zoomvroom Tech Talk

Do Diesels Run Cooler Than Gasoline-Power Cars and/or Hybrid-Electric Vehicles?

Okay, for those of you who helped me with my science fair project, daydreaming may occur.  For those who did not help me, listen up, and look.  The popular urban myth is that a diesel engine will run cooler than a gasoline engine and/or a hybrid-electric engine.  I had always been interested in this myth, and wanted to find it out for myself.  I decided to try and figure out if it was true.  It wasn’t.  How did I figure it out?  Google is not the answer.  A science fair project was the answer.  For me.  Read below to find out what my findings tell us!

The hypothesis states:  If a diesel engine idles at 9 degrees Celsius, then it runs cooler than hybrid-electric engines and/or gasoline-power engines.  

Some research has been done to see if this myth is true.  From what I found, in 1998, the EPA, CalTech, and UC San Diego all did similar (if not the same) experiments.  The EPA wanted to know if heat on an engine decreased fuel economy, and CalTech and UC San Diego wanted to know if electric motors ran cooler than diesel engines.

My materials list was relatively short, compared to the other projects.  It included:  

  • Texas Instruments Thermocouples and Data Readers
  • 2003 Chrysler Town & Country LXi AWD 3.8L V6
  • 2003 GMC Sierra 2500 HD 4X4 6.6L Duramax Diesel
  • 2013 Toyota Prius Plug-in 1.5L Hybrid-Electric
  • Duct Tape

My procedure was a bit more complicated:  To start the experiment, the car had to be measured “cold” – before it had been turned on.  The thermocouples were then attached to the:  Radiator, engine block, and exhaust pipe.  All measurements were taken in degrees Celsius.  Once the measurements had been recorded, the outside temperature was taken (as a good base to compare against).  The car was then started and allowed to run for five minutes without the climate system running.  When the clock hit five minutes, the car was turned off, and the measurements were taken again.  The different temperatures were compared against one another.

The results are what I expected.  I must be a car guru, since I was able to predict this (or at least I read my research!!). Since I can’t draw a table on WordPress, I’ll have to go by car, okay?

  1. 2013 Toyota Prius Plug-in:  Engine block cold:  17 degrees Celsius, Engine block heat after five minutes:  21.8 degrees Celsius, Radiator heat cold:  14 degrees Celsius, Radiator heat after five minutes:  13.9 degrees Celsius, Tailpipe heat cold:  15 degrees Celsius, Tailpipe heat after five minutes:  14.1 degrees Celsius, Temperature outside:  16 degrees Celsius.
  2. 2003 Chrysler Town & Country*:  Engine block heat cold:  30 degrees Celsius, engine block heat after five minutes:  58 degrees Celsius, Radiator heat cold:  13 degrees Celsius, Radiator heat after five minutes:  14 degrees Celsius, Tailpipe heat cold:  18 degrees Celsius, Tailpipe heat after five minutes:  17 degrees Celsius, Temperature outside:  13 degrees Celsius.
  3. 2003 GMC Sierra 2500HD:  Engine block heat cold:  9.2 degrees Celsius, Engine block heat after five minutes:  9.2 degrees Celsius, Radiator heat cold:  8.5 degrees Celsius, Radiator heat after five minutes:  8.7 degrees Celsius, Tailpipe heat cold:  9.0 degrees Celsius, Tailpipe heat after five minutes:  16.2 degrees Celsius, Temperature outside:  15 degrees Celsius.

By crunching the data, one can easily find out that the GMC Sierra 2500HD 4X4 6.6L Duramax Diesel easily runs cooler than any of the other vehicles used in this experiment.  An optimal idling temperature for a diesel engine is 9.2 degrees Celsius.  Both above and below this temperature, the engine will run smoothly.  However, at heat greater than 75 degrees Celsius, the idle quality will start to degrade.  By the heat redline of 104 degrees Celsius, the idle quality of the vehicle will have degraded to such a point that it will crack the engine block, or cause some other form of damage to the engine.

For those of you interested in doing a similar experiment, here are some similar experiments that you can do:  Only hybrid-electric vehicles, only gasoline-power engines, and only diesel engines.  These results can then be compared to the temperature gauge in the vehicle.   A final experiment could be measuring the temperature of the engine from the temperature gauge alone.

*The asterisks by the 2003 Chrysler Town & Country LXi AWD 3.8L V6 are important – the experiment was conducted twice.  The first measurements may have been a bit inaccurate due to the fact that the Town & Country had just been driven for over an hour.  The second experiment was what I expected, as the car had sat overnight.

I didn’t make it to the County finals, but I loved my topic.

Many thanks to Mark Miller for providing all the instrumentation, and to Unc Howie for being such a good sport and not even asking for clarification when I said “I want to do a science experiment on your brand new Prius.”  You guys are the bomb!

zoomvroom Tech Talk

How a Car Engine Works

Ever pop the hood of your car and wonder what’s going on?  In today’s post let’s learn about your car’s engine.

Currently, the fastest way to high performance and fuel efficiency is to use the internal combustion engine.  The combustion (explosion) occurs inside the engine, and the energy is used to propel the vehicle forward.  The internal combustion engine has many forms, such as, diesels, gas turbine, two-stroke and Hemi engines are all part of the family.

On the other hand, there is an external combustion engine. In an external combustion engine, the energy (fuel) is burned outside the engine.  This energy propels the vehicle forward.  The best example of this would be a steam engine on an old-fashioned car or train.

Most cars use the four-stroke combustion cycle.  This converts gasoline to movement.  The four strokes are:

1. Intake stroke.  The piston is at the top and moves downward.  When it is halfway down, the intake valve opens and fuel and air come in and mix in the cylinder.

2. Compression stroke. Compression (or squishing) of the fuel/air mixture by the piston.  The molecules are being crushed as the piston moves up in the cylinder.  All the valves are closed.

3. Combustion stroke.  Here comes the job of the spark plug.  The spark plug emits a spark (sent from the distributor via the electrical system) and ignites the fuel (air/gas mixture).  The resulting explosion drives the piston down.

4. Exhaust stroke. When the piston is at the bottom of it’s up/down stroke, then the exhaust valve opens and as the piston moves up, it pushes the waste gasses (CO 2 and NO 2) out the exhaust system and polluting our beautiful atmosphere.  Now the vales are all closed.  Trivia: NO 2 is nitrous oxide and is used for giving race cars a quick boost of speed.  Mostly used for dragsters.

Now the cylinder is ready to repeat the intake stroke and start all over again.  Diesel engines are different because they don’t have spark plugs.  I’ll explain that another time, so stay tuned!

zoomvroom Tech Talk

Science Period!

What the Z@%$ IS Thermodynamics?  Well, it’s a branch of science that deals with heat; more specifically heat transfer.  It has four laws: the zeroth law, the first law, the second law and the third law.  If you are wondering why there is a zeroth law, it is because when scientists were first researching the properties of Thermodynamics, the scientists already had figured out the first, second, and third laws.  Then  another component was discovered, so……. the zeroth law came into being.

The zeroth law of Thermodynamics states that when two or more objects (i.e.:  two or three metal rods) come into contact, something called Thermodynamic Equilibrium will be attained.  Thermodynamic Equilibrium is the transfer of heat.  The first law has a bit to do with the zeroth law:  The first law of Thermodynamics states that energy cannot be destroyed or created.  It can only be transformed or transferred.  For example, when a bomb goes off, all the potential energy inside of the bomb is transformed into kinetic energy.  The second law of Thermodynamics is an expression of the tendency that over time, differences in temperature, pressure, and chemical potential equilibrate in an isolated physical system.  The third law of Thermodynamics states that if all the kinetic energy could be removed from the Universe, a state called “Absolute Zero” would be attained.  Absolute Zero will occur when the temperature of empty space reaches 0 Kelvins, or -273.15 Celsius, or -459.67 Fahrenheit.  Absolute Zero will be attained when all the matter and energy of the Universe is randomly distributed.  Of course, this is only the bare basics of Thermodynamics, and if you are interested in learning more, please Google it!

School, science and cars have coincided to create a new project.  I decided that Thermodynamics and cars was the answer! I plan to conduct an experiment on different types and sizes of engines to determine which engine will run the coolest.  Among others, I plan to measure the engine heat of a 2003 GMC Sierra 2500HD with the Duramax diesel engine,  2004 Ford F150, 2003 Chrysler Town & Country with the 3.8 liter V6.  My belief is that the diesel will run the coolest, followed by the F150 and the Town & Country.  Diesel powered engines run at lower temperatures than gasoline powered engines.  Since diesels have peak horsepower and torque at lower RPM’s, they should run at lower temperatures than gasoline cars.  Since most diesels are large (above 6 liters, but there are some that are 2 liters and smaller), engine size is also a possibility.

If you are local and are willing to or would like to participate, let me know.  I know that some of you out there have small engines, hybrids and diesels that are calling out to have their temperature taken (doctor, doctor!).   Stay tuned for more posts on this awesome experiment!


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The Challenge is on!

One of my loyal readers, Hudsonjet has “thrown down the gauntlet.”  Hudsonjet has challenged me to do definitions of “valve sleeves” and “valve shims.”  I can’t back down from a challenge, so hold on for a wild ride!

Dear Hudsonjet,

I am sad to inform you that there is no such thing as the “valve sleeve.”  However, there is a sleeve valve.  I hope that this is what you were thinking of.  If not, than this mistake is on me.  I did some research on sleeve valves, so enjoy.

A sleeve valve is a type of valve that usually has a metal sheet around it.  (This helps the engine rev higher without danger of breaking the catalytic converter.  This type of valve is popular in heavy machinery or heavy-duty trucks.  The exhaust gets so hot that there is danger of damaging the engine valves.  The sleeve valve protects the integrity of the valve.  The sleeve valve also prevents oil from leaking too much.

For the less mechanically inclined, an engine valve forces air into the cylinder, where it is mixed with the fuel, and then the spark injector makes a spark.  There is a small explosion, and then the piston forces the mixture up into another engine valve.  The mixture is then sent to the catalytic converter, which cools down the mixture, and sends it through the muffler and out into our wonderfully polluted atmosphere.  Pretty amazing, isn’t it?

A valve shim is a disc of hardened metal that has a very precisely calibrated height to adjust the clearance of the valve lobe that is on an engine valve.  Without the valve shim, the valve lobe would flop open and stay there.  The valve shim forces the valve lobe to go back down and open when the fuel/air mixture comes out of the cylinder.The valve shim’s part in the engine play is sitting on top of the valve lobe and preventing engine gunk from entering the combustion chamber.  This is a very important part, because without it,  your mechanic would be a millionaire within a few days!  Without the valve shim, your valve lobe would allow engine gunk to enter the cylinder, and blow the piston.  Thank god for valve shims….

So, my readers, how did you enjoy these little answers to Hudsonjet’s questions?  You tell me, was I stumped?  Hudsonjet, were these the correct answers to your questions?  Anything to add?  Anyone else care to try and stump me on ‘Definition Day’?

Tune in Tuesday for a special post!

zoomvroom Tech Talk, The auto dictionary. Look it up here!

I Have You in My Clutch(es)!

What has a clutch?  Just about anything with a motor.  Chainsaws, cars, planes, even the electronic razors men use to shave with!

What is a clutch?  Well, let’s dive in and see!

A clutch is a mechanical device that is attached to a manual transmission gear box, which is outside the engine.  Also, the clutch pedal is attached to the clutch.

Clutches are very important when a machine has  two rotating shafts, or two moving parts.  Clutches are instrumental in a car because it smoothly transfers horsepower and torque from the spinning engine crankshaft to the transmission, without slippage (clutch slippage is where the friction materials inside of the clutch’s flywheel [which is attached to the engine’s crankshaft] wear out, and the clutch is slipping as a result of varying speeds)

Friction is necessary to the operation of  every clutch.  Friction is the rubbing of two or more objects.  The clutch’s job is to eliminate as much friction as possible.  Thus, the friction between the clutch plate and flywheel is  sent through the clutch, where it is dissipated.

When a driver presses the clutch pedal, it releases the pressure plate, which pushes the pressure plate against the clutch plate against the flywheel, and causes the non-spinning transmission to spin.  When the clutch pedal is depressed, the transmission is still spinning, but there is no need to press the clutch pedal:  You will just need a clutch sooner.

If you drive a manual transmission car, and are driving up a hill with a loaded car, and are going up a steep hill in a gear that is too high, you will burn out the clutch; bringing a tow truck and quite a few large bills.  And a happy mechanic… Besides, who REALLY wants that?

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Survival of the adaptive

The car world according to Darwin.  Since the Ford Taurus made a comeback in 2010, Ford engineers have been working harder than an air traffic controller at La Guardia.  They have been experimenting with radar to avoid the immenent threat of a head-on collision. 

Here is what George Mone of the magazine, Wired, has to say.  “Heading south on the New Jersey Turnpike, Ford Motor Company engineer Jerry Engelmen swings his 2010 Ford Taurus into the left lane to pass a semi.  The Taurus hesitates, slowing down, and then Engelman adjusts his heading.  The car takes off. 

“Larry,” he calls to his colleague in the back seat, “write that down!” 

Engelman is driving, but just barely.  The Taurus has a radar-based adaptive cruise-control system that lets him set a top speed and then simply steer while the car adjusts its velocity according to traffic.  He’s been weaving and changing lanes, doing between 45 and 70 mph- and hasn’t touched a pedal in an hour.” 

Since 2007-8, Ford engineers have been working on this particular system.  They have logged over 60,000 miles a year on a few test cars with the adaptive cruise-control system.  This tech has been around for a while.  Jaguar, Mercedes-Benz and Volvo have all offered this technology since, at least, 2004.  But now its afforable.  Ford now offers the system standard on the Taurus SE model, and hopefully will be putting it in the Super Duty line of trucks by 2013.  The system is similar to the one used in small private planes (such as a Cessna 172).  

The system works by projecting radar beams forward and sideways to look for anything that could cause an accident.  It emits pings, which warn the driver, and tell the cruise-control box that there is a potential hazard ahead.  The radar’s reach is as wide as three Taurus’ put exactly side to side.  On a ten-lane highway, the car will be actively looking at three or four of the lanes on each side.   If there is an immenent collision, the car tightens the seatbelts, warns you, and primes the brakes. 

Engelman says that the production version is pretty much flawless.  Good.  Imagine me driving a Taurus SHO down a quiet country road (of course, I am NOT speeding), and all of a sudden, there’s a dump truck pulling out of a driveway.  I’d probably stop short, thanks to the quick reaction of my radar assisted cruise-control.  But my best guess is that I’d have a seatbelt-shaped bruise across my chest!  I think that I’ll probably be getting the Taurus as my first car, when I’m 16 because my mom thinks that teenage boys plus gas pedals equals disaster!  Whatever.  Call it new math.

Darwin would be proud of the system.

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Can You Trumpet like an Elephant Motor?

You’re probably thinking “I am NOT going to comment on this post!”  Well, you might want to.  This post is on the infamous “Elephant Motor.” 

The so-called ‘Elephant Motor’ is a 426 cubic inch Chrysler Hemi engine.  It is called the elephant motor because of its huge displacement (the volume of air displaced when the engine is turned a cycle by the pistons – in this casr, 426 ci), and huge power output (425 horsepower).  And that’s only in stock form! 

The Elephant Motor was developed for NASCAR in 1963.  Its first race was in a Plymouth Belvedere, in 1964.  For many years, the 426 Hemi won many races in NASCAR. 

In my opinion, the true Chrysler Elephant Motor is the 440 Six-Pack Hemi.  VROOM!

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What’s A Firewall, Dad?

Tech Talk Day!

Well son, a firewall is a wall between the engine and passenger compartments.  With a front-engined vehicle, the firewall is part of the induction cowl, and ahead of the passenger compartment.  With mid or rear- engined cars, it is behind the passenger compartment.

The firewall protects the passenger cabin from an engine fire.  Most firewalls have carbon-fiber in them to protect from the engine flying backward into the passenger compartment.

Way back when, firewalls used to be about an inch thick, and made out of steel.  The only thing that could break them was a bomb or a massive engine fire.  Nowadays, they are about half an inch thick, and extremely strong.

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Brake horsepower, what it really means

Brake horsepower (bhp) is different than horsepower.  Bhp is the output at the flywheel (a heavy, round metal plate on the end of the crankshaft that is a vibration damper, and balance member.  It also smoothes out the power pulses as each cylinder fires), as measured on a dyno-test (where the maximum amount of horsepower and torque are measured).  Back in the old days, there was a device called a “prony brake,” which was used to determine the maximum amount of torque.  Horsepower was then calculated from torque and rpm.  Horsepower is the measurement of the maximum amount of the work an engine can perform.  It can be described as a way to move a weight a given distance- to apply leverage in a given period of time. 

Here is an example:  Let’s say a 5.4 liter V8 makes 320 bhp; the hp would be about 305.  That is because the transmission’s gears have to spin all that horsepower and torque, before it gets to the driving wheels.  If there was no transmission, all 320 horsepower would be going straight to the drive wheels. 

But, since there are transmissions, the automakers often dyno-test the engines to see how powerful they are.  The Smart Car makes 80 bhp, but once the horsepower is put down to the wheels; it totals 70 horsepower.  Back in the early days, 70 horsepower would have been reserved for an airplane!  Now look at cars today, the average economy car makes 115 horsepower!        

For an example of bhp; a horse has 1 bhp, because there is no tranny or gears to turn:  Its “transmission” is simply muscles!  Now, just imagine that horse pulling a wagon.  That would bring the maximum amount of horsepower to about 0.89 horsepower.  That really isn’t much… 

Knowing how much your bhp is comes in handy if you like to tow/haul.  If you are towing and don’t know how much bhp you have, it can be kind of scary!  So be careful!  And, no, I’m not trying to be your mom!

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Cruise Control, the awesome invention

Cruise control has been around for a long time.  The modern cruise control was invented by a blind inventor and engineer, Ralph Teetor.  Teetor invented it after driving with his lawyer, who kept speeding up and slowing down when he was talking.  Ralph must have found that annoying because he then invented cruise control.  Teetor’s assistant helped him draw up the plans.  Testing occurred with a mock dashboard, pedals and steering wheel set up in Teetor’s lab.  Teetor could then “drive.”  The first car with cruise control was the 1958 Chrysler Imperial.