# Tag Info

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Is there a theoretical equation that is used to define engine load? It's not theoretical, but real. According to SAE International SAE J1979 / ISO 15031-5 (dated: 2014-08-11), calculated engine load is calculated by the following equation: LOAD_PCT = [current airflow] / [(peak airflow at WOT@STP as a function of rpm) * (BARO/29.92) * SQRT(298/(AAT+...

6

To get us on the same footing, I'm going to assume by saying "clutch pressed halfway" you are suggesting the clutch be halfway engaged (meaning, you are still getting power from the engine, but it's not fully engaged). What you are talking about is called slipping the clutch. It is a process whereby you can get the engine within the power/torque ...

6

You can determine the gear by comparing the engine RPM and the vehicle speed. Most cars that have a shift light though do not actually know what gear they are in, they use engine RPM, engine load and throttle position. A near stall could be determined by looking at engine load and RPM. Low RPM and high load will give it away.

5

The only curved bore designs I am aware of are toroidal I have been unable to find a match to the drawing, not even close. I took a hard look at steam engines as well. Here is an example of a toroidal design Here is a modern mock up of a similar design.

5

Doesn't it suck up only as much as engine speed and throttle position allows? No, throttle position and engine load determine the quantity of air consumed. It can be quite hard to understand at first how a naturally-aspirated engine can ingest different quantities of air at the same RPM. Here's what the Engine Management Fundamentals chapter of the Bosch ...

4

60 MPH assuming you are in the same gear at both speeds. At a constant gear, your engine turns at a fixed ratio to the distance you travel. So if you travel from A to B your engine will always turn X revolutions, regardless of speed. In other words, the piston experiences the exact same number of cycles regardless of 60 or 70 mph Air friction increases ...

3

A normally operating engine regains pressure almost instantly. Oil residual stays in the bearings and on parts for quite some time after the engine is turned off. As soon as the engine starts turning the oil pump pressure begins to build. This only takes a second or so. Unless there is something wrong with the engine, or the oil pump, I doubt there would ...

3

While @Robert-Ryan is technically correct, I'd be surprised if there was a measurable difference in engine lifetime. Engine wear is dominated by cold starts. Once the engine is thoroughly warm, engine wear is minimal. If you want to maximize engine life, minimize the number of short trips where the engine doesn't get warm, or invest in an engine block heater....

3

Engine load is determined by a ratio between current air flow and the maximum air flow at the same RPM. The engine computer has a look up table of maximum air flow as a function of RPM for WOT values. This table is generated by the manufacturer using an engine dynamometer. To generate the table the engine RPM is held constant (with the dynamometer) and the ...

3

Air flow is purely based on throttle position and engine revs on a normally aspirated engine, adding a charger (turbo etc) adds complication. With the throttle fully open, every inlet stroke is going to take the maximum amount of air (and therefore fuel) into the cylinder. This air intake can then be multiplied by the engine revs. If the throttle is not ...

2

That's a difficult thing to answer without knowing the power characteristics of the engine. Best measured with a dynamometer. Peak horse power and torque are 2 different things and dont necesarily occur at the same rpm. Increases in power output is seldom a straight line, ie doubling the revs doesn't necessarily mean doubling the power. Power at half revs ...

2

Engine load is measured by the MAF sensor. In other words, it measures how much air (and fuel) you're sucking into the engine and then compares that value to the theoretical maximum. When I modified my Subaru's fueling, boost and ignition maps, all the tables plotting engine load to RPM referenced engine load in CFM (Cubic feet per minute). It basically ...

2

It won't necessarily damage either your engine or transmission. You should realize it will cause more engine/tranny wear due to higher than normal RPM usage. You'll also experience lower fuel mileage.

2

Car engines are definitely made better today, but transmissions aren't. Stick your arm out the window as you drive and feel the wind resistance at different speeds. That's the best clue to what your transmission endures. As for the high rev operation...your computer helps the engine, but not the transmission in most cars. If your car isn't climbing up ...

2

Don't do that every day and you'll be fine. There are two kinds of damage over-revving could cause: Firstly, the mechanical damage caused by too fast rotation speed. The rev limiter protects against that. So it doesn't matter whether or not you hit the rev limiter as long as the rev limiter is working fine. Secondly, the accelerated wear. If you do that ...

2

If the engine is truly locked then there are a number of problems that might cause that. Some that come to my mind are: Lubrication problem caused one or more rod or crank bearings to seize. Lubrication or overheating caused a piston to seize in the sleeve. Valve breaks and jams the piston. Excess fuel or oil into the cylinder causes hydrolock. Broken ...

1

Drilling holes big enough to allow a socket through would weaken it a lot. And as you don't want to weld new nuts on then you would not be welding up the holes either.... I suggest you do it properly or get it done properly and rivnuts are not strong enough.

1

What @Old-School Engineer says is correct. Wind resistance (aka drag) increases exponentially with speed. The (simplified) formula is drag = (constant)*(velocity^2). So for example, going from 30kmh to 100kmh, the drag is 11 TIMES HIGHER. As a result, even though the engine is spinning at the same speed, it is consuming more fuel and air to maintain that RPM ...

1

No is the simple answer. The voltage output from the alternator varies, as you found out, with engine speed. It also varies with the state of charge of the battery and, to make it more complicated with the type of charging control system - some have a very "intelligent" control fitted. The best solution for engine load information is from the OBDII (if the ...

1

I think the statement on page 329 is a general on put in all their owner manuals. They also list all the hitch classes, but that does not mean your car can handle them. Searching has not resulted in any "Towing Packages" for the PT Cruiser that goes beyond 1,000 pounds. To answer your question, there isn't anything you can add. Class I hitches are all that ...

1

We built the engine, we called the company Pivotal Engines. worked well but fell victim to management issues. http://www.pivotalengine.com/pistonrocking.html

1

Don't know if anybody has documented this, but I think it is self-evident that slower speeds and lower rpm's will result in greater longevity. Imagine driving your car at a steady 5000 rpm, and consider it's lifespan compared to 2500 rpm.

1

100% engine load is the situation where the throttle flaps are wide open and fuel system is providing as much fuel as possible and the engine is at peak torque but the revs are not rising. This type of scenario can be seen in the real world when a vehicle with a heave trailer attached is climbing a steep hill, in a low gear and with foot flat to the floor, ...

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