Monday, July 30, 2012

Mini elm tree

I pulled this little elm out of the ground a few days ago. I chopped it short and cut some of the roots. Then I put it in some "recycled organic material" plus a little nitro.. I didn't figure it'd survive, but nitro makes every plant happy. This is 1 week after planting the stump.

Wednesday, July 25, 2012


Writing words is in the blood. I'm the son of a journalist and accomplished author, and the brother of an accomplished author. I've been told I'm a good writer, then a bad writer. For example, the entrance exam at a community college scored me very low on the essay portion, due to my not following the format. In fact, they scored me so low, I didn't even get into a required 101 level writing course. Bad writer. Academically speaking, I'm too informal. Maybe that doesn't count.

I found this simple script that removes wordiness from text by removing or simplifying words and phrases.
Zinsser transform:

And the nice, complete with library of transforms you can add to, Python script:

Monday, July 23, 2012

Flashback F100s

I love this site: 

All USA-made restoration, reproduction and original parts for old Ford F100s.

Tuesday, July 17, 2012

Timing chain guide rails

The V8 in the 500SEC (Mercedes M117 engine, 5.0 liter) is interesting. It has a forged crank, pistons, rods, light but stiff aluminum block and heads, double row timing chain, some other interesting bits for that time. OHC, 2 valve per cylinder, and like most benz engines have stainless valves with the exhaust valves sodium filled, hardened seats, polished ports, internally balanced and factory cc'd.
They do have a serious flaw though. The SOHC heads require a very long, very heavy timing chain, which is common on German cars of the 'investment' grade, which drives the valve and ignition timing.    The chain is guided and tensioned by a number of plastic guide rails. These are consumable items, since they are friction surfaces, subjected to wear by having a heavy steel chain under tension dragged over them at 1/2 the engine's RPM. I've seen some worn through to the aluminum backing underneath, which means bits of aluminum and plastic have ground off into the sump, and that the timing is waay off, chain probably wearing badly, etc.
This would be a problem on engines with bad cam oilers, bad chain tensioners, people not getting oil changes, bad/wrong oil, other simple things like that which shouldn't happen to a well maintained car. However, these were built more than 25 years ago, and nobody knew then how long the engines would be used or what time and chemical breakdown would do to the plastic guide rails.
BTW I don't think anyone had trouble with the rails in the 80s, not at least like they did with the weak single row timing chain on the 380 engines, which was later replaced with the double row chain.
Long story short, the guide rails will get brittle and break off, fall down into the timing cover and get stuck between the chain and teeth of a cog. This will destroy the engine beyond any reasonable repair, as the timing chain can jump a few teeth, break, or otherwise cause valve/piston interference, after which you will have nothing left but a block that may be salvageable.

In the above picture, the front timing cover is off, exposing the crank timing sprocket, idler, tensioner (left side) upper guides (white plastic sticking out of the heads). This engine has been conveniently pulled out of the car..
I think the labor on changing out all of the guide rails (at a good mechanic) will come to around $7k, plus all of the "While you're in there" shit that you'll want done, somewhere around $9k.

I didn't have any power problems or slapping noise at startup, or any indication that there was anything wrong with the engine except that I hadn't actually opened it up to take a look. That could have been a bad engine blowing mistake.
This is where it pays to know what you're getting into when you buy a used car. Know EVERYTHING about it. Become an expert in that model before you buy it so that you know what to ask, what to look for, how much it will cost to fix (time+money), whether or not you can drive it or have to trailer it home.
The above sequence shows what the guide rails look like when they've failed. It just broke in half, one half of which is bumping around down there on the ignition sprocket, just waiting to get chewed under..
A new set of guide rails (upper only) costs about $18, and they're white as the driven snow, unlike this one, which is brownish-oil colored, indicating it's chemically transformed over the years into a fragile, brittle time bomb.
To swap out the upper rails took about 4 hours, including the 'while your in there' shit, but without removing the front cover and getting at all the lower rails. The timing chain is showing no stretch, which is nice and unexpected, the timing gears aren't worn any more than they should be at this point.
One thing that's a concern with certain engines is one wearing part being of a dissimilar material or less wear resistant than the part wearing on it. For example the cams and sprockets are cast iron, but the chain is an alloy suitable for chains, the lifters of a hardened steel like 4150 or something even harder.
Of course all these parts are protected by a sheet of oil, but it's not a 100% friction barrier in any case.

Lightbox is dead?

If you are reading anything below that is missing a photo, it's because lightbox (the service) died.
I don't know why (because maybe they ran out of money?), or when it will come back on line, if ever, but until then, use your imagination?
I'll be finding some better way to take pictures and create posts automatically..
Or maybe I'll just write a little Android app that does this. I'll call it "instagramme". Billion dollard idear right thur.