Nice car engine animation

Impressive. It's much more than just one animation -- it's an illustrated explanation of various parts of an engine, where all of the illustrations are animated. Nice!
 
Wow thats is so timely Bill! Just the other day I changed the airfilter on the SUV and was explaining to my wife and daughter why it was important and how it helped improved gas milage. I then tried to explain to my daughter how an engine works ie air, fuel, ignition, explosion, compression exhaust etc. ( I got the blank stare ......she is 17) Now I can show her this video:D
 
AdamZ said:
( I got the blank stare ......she is 17) Now I can show her this video:D
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I might even try to show my wife this animation, but I still may get the stare. :mad2:

At least she's never filled hew car with gas, seven years now with the diesel and not one mistake.
 
Simplified, but nice.

Adam, changing an air filter won't make any difference to fuel mileage unless you still have a carburetor. It may make the engine weak. And there is no explosion. Pistons don't move by impulse. They move by increased pressure from a clean, smooth burn. If it explodes, you hear a characteristic rattling sound, and remove little bits from the surface of your piston.
 
MAKG1 said:
Adam, changing an air filter won't make any difference to fuel mileage unless you still have a carburetor.
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Increased induction resistance means increased parasitic loss and lower efficiency.
 
PilotAlan said:
Increased induction resistance means increased parasitic loss and lower efficiency.
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No. It's exactly equivalent to closing the throttle, with a slightly wrong position measurement (which your PCM will adapt away). It will cut off top speed, but will not affect mileage. If you have mass air fuel injection, it won't even need any adapation.

Don't believe anything an auto parts marketer tells you. They lie a LOT more than politicians. Not the least is "forgetting" to mention that fuel injected engines don't have choke plates.
 
MAKG1 said:
No. It's exactly equivalent to closing the throttle, with a slightly wrong position measurement (which your PCM will adapt away). It will cut off top speed, but will not affect mileage. If you have mass air fuel injection, it won't even need any adapation.

Don't believe anything an auto parts marketer tells you. They lie a LOT more than politicians. Not the least is "forgetting" to mention that fuel injected engines don't have choke plates.
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Yeah, and you'll break the speed of sound if you jump off a 25 story building. :rolleyes:
 
PilotAlan said:
Increased induction resistance means increased parasitic loss and lower efficiency.
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No.

If you want to drive the same speed, you need to deliver the same torque (which will be less than the wide open throttle torque most of the time). So, you have to drop the pressure in the intake manifold somehow. It is done by letting the throttle close until the air flow and manifold pressure are at whatever value they need to be to maintain your speed. This reduced manifold pressure increases pumping work and results in an inefficiency. However, if you have a dirty air filter, you get a pressure drop across the filter in addition to the throttle body so you have to open the throttle to maintain the same air flow / manifold pressure to maintain the torque / speed. You end up with the pressure dropping in two places instead of one, but the sum of the drops (and hence, the loss due to pumping work) is the same.

Now, in the olden days (when I started working in the industry) carburetors did not do as good a job of matching the fuel flow to the actual air flow as the current crop of electronic engine controls (If you are driving a Ford, I wrote a good part of the algorithm that does this). And, with a pressure drop across the air filter, the air flowing through the carburetor was less dense which resulted in a richer mixture (just like altitude in your airplane) and that richer than desired mixture would reduce the fuel economy by making the actual combustion less efficient and increasing the engine out unburned hydrocarbons and CO.

So, at one time a dirty air filter had a big impact on fuel economy, but technology has changed to fix that problem.
 
MAKG1 said:
No. It's exactly equivalent to closing the throttle, with a slightly wrong position measurement (which your PCM will adapt away). It will cut off top speed, but will not affect mileage. If you have mass air fuel injection, it won't even need any adapation.

Don't believe anything an auto parts marketer tells you. They lie a LOT more than politicians. Not the least is "forgetting" to mention that fuel injected engines don't have choke plates.
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Exactly. An air filter is nothing more than a (slight) restriction in the induction system. Just like the throttle. In most cases, the air filter is oversized enough that even a very dirty filter will have a negligible impact, and the impact won't be on MPG, it will result in a slight decrease in power developed at wide open throttle. The engine's computer is looking at a throttle position sensor, mass air flow sensor, manifold absolute pressure sensor and O2 sensors in the exhaust so that it knows exactly how much fuel to put in the engine, by varying the pulsewidth (open time) of the fuel injectors.
 
MAKG1 said:
Simplified, but nice.

Adam, changing an air filter won't make any difference to fuel mileage unless you still have a carburetor. It may make the engine weak. And there is no explosion. Pistons don't move by impulse. They move by increased pressure from a clean, smooth burn. If it explodes, you hear a characteristic rattling sound, and remove little bits from the surface of your piston.
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Thanks for the info. When ever I change the airfilter I notice a slight increase in mpg. Perhaps its just the placebo effect or I'm more concious of the way I drive:dunno: Perhaps I should have used the word ignition?
 
AdamZ said:
Thanks for the info. When ever I change the airfilter I notice a slight increase in mpg. Perhaps its just the placebo effect or I'm more concious of the way I drive:dunno: Perhaps I should have used the word ignition?
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Driving style has a HUGE impact on mileage along with weather and traffic and...
 
Capt. Geoffrey Thorpe said:
Now, in the olden days (when I started working in the industry) carburetors did not do as good a job of matching the fuel flow to the actual air flow as the current crop of electronic engine controls (If you are driving a Ford, I wrote a good part of the algorithm that does this).
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It's not so much that they did a poor job of matching (though it's true). It's that the air filter was on the wrong side of the choke plate, so a plugged filter was equivalent to pulling the choke as well as the throttle, which would make it run rich.

I didn't know you worked on EEC. I've seen some reverse engineering studies on EEC-IV, and it's a lot more sophisticated than one might expect from early 1980s technology. I used to drive a Bronco II equipped with EEC-IV, and it got equivalent mileage to my 2000 Saturn (go figure).
 
MAKG1 said:
It's not so much that they did a poor job of matching (though it's true). It's that the air filter was on the wrong side of the choke plate, so a plugged filter was equivalent to pulling the choke as well as the throttle, which would make it run rich.

I didn't know you worked on EEC. I've seen some reverse engineering studies on EEC-IV, and it's a lot more sophisticated than one might expect from early 1980s technology. I used to drive a Bronco II equipped with EEC-IV, and it got equivalent mileage to my 2000 Saturn (go figure).
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Not really the same since the bowl vents between the choke and the air cleaner...

I worked with carburetors (feedback and not) with the Ford "ECU" then the "MCU". And then EEC-IV, and PTEC and... Different jobs over the years related to fuel economy / emissions and powertrain control / diagnostics.
 
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