Thursday, March 24, 2011

Modification: Lightweight Flywheel

A lot of people ask if they should buy a lightweight flywheel for their car. My 2 cents are: If you can get it cheap, when you've already got the car apart for a clutch job, do it. It's been a big plus in every car I've ever done it on, noticeably accelerating faster, but I've always gone from factory, where all the weight is on the outside, to aftermarket aluminum with NO weight on the outside ring. Why does that make such a big difference?

First, let's go over why the factory flywheel is so heavy. Manufacturers put weight on the outside (perimeter) of the flywheel to increase the moment of inertia. Check out a picture of a factory flywheel here. The higher moment "stores" more energy, so it feels to the driver as if you have more torque when starting from a stop. Another big plus for manufacturers to have heavy flywheels: smoother idle, as it takes more energy to speed up or slow down the wheel, so it "smooths" the dips and peaks of the four-stroke cycle of your engine. Also, shifting becomes a bit easier, with the revs changing more slowly.

Those sound like things you wouldn't want to sacrifice, until you realize that you are sacrificing performance for a perception of performance.

A lighter wheel (really the perimeter around the wheel, the weight inside the wheel matters much less) allows you to speed up and slow down the engine much faster - that means quicker acceleration (more effective in lower gears where the engine is changing speeds faster) - and it's less overall weight in the car.

The downsides are that your idle can be rougher the lighter you go, and you have to rev the engine a bit more on every launch. Lighter flywheels also transmit changes in speed (both from the engine or the tires) with a lot less "smoothing" so it makes for a bit of a rougher ride.

The intensity of these factors varies from car to car and flywheel to flywheel. In some cars it is barely noticeable, in others it will amaze you.

The effect on MPG is probably very small, you'll drop some MPG if you have to raise your idle, you'll gain some if it causes your driving habits or if the weight makes a big impact.

Now that you've learned about heavy or light flywheels, don't forget about dual mass flywheels. They use springs to absorb the shocks of driving, giving you a smoother ride then even a very heavy flywheel.

The downside being added complexity, price, and they can fail.

Tuesday, March 22, 2011

A rotary engine story, or, The $200 TII

Once upon a time, a friend of mine (Theo) said a classmate of his told him his RX-7 Turbo II blew it's engine and for $200 Theo could have it. He didn't want it but he offered the car to me, and I gladly accepted.

I paid and Theo brought me the car. Looked decent, except the exhaust rotted from sitting so long. I checked it out, no compression. Squirted some oil in the spark plug holes, rotated the engine, repeat a few times, put plugs in, hooked the car via tow rope up to Theo's 1993 Honda Civic. I popped a battery in, turned it on, and just sat in the car with it in gear and my foot all the way down on the gas while Theo drove in circles at about 10MPH.

After a few minutes of this you could hear the exhaust note was changing, smoke started pouring out the back.

A few more minutes and I noticed I was catching up to Theo's car at WOT . . . . but if I hit the clutch the car wouldn't run on its own.

Around a few more times and you could hear the turbo spooling . . . and it ran . . . .

With a bit of cleaning and a few fixes it passed MD inspection and was my daily driver for over a year, then I sold it.

Thanks, Theo!

Thursday, November 18, 2010

The Abomination

Sorry I haven't updated in over a year. Been busy with health problems, work, and family. To make it all better, have a picture of what the pipes under my sink looked like when I bought the house.

How many things can you find wrong with this picture?

BONUS: Here is a Cat5 Ethernet drop that's been hit by lightning!

Personally, I really like the design left on the walls.

Sunday, September 20, 2009

Irish Cream!

350ml decent whiskey (you can adjust the kind and quantity based on taste, the whiskey does not have to be Irish)
1 14-oz. can sweetened condensed milk
1 cup heavy cream
2 tall tbls hot coco mix (you can use 2tbls of chocolate syrup, but I like the taste less)
2 tsp. instant espresso (you can use instant coffee too)
2 tsp. vanilla extract
1/2 tsp. almond extract

Throw it all in a blender, then a jar, then chill in the fridge.
You only need to blend it for a short time, 40 seconds at most on a rather slow setting - if you over blend it you'll churn your milk to butter.

It'll last a month or two in there.

Shake well before serving. Serve over ice. Or ice cream. Or as I prefer, in cold brewed, iced coffee, with a shot of mint.

I'd love to hear what you think of the recipe, or what variations you use (I've read about people adding raw eggs to make it creamier, or coconut extract for a slightly different taste). So leave a comment :)

Thursday, September 10, 2009

Cold brewed coffee

I guess you can say this coffee is more "eco-friendly" because it doesn't use heat. It's also more "delicious." I like the way coffee tastes when brewed this way, you get a lot more of the subtle flavors and a lot less of the undesirable ones. I've also noticed it really smoothes out the "bitter" taste of some coffees.

- Mix 1 cup coffee grounds to 4.5 cups water

- Stir it every so often till the grounds become saturated and sink to the bottom.

- Let it sit for 8 hours (a lot like sun tea)

- Filter it (I stick a wire strainer over a pot and put a paper towel in it)

- Filter it again (I use a regular old coffee filter in the strainer this time, and just like a tea bag, don't squeeze it to speed it up)

- Store it in the fridge for whenever you want coffee.

It'll come out more concentrated, so you may have to dilute with water to taste - or if you're like me, don't dilute it at all, and just mix some Irish cream and a shot of mint in with it, and pour it over ice.

I'd love to hear what you think.

Friday, June 19, 2009

Attic Mayhem

Simply put, your roof and attic are the most important parts of your house - anything else is just extra stuff holding the roof and attic up. The whole purpose for a house is to be a place to live in that will protect you and your stuff from the weather, and your attic and roof are what does almost all of the protecting. The roof keeps rain out of your attic, and your attic keeps the house at a reasonable temperature.
The attic keeps the heat in your house during winter, and the heat out during summer. The attic will get extremely hot during the summer, from the sun heating up those dark-colored asphalt based shingles. It will retain that heat long into the night, forcing you to run your A/C a lot longer. There are three solutions to this problem:

1) Vent the attic, get that hot air out of there.

There are many ways to vent your attic, and it can get pretty complicated if your roof is a complex shape. If your roof was properly built in the first place, it's designed so that cold air comes in from the soffits (vents under the overhang of your roof) and flows out through a vent at the top of the roof, allowing a constant "wash" of cold air over the underside of the roof. If you have a crappy old house, like I do, you might just need to install vents and an exhaust fan. Click here for some pictures and demonstrations about what I am describing. This is also important for keeping moisture out of the attic.

If you have mold, mildew, and rusting nails in the attic, it's probably not venting moisture well enough.

2) Insulate the attic, or separating your living area from the inferno over your head.

This is the most important part of your house to insulate. Here is where the heat of the sun is kept out during summer, and the heat from your heater is kept in during winter. Different areas have different standards for how much insulation goes into your attic, for example, in Maryland the standards are:

- Attic: (Green: R-49) (Std: R-38)
- Floor: (Green: R-30) (Std: R-25)
- Exterior walls: (Green: R-18 to R-22) (Std: 13)
- Unventilated Crawl spaces: (Green: R-25) (Std: R-19)
- Basement walls: (Green: R-25) (Std R-11)

You can see that the attic calls for the highest R-value of insulation in the house.

You have a lot of options for how to insulate the attic, If your attic is pretty open and square, like mine, you can use rolls of fiberglass, or you can use blow-in insulation (for those hard to reach areas, or if you're too lazy to roll out the fiberglass). Another option is spray-in insulation, it's expensive but is supposed to be the most effective.

You don't want to compress the insulation once it is in, the air inside the insulation is one of the things that gives it such great insulating properties.

Use a mask when laying fiberglass, and rub all exposed skin with baby powder before starting work, it makes the glass much less likely to stick to you and saves you tons of itching. I tried this, it works.

3)Reject heat before it even gets into the attic.

Don't use black shingles, they soak up the sun. If you already have them, many companies offer a aluminum-based silver paint that not only protects your roof, but helps reflect heat away from your house.

If your roof is the right shape, it will reflect and focus the heat onto your neighbors house, causing it to explode. Wear eye protection.

Now, if you're one of those idiots who bought a really small house with no space to store anything (like myself), then you probably want to turn your unfinished attic into storage space. That is what I chose to do, because the roof is so low you can't even stand up in the middle of the attic - turning it into living space would be pointless, wasteful, and cruel to your guests if you turn it into a guest room. I went to Home Depot (boo) and grabbed the cheapest flat wood I could find that would still hold my weight - half inch OSB (chip board) at $5.22 per 4x8 sheet. I had them chop it in half into 2x8 sheets to make it easier to transport and manage (it's free to have them cut your wood).
My house is divided into two sections, the addition, and the old house. The addition has proper 2x6 supports and is very sturdy. I simply put the OSB down and nailed it in place, sometimes notching the edges to allow a wire through. The old house has 3x3 beams, and is not even remotely sturdy. There are many solutions, but I just wanted storage space. So I made supports by cutting a 2x4 to fit and screwed one end into the joist (the 3x3 beam I was going to be standing on) and screwed the other end into a rafter (the slanted beams holding up the roof deck). Then I notched the OSB to fit around the new supports.

Now I have a floor I can walk on and store stuff on in the attic.

My friend Mark did most of the measuring and cutting for me, everyone needs a Mark. They may be out of stock of Mark at Harbor Freight, check back in the future.

Wednesday, April 29, 2009

Ceiling Fans: The Hanging Menace

Here in Maryland it was dry, windy and freezing only a few weeks ago, now the mercury has climbed above 90 degrees, the wind stopped, and the humidity hit the point where you only have to inhale if you want a drink of water.

As the local power company knows, Montgomery County, Maryland usually welcomes in the weather with the cacophony of a couple hundred thousand air conditioners turning on at once, converting piles of money into pure Colombian uncut cold air. One of the multitude of roaring air conditioners was attached to my house, it's metal tentacles reaching out and taking money out of my wallet and beating up the occasional kid for his lunch money.

I was alarmed, and not just because my air conditioning unit was mugging people - I was alarmed at the fact that the air conditioner took a very large amount of energy to make the house a bearable temperature, and due to the lousy insulation in my old house, it had to keep using a lot of energy. I calculated it out to an extra $100 to $120 a month to keep our house cool.

I needed a solution, so I turned to the best model I could think of for saving money, an industrial revolution era sweat shop. Looming far over the heads of the hapless and overworked rabble below, powered by their rage and their deep-rooted hatred of humanity, the ceiling fans loom.

The history of the ceiling fan goes back a long way, and with modern fans the concept is the same, move air around. In a modern home, the ceiling fan is usually only noticed when really dirty or unbalanced - or if it is mounted too low and some unsuspecting fool tries to take off their coat and accidentally hits the fan, sending the dust that's been sitting on it for twenty years flying everywhere, but I wouldn't know anything about that. When functioning properly, the fan gets a nice breeze going in the room, just enough to be comfortable without being obnoxious. It makes higher temperatures bearable without actually dropping the temperature.

Unlike an air conditioner, fans take very little energy, usually around 80 watts on their highest setting, around the power use of one of your ancient Edison-era earth-destroying incandescent light-bulbs. That is why they became very popular in the 70's energy crisis. In fact, they liked ceiling fans so much in the 70's that they had to invent platform shoes so everyone could be closer to them.

In the winter you can set the fans on reverse to push the hot air that collects on the ceiling back down to to you. I haven't tried this myself yet.

There is a huge selection of fans to choose from, though the newer fans actually tend to be much lower quality then the older fans (for example, older fans tended to come with solid wood blades instead of particle board). I read a bunch of articles going on about blade pitch and shape and motor quality, but for my price range I just wanted a fan that worked well and was cheap. I got three from Home Depot, made by Hampton Bay. $40, $50, and $60. If you want to spend a lot more, you can get nicer fans, but for me to spend more money on a money saving device, it better deliver more value - such as allowing me to travel through time or get along with my mother-in-law.

Fans come in a lot of different sizes, but almost all of the ones for sale at Home Depot were 52 inches (a measure of the diameter of the whole unit, not just the blade). To find the proper size for your fan, check out the handy chart here. I have low ceilings so I got "flush mount" fans (most fans have a "flush mount" feature). The theory behind the number of blades a fan has is more blades, more air moved at a slower speed, so less noise and bearing wear.

Installation of these fans is pretty easy, despite the massive instruction novel included with them. Installation is made even easier if you have a great friend like Mark helping you install them. For all three of the fans I had to install, I was replacing an existing light fixture, so the wires were already there. Also, they were strong enough that I did not have to reinforce the receptacle. If you do have to reinforce yours, it's not that difficult, and a lot of fans come with kits to help you do just that (not that you really need them, a 2x4 and some screws will do the job nicely)

The first fan I got went over the kitchen table, it's a 52 inch that did 4000 CFM (Cubic feet of air Per Minute) on high. Unless you were sitting directly under it you didnt feel much air at all. In the bedroom I installed a 52 inch fan that featured 5000 CFM on high and it was perfect. Just a warning to you, don't expect hurricane force winds from a regular cheap-o store bought ceiling fan, you don't really want that, you just want the air moving so that you'll feel a lot cooler and the humidity wont drown you. They look nice too.

It's nice falling asleep knowing that you're comfortable and the A/C isn't on all the time, sucking up money and small children, and the breeze is nice too.

If you are considering getting a ceiling fan, Wikipedia, despite it's obvious biases, actually has a really nice article on them.