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Posted

Hello,

 

can someone please explain to me why F1 engines are so good.

 

even tho they are very low literage (which is capacity right?)

 

i konw thye can rev up to 20krpm.

 

 

so is that all an engine needds... to be able to rev ridiculously high? to be an awesome engine.

Posted

They are so good because they only need to go for about 100-200 Km. Actually, if it lasts for more, it's sent back to the manufacturer - for further pushing.

 

You can have a three liter engine in several ways, depending on the stresses on the materials:

 

Ford: 3L V6 - 150 HP, mean time between rebuilds/repairs: 250.000 Km.

Theoretical 3L turbo: 300-400 HP, mean time between rebuilds: <100.000 Km. Turbo engines that are pushed high need rebuild kits for turbos and engine every 60.000 Km.

F1: 3L turbo (variant) - 900 Hp, mean time between rebuilds: 300-500 Km.

 

Also, they are a *lot* more expensive, since more power generates more heat, you need better cooling, better oiling, better everything. Stresses build up on materials a lot closet to melting point, thus less resilient.

 

In theory you could pump whatever you need out of whatever engine, limited by efficiency alone. Higher RPMs require better balance in the engine, more expensive springs/valves/whatever, but 3 times the RPM means 3 times the has and oxygen, which translates in three times the power.

 

It's not really that complicated as long as you are not the engineer that has to keep pistons at near melting point. You can push your own engine at typically twice+ the power, but the heat is your enemy - it was never designed to conduct and dissipate that much heat so it heats locally passing the piston heads melting point, destroying them.

 

That's why powerful turbo kits also come with replacement heads and/or better cooling. Some have intercoolers, oil coolers, supplemental cooling, bigger radiators, more powerful pumps and so on.

 

Older F1 engines were 3000 cmc (3l) and developed around 900 HP. Newer limitations are for 2500 and they "dropped" to 750 HP. This is from memory.

 

But the rule of thumb is (and it's not really disputed) is: the more power off a liter of capacity, the more the repairs and the more sensitive the engine.

 

That's why your long life vehicle has around 50 HP/liter, sportier, more expensive cars have some 75 with 100 at the very high end. Above that they become unreliable, need loads of maintenance and are generally unpopular as "bad cars".

Posted

thank you. thats was a worthy reply!!!!!!

 

 

so is that also why rotay engines are better... for they are following similar principles to F1 engines?

Posted

rotary engines are better because theyre alot smaller for the same amount of power

 

and they last alot longer than an otto design engine(cylidrical piston)

they last alot longer because there is virtualy no vibrations

Posted

If you're talking about a Wankel engine, then I don't really agree with that. They do have serious sealing issues with rotary engines. Although they do vibrate a lot less, I'm not sure the seals will keep their tightness on the long run...:confused:

Posted

The Rotary engine loses its seal between the piston and the casing after running for a while and it only loses its seal on half of the engine, more specificaly the combustion and spark side. The intake side stays relatively cool due to the constant intake of air. The combustion side of the casing expands causing a small but evident gap between the casing and the piston. But when the whole engine cools the casing shrinks and will regain its seal. Well, for the first 100 degrees of operation.

 

TADA!:D

Posted

I also believe he's referring to the Wankel engine.

 

In which case, check here for an advantage/disadvantage analysis in a clean, simple manner.

 

The race for engine power at affordable prices pushed for some odd technologies. More valves per cylinder, forced air induction, injection, Honda's VTEC(Variable Timing, electronic cams), variable combustion chambers (I believe it's also in Honda's implementation) which vary compression, and so on.

 

Some take the good path forward and push engine by implementing technology over the design (Honda's VTEC allows for 160-190 HP from a 1.6L naturally aspirated engine, over the previously mentioned 100 HP/liter), others dust off old technologies. The Wankel engine was used in cars before (source?) but was dumped for other reasons - smoking, gas guzzling, etc. It still can deliver more power because it's more solid (less moving parts) and can rev higher with lower tech, meaning you can get more off the same liter capacity but the efficiency means that you usually get less kilometers off a liter of gas in the tank. New catalyst tech allows for tolerable smoke but on the market the Wankels failed - people opt more for a TDI (less reliable, but has warranty, more economical) over the Wankel (more reliable, company wins. More gas, you lose).

 

They are smoother in power delivery but then again if you want smooth you get a V engine (V6+balance, V8, etc). Also, V engines (and other non-linear designs) are also smaller for the delivered power and the gain was not enough. I have serious doubts about marketing such an engine.

 

The big plus is reliability, but you can get an engine to run 250.000-300.000 km nowadays with zero maintenance (minus consumables) which for a city dweller can mean 20 years. How much more reliable can you get?

 

So the short answer is no, the Wankel is not better than the good'ol engine in your car. And since there is resistance to new technology (spare parts, qualified personnel, etc) it's unlikely we'll see those.

 

If you really want something to look up at it's the electric engine. Past it's battery issue, newer motors can deliver power in a controlled manner and have so many advantages they would replace gas cars in a blink of an eye:

 

* Power is safer to use

* EMotors are more controllable, you get full torque at any RPM, including that 60 RPM you get when starting from a full stop.

* EMotors don't idle, consuming power; They don't start with a starter and stop controlled by electronics.

* EMotors can recover power during braking

* EMotors are more efficient. MUCH more.

* EMotors can be oversized with little penalty. You could have 4 250 HP motors under the hood and drive with 10% power (100HP). In emergencies you can drain the batteries and have 1000HP at the wheels

* EMotors don't require complex gearing to allow for idling, clever designs need no transmission, engine(s) can be mounted on the wheels.

* EMotors can spin safely to 20.000 RPM, some even higher, so 2 gears or no gears is OK. Some hi-tech motors can go 150.000 without shaking themselves apart.

* EMotors don't require that many liquids, so many moving parts, precise spark/valve timing and complex servos to control power for anti-skid, assistance, etc.

* Electric power can be stored in buffers (capacitors) for emergency overdrives.

 

I could go on forever. A town car, a speedster and the torque of an off-roader are all there. The record for the best acceleration is in the engine(s) of an electric car. It's just that you have to charge it for every other run.

Posted

another bonus with emotors (its more a specialized bonus though) is that if your willing to trash the engine, you can squeeze out more power than its rated for for a short period of time. this could be used on emergency vehicles or even in the military.

Posted

an the rotary engine i was talking about, is the whatever engine is in the MAZDA RX-7, which to my understading is the wankel engine.

but we dont call it that around here :)

 

does anyone know, why the the RX7's (the latest model ones) are faster or more usually used in high performance tuning OVER then TWIN ROTARY RX8.

from what i have heard, the twin rotaries dont compute to be twice as good as two rotaries. could someone claer that up for me.

 

and with teh EMOTORS, is their only prominent issue the power source, if that was solved.. they would be implemented internationally?

Posted
an the rotary engine i was talking about, is the whatever engine is in the MAZDA RX-7, which to my understading is the wankel engine.

but we dont call it that around here :)

 

Indeed. You should, since it's not a rotary engine - a rotary engine ... well, rotates. Just kidding, it'll never be called Wankel.

 

does anyone know, why the the RX7's (the latest model ones) are faster or more usually used in high performance tuning OVER then TWIN ROTARY RX8.

from what i have heard, the twin rotaries dont compute to be twice as good as two rotaries. could someone claer that up for me.

 

Sorry, not a Mazda fan. My car is a V6. However, Wiki says

The RX-8 is powered by a 1.3 L (1' date='308 cc) naturally-aspirated RENESIS 13B Wankel-type rotary engine, which features newly designed side intake and exhaust ports. The engine is smaller and lighter than previous rotaries, primarily due to the lack of a turbocharger and associated parts.

[/quote']

 

If RX7 was turbo and the RX8 is not it's easier and cheaper to push a turbo engine (Wankel or not) because the parts have been designed to take higher temperatures and pressures, as well as already sized cooling and other electronical tricks.

 

You can push a 150HP TDI (Turbo Diesel) to 170 via a chip upgrade (200$). You can also push a 1.8l Kompressor (Golf G60) from 160 HP to 190 HP by changing the pulley on the compressor (smaller wheel means higher kompressor RPM, meaning better pressure). How expensive is a pulley?

 

Now pushing a 1.5L aspirated (75 HP) to 130 (turbo) you need at least 1000E in parts - no manufacturing of parts, no expertise, no mounting (DIY).

 

I'm guessing they push the turbo versus the aspirated in which case the RX7 would be by far the favorite.

 

and with teh EMOTORS, is their only prominent issue the power source, if that was solved.. they would be implemented internationally?

 

I'd say so. I'd drive one for various reasons. Main reason being upgrading the engines to the best I could find - effectively allowing me to deliver 1000 HP in a maneuver. You'd need something along the lines of a 5000 cmc kompressor or similar just to keep in line with me to 100 km/hour. Your gas car would be in excess of 100.000E to do that, mine would be some 10% of that price (20% with upgrades).

 

Oh and a solar panel for those short (and now free) trips to work. Hey, free trips to work. In a dragster. Do *you* see a problem?

Posted
Hello,

 

can someone please explain to me why F1 engines are so good....

You have a number of good answers, but I don't think anyone's mentioned this one.

 

The power output of an internal combution engine is a function of the rate at which it burns fuel. Spinning the engine faster increases the airflow rate, which means more power. So, other things being equal, a 2.0L engine spinning at 20k RPM will make about the same power as an 8.0L engine spinning at 5k RPM.

 

One problem with rotary engines has to do with the fact that the combustion chamber is swept over a large surface area during the cycle, which increases heat losses during combustion and thus reduces efficiency.

Posted

In theory you could pump whatever you need out of whatever engine, limited by efficiency alone. Higher RPMs require better balance in the engine, more expensive springs/valves/whatever, but 3 times the RPM means 3 times the gas and oxygen, which translates in three times the power.

 

anyone's mentioned this one.

 

I did. Nothing about heat dissipation, though, but I think that's a good thing, since it's a thermal engine with two sources, so the hotter the explosion and the cooler the engine, the better you get. The hotter the engine, the hotter the air-fuel mix, so the less you get into a cylinder.

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