How does a PCV valve work? What is it?

More then once I've had people ask me "Why do I even need a PCV valve? Can't I just cap it off?" Unlike most other things that are classified as "Emissions Controls Devices," the PCV valve is not useless. PCV stands for "Positive Crankcase Ventilation." What in the world does that mean? To get to the bottom of this, first we'll have to go over some basics:

You should vent the crankcase: We all know about the top of the pistons going through the 4 stroke cycle, but some of us forget about what is going on under the piston, in the crankcase. The crankcase is basically the entire "bottom half" of your engine, containing, you guessed it, the crank. Under the crank is usually a sea of oil, and above that, oil is being squirted or secreted out of many different holes and openings. As each piston drops, the pressure increases, and as each piston rises, the pressure decreases. If you pressurized the crankcase, the pistons would have to fight the pressure to move, so you have to vent the crankcase.

Ok, just cut a hole in the valve cover and put in a filter, that’s your vent, right? Well, it would work for that purpose, however, there are still two more concerns:

Blowby, and her ugly friend, Emissions: Because the seal of the piston rings is not perfect, during combustion, some of the unexploded or even burnt intake charge gets into the crankcase. This is called "blowby" and it gets worse as the car ages and the piston rings wear down. Blowby is a problem because it is acidic, possibly corrosive and explosive. You wouldn't want those gasses igniting outside the combustion chamber, would you? The water vapor in blowby gasses can condense when you turn off the car and cause rust. If left alone, blowby can cause viscosity breakdown (thinning) of your oil, and to top it off, these unburned hydrocarbons are bad for the environment. So you shouldn't just stick a vacuum on your crankcase and suck everything out into the atmosphere. Besides, there is a cheaper solution then going out and buying a vacuum; because your engine's intake is already a vacuum!

So what the manufacturers did is they put a hole in one side of the crankcase and connected it to your air filter, so that it can take in fresh air. This is usually called a "Crankcase breather." On a "V" engine this is usually done on one valve cover, and then the other valve cover is connected to your intake manifold. That way, when you're driving, the engine will suck up all the hydrocarbons and burn them, and keep your crankcase under a vacuum.

Sounds great, right? "But Jason," I hear you saying "It's called a PCV valve, why is there a valve there?" "Silence!" I'll yell, because you're interrupting me, you jerk.

So why use a valve? Your engine vacuum is not a constant. At idle, and at low engine loads and cruising, your engine produces lots of vacuum. However, at more aggressive driving (You know, like in DC?) the engine vacuum is much lower. To keep the vacuum in the crankcase high, they put a valve in that closes at low engine vacuum.

Another reason for the valve: inside the crankcase, oil is flying all over the place creating a mist, or just a splashing such a way that can get sucked into the engine through the PCV. That's mostly OK, as the engine can happily burn such a small amount of oil. However, it needs to be quite hot to burn the oil, and lean fuel mixtures from cruising are a lot more "oil burning friendly" then colder, rich fuel mixtures from hard driving.

Back in the 60s and earlier, cars used to just be equipped with a draft tube, which would just come straight out of the crankcase and out into the atmosphere. The "road draft tube" would use the air passing by to induce a vacuum. It would also randomly dump oil on the road, and just vent unburned hydrocarbons.

Some companies claim to have special PCV valves that make your car get 30% more fuel economy and the like, and like fuel line magnets, you should just ignore those.

A lot of people put "Oil Catchcans" on their PCV line, to catch the oil coming out before it gets into the engine. This keeps the inside of your intake manifold cleaner, and is a matter of personal preference for most vehicles. You can either make one yourself or just buy one pre-made online.

If your PCV valve goes bad, it will either fail "open" and always lets everything through, and that can lead to problems like oil-fouled spark plugs. The PCV can also fail closed, causing problems such as oil coming out your breather tube and soiling your air filter. If your system doesn't incorporate a breather tube, or it's clogged, your dipstick may pop off from the pressure, and your engine will run a little worse, possibly burning more oil.

Electric fan conversion for $20

Why electric fans?

A lot of people want to convert to an electric fan for their cars, either because their stock "clutch-type fan" is dead, to save energy, or to free up space in the engine bay.

Some people say that electric fans do not save energy, the reason being that you lose energy by converting it from kinetic energy into electricity, then back into kinetic energy, unlike the stock fan that is just belt driven without the conversions. This would be true, but only if the electric fan ran at all times. It saves energy by only turning on when it is needed. This is why most modern cars have electric fans. The engine does less work, so you get a little more power and slightly better fuel economy.

I removed my stock clutch fan in my Mazda RX-7 and replaced it with the stock twin fans out of a first gen (Mark I, from the eighties) Toyota MR2, and I did it for about $20. The reasons were simple. The most important reason I did this was that the stock clutch was dead, and a new one costs more then the MR2 fans at a junkyard. I also like having all that room in the engine bay, making it easier to change belts and observe engine operating conditions.

What electric fan should I use?

You can use almost any electric fan you'd like, I would recommend grabbing the twin fans out of a Mark II MR2 if you can, because they are less likely to be rusted out then the Mark I fans, and they look much nicer. The parts are interchangeable, and the motors have been upgraded. In fact, if you have dead Mark I fans, you can get rebuilt motors for the Mark II and turn the old motors in for the core charge.

Installation

This install is on a 1990 Mazda RX-7 Convertible with A/C. Your setup will vary, and you can find a different set of fans (or fan) from another junkyard car, just make sure it covers the radiator well and works with your shrouding.

The dual MR2 fan shrouds are made of metal and fit almost perfectly with a little bending. As anyone who has ever owned an Mark I MR2 knows, everything metal on the car rusts out, so I had to wire wheel and then paint these fans (I did too quick a job on the shrouds, in my opinion). Then I painted the (previously off white) fans black with some KRYLON PlastiCote. I really like the way they came out (scroll down for pictures).

I put regular house weather stripping along the edge of the fan and then set it on my radiator. I cut a few lengths of coat hanger up and then bent them in to create the brackets to hold the fans in place. If you want it to look nicer, you can use zip ties through the top of the radiator. Next, I bent the metal of the fan shroud flat around where the coolant hoses are run (I don't like the idea of my soft rubber hoses touching a vibrating metal fan shroud)

I tested each fan for polarity by applying battery voltage, and then set them to pull air through the radiator. This is important, you don't want the fans fighting incoming air. I then ran the ground wire to the chassis right next to the fans. I used all 8 gauge wire, this is important, you don't want to use too small a wire or it will heat up, and might even cause major issues. The positive wire went to a relay.

Controlling the Fan

Now, you can have the relay powered by a switch that you manually flip (that's no fun, and kinda dangerous if you forget to flip the switch), a thermoswitch (sounds good to me) or an aftermarket ECU (thats what I did). If you don't use an ECU, you can use an aftermarket temperature switch, or just build your own.

I have the The MegaSquirt ECU set to switch on the relay on whenever it sees the engine temperature go OVER 200F (210F is the maximum acceptable operating temperature) and switch it off around 184F.

The temperatures you set will be dependant on what car you install your fans on, and what thermostat you are running. If you're in doubt, just set it to 200F.

Results

When the fans come on, it's insane how fast they cool down the radiator. You can put your hand behind the airstream and FEEL the temperature drop in the air coming off. The coolant sensor input to my ECU hesitates a little, (The waterpump has to circulate the cool water, then the sensor has to catch up) then the display shows the temperature drops 20 degrees almost instantly!

These fans are much quieter then the Black Magic or Flex-a-Lite fans that I have heard. The fans do not over tax my stock alternator either.

Test fitting the fans:


Bending to clear the lower radiator hose:


You will have to bend it on top for the upper radiator hose too.

I would post better pictures, but a bit after I installed these fans, the car was stolen! I hope this writeup has been helpful for you, feel free to ask questions in the comments section!

Plastic on demand

I was reading this fascinating page on a fellow making an android, and I saw he was using this stuff for mounting the engines that he only called "Polymorph." When I looked it up I found out what amazing stuff it really is.

Friendly plastic. Shapelock, Polymorph. It has many names, but it's all the same wonderful stuff. You can buy it either plain (white) or in a vast assortment of colors. It's non toxic and biodegradable, safe and fun to play with, and has an untold number of uses.

When you buy it, it comes in the form of small white pellets that you drop into hot water (90F to 150F based on how malleable you want it, it only takes a few seconds) pull it out, squeeze out the excess water and shape to your hearts content. You can use tools or your bare hands, it shapes a lot like clay. When it cools down it will be as hard as nylon. If you ever get tired of its current shape, just drop it back into hot water and it will return to a malleable mush, it's totally reusable.

It is great for use in making molds, orthopedics, models, impromptu tools, and much more.

It can be painted, and when hot it sticks to whatever you want, but if that is not the desired effect, just splash the surface with a little cool water and it will no longer be sticky.

Want some? It's not really that expensive, as a little goes a long way. Here are some places you can go to buy some of this wonderful stuff:

Shapelock.com - Before shipping (About $8), sells for around $23 a lb ($25 for 500 grams)
Sculpt.com - 28oz for US$42 is about $23.3 a lb for "Friendly Plastic"
Amaco.com - If you buy the 25lb bucket for US$540, you're looking at $21.60 a lb of "Friendly Plastic"
RapidOnline.com - For 1KG of "Polymorph," you'll be set back US$30 + VAT for $16 a lb.

Rotary Teardown #1 - Vax's Engine

This weekend I finished tearing down a customer's rotary engine (13B) from an RX-7, and I figure I'll post the results here, and clarify what the pictures mean. This engine is out of a Series 4 Mazda RX-7, it is the Naturally Aspirated version of the engine, meaning it did not come with a turbo. This engine (I believe) has over 150,000 miles on it.



This is the engine with the front cover first removed. You can see the oil pump with the chain around it, and the CAS (Crank Angle Sensor) worm gear on the nose of the eccentric shaft. Everything here looks normal for an engine with high miles except for that counterweight . . . .



The front counterweight is usually coated in oil. This coating drips off if the car sits for a long time. With the protective coating of oil gone, combined with moisture from some short distance driving (where the engine did not have time to warm up and steam off the water) probably caused this rust. The oil pump also had some small scratches on the aluminum internal arm, indicating that old or crappy oil had been used, as even high mileage 13B engines tend to have very little wear on the oil pump.




With the rear iron removed, you can see the rear rotor. I could immediately tell that it was blown because two of the apex seals were retracted into the rotor. Normally they are pressed firmly against the housing, it's not easy to tell in this small version of the picture, check out the larger version here and look at the topmost seal. Note the distance between the seal and the housing.



Here, we can see that when the apex seal blew, it took a chunk of the rotor with it. Those parts flying around in the combustion chamber took out the housing. All would have to be replaced if the customer desired to have this engine rebuilt.


This is one of the many scratches on the rotor face left by the apex seal.

Here, I'm cleaning out the coolant passage of the front rotor housing. This is the better of the two, in that it's not completely blown by having a metal seal smashed into it repeatedly.



My guess is that this is the result of mixing Dexcool with the regular green coolant. Some people think that it's the result of too much tap water and stop leak. Personally I've seen the results of using "Bar's leak," and it's not this bad.



Again, the better of the two rotor housings. You can see the gouge left by the corner seal in the surface of the housing. Also you should note that the housing is shiny, it's not supposed to be, it should have a whitish matte finish over the metal, it's a special oil retaining coating to prevent stuff like this from happening. High miles and crap oil is my guess for what happened here.


The one perfectly decent internal part recovered (not counting the obvious stuff like the eccentric shaft). The front rotor. It is a "C" weighted rotor, so it will need a similarly weighted rotor to replace it's brother that was lost in the line of duty. This rotor can be cleaned up and returned to service.

For larger versions of all these pictures, check out my photobucket album. Feel free to ask any questions in the comments section.

Why are Some People so Terrible with Money?

"If you can't afford it, you don't buy it."

Sounds logical, right? Yet it seems quite a few people have gotten into big trouble with that concept.

Maybe because they don't have a concept of how much money is really coming and going. That is why it is important to at least have an idea of a budget. It doesn't take that much time, and there are tons of tools to make it easier. A major cause of marital strife is money, so even if you're not married, at least get some practice putting your finances in order. If you are married, I'm sure your wife will be impressed when you have a pretty looking spreadsheet for her the next time she asks where all the money is going.

Think that is too much work? Check out Mint; "Mint connects to over 5,000 US banks and credit unions, credit card, brokerage, and mutual fund companies to keep your transactions and account balances automatically up-to-date. Mint even auto-balances your checkbook and auto-categorizes your transactions. Set it up once and you’re done." Best of all, it's free!

Once you have a budget set up, you can sit down and make logical decisions about where to cut back without making much sacrifice. My favorite thing about helping people set up budgets is watching their faces when they find out how much their diet coke costs per month. One fellow I helped was spending over $2000 on diet coke per year (He drank a lot per day)

That's . . . almost the price of a car . . . every few years.

Why save money? I don't make a lot of money compared to everyone else in the area I live in, and my wife is a stay at home mom, but I still live a whole lot more comfortably then people who make more then me, because as soon as they get money they just spend it. Some people I know, after a week or so, have no idea why they don't have money and are living paycheck to paycheck, and after a while they end up maxing out a few credit cards.

Then some people even turn around and blame the credit card/lending companies. I can understand complaining about predatory lending, but it wouldn't work in the first place if people just paid back what they owed in the first place.

Don't spend more then you make. If you can't handle that, get rid of your credit cards.

Personally, I like credit cards for the convenience, and for the rewards. I put everything on my credit card that I possibly can. I get reward points that I redeem for gas cards. I pay off the balance in full every 2 weeks. It's free gas, about $1 worth for every $60 to $100 spent.

Though the MoneyAnswerGuy disagrees with me there, and says that no one can use a credit card responsibly.

Check out what different credit cards have to offer at the CreditCartGuide or CardOffers

Or you can read some other guy on the topic of "Why Are Some People so Ignorant About Money?"

Why Deaden? Who says you need serious beats to benefit from it?

Hello everyone! Dan here from the MoCo Eats blog! I'm here to ask you if you're tired of being forced to crank your radio up every time you go past 45 mph just to hear what song is playing? Does your car sound like a thin metal can when you slam the door? There is a simple solution to that, it doesn't cost that much at all, and when you're done, your car will have that luxurious feel that much more expensive cars do.

There are many places in your car or truck that have nothing but a very thin layer of sheet metal separating you from the road. The trick to making your ride quieter is to drop the "resonance frequency" of these thin pieces of metal by making them thicker; and the more road noise and metal vibration you can stop, the better everything in your car will sound.

There are many many places to buy sound deadener for your car, and there are literally dozens of different types, grades, thicknesses and even colors. There is roll on, stick on, and glue on, and even spray on. So where do you start?

My journey started with a place that sells some of the best sound deadener that I know of. It's the thickest, and not the most expensive. www.edesignaudio.com . Not only do they have the kind you paint on with a brush, but they also have three different kinds of self-adhesive materials. Their prices are significantly lower than Dynamat and most deadener you can buy in retail stores, but I kept digging and found some stuff that was even cheaper. Do a google search for R-blox, or Fat Mat, and Brown Bread.. I bought 100 square feet of R-blox for $89.00 plus shipping. Here is the key: you want the most mil for the buck! While the stuff I bought (r-blox) is a lot cheaper than e-dead, it is also quite a bit thinner. For example the eDead UE is 120 mils, and the R-blox is 50 mils. That means I would have to put three layers down to exceed the thickness of the eDead UE. Fortunately what I bought came out to less than $1 per sq-ft and the eDead is $3.50/sq-ft. So to me it seemed worth having to do a couple layers.

The kind that comes in a can is also quite important to mention because it is the only kind that can go ANYWHERE! You typically won't want to use the sticky roll material on anything that takes extreme heat and is upside down. For example you wouldn't want to use it on the inside of your roof. However, if you were to buy the liquid, you could paint it on the roof and never have to worry about it falling down in the heat. For the sake of simplification, today I'm just going to be talking about the self-adhesive type of sound deadener since that's what I bought. Obviously the technique is going to be different for the kind that is painted on.

The first step is to remove as much covering as you can. The car’s covering… not yours… This involves door panels, carpet, and any plastic that you can remove. Be careful not to break anything, and if you do break anything, I’m sorry for your loss. Please don’t call me. ANYWAY, at this point your door should look something like the picture on the right. Perhaps yours doesn’t have a plastic covering, regardless, this plastic covering needs to come off because you need to release the invisable noise gremlins that live inside the door. Also because you will be reaching your hands inside the door to apply the sound deadening agent.

The reason we are starting with the door is because the entire panel on the outside of the car is most likely just a single thin sheet of metal. This is a good time to clean the door panel with Windex or some other grease-fighting spray to help the sound deadening adhere properly to the panels. Just for fun when you’re done cleaning the dust and dirt off, knock on the outside of your door panel just to hear what it sounds like "Before" you apply the sound deadening… You’ll thank me later when you hear the "After."

Now, cut pieces that are small enough to fit through the holes in the door panel, so you can apply them from the inside. Once you cut them, peel one corner and press that to the
place you want it then peel the protective layer until the whole piece is stuck. Repeat as necessary until the whole skin is covered inside. Just to warn you, I ended up with a lot of cuts and scrapes on my hands from this step, so be careful! Then be sure to use a roller (or, failing that a metal spoon works fine) to really press it down onto the panel.

Next step is to apply it to the outer part of the door (the part that will be covered by the door panel.) Cut a large, but manageable sized piece off of the roll. A good rule of thumb is the bigger the better for the pieces. The more seams you have, the less effective it becomes. My door has a metal arm rest in the middle that is riveted in place, so I opted to do two pieces instead of one and just work around that piece.

You have to be very careful to not stick the deadener over top of any moving parts! One solution is to cover them all with aluminum foil, but I have found this to cause rattles later. What I do is line the piece up over top of the moving parts, then cut the backing paper around them. This keeps the adhesive from touching any moving parts and you don’t have to worry. Here’s a picture to show how I did it.

Now back to the outside of the door . . . Here’s a shot of the first piece on.

Just like the inside of the door panels, start at one side and peel back a couple inches of the backing paper. Stick that to the door and then slowly with one hand pushing and the other hand pulling off the backing paper, work in one direction until the whole piece is applied. Now take a roller and work it into the contours of the door.

Here's a quick before picture showing how it looks after you work it into the contours using your roller (and/or spoon).

And this is after!

A good way to tell if you’re using enough is to knock on parts of the door. If it still rattles you can add another layer and press it down harder. This really makes a huge difference. I had to cut a couple holes in the deadener to let wires through, but when I got the wire through, I put a small square of deadener over the opening so the door panel remained air tight.

Now the only step left is to re-attach your door panel and go for a ride!

This mod makes such a huge difference on how my car sounds on the road. It dramatically reduced the road noise and tire noise. My stereo sounds better, and I don’t even have to turn it up when I hit 70mph! In fact, I even have a fun story from my experience. On my way to work the morning after I finished this project, I called my wife and asked her how it sounded and it went something like this…

Me: “Hi honey! How do I sound?”
Her: “You sound great, are you in your car?”
Me: “I am… so you don’t hear any road noise or anything?”
Her: “Nope, it’s silent.”
Me: “Cool! I’m doing 80!”
Her: “WHAT?!”

The doors make the most difference, but you can do this modification anywhere there is thin metal or insufficient deadening material on the car. Some places to look are transmission tunnels and the firewall in the engine bay.

Please be sure to share your experiences! We'd love to hear from you.

Seven useful websites for help with the high price of gas

Sure, there's tons of news about how high energy costs are, and how that's driving up the price of food and other goods, but these sites stood out to me, and I'd like to share them with you.

1) Ten things you can like about $4 a gallon gas - "But it's also true that Americans are finding options where there seemed to be none. They're ready to change — and waiting for their infrastructure to catch up. They are driving to commuter-rail lines only to find there are no parking spots left. They are running fewer errands and dumping their SUVs. Public-transit use is at a 50-year high. Gas purchases are down 2% to 3%. And all those changes bring secondary, hard-earned benefits. "

2) Website lets drivers lock in gas prices - "A recently introduced service called MyGallons.com allows drivers to fill up their tanks sometime in the future but at current prices, using a debit-like card which banks gallons rather than dollars."

3) Gas Savers - "A community of fuel economy enthusiasts. Our typical member does not own a hybrid. Our typical member is like you: With a normal vehicle and a desire to increase the fuel economy of that vehicle. Whether you want to save money, save the environment, or just reduce our dependency on foreign oil, there is a place for you here! Perhaps you just wish to have a way to track your fuel consumption. Using our garage you can create a profile for your vehicle and start tracking your fuel consumption. You can even compare gas mileage with other members in the Garage. Join GasSavers, do your part, and start associating with people like you. You don't have to be a mechanic or a gear head in order to change your fuel economy, you just have to know what to do."

4) EcoModder - "An automotive community where performance is judged by fuel economy rather than power and speed. EcoModders employ a combination of vehicle mods, driving techniques, and common sense to squeeze every penny out of the pumps. Reasons for becoming a member range from the economical to the ecological. More info about where EcoModding came from."

5) Gas Buddy - "Now you can see what gas prices are around the country at a glance. Areas are color coded according to their price for the average price for regular unleaded gasoline. Click here for the Canada National Gas Temperature Map."

6) Motorcycle Fuel Economy Guide - As oil prices rise across the world, gas prices just keep rocketing up too. Cheap gas seems to be a memory of the past as we all look to save money on fuel, and saving is never all that fun. Why not do both? Save your money and have fun at the same time; on a motorcycle! . . . Motorcycles are some of the best vehicles to give you the best economy, efficiency, and gas mileage. See and compare all different models from the major manufacturers all in one spot."

7) Gas Edge - "Find out if it's worth the trip for cheaper gas! Sure, the gas station across town has a lower price on gasoline, but is it really worth the trip? Will you save more money on the gas then it costs to drive to the cheaper gas station? Use this free calculator to find out"