water pump area. The XK water pumps after mid 1969 had larger impellers and were “deeper.” I used the original cover, since I wanted to use the old pump and its belting system. One change that we noticed, and that is still a bit mysterious to me was the machining around the frontmost edge of the crankshaft semicircle on the XJ6 cover. It was flared on each side. I believe this was be design and not from wear, though I don’t know exactly what might have been the purpose. A different seal?

Now that the 1963 version of the timing chain cover and water pump are fitted, I do have to admit that the newer design looks better engineered, with probably higher water throughput. I chose the original because I feared that the forward extension of the XJ6 water pump was too much. The later water pump is bigger overall, and the belting for the XJ6 is more complicated, but there isn’t all that much space between the front of the engine and the back of the “picture frame.”

Differences of oil pan and sump plumbing

The XJ6 oil pan is significantly different from the E-type’s. It has a blubous protrusion that extends off-center toward the right. The oil intake from the sump comes up near the rear on the XJ6, while on the E-type, the sump intake is centrally located. I wanted to keep the XJ6 sump, actually, but I was concerned about clearance in the subframes. I asked a couple of people about the fit, and Dick Maury let me know about the fit problem of oil pan and the sump intake, and he let me know of some of the adjustments that come with the changes on the oil filter mount. He has been around the block (and through some slalom courses) with his Jaguar cars, including a modified 1971 E-type.

Oil pickup pipes, XJ6 and E-type. I’m holding the pickup pipe from the 3.8 liter E-type above the setup on the 1979 XJ6 4.2 liter. You can see how much farther back the XJ6 pickup pipe goes. The E-type oil pickup is centrally located. There is a small bracket just above my thumb on the E-type pipe. I removed that before installing it.

The E-type sump intake pipe is quite a bit shorter than the one on the 1979 XJ6, which pulls oil from the large deep collector at the rear of the oil pan. But interchange is easy, since there is only one pipe to worry about, and it’s the same diameter for the E-type and the XJ6. The oil pump on the 4.2 liter engine is said to be better — larger capacity or better efficiency, I believe — but that makes no difference as far as pipe sizes. Bill McKenna’s very correct restoration of his 1963 E-type coupe included a 4.2 liter oil pump — one of the very few deviations from the 3.8 liter setup he did. Bill commented in his report that he had to make some changes to the “oil pickup pipe,” though I didn’t have to make any changes.

The E-type oil sump pipe in place. The pipe was a good snug fit, and I used the brackets from the original XJ6 pipe to fasten it. I don’t know what changes Bill McKenna had to do to get his 4.2 liter oil pump installed, but I didn’t run into anything peculiar.

It’s literally a five-minute job to replace the long pipe for the shorter E-type pipe. The original 3.8 liter oil pan is a drop-in fit on the 4.2 liter block and will fit in the car with the original oil pan, though it might not with the XJ6 pan. (An aside: I probably would have stayed with the XJ6 pan if I could, because it seemed to me to have larger capacity and the oil uptake looks to me to be a bit better thought through. It is, of course, a quite noticable deviation from the 3.8 liter oil pan design.)

Oil filter mount differences

1979 XJ6 4.2 liter oil filter mount. There are several changes from the 1963 3.8 liter engine that appear in the oil filter mount. The cam oil feed comes off the top of the mount, rather than from its own hole in the block, as is the case on the old 3.8 liter block. The pipe for the oil pan connection comes off the rear part of the mount on the XJ6 instead of at the bottom. That change means some fettling, of course, and that’s not in this photograph. And, of course, the mount is designed for modern spin-on oil filters, thank goodness. To the right of the mount you can see the holes for the XJ6 motor mounts.

The oil filters change much for the better between 1963 and 1979. The old felt filter replacements gave way to nice and easy spin-on filters. The oil filter mount on the 1979 engine is ready to accept a regular modern filter.

The old felt-insert oil filter. This huge thing is the oil filter setup for the old 3.8 liter E-type engine. There are spin-on adapters available from several vendors, but the 1979 XJ6 engine has the spin-on filter setup already in place. See the oil pressure sensor on top of the filter mount.

And beyond the simple change to spin-on filter mounting bracket come, of course, the complications. On the 3.8 liter engine, the hose to the oil pan comes right off the bottom of the oil filter bracket, and so the hose run on the old engine is straightforward — though (as many have noted) it’s complicated by different outer dimension pipes fitting to each hose end. On the 1979 XJ6, the rubber hose is only an inch or two, connecting to a pipe running to the bulge in the pan that caused me the worry about fit into the subframes, since it extends fairly far to the right. On the XJ6, this pipe heads to the rear, and so the fitting on the oil filter bracket heads toward the rear. The upshot is that the run from the bracket to the oil pan pipe mount is a little contorted when you use the E-type oil pan and the XJ6 oil filter mount. Surely it’s not a straight shot. Dick Maury told me that he used an XJ6 engine in his race car, and he took advantage of the hose changes to fit an oil cooler. It’s a tempting thought, but I don’t think I want to add a complication at this point.

On the old oil filter mount setup, the oil pressure sensor comes off the top, and on the XJ6 the sensor is on a separate aluminum block mounted to the rear of the oil filter mounting bracket.

The XJ6 oil filter mount has the connection for the cam oil feeds as well. It is on top of the mount. Dick said that it is possible to add the connection in the regular E-type location (on the lower rear left side of the block) by drilling and tapping a hole, but this XJ6 setup suited me just fine. The XJ6 block casting, by the way, is flat where the cam oil feed oil would go, so this would be a small alteration for a machine shop to accomplish.

The 4.2 liter block has some mounting differences, though the block itself was designed as a replacement option for earlier XK engines, too. So there is (mostly) backward compatibility for earlier setups, sometimes slightly ingenious ones.

Motor and other mounts

Just forward from the oil filter mount there is a significant change from the old E-type setup. The motor mounts on the XJ6 are set farther back — more or less centrally on thge block. But, this is no big deal, because the tapped holes for the old E-type motor mounts were retained on the XJ6 and used for other purposes like the power steering pump and air conditioning compressor (I believe).

XJ6 and E-type motor mounts. Just forward of the oil filter mount is where the XJ6 motor mounts go, while the E-type mounts are set right at the front of the block. The picture shows both mounting brackets in place, with the loosely fit, rusty one being the XJ6 version.

It’s really just a matter of putting the E-type motor mounts in their correct place. — A straight and simple bolt-in job. (I’ve never Ebayed a thing in my life, but I might give it a whirl with these excess XJ6 parts I’ve got.)

Old generator mount bracket won’t work. That’s my hand holding the old generator mounting bracket in the approximate place it would go. The 4.2 liter block doesn’t include the holes for the old generator bracket, so you have no choice but to upgrade to the alternator. I suppose it would be possible to create a bracket that would do the trick, but the question is why? The place for the alternator bracket is apparent — just above the bracket are two tapped holes.

However, when you jump from the old 3.8 to the newer 4.2 liter, you pretty much have to say goodbye to your generator, not that you probably wouldn’t mind that in any case. The generator bracket holes are completely missing on the 4.2 liter block. On the 3.8 liter block, these holes are placed just above the motor mount holes. On the 4.2 liter engine, the alternator mounting bracket fits much higher on the block. (See photograph on the left for what the 4.2 liter block holes look like.)

I’ve learned from a few telephone calls and emails that the 4.2 liter E-type alternator mounting bracket is pretty rare, unless you’re willing to use a bracket for cars with air conditioning. There are two part numbers for the bracket, C25158 for the Series I and C30615 for the Series II (both for non-air-conditioned cars). I called one fellow who deals with Jaguar salvaged parts, and he told me that he didn’t have any but that the brackets are available from the Usual Suspects. Then he then laughed and said, “But I bet you were trying to avoid having to use junk.”

Oh, well. I guess I might have to use junk — pricey junk at that. Or, I’ll get the part and make a non-junky replacement myself and Ebay the replacement with the excess XJ6 parts. It really depends on whether the new part I need turns out to be of lower quality than I want, I guess. The issue of part quality has been coming up quite frequently on restoration forums, and not just the forums devoted to the Jaguar marque.

The alternator upgrade (or at least “changeover”) has been well documented. It involves changing the ground from positive to negative. You don’t have to stick with a Lucas alternator, which is a blessing, I think. AC Delco alternators have been used (and it seems to me that Classic Jaguar has offered an upgrade kit using an AC Delco unit). Ray Livingston has described a way of using a Hitachi pickup truck alternator for an upgrade of the 3.8 liter setup. This requires a special bracket available from XKs Unlimited (part number 08-0399 in their 2005 catalogue, p. 316). But the same processes would work for installing a Hitachi on a 4.2 liter engine, using a standard alternator bracket. Ray’s documentation is available from XKE-Lovers (PDF).

Speaking of mounts, I got my parts from Terry’s Jaguar Parts, and I got new motor mounts, a bushing for the upper engine mount, radiator mount bushes, and a new fuel sump gasket from Motorcars, Ltd. The engine of course, is practically ready to have the transmission mounted, so this restoration journal entry is still behind the curve, so to speak. I’ll trade timeliness for some thoroughness. And there are some issues still to be dealt with — adaptations for the old (nicer) value covers, the crankshaft pulley, and of course, the alternator. So, there are still things to square up before this one runs.

June 2007 – Cylinder head differences, ’63 and ’79

The head — 1963 E-type v. 1979 XJ6

As a side note before launching into depictions of the 3.8 and 4.2 heads, I discovered in my reading that Jaguar wasn’t the first to have bored out the 3.8 (or, maybe, the 3.4) liter engines to 4.2 liter displacement. It was reported that race teams had done so well before Jaguar decided to bore the XK to the max. If that was the case, I think Jaguar’s design for the 4.2 paid more attention to cooling than a race team could have. The major differences between the 3.8 and 4.2 liter versions of the XK seem to me to concern cooling.

Essentially, the cylinder heads are the same with the expected differences from the placement of the bores for the 3.8 and the 4.2 liter displacement. It’s quite apparent that the XK block couldn’t have gone any bigger than 4.2 liter, by the way. The bores are tight. The cylinder heads differ in the way that they handle cooling, though.

On the intake side, the XJ6’s 4.2 includes additional holes for coolant to be passed to the manifold. These holes may well be in the 3.8 head, too, though they seem to have served as a way of clearing the casting before they were plugged.

The only physical alterations to the 1979 XJ6 cylinder head were plugging these coolant holes with Dorman plugs (number 555-020) and removing an emissions control device (see below). Otherwise the head looks to me to be quite close to the earliest 4.2 and 3.8 liter versions perhaps except for some coolant holes at the rear and a somewhat stouter casting in the front timing chain area. Of course the machining was also slightly different for the hemispherical chambers for the differently sized engines, but the external intake side was similarly machined to accept the intake manifolds, one piece for the XJ6 and three-piece for my SU setup.

Here, as below, the top picture shows the 1979 XJ6 head, and the bottom shows the 1963 3.8 E-type head.

XJ6 4.2 liter head, intake side. The two round coolant holes were already plugged with Dorman 555-020 inserts before I took this picture. With the exception of those open holes, the XJ6 head is machined the same as the 1963 3.8 liter head.
E-type 3.8 liter head, intake side. The holes that were later used for coolant were plugged with threaded inserts in the 1963 3.8 liter head for the E-type. Other Jaguar models using the 3.8 liter head may have used the holes for coolant, but I haven’t looked into that.

The top of the 1979 head sports six holes on the plane where the spark plug holes are located. They sit on the left side of that surface and are positioned between the holes for the left-side head bolts. These holes are for an emissions control device, lines for which attached to a manifold and had an attached heat-deflecting barrier. I’ve been told that this emissions device is commonly removed on XJ6s of the time and the holes plugged. Actually, when we removed the lines and the fittings from the head, they were hopelessly plugged with grime so I doubt they served any purpose. The holes led into the exhaust side of the head. They might simply have been intended as a means of speeding warm-up.

The three plugs on the XJ6 head were unbranded Dorman-like inserts. The 1963 3.8 head used bolts to do the plugging. I believe these holes were for clearing the cast. The 1963 head gives the impression that the bolts do some reinforcement work, and even if they did not, the process of threading the holes for these inserts (and, for that matter, for the holes on the intake side) must have taken some time and care. Certainly that required more work than inserting plugs into the XJ6 head.

XJ6 4.2 liter head, top view. No paint on this one, and as a matter of fact very little worry about appearances. Grinder marks were plainly visible. Note the plugs in the three cast clearing (probably) holes and the emissions control device holes offset from the spark plug holes. Otherwise, from the top the 4.2 head looks just like the 3.8 liter E-type head.
E-type 3.8 liter head, top view. The gold paint is a bit taken off from the head cleaning, but the polished aluminum and the paint dress up this head. Instead of pressed in plugs, threaded bolts fit into the three holes along the head. Otherwise, there’s not much besides the emissions device holes on the 4.2 liter head to distinguish this one.

Bottom’s up, the head is nice and true, just back from the machine shop. At the rear end of the head, there is a major difference from the 3.8 head. The 4.2 liter head has two coolant holes that appear in an extension of the cast, at least when it’s compared with the 3.8 liter head. The 3.8 liter head more or less has a flat rear wall, while the 4.2 liter head flares out as it meets the block. Of course, the bore locations vary between the 3.8 and 4.2 engines. The XJ6 head has twelve additional coolant holes that are inset more to the midline of the head, fore and aft. These small holes roughly meet the block where a machined cut sits between the bores. Coolant going through those cuts certainly was effective and the cuts themselves probably allowed for expansion in the metal between the bores. (I’ll probably take some pictures to illustrate this difference when I muster up the strength to move the 3.8 block around a bit.)

The 4.2 liter head also cut pairs of coolant slots in the outermost positions adjacent to the bores. I’m not exactly sure what the purpose of that was unless to strengthen the face a bit. The 3.8 liter head has large single slots in the same position. The 4.2 liter head looks a bit beefier. Walls are thicker in the front, and the hole sizes are smaller, yet there seems to be more coolant flow possible, and more directed flow at that. I’ve not weighed either head, but I’d bet the 4.2 would be noticably heftier.

XJ6 4.2 liter head, bottom view. The bottom is the most different from the 3.8 liter head, in that the coolant holes are more numerous both in real numbers of vents and by the addition of the two new vents at the rear and ten holes near the bores. It seems obvious that the engineers paid a fair amount of attention to cooling the 4.2 liter engine. In comparison to the 3.8 liter head, the aluminum casting is a little stouter, as the walls at the front timing chain cover show.
E-type 3.8 liter head, bottom view. In comparison to its larger brother, the 3.8 liter head seems simple in design. Where the 4.2 liter head split long slots into two, the 3.8 let the casting have long coolant slots adjacent the bores. The small, near-bore coolant holes on the 4.2 are absent here. The casting is a little thinner on the front, and on the back wall of the timing chain cover, a small “V” is grooved in front of number six cylinder.

XJ6 4.2 liter head, rear view. Note the bulge and the extra aluminum in the casting at the very end. This bulge is where the additional two coolant holes fit. The rear end of the cam areas are a little different.

The extra metal on the rear end of the 4.2 liter head is easiest to see with the two heads side-by-side. This extra bulge is practically unnoticeable from the top, since it only flares out from the back face of the head about an inch from the base of the head. I don’t know exactly where the coolant goes within the head itself, especially since the internals of the castings are both quite airy — filled with voids at least. The two extra coolant holes that the extra metal allows must have served the coolant needs of the head itself, however. The holes are actually quite well removed from the cylinders in the block, and I have assumed that the flow from these extra holes would have be down from the head, probably originating from areas nearer the cams than the valves.

You can see one challenge in the new head — it doesn’t have holes for the bolts attaching the tach generator or serving to block off the end of the cam area. On the XJ6, the lower semicircular void was fit with a rubber plug, and the value covers lacked any semicircular cutout. If I refit the tach generator, it would probably be merely ornament in any case, since the cam end won’t drive the generator, I believe. I might drill and tap the holes, though. I don’t know if I want to put up with a make-do plug.

E-type 3.8 liter head, rear view. No extra metal here. The head ends straight off the back. Note the threaded holes to fit the tachometer generator (right side) and the hole cover (left side). The area around the cams are more subtly cast than in the 4.2 liter head.

I have an intake head gasket from the 3.8 — it looks to me pretty much the original, since it’s as thin as could be. And I have a new head gasket for the 4.2. I have yet to compare them, except in the most cursory fashion. The new gasket is considerably thicker, with metal rings fitting the holes for the bores. I thought about asking Ray Livingston for his special spreadsheet to determine actual displacement, but I wonder if it would apply on this engine. This one has 8:1 pistons, I’m almost relieved to say. Even with some shave off the head, the compression shouldn’t exceed 9:1, and least by much, and I’ll be running premium gas anyway.

Aaron got the upper end and bottom end gasket sets for me, and when I can retrieve a few tools from neighbors, I’ll be setting things back to rights. Terry’s Jaguar Parts is sending the last bits (as far as I know) and a cam setting tool. So, we’ll soon be good to go.

I’m hoping that the next entry will do the same job on the block and its accessories. I have learned that some 3.8 E-type elements will need to be refitted on the engine, and the oil filter fitting that I was happy to see on the new engine might actually prove to be a bit of a challenge.