Friday, October 24, 2008

Oh My Aching Back!

I've got a broken back!

As a result of the cancer, my third spinal vertebrae has suffered a compression fracture. This was discovered by last weeks MRI ( Magnetic Resonance Imaging ). The fracture explains the pain I've been experiencing, as well as the steady increase in that pain. A month ago I could work standing up for about 20 minutes before the pain became too much to take. That has been steadily decreasing until it's reached the point where it takes barely five minutes for the pain to rise to the point where I can't stand it and have to sit down. Sitting down causes the pain to stop increasing but the pain is still there and it takes a lot of pain-killers... or a lot of time... before I can move about.

Imagine not being able to take a pee... or to fill a glass of water at the sink... or even to walk from the bedroom to the kitchen.

So they did the MRI and there it was: the third lumbar vertebrae was so badly honey-combed by the tumor that it had been crushed: a compression fracture.

There is a surgical procedure that is supposed to offer some relief. How much depends on who you talk to. So far I've found only one person who has had the procedure done; a woman a little older than me who suffers from osteoporosis. She says the pain is less but has not been totally eliminated. To her the advantage is that the pain does not become steadily worse when she tries to do housework or ride in a car.

If you talk to the people selling it, the surgery is the best thing since beer in cans.

I guess I'll just have to wait and see. Personally, I don't see how the pain could be much worse. It has gotten to the point where I'm pretty much trapped; unable to move about. If I can't move, I can't get the exercise I need to keep my remaining muscles in shape. If I just sit here like a bump on a log my body will slowly deteriorate to the point where I can't move, not because of the pain but because I simply lack the ability to do so.

The surgery is an out-patient procedure that takes only a few hours. The earliest they can get me in is about two weeks from now; maybe a little less. I'll try to keep you posted.

-R.S.Hoover
-24 October 2008

Sunday, October 19, 2008

MRI, Clearancing the Camshaft and Me


The x-ray mentioned in my last blog entry revealed nothing amiss. The pain is still there as is a monstrous swelling the size of a grapefruit that is its apparent source. But the swelling is all soft tissue; it offered nothing for the x-rays to 'see.' So I pulled up my pants and went home, accompanied by my lump and the pain. The next step was to schedule me for an MRI scan, which underwent on Friday.

MRI stands for Magnetic Resonance Imaging and takes advantage of two fundamental laws of physics. The first is the fact that every atom has a unique resonant frequency. The second is that fact that if you disrupt the local magnetic field, each atom will generate a small but distinct signal. The MRI machine provides a powerful magnet to disrupt the local magnetic field and a sensitive receiver to pick-up the signal given off by those disturbed atoms. (Yeah, I know... but I'm not talking to you, I'm talking to folks who don't have EE after their names.) That signal is fed to a computer and the computer puts the signals together to form an image. Of course, that image is only for a single slice of the target. To come up with a picture that makes sense you'll have to run the thing down the length of whatever you are trying to make an image of, then have the computer put all those 'slices' together.

The big advantage of MRI over basic x-rays is that everything generates a 'signal' of some sort. The signal from good tissue will be slightly different than the signal from bad tissue. That means you can now 'see' soft tissue, whereas the x-ray would blast right through them and not 'see' a thing.

I'm a ham radio operator (KA6HZF) and have a strong interest in stuff like MRI machines, which were invented only a few years ago, relatively speaking (they're about three years older than the Personal Computer, for example). Imagine a sewer pipe about as large as your shoulders. Rig a pair of runners on each side of the interior of the sewer pipe. The runners support a narrow table, allowing it to be rolled into the sewer pipe. You lay upon the table and get shoved into the sewer pipe, your shoulders touching the sides, your nose scant inches from the plastic surface. If you are even moderately claustrophobic, this is not the place to be.

An enormous coil is built around the sewer pipe and an equally enormous magnet spins around the outside of the sewer pipe. The magnet will cause anything within its field to give off a faint but distinct signal which will be picked up by the coil and fed to a computer. The computer performs a bit of mathematical magic on the signal and aligns that slice with the previous slice so that when you are done the slices will form a coherent image. The nice thing here is that the image will show soft tissue as well as bones and the odd bits of shrapnel.

This past Friday I reported to the Keeper of the Keys and she sent back to where Bill, ex-Air Force but a pretty good guy in spite of it, laid me down on a narrow bed and shoved me into the sewer pipe. Hit the big red button and the MRI machine commenced to hum and groan... okay, the groans were mine but the machine did hum a bit.

It took less than an hour for the MRI machine to slice me into electronic ribbons which were recorded by the local computer and stored. These would be processed by a more powerful computer which would combine them into an image. The image would be sent to the physicians and they would try to figure out what was causing the bulge on my hip.

So whats all this got to do with camshafts, fer crysakes!

Well... nothing, really. Except the camshaft in the picture is going to be installed in an engine fitted with a crankshaft having a throw of 41mm (stock is only 34.5mm). That means the connecting rods are sticking out 6.5mm farther than on a stock engine. And that means they are going to hit the camshaft.

Six and a half millimeters is 0.2559" - a full quarter of an inch. In the stock engine the connecting rods miss hitting the camshaft by about an eighth of an inch. In the big-bore stroker the connecting rods are about an eighth of an inch too long. So we have to grind away about an eighth of an inch to give them clearance. In fact, that's what this operation is called: Clearancing. It applies to the crankcase as well as the cam shaft.

The tricky bit is knowing where to grind away, and how much to grind away. In the case of the cam shaft, if you'll click on the image it will give you a blown-up view, allowing you to see where I've ground away metal from cam shaft. You can also get some idea of how much metal I've removed. If this is the first time you've clearanced an engine, odds are you'll go a bit too far. What you need is a gauge, something to tell you when you've gone far enough. (Remember, the camshaft must be strong enough to withstand the torque needed to open the valves. If you grind away too much metal... or leave a sharp edge that will allow a crack to get started, the camshaft will break.) Fortunately, you already have a gauge. It is the assembled crankshaft. That is, the crankshaft with all four rods installed. With the camshaft properly meshed with the crank (ie, with the dots properly aligned), rotate the crankshaft and observe the position of the rods as they swing past the camshaft. You want about sixty thou of clearance. Any more and you'll just weaken the camshaft whereas any less and you're liable to have a collision when the engine heats up.

-Bob Hoover

Monday, October 13, 2008

California Living


Mondays are always interesting. That's when we get to do all the things we should have done on Friday but forgot, and over the weekend when we were just too damn lazy, such as the Worm Roundup.

I'm a native Californian. I've never seen anything unusual in being able to pick vine-ripe tomatoes for the Christmas dinner salad. Or going skiing in the morning and surfing in the afternoon. Or visa-versa, depending on the tides and the weather.

But if you fail in your duties as a Worm Rounder-Upper there won't be any ripe tomatoes for your Christmas dinner, nor those BLT's you like to build. But Monday is also the day when the physicians treating my cancer decreed that I would have Mr. Roentgen's Mysterious Rays blasted through my right hip, into a photographic plate about 12 x 18. In fact, X-rays are about the last ditch when it comes to photographic plates, what with regular cameras and film being replaced by memory chips, disks and tapes. (I've got a hunch we'll soon see the last of film in x-rays, as a layer of fluorescing material is bonded to an ultra-high density array of photo-sensitive sensors. The resulting image would probably be a couple of gigabytes at a minimum and a terabyte isn't beyond reason. The advantages of a digitalized x-ray are almost too numerous to mention. This method is already in use in various scanning devices,(*) in which the digitalized data from a MOVING x-ray -- or other short wave-length emitter -- are fed into a computer which then generates a 3D image of the target area. (*) CAT Scan, PET Scan, SAT Scan and so forth.) But so far, no one has applied that technology to the Plain Vanilla x-ray machine, where you pump a few million volts between the cathode and the anode of a specially configured vacuum tube and direct the resulting X-rays toward the target, behind which you've placed a sheet of photographic film. To get to the film the x-rays gotta pass THROUGH the target, be it toes or telephones and the resulting image depicts the ease or difficulty of that passage.

The cancer is in my lower back and the pelvic girdal. Recent episodes of pain indicate that it may have gotten to my right hip as well, hence the need for Mr. Roentgen and his Rays. Which kept me from my duly appointed rounds in the garden and allow certain visitors to reach an unruly size, as shown in the photo. We don't use insecticides. But a lot of folks do. The catapillars quickly become immune to the stuff. But the birds that would normally eat the catapillars don't. The insecticides build up in the catapillars until they become toxic to birds. No more birds.

So I pick them off. Doesn't take long because we only have about half a dozen tomato plants, more than enough for our needs. A lot of folks from exotic places like Detroit or Buffalo give you funny looks when you mention growing tomatoes all the year 'round. But the worms believe it -- big wormy smile on their little wormy faces. Mebbe I could rig up some kinda portable X-ray emitter, couple of passes and all them caterpillars would be gonners. But until then I am the Official Worm Rounder-Upper. One of the burdens of living in California.

-R.S.Hoover

Wednesday, October 8, 2008

Shipmates



Some time last spring one of my brake cylinders failed. I jacked up the bus, pulled the drums and gave her a brake job with new cylinders and shoes on all four. Bleeding brakes, you start with the wheel farthest from the master cylinder, which is the right-rear, then the left-rear, then right-front and finally the left-front. Working alone, bleeding your brakes can be a bit of a chore and my ass was dragging by the time I got to the left-front. Turns out, I didn't do a very good job of it and ended up with a bubble of air in the front braking circuit.

It wasn't a major problem. The bus would still stop okay and I kept putting off fixing it. then I got sick. Then I got sicker and in June, 2008 I was diagnosed as having Multiple Myeloma, an incurable form of cancer. Incurable but treatable. I underwent radiation therapy then began a regime of chemotherapy.

Our house is about 300 feet from the road. Each week we haul our trash down to the road-side using the VW bus. Until the bus decided it didn't want to start. It took only a couple of minutes to isolate the problem to the starter, most likely in the solenoid. The repair is straight-forward: jack up the bus, remove the starter, repair or replace the starter and reassemble.

Unfortunately, thanks to the cancer I had lost nearly fifty pounds. I could barely lift a Volkswagen starter and any thought of doing the repair was ludicrous. It would have to wait until I was stronger. But that meant my wife would have to haul the trash in her cute little Mercury 'Tracer,' often having to make two trips.

Then I got a message.

CWO4 Darrell Daniels owns a couple of Volkswagens and lives about 20 freeway minutes from my house. Could he lend me a hand?

Boy! Could he!

Today -- Wednesday the 8th of October 2008, Darrell and his son Nick drove up to my place about noon. I had just about enough steam left in me to point my cane at the bus but that's all it took. Darrell jacked it up, braced it with jack-stands and had the starter out in less than half an hour.

Did I mention the temperature was ninety-six? I didn't, huh. Well, maybe that's good. Because the temperature was nearly a hundred! (I didn't mention that to Darrell either.)

I had a spare starter but it was in pretty sad shape. Since the problem appeared to be in the solenoid Darrell whipped out a VOM and checked them, comparing the bad starter to the replacement. The solenoid on the replacement checked out okay but the one he'd just removed from the bus was toast. He suggested re-using the old starter after swapping solenoids, so that's what we did.

To re-install the starter you have to get the nut onto the upper-right engine-mount bolt, which is concealed behind the blower housing. This is best done by someone with an extra elbow. With Darrell underneath the bus, Nick dove into the engine compartment, found the invisible bolt and ran-up the nut entirely by touch.

Nice Job! Of course, it wouldn't start. Having sat there for a couple of months, the bus' battery was down to eleven volts, dropping to about 6V when you tried to start it.

Jumper cables.

Vrrooomm!

The whole job had taken Darrell and Nick just over an hour.

Was there anything else they could help me with?

Well.... there is this little brake problem...

With Nick to pump and Darrell to wrench, they chased the bubbles out of the front braking circuit. Step on the pedal, it feels like it's embedded in concrete.

So I'm back in the Trash Delivery business :-) My wife will probably have to help me load -- I'm still as weak as a kitten -- but the old bus is ready to roll, thanks to Chief Warrant Officer Daniels and his son Nick.
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