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mindgam3 · 08-11-2004, 05:22 PM

I thought we'd start with the most obvious thing that makes up the F1 car.... the engine

I've picked a very nice article from F1 Technical for you (thanks to them

enjoy reading....

Note to RC45 and greywolf: take note of the mentioning of VE, ME and TE

THE ENGINE

"The formula one engine is the most complex part of the whole car. With an amazing horsepower production and about 1000 moving parts, this sort of engine makes the greatest cost on a F1 car. Incredible revs exceeding 17,000 rpm and extreme high temperatures make it very hard to make that engine reliable. This table shows current FIA limitations concerning an engine.

Engine capacity must not exceed 3000 cc.
Engines may have no more than 5 valves per cylinder.
Supercharging is forbidden.
An engine must consist of 10 cylinders and the normal section of each cylinder must be circular.
The use of any device, other than the 3 litre, four stroke engine to power the car, is not permitted
Variable geometric length exhaust systems are forbidden.
The basic structure of the crankshaft and camshafts must be made from steel or cast iron.
Pistons, cylinder heads and cylinder blocks may not be composite structures which use carbon or aramid fibre reinforcing materials.

At the moment, all f1 engines can produce more than 780 bhp with 10 cilinders in V. These engines are mainly made from forged aluminium alloy, because of the weight advantages it gives in comparison to steel. Other materials would maybe give some extra advantages, but to limit costs, the FIA has forbidden non-ferro materials. In this quest to decrease engine weight, the 1998 Mercedes-benz engine was possibly one of the most revolutionary engines ever built. Ford started a new trend that year to drastically decrease the weight of the engine, and thus also improving its performance. Ford Cosworth had been able to produce an engine that was at least 25kg lighter than any other engine. Although they suffered some reliability problems trghout the season, the engine was an example for the others, as it allowed teams to shift some weight in the car. That could be placed more on the front wheels or on the rear wheels which could help the steering or the acceleration of the car.

It's not exactly known how much oil such a top engine contains, but this oil is for 70% in the engine, while the other 30% is in a dry-sump lubrication system that changes oil within the engine three to four times a minute.

Difference with road engines

Higher volumetric efficiency. VE is used to describe the amount of fuel/air in the cylinder in relation to regular atmospheric air. If the cylinder is filled with fuel/air at atmospheric pressure, then the engine is said to have 100% volumetric efficiency. On the other hand, turbo chargers increase the pressure entering the cylinder, giving the engine a volumetric efficiency greater than 100%. However, if the cylinder is pulling in a vacuum, then the engine has less than 100% volumetric efficiency. Normally aspirated engines typically run anywhere between 80% and 100% VE. So now, when you read that a certain manifold and cam combination tested out to have a 95% VE, you will know that the higher the number, the more power the engine can produce. Bacause turbos are not allowed in F1, this item does not differ that much from a normal road engine.
Unfortunately, from the total fuel energy that is put into the cylinders, everagely less than 1/3 ends up as useable horsepower. Ignition timing, thermal coatings, plug location and chamber design all affect the thermal efficiency (TE). Low compression street engines may have a TE of approximately 0.26. A racing engine may have a TE of approximately 0.34. This seemingly small difference results in a difference of about 30% (0.34 - 0.26 / 0.26) more horsepower than before.
From all that power generated, part of it is used by the engine to run itself. The left over power is what you would measure on a dynamometer. The difference between what you would measure on the dyno and the workable power in the cylinder is the mechanical efficiency (ME). Mechanical efficiency is affected by rocker friction, bearing friction, piston skirt area, and other moving parts, but it is also dependent on the engine's RPM. The greater the RPM, the more power it takes to turn the engine. This means limiting internal engine friction can generate a large surplus in horsepower, and where in F1 the stress is on power, on the road it is also on fuel consumption.
These main optimization necessities are what causes the engineer's headaches. At the end of the line, an F1 engine revs much higher than road units, hence limiting the lifetime of such a power source. It is especially the mechanical efficiency that causes formula one engines to be made of different materials. These are necessary to decrease internal fraction and the overall weight of the engine, but more importantly, limit the weight of internal parts, e.g. of the valves, which should be as light as possible to allow incredibly fast movement of more than 300 movements up and down a second (this at 18.000 rpm).

Another deciding point trying to reach a maximum of power out of an engine is the exhaust. The minor change of lenght or form of an exhaust can influence the horsepowers drastically (for more information about exhausts, look at the article concerning this topic in the Mechanics part).

Engine type

Considering internal combustion engines (thus leaving out oscillating and Wankel rotary combustion engines), there are basically three different types of building an engine. The difference here is how the cylinders are placed compared to each other.

Inline engines, where all cylinders are placed next to (or after) each other are not used in Formula one since the 60's.
Boxer engines are actually one of the best ways to build an engine, if all external factors allow it. Two cylinder rows are placed opposed to each other. These engines became popular in F1 because of the low point of gravity, and the average production costs, but later on disappeared out of the picture as this type of engine is not sufficiently stiff enough to whitstand the car's G-forces in cornering conditions.
V-type engines, as currently used in all F1 cars. As you can see on the picture, it is the same principe as a boxer engine, although the cylinder rows are located both above the cranck shaft, where in boxer engines, these are constructed aside it. With this type of engine, the first question you should ask yourself is how large should the V angle be. Currently most F1 cars run with a 72°, Renault runs a 112° engine in order to obtain a lower gravity point but having to cope with more vibrations and a decreased stiffness of the engine part.
The size of the V angle has to do with firing sequence and primary balance. A circle has 360 degrees and the (included V angle x the number of cylinders) must be a function of 360 in order to achieve evenly spaced cylinder firing and primary balance. That is why a 90 V has either offset crankpins or a funny firing order. That is why a boxer engine is an ideal layout. The cylinders are opposed at 180 degrees so having 2 or 4 or 6 or 8 or 10 or 12 isn't that big a deal. Perfect primary balance is easy to achieve, as long as the reciprocating and rotating parts are in balance and, the firing order is always evenly spaced. However, a boxer in an F1 car would be ungainly.

Cooling

Just above the driver's head there is a large opening that supplies the engine with air. It is commonly thought that the purpose of this is to 'ram' air into the engine like a supercharger, but the airbox does the opposite. Between the airbox and the engine there is a carbon-fibre duct that gradually widens out as it approaches the engine. As the volume increases, it makes the air flow slow down. The shape of this must be carefullly designed to both fill all cylinders equally and not harm the exterior aerodynaimcs of the engine cover, this all to optimize the volumetric efficiency.

This picture shows the whole engine part and surroundings on the Toyota F1 car of 2002. The black carbon box above the engine is the airbox, providing air to the engine to be mixed with fuel in the cylinders. Secondly, the flat panels located nearly vertically in the front of the side pods are the radiators. These use air flowing through to cool down the engine and its oil. The position can vary a lot, as it is not a much importance as long as it can catch enough air, preventing the engine to overheat. One thing that greatly influences the radiator positioning is to lower the side pod and improve the coke bottle effect, thereby optimizing aerodynamic efficieny."

Full Article with Pics

08-11-2004, 05:22 PM	#2
mindgam3 Regular User Join Date: Jun 2004 Location: Cambridge, UK Posts: 2,279	I thought we'd start with the most obvious thing that makes up the F1 car.... the engine I've picked a very nice article from F1 Technical for you (thanks to them enjoy reading.... Note to RC45 and greywolf: take note of the mentioning of VE, ME and TE THE ENGINE "The formula one engine is the most complex part of the whole car. With an amazing horsepower production and about 1000 moving parts, this sort of engine makes the greatest cost on a F1 car. Incredible revs exceeding 17,000 rpm and extreme high temperatures make it very hard to make that engine reliable. This table shows current FIA limitations concerning an engine. Engine capacity must not exceed 3000 cc. Engines may have no more than 5 valves per cylinder. Supercharging is forbidden. An engine must consist of 10 cylinders and the normal section of each cylinder must be circular. The use of any device, other than the 3 litre, four stroke engine to power the car, is not permitted Variable geometric length exhaust systems are forbidden. The basic structure of the crankshaft and camshafts must be made from steel or cast iron. Pistons, cylinder heads and cylinder blocks may not be composite structures which use carbon or aramid fibre reinforcing materials. At the moment, all f1 engines can produce more than 780 bhp with 10 cilinders in V. These engines are mainly made from forged aluminium alloy, because of the weight advantages it gives in comparison to steel. Other materials would maybe give some extra advantages, but to limit costs, the FIA has forbidden non-ferro materials. In this quest to decrease engine weight, the 1998 Mercedes-benz engine was possibly one of the most revolutionary engines ever built. Ford started a new trend that year to drastically decrease the weight of the engine, and thus also improving its performance. Ford Cosworth had been able to produce an engine that was at least 25kg lighter than any other engine. Although they suffered some reliability problems trghout the season, the engine was an example for the others, as it allowed teams to shift some weight in the car. That could be placed more on the front wheels or on the rear wheels which could help the steering or the acceleration of the car. It's not exactly known how much oil such a top engine contains, but this oil is for 70% in the engine, while the other 30% is in a dry-sump lubrication system that changes oil within the engine three to four times a minute. Difference with road engines Higher volumetric efficiency. VE is used to describe the amount of fuel/air in the cylinder in relation to regular atmospheric air. If the cylinder is filled with fuel/air at atmospheric pressure, then the engine is said to have 100% volumetric efficiency. On the other hand, turbo chargers increase the pressure entering the cylinder, giving the engine a volumetric efficiency greater than 100%. However, if the cylinder is pulling in a vacuum, then the engine has less than 100% volumetric efficiency. Normally aspirated engines typically run anywhere between 80% and 100% VE. So now, when you read that a certain manifold and cam combination tested out to have a 95% VE, you will know that the higher the number, the more power the engine can produce. Bacause turbos are not allowed in F1, this item does not differ that much from a normal road engine. Unfortunately, from the total fuel energy that is put into the cylinders, everagely less than 1/3 ends up as useable horsepower. Ignition timing, thermal coatings, plug location and chamber design all affect the thermal efficiency (TE). Low compression street engines may have a TE of approximately 0.26. A racing engine may have a TE of approximately 0.34. This seemingly small difference results in a difference of about 30% (0.34 - 0.26 / 0.26) more horsepower than before. From all that power generated, part of it is used by the engine to run itself. The left over power is what you would measure on a dynamometer. The difference between what you would measure on the dyno and the workable power in the cylinder is the mechanical efficiency (ME). Mechanical efficiency is affected by rocker friction, bearing friction, piston skirt area, and other moving parts, but it is also dependent on the engine's RPM. The greater the RPM, the more power it takes to turn the engine. This means limiting internal engine friction can generate a large surplus in horsepower, and where in F1 the stress is on power, on the road it is also on fuel consumption. These main optimization necessities are what causes the engineer's headaches. At the end of the line, an F1 engine revs much higher than road units, hence limiting the lifetime of such a power source. It is especially the mechanical efficiency that causes formula one engines to be made of different materials. These are necessary to decrease internal fraction and the overall weight of the engine, but more importantly, limit the weight of internal parts, e.g. of the valves, which should be as light as possible to allow incredibly fast movement of more than 300 movements up and down a second (this at 18.000 rpm). Another deciding point trying to reach a maximum of power out of an engine is the exhaust. The minor change of lenght or form of an exhaust can influence the horsepowers drastically (for more information about exhausts, look at the article concerning this topic in the Mechanics part). Engine type Considering internal combustion engines (thus leaving out oscillating and Wankel rotary combustion engines), there are basically three different types of building an engine. The difference here is how the cylinders are placed compared to each other. Inline engines, where all cylinders are placed next to (or after) each other are not used in Formula one since the 60's. Boxer engines are actually one of the best ways to build an engine, if all external factors allow it. Two cylinder rows are placed opposed to each other. These engines became popular in F1 because of the low point of gravity, and the average production costs, but later on disappeared out of the picture as this type of engine is not sufficiently stiff enough to whitstand the car's G-forces in cornering conditions. V-type engines, as currently used in all F1 cars. As you can see on the picture, it is the same principe as a boxer engine, although the cylinder rows are located both above the cranck shaft, where in boxer engines, these are constructed aside it. With this type of engine, the first question you should ask yourself is how large should the V angle be. Currently most F1 cars run with a 72°, Renault runs a 112° engine in order to obtain a lower gravity point but having to cope with more vibrations and a decreased stiffness of the engine part. The size of the V angle has to do with firing sequence and primary balance. A circle has 360 degrees and the (included V angle x the number of cylinders) must be a function of 360 in order to achieve evenly spaced cylinder firing and primary balance. That is why a 90 V has either offset crankpins or a funny firing order. That is why a boxer engine is an ideal layout. The cylinders are opposed at 180 degrees so having 2 or 4 or 6 or 8 or 10 or 12 isn't that big a deal. Perfect primary balance is easy to achieve, as long as the reciprocating and rotating parts are in balance and, the firing order is always evenly spaced. However, a boxer in an F1 car would be ungainly. Cooling Just above the driver's head there is a large opening that supplies the engine with air. It is commonly thought that the purpose of this is to 'ram' air into the engine like a supercharger, but the airbox does the opposite. Between the airbox and the engine there is a carbon-fibre duct that gradually widens out as it approaches the engine. As the volume increases, it makes the air flow slow down. The shape of this must be carefullly designed to both fill all cylinders equally and not harm the exterior aerodynaimcs of the engine cover, this all to optimize the volumetric efficiency. This picture shows the whole engine part and surroundings on the Toyota F1 car of 2002. The black carbon box above the engine is the airbox, providing air to the engine to be mixed with fuel in the cylinders. Secondly, the flat panels located nearly vertically in the front of the side pods are the radiators. These use air flowing through to cool down the engine and its oil. The position can vary a lot, as it is not a much importance as long as it can catch enough air, preventing the engine to overheat. One thing that greatly influences the radiator positioning is to lower the side pod and improve the coke bottle effect, thereby optimizing aerodynamic efficieny." Full Article with Pics