How to properly measure the performance of a heat engine

How to properly measure the performance of a heat engine?

From interview / article I made for Passerelleco magazine.

Is the “Pantone” engine a solution for driving while reducing pollution and consumption? For pollution, it seems to bring a clear improvement. For consumption, the most contradictory claims circulate, and sometimes, the pantone is adorned with extraordinary virtues, such as the possibility of burning all kinds of fuels, from petroleum to battery acid or radioactive waste! And consumption sometimes shows 50% savings. In fact, when we dig a little, we often see the absence of consumption measures!

It is to share things that this article offers engineers have realized a pantone mounting measure the performance of their consumption assembly. We ask you, if you conducted a successful adaptation, to make power measurements and send them to us. Thank you in advance !

And if you are wondering how to do it, Christophe Martz, “mechanical engineer”, explains how to do it best. Basically: for precision, it is necessary to control 2 quantities: the load of the engine and the fuel consumption (in other words what goes in and what goes out of the engine…).

1) Maintain identical conditions and load

To compare consumption must carry out measurements in the same test conditions before / after adaptation.

However, weather conditions and altitude may affect up to 20% performance. In the case of a vehicle, so be testing in similar weather conditions and at the same height!

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In the case of a generator, the charge must be resistive (avoid electric engines). Then, the resistance (and thus the load and consumption) varies beyond a certain temperature. It therefore should be cooled by a flow as a flow of air or water, to keep it at the same temperature.

2) Measure consumption

If you make sure to have an identical load, then you can make an accurate measurement of consumption.

There 2 possible ways:
a) to measure volume / weight set: drawn at constant power, measure how long it takes to consume a volume / fixed given mass.
b) measures to set duration: power drawn constant and time constant measurement, measure the amount of fuel consumed during this period.

I have a preference for the method), which is generally easier to implement. I therefore recommended that the experimenter. I also recommend to the mass action, not volume. It's much more accurate to within have graduated glassware. An electronic scale to 5 g accuracy sufficient to make significant steps.

Warning: 1 L GO or gasoline does not weigh 1 kg:
the gas density is 0.75 g / cm3
the gas oil density is 0.84 g / cm3


You can not compare a carelessly volume of gasoline evaporated in a bubbler with respect to a volume of gasoline consumed in a carburetor. In fact, the essence being composed of more than 130 constituents, are the most volatile components that are consumed in the bubbler first. These constituents have recess of energy characteristics (PCI) different gasoline "pure."

Christophe Martz has shown that the residual gas in the bubbler after 20 minute had a calorific value divided by 2 compared to the fresh petrol! And that is why a modified engine stalls after a time running EVEN if there is gas in the bubbler!

From then on, this remaining volume must also be added, because even if it was not “burned”, it was still “consumed” since it became unusable ...

In the case of a vehicle?

It's more delicate ...

1) For charging, always make the same trip with the same driver if possible with the same vehicle mass (full level for example). - Compare consumption on the same type of route (urban, motorway, etc.) and under the same weather conditions if possible.

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2) For consumption: Making measurements on the greatest possible distance.

Caution: On diesel, the reservoirs are deformed due to the hot gas oil that returns from the engine by the return pump. In addition, avoid measures half full because gas oil expands, or wait a few hours or overnight before refueling.
Put an auxiliary tank of small volume (20 L) it is possible to weigh can be a good solution but needs to draw new hoses.
Finally, it is best to take the fuel still in the same station as the quality change, and even a tank and a delivery to another!

A passage on the power test bench is the best way to ensure you have a constant load. As this is an expensive operation and very short in duration, it will be impossible to make adjustments during this passage on the bench, unless the garage is a friend.
Install an instant flow meter allows to have an idea of ​​consumption. There are ultralight and small aircraft flowmeters are suitable.

We must measure the consumption when the settings are optimum. The most important point is setting the proper spray and proper air / fuel setting.

Finally, it seems that the consumption of a modified engine decreases over time ... so wait a few hundred or thousands of kilometers to measure the consumption ...

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