Hopefully when you changed your car's timing set, you didn't toss the old gears and the chain. I almost did, but my wife showed me this: http://www.uncommongoods.com/product/auto-timing-chain-and-gears-wall-clock
$125 US plus shipping. Right.
So I decided to kludge this together for my brother's 40th birthday.
Bonus: you don't need to weld a thing! Although I'm a welder, I like the idea of the gears and the chain suspending each other. Besides, if your car used a belt, you wouldn't be able to weld them, since the belt is made of rubber and twigs and cat pelts.
Step 1: Parts
Timing gear set: crank gear, camshaft gear and timing chain (free or cheap)
Clock movement kit with hour and minute hands ($8.00 US online) - This one has a 5/8" shaft and Maltese cross hands.
AA battery (depends on your clock movement) ($1.00 US, or less)
second hand for clock
clock's wall-mounting bracket
paint(s) and primer of your choice - spray paint is the easiest
masking tape and razor blade
nail or screw from which to hang the crank gear (the smaller of the two gears)
1/2" to 5/8" thick spacer for the nail or screw (to offset the thickness of your clock movement's plastic case
self-adhesive numbers or dots
Step 2: Tools and supplies
small wrench or socket - to tighten clock shaft nut to gear (gently!)
wire to hang chain and gears to dry
latex or nitrile gloves
clean lint-free towel or rag
wax/grease remover for paint prep, such as DX-330
large washer, stainless - to tighten clock shaft nut against face of cam gear
bushing - to center clock's shaft in center hole of cam gear (11/16" O.D x 5/16" I.D x 1/2" tall in my case)
paint - I used Rustoleum's Sunrise Red, gloss black, and Plastikote's clear gloss spray cans
wax paper - to set clock hands on for painting
heater to dry paint
clean brush to degrease parts
hammer to drive the nail into your wall
Step 3: Clean parts are happy parts
You will need to clean the oil, dirt, grease and fingerprints from your gears and chain, otherwise the paint won't stick.
I borrowed a parts cleaner which removed most of the oil from the timing set. Then I suspended the chain with baling wire, sprayed DX-330 into all its crevices and brushed it clean. This took several sessions.
Let it all drip dry.
Step 4: Paint
Remember, kids, the first half of "painting" is "pain." Actually, the hardest part of this step is watching the paint dry.
I taped a sheet of wax paper to some cardboard - I figured the delicate hands would be easier to pull up away from the painted wax paper, instead of gluing themselves to the cardboard. And they were.
Mask off anything you don't want painted (like the car or the dog), prime the parts if you like, and paint away. Follow the instructions on the paint can.
First attempt at painted the alignment dimples red: The syringe came without a needle (so it was sloppy), because it was for medicating our chickens, and chickens don't like needles; they're... chicken. (You just never know when your hens will come down with human pox.) Twisted up paper towels worked better for detail work.
You can see the alignment dimple painted. Stupid syringe.
I sprayed clear gloss paint over everything to make it shiny and seal in the red dots.
Step 5: Good timing
Insert the clock's shaft from behind the larger [cam] gear. Insert your bushing if needed. Add the large washer.
Install the clock's washer and nut to secure the clock to the gear. Tighten by hand or gently with a wrench.
Carefully press the hour hand onto the shaft, then the minute hand with its oval or "double-D" shaped hole. If you're using the second hand, lightly press it into the center of the shaft.
Correctly insert your fresh battery in the clock's battery holder. Set the current time using the clock's little serrated wheel (usually above the battery). If so equipped, move the clock's ON/OFF switch to the ON position.
Run your chain around the large clock/gear.
Pull the top of your chain up using the smaller gear, and holding the small gear, lift the entire timing set up off your filthy garage floor and hang it on your filthy garage wall. Now is a great time to add numbers to the gear's dial face if you wish. Or you could paint some of the teeth to denote clock positions.
Note: this is opposite of how the timing set would appear in your vehicle's engine - the small gear for the crank would be at the bottom. You could certainly flip the whole contraption 180 degrees, but then you'd have to find a job for the little crank gear to do.
Time's up. Congratulations, you've made your first car part art. It's a start!