September 2008 – Engine runs!

The old beast runs!

This one is for Aaron, who is now off on his own in Mooresville. And this is the last web entry for the fifth year of restoration; the next entry will start the sixth year! Maybe the sixth year will be the year of driving the old beast.

If a picture is worth a thousand, words, I thought, why not try a video? Well, I’m sure it’d be worth another 10,000 words or so, but the camera we have is very, very old. Fifteen-second

videos is about all it can handle, and that doesn’t quite cut it. However, take three 15-second videos, and maybe you’ve got a shot at, say, the equivalent of 2,500 words. So that’s what we’ve tried here. A before the start video, a start video, and an (inadvertent) after-the-start “Woo-Hoo!” video. The actual start video, as you might note by the absence of ear protection, doesn’t quite fit the sequence. It’s actually the second start, not the first — a historic recreation, as it were.

But this was really, really fun! More fun than we’ve had with the car in ages and ages. More fun than … even spraying color (as we did almost exactly four years ago)!

There were some extraordinary requirements for this start. First, the starter button (charming thing), still won’t play well with the solenoid. I believe this is a matter that has more to do with the starter solenoid setup than the starter button. I checked out the button and all is well. The wiring diagram for the solenoid seems straight-forward enough, but I have to wonder about the “downstream” things like the coil and the mysterious distributor. It could be that the poor solenoid is expecting some downstream happenings that, well, just aren’t. The result of this confusion was that I couldn’t just press the starter button to have the engine come to life. I had to hotwire it. A simple matter of taking the starter wire and bridging the solenoid leads manually.

It works just great, and should be a lesson in how easy it is to steal a car like this. Thirty-seconds under the hood and you’re driving it.

There are also some very loose ends — quite literally — that have to do with the wiring. As the good XJ6 folks on Jag-Lovers told me, I needed to fit an amplifier to the distributor in order to get spark. I figured that it was best to make sure the system worked before making the necessary fittings for the amplifier, and so I have temporary wiring in place for the amplifier. On an XJ6 from the late 1970s and 1980s, the amplifier was grounded to the body, and I’ll need to make sure that the grounding is suitable for this piece. The wiring from the distributor to the amplifier is fairly short, probably about 10 to 15 centimeters, so the fitting needs to be in close proximity to the distributor. The leads that run to the coil are not that long either. I haven’t done it yet, but I am going to fashion a metal bracket that will hang on the left subframe forward, near the picture frame junction. The bracket will be partially obscured and hang on the engine side of the frame. It won’t be up to concourse standard, but the engine will work (and reliably, I hope).

The video of the actual start makes it appear that it was just a matter of doing the hotwiring, and after things were set that was the case. I was amazed at how quickly the old engine came to life. (The cylinder head redo probably had some influence on that, of course.) Getting to that point was a bit painstaking, since Aaron and I wired the distributor badly. We consulted the shop manual that showed the old 22D distributor in its illustration, and we took the illustration a bit too literally. We identified the wrong connection on the AB14 cap as belonging to cylinder number 6 — the frontmost one. The confusion had to do with the different orientation of the vacuum advance on the 22D and AB14 setups.

The result was that our wiring was off by one. And the result when I tried to fire thing up was a bit disconcerting. Instead of a popping, exploding coming-to-life, the engine became a several hundred pound flamethrower. Flames poured out of the exhaust manifolds, sometimes mustering a bit of an explosion. But, alas, no joy. I managed to singe the hair off my right arm in my starting attempts.

In order to set things to rights, I focused first on the carburetors, since the thing seemed to me to be set extraordinarily too rich. They seemed OK to me, though I know they’ll need tuning. Manipulation of the distributor timing just didn’t work. I then did things the right way, and turned the engine to 12° to 14° before Top Dead Center (TDC) markings on the crankshaft dampner. That orientation should point the distributor rotor toward the setting for cylinder six. And when I looked, the error was immediately apparent. We had the wires offset by one plug. Fixing that was as easy as moving wires over.

With the wires in the right place, the engine immediately came to life. Totally amazing. Wonderful to witness.

The thing is loud without an exhaust system coming off the manifolds. I can hardly wait to fit that, so the characteristic Sir William’s Six Symphony can ring around Rougemont. But the exhaust system will need to wait for a bit. I’d first like to set the things straight that are dangling on wires. There are also a couple of coolant leaks that need attention.

I wish that Aaron had been able to be on hand for the initial start, but he was able to hear the engine via a telephone connection. He’s moved to Mooresville (north of Charlotte) to attend the NASCAR Technical Institute. He said he could tune the carbs, and I believe he could, especially after he has that training behind him.

More on the ignition system

Peter Crespin mentioned on the Jag-Lovers XJ forum that he likes the AB14 distributor, and now that I’ve looked at it and read a little about the physics behind it, I think it makes sense, too. There really isn’t much to go bad — at least as far as moving parts are concerned. Aside from the parts that spin (and do so deep within the engine), nothing touches enough to do anything counting as friction. I’ve reused the picture from the previous web page to illustrate this. The star-shaped round thing spins, of course, but it doesn’t physically touch anything to its sides. The influence is little more than a purturbation of, well, mysterious tiny things or, as the physicists would have it (at some times and other times, not), waves. I don’t know, as I suppose it matters which way you’re looking at the thing … so Professor Heisenberg. The main thing is it causes spark. (If you’re interested, head to the prevous web page and click on the links associated with “reluctor” and “Hall effect.” Probably read the Hall effect article first, and don’t sweat the mathematics.)

Spark was a bit elusive, simply because I hadn’t a clue about what I was dealing with, except that the innards of this distributor didn’t look very familiar. I needed another part to complete the setup — an “amplifier” that sits between the distributor and the coil, with the two leads from the distributor heading into the amplifier and two wires out heading to the coil’s positive and negative posts. David Boger had the piece, and he shipped it to me pronto.

Sure enough, the system is the AB14. The Lucas label proclaimed it.

I hooked the amplifier up by just plugging it in, and I hoped for spark. But, nope, there was no joy, not even a little cold burst of electricity. A little study of the amplifier itself was instructive, though. The mounts on the back are quite purposeful; they’re little triangular outcroppings that convey solidity and contact. So I figured that the housing and the little triangular mounting parts were intended to serve as grounding points as well. A quick grounding wire attachment was all it took. I had ground and spark.

This was one time when I think reading the instructions would have been nice, but I got by with good counsel from the folks at the forum and a little critical thinking. I have gathered enough little bits of evidence to lead me to believe that the engine was a late 1979 year product, very likely an engine that would also have a home in a 1980 model year car. I recall that the donor car was a model 1979, but the build date might have been late. It might have sported some features that would be common in the following model year. Peter Crespin wondered out loud whether the setup I have was an early AB14, and I know when I got the replacement distributor cap, the NAPA fellow told me that it was “actually” a 1980 model cap. I suppose I could investigate with a little bit of work.

But, heritage questions of a replacement engine are much less important than the fact that the thing turns, works, and is loud without an exhaust system!