nitros

[Gunni]

search the word melt on these pages!!

http://www.beckracing.com/page14.htm
http://www.nitrous.info/engine-preparat ... itrous.htm
http://www.ehow.com/how-does_4897788_ni ... gines.html

There is nothing specific about Nitrous apart from the 1800F burn, wich is close to the 1600F you can see on some boosted applications.

Obviously I AM talking about adjusting fuel and timing just like anybody would do on a boosted engine.


Heat melts pistons, torque breaks them and bends rods.
Knocking destroys pistons.

M30´s just have 8.8:1 compression and examples of them running more then 400hp stock. Tha tells me that the torque they create does not destroy pistons or rods.

So it would have to be the higher temperatures that cause piston melting.

[GeoffBob]

I want to learn and ask for the person to explain where they came to the learning.

Your posts read as confrontational statements, not questions.

[Barx325i]

that's the way I interpret things.. the botom end can probably take the power, it's the heat..

[UweM3]

sorry, by bleed valve I mean one of these ecotek things.. on a standard m42 http://www.potn.co.uk/p75710.htm

I started a tech thread to counter my hijack

sorry but what an utter rubbish! 29% fuel savings! Yeah and the pope gets married next month.....

But look at the testimony of these top publications:

Max Power magazine
Revs magazine
Redline magazine

oh that really changes my opinion..............NOT!

[Gunni]

I want to learn and ask for the person to explain where they came to the learning.

Your posts read as confrontational statements, not questions.

That´s often the best way to call out people who have misunderstanding of things.

I´m doing some nitrous reading right now and will try to find solid information that either proves him right or my assumption right.

If you Geoffbob have a link with solid information I´d be happy to read it.

[GeoffBob]

That´s often the best way to call out people who have misunderstanding of things.

But, I suspect, also a good way to upset someone who does know what they are talking about.

If you Geoffbob have a link with solid information I´d be happy to read it.

Gunni, no links, but from memory the problem has to do with the cylinder pressure as a function of time due to the way the NOX decomposes and supplies oxygen to the combustion reaction.

Do the following gedanken experiment:
Fill a tin or cylinder with air and compress it and the air will heat up due to adiabatic heating (fundamental law of physics). For as long as the pressure is maintained the compressed air will try to pass its heat to the walls of the tin/cylinder. If the air is pressurised for only a very short time it will have very little time over which to heat the cylinder, and thus very little of its adiabatic heat will be lost.

The same is true in an engine (with the excpetion that the heat is predominantly due to the heat of combustion). If the BMEP is due to a lower pressure sustained over a longer time then there is more time over which to heat the surroundings. this results in lower thermal efficiency (and the surroundings get hotter due to more heat conducted to them) than the case of where the BMEP is due to a short duration large value pressure. This is why high compression ratio engines have higher thermal efficiency and therefore produce more power for a given quantity of combusted fuel.

NOX injected engines essentially deliver more heat to the combustion chamber due to the fact that the combustion pressure (which drives the piston) is sustained at a lower value (compared to an equivalent FI engine) for longer. A NOX injected engine, therefore, effectively has a lower thermal efficiency and transfers more of the heat of combustion to the block, head and pistons.

Hope this helps.
Geoff

[zaust]

I'm not as well versed as you mate lol.

So in basic, the initial n2 injection will be a shorter much more colder, compressed amout of air and fuel. In turn the explosion will be much bigger which is where the extra heat is comming from.

With fi you are not making a bigger explosion in the cylinder, you are forceing every thing through quicker, so it's not heat you need to worry about, it becomes the tolerance of the items that are getting the constant force.



Think that's put correctly.

[Gunni]

From what I have gathered now is what GeoffBob states about the mean pressure and thus the time the heat can get into the walls, head and pistons, which is the ultimate problem.

More of the reading I have done is that this problem can be overcome with a better form
of nitrous injection into the manifold. According to the owner of Wizards of Nitrous.


Thanks for the compiled info GeoffBob I had to read alot to get to that information.

[GeoffBob]

Zaust, sort of.

For two engines of similar HP, the total "push" given to the piston in each case is roughly the same.

However, and this is where the two differ, one gives a short sharp push, while the other gives a longer softer push. They both amount to the same total "push", but each pushes the piston over a different length of time, and at a different combustion pressure.

In reality there's actually not too much of a difference between the two cases. However, the drop in thermal efficiency (in the case of NOX) is enough that your figure of 340hp for NOX, compared to 400hp for a turbo or supercharger, sounds about right.

FYI, I am not a big fan of NOX since I prefer track racing. However, on a home built drag car I consider it an essential item. You don't need a cow in the car when you want milk on the road, not when you can take a flask of it with you and you only want one or two sips at a time.

[GeoffBob]

Thanks for the compiled info GeoffBob I had to read alot to get to that information.

You're welcome Gunni.

[zaust]

Zaust, sort of.

For two engines of similar HP, the total "push" given to the piston in each case is roughly the same.

However, and this is where the two differ, one gives a short sharp push, while the other gives a longer softer push. They both amount to the same total "push", but each pushes the piston over a different length of time, and at a different combustion pressure.

In reality there's actually not too much of a difference between the two cases. However, the drop in thermal efficiency (in the case of NOX) is enough that your figure of 340hp for NOX, compared to 400hp for a turbo or supercharger, sounds about right.

FYI, I am not a big fan of NOX since I prefer track racing. However, on a home built drag car I consider it an essential item. You don't need a cow in the car when you want milk on the road, not when you can take a flask of it with you and you only want one or two sips at a time.

Under stood.

This is going to be fun when i start looking for a shwitzer to bolt on next year

[jonnyboy]

Wat would a m20 2.5 be like with nos i wana do it