Diesel in F1?

[Ciro Pabón]

45.000 rpm? If it's a Tee Dee, it's a two stroke engine... although I have to admit it works as a diesel engine once the glow spark plug stops working, but using two strokes instead of four. It works on methanol, castor/synthethic oil and nitromethane, btw.

However, flyn is right: the fastest diesel engine is the Space Bug, once you put in place the Davis diesel converter kit, made by Bolton. It doesn't work on nitro, it works on diesel fuel. How Mr. Robert Davis managed to overcome the "slow flame front", that Riff_raff mentions, beats me.

Fastest revving diesel in history. Throw in a turbocompressor and Confused Andy has the kind of engine he's looking for. He needs a really light F1 car if he's goint to use this one (and a tiny, tiny driver, like Hamilton in the Banco Santander new ad, where he is part of a model car).


An interview with Bob Davis, father of micro-diesel engines.

This engine throws away all the conventional wisdom I've learned (so much for conventional wisdom!) about diesel engines: it uses diesel fuel and it includes a contraption called a "contra-piston" which is a plug inside the chamber (it goes in place of the glow spark plug). You use a hex wrench to "push" the contrapiston into the chamber, increasing compression. You can change the timing that way (pushing it advances the timing and increases compression). Funny that you risk detonation when you push it too much. It's not your run of the mill diesel engine, of that I'm sure. It gives you the most powerful model plane in the show (0.8 Hp from a 0.4 cu.in. engine).

Assuming that's what flyn is talking about... Of course, he could have in his garage a 45.000 rpm V8 Diesel: then I have to assume he's working on the final details of the USF1 car....

[Belatti]

Ciro Pabón, have never read so much rubbish.

Wrong on so many levels

Please, be more specific mistery F1 engineer. I would like to know why you said that...

[flynfrog]

Mine is an rc car engine Ciro. It is fired off of nitro alky blend. but I like my engines to be From the boot country http://www.novarossi.us/

[F1_eng]

Because most it what was said is completely wrong.

How can an engine with CR of 24:1 be inducting 3 times as much as one with 8:1 CR?
Complete lacking in understanding of one of the most basic engine principals.

I can't remember all the things wrong, I might have a look through it again but it was very painful reading.

Detonation caused by flame speed faster than speed of sound which causes damage to the engine?


Some other points about why diesels are so efficient, again completely missed the mark.

I haven't read the post again because it was awful and I haven't read the latest post for the same reason.

I am only voicing my concern because it's very bad idea when someone asks a genuine question to give missleading information, the person asking the question is actually in a worse position after a wrong answer since he thinks he knows the reasoning behind something.

[Giblet]

Because most it what was said is completely wrong.

How can an engine with CR of 24:1 be inducting 3 times as much as one with 8:1 CR?
Complete lacking in understanding of one of the most basic engine principals.

I can't remember all the things wrong, I might have a look through it again but it was very painful reading.

Detonation caused by flame speed faster than speed of sound which causes damage to the engine?


Some other points about why diesels are so efficient, again completely missed the mark.

I haven't read the post again because it was awful and I haven't read the latest post for the same reason.

I am only voicing my concern because it's very bad idea when someone asks a genuine question to give missleading information, the person asking the question is actually in a worse position after a wrong answer since he thinks he knows the reasoning behind something.

It's even worse when you argue the point, and your only argument is "I only read it once, I can't remember what is wrong, but it is."

You simply need to do better than that. We might as well discuss like this:

Ciro: Yes!

You: No!

Ciro's post, while it might not be right according to you, was a well arranged post that took time and energy to put together, for OUR reading and enjoyment.

You could at least return the respect by actually reREADING his post and debating what is wrong with it.

Otherwise you might as well participate in youtube discussions, as they have as much substance as your post.

What do you guys think of this motor :

http://www.regtech.com/Radmax_Technolog ... Principle/

[youtube]http://www.youtube.com/watch?v=Mfd4YIu7 ... re=related[/youtube]

I'd love to see $$$ put into this and see where it can go.

TWO MOVING PARTS

[F1_eng]

"You pack more air into the combustion chamber, you use a fuel with higher energy content, so you get much better torque."

It is not always the case, the limiting factor generally with gasoline it the throttling wich dictates air intake so at full throttle and moderate engine speeds, a gasoline engine volumetric efficiency would be more optimised than a diesel engine. This is also a function of cylinder displacement, so with a displacement of a certain size, you won't get any more in to a diesel engine than you would a gasoline, in fact the gasoline would perform better over a wider range than the diesel would in general terms.

"That is quite an achievement in an endurance race because a Diesel engine is more "stable" than a gasoline powered one: you pay your price in designing for high stresses, but the engine you get works at a slower pace."

What does this mean???

"Actually, you pack so much "punch" in every power stroke that you can allow yourself to run it very slowly, thus the wearing is smaller. Think that Diesel engines put 3 times more air into the chamber than Otto engines (1:24 compression ratio, tops for a Diesel, vs 1:8 compression ratio, lower end of gasoline powered ones)."

Absolute rubbish, the extra "punch" you put in does not equate to the ruduction in speed endured.

"You compress only air, and by compressing it you make air so hot that almost all the fuel you inject burns. So, a diesel engine is a lean engine, which means it uses less fuel."

So you from previous "explanation" you use a fuel with a higher energy content, but you use less of it? The different in gasoline 44Mj/Kg to diesel 45Mj/kg is very slight but it is said you can use less of it. But in a previous post it was said you use fuel with a higher energy content but for this to be of any use, the total energy in the cylinder would have to be higher to be of any worthwhile use. You do not want to compress "only air" as the combustion process, a diesel does require time to go through the different phases so starting this early is a good idea but with only a limited amount of fuel as not to start the mid-burning phase where optimum combustion occurs.

"On the other hand, an Otto engine is limited by the atmospheric pressure: how much air can you get into the engine? It depends on its suction ability, if you get my drift, as the cool equations show."

The equation is correct theoretically but dynamic compression is not accounted for which is the true value and at different engine speeds, is completely different for all engines, it drops off sharply with speed for diesel engines. How is "Otto" limited by atmospheric pressure? There are plenty of charged gasoline engines. As with all orifices, they are limited by the speed of sound!

There's also mention of the flame speed causing detonation which is blatantly incorrect, it is related to the un-burnt zone conditions. The shock-waves are a side-effect of detonation, not a cuase.




Overall a very poor and miss-leading post. Also diesel enginges do not procuce more torque because they are heavier.Why not make the whole thing from cast iron which could still sustain the speeds but be even heavier?

I really didn't like finding specific faults but you requested it Giblet.

Regards

[Michiba]

Because most it what was said is completely wrong.

How can an engine with CR of 24:1 be inducting 3 times as much as one with 8:1 CR?
Complete lacking in understanding of one of the most basic engine principals.

I can't remember all the things wrong, I might have a look through it again but it was very painful reading.

Detonation caused by flame speed faster than speed of sound which causes damage to the engine?


Some other points about why diesels are so efficient, again completely missed the mark.

I haven't read the post again because it was awful and I haven't read the latest post for the same reason.

I am only voicing my concern because it's very bad idea when someone asks a genuine question to give missleading information, the person asking the question is actually in a worse position after a wrong answer since he thinks he knows the reasoning behind something.

This forum is full of people like this, ie, too much confidence, not enough knowledge.

I once read a post (where the poster saw an image of Ferrari's attempt at a ddd) and claimed that he could have swallowed some CF and shitted out a better diffuser. Joke aside, his confidence lead him to believe that he knew more than the ferrari designers. Just one example.

[Giblet]

"That is quite an achievement in an endurance race because a Diesel engine is more "stable" than a gasoline powered one: you pay your price in designing for high stresses, but the engine you get works at a slower pace."

What does this mean???

It means that the engine has to endure less mechanical stresses in some areas due to it's smaller operating window of revs. Vibration is a huge enemy, and pure fuel burning efficiency is not the only factor to consider in a race. It could be argued that diesels are superior racing motors, based on their success in their limited time since introduced by Lola and adopted (stolen) by Audi.

In short, you did a great job of defending your position, but instead of coming across as a someone who wants to engage in the discussion you sound more like someone who just wants to be right, and a know it all. I am sure this was not your intention, but que sera sera.

On this site, there is always someone who knows more, and has more experience than you. I am not an engineer, and have limited mathematical abilities to follow some of the discussions on here, but I have learned a lot through discussion, and also learned that calling someones post rubbish out of the gate will only draw a negative response.

[F1_eng]

Michiba, is your post aimed at me or agreeing with me?

"It means that the engine has to endure less mechanical stresses in some areas due to it's smaller operating window of revs. "

Unfortunately this is not right, although the speeds are lower and of a smaller range, factors such as bearing stresses and cylinder side-wall loadings are still much higher than their gasoline competitors. This is why the diesel engines tend to be heavier due to the components required to safely deal with these stresses.
Audi's aim with the R15 engine was to reduce its weight and move its position in the car by shortening the engine, hence V10 over a V12. The problem was that you then have to deal with slightly more stress per bearing shell, not only because there are less of them but you are increasing the force generated by each cylinder so you get higher overall bearing stresses. Also a factor was the bore and block structure which has to deal with these stresse. Audi did look in to a V8 engine rather than a V10 but they found the V8 would end-up being heavier than a V10 due to the increased rigidity required by the block structure and the underlying problem of bearing stresses.

I am in no way commenting that diesel are not superior racing motors

"In short, you did a great job of defending your position, but instead of coming across as a someone who wants to engage in the discussion you sound more like someone who just wants to be right, and a know it all. I am sure this was not your intention, but que sera sera.

On this site, there is always someone who knows more, and has more experience than you."

I do always want to be right, who doesn't? You sound very patronising Giblet.
In regards to always someone who knows more, perhaps true about a hobby such as knitting but when it comes to the engineering and design of cars, I seriously doubt that. I don't think you are in a position to comment on people's knowledge without knowing enough about them and what they have achieved. I would love to tell you who I am and what I do, but unfortunately I think it would cause more issues than it's worth.
All I will say is, there's a comment by Michiba about designing better than Ferrari designers, current track record proves that is the case in regards to myself.

My original post was in letting readers know that what they were reading was wrong, almost in its entirety. No information is usually better than wrong information.

Regards

[Giblet]

You failed my test.

I posted a fact about diesel engines that can not be debated, and you still say it's wrong. There is arguing for the sake, and discussing fact.

"It means that the engine has to endure less mechanical stresses in some areas due to it's smaller operating window of revs. "


What exactly is wrong with this statement? An engine that at 18,000 rpm will endure less stress in some areas than one that revs to 10,000rpm, and 10,000 is generous. I guess you could have just misread, but you are educated and shouldn't have missed what I was saying.

I am happy that you are so successful. I wish I had known what my passion was when I was still in school. I look forward to reading any info you put forth, as for rubbishing statements with no context, nobody needs that You put a couple users in a bad way over your condescending comments about Ciro's post, and assume it is because there is something wrong with our attitudes?

We've had people involved directly in F1 speak here to us before. In the case of the Mclaren Hydristor for example. Glad to know your knowledge/experience is here as well, whatever it may be.

We value all kinds of opinions and stances form all kinds of people in this community.

Always attack the post, and not the poster.

[xxChrisxx]

"It means that the engine has to endure less mechanical stresses in some areas due to it's smaller operating window of revs. "

Unfortunately this is not right, although the speeds are lower and of a smaller range, factors such as bearing stresses and cylinder side-wall loadings are still much higher than their gasoline competitors. This is why the diesel engines tend to be heavier due to the components required to safely deal with these stresses.

One major oversight of your list is dynamic streses due to the inertia of reciprocating parts.

Diesel conrods have to endure much less stress amplitude change and thus are more resistent to fatigue than higher revving petrol engines.

At very high rpm, stresses due to anything else but inertia become almost irrelevent.

This oobviously doesnt affect the block or piston too much, but has an impact on conrods and to a lesser extent crankshaft.


Admittedly some of Ciro's statements I would argue were false. However the way you went about refuting them only serves to agrivate people.

On this site, there is always someone who knows more, and has more experience than you."

I do always want to be right, who doesn't? You sound very patronising Giblet.
In regards to always someone who knows more, perhaps true about a hobby such as knitting but when it comes to the engineering and design of cars, I seriously doubt that.

The statement you made regarding you essentially being the best engineer in the world only serves to show that you are sufferiing from unwarranted self importance. Probably the worst internet disease there is.

Noone is the top expert at every field. It is always true that seomeone knows more than you do.

[Jersey Tom]

It honestly makes no difference to the sport whether F1 is powered by gasoline, diesel, or alcohol.. what size the engines are, or whatever. Who --- cares how high a diesel engine can rev? Makes no difference.

I still say I'd rather have a racing class with:

a) Open tech regs
b) You are given X amount of BTUs of race fuel of your choice per weekend
c) You have an annual budget cap
d) Go race.

If you want to see a formula that's the pinnacle of creativity, diversity, and technical development.. IMO that's the way to go.

[riff_raff]

I heartily agree with Jersey Tom. The best rules are the ones that give every team an equal starting point, as far as possible. And then let the best team win.

Using open rules with a fuel energy content formula and sane budget limits would produce some really creative race vehicles and propulsion systems. As a mechanical engineer who designs transmission systems, I love the idea.

The only stumbling point is that much of the mega-bucks sponsor money required to race originates with the auto industry. And the auto companies prefer that the race cars at least marginally reflect the products that they are selling. Thus the continued use of 4-stroke, recip piston, gasoline engines in most auto racing series.

Regards,
Terry

[F1_eng]

"One major oversight of your list is dynamic streses due to the inertia of reciprocating parts.

Diesel conrods have to endure much less stress amplitude change and thus are more resistent to fatigue than higher revving petrol engines.

At very high rpm, stresses due to anything else but inertia become almost irrelevent.

This oobviously doesnt affect the block or piston too much, but has an impact on conrods and to a lesser extent crankshaft."

Precisely why I mentioned about diesel bearing life problems, so no, it wasn't an oversight. It would be a litte more difficult meantioning stresses in an engine from a static point of view as you seem to have implied. The reason the bearings suffer higher stresses on a diesel is because they are experiencing higher inertia loadings than a gasoline would at that speed.
The rate of load application to the con-rod for a diesel is much higher, purely due to the combustion mechanism. Injector technology at present is developing to try and improve the rate of application which will certainly help matters.
These inertia loadings in the con-rod are transfered to the block more than you would imagine. The con-rod when compressed has to apply an equal and opposing force, when this is applied at a considerable rod angle, the resulting side-force in to the cylinders and block is quite alarming. I can dig out some numbers if you would like to get an idea.

[riff_raff]

F1_eng,

You are correct when you say that reversing inertia loads can predominate in a very high speed race engine. But these inertia loads only really affect the conrod structure and rings. The most likely point of failure in a modern F1 engine, even with pneumatic valve springs, is an intake valve bashing a piston.

A highly boosted diesel engine has a much worse combustion pressure and thermal load condition on the piston structure than a N/A gasoline race engine. Even though the diesel runs at much lower revs than the gasoline F1 engine. Plus, the higher peak cycle pressures in the diesel produce much greater torsional stresses in the crankshaft, and require much stronger gears and components in the transmission.

As for the rod structure and bearing inertia loads, the N/A gasoline race engine has a lighter piston and rod, but revs higher. The highly-boosted diesel race engine has a heavier piston and rod, because it has much greater peak combustion loads. But the higher combustion and intake pressures acting on the piston also help to relieve those inertia loads.

Finally, the point that I haven't seen discussed yet, is that diesel fuel has a much better energy density than even gasoline. Couple that with the more thermally efficient combustion cycle possible with a CI diesel engine.

Regards,
Terry