Forged Piston Problems

[Stingpuller]

nos

You still say the same. Its not more air than you would have with a higher boost. The hotter air (more boost) imho would cause more problems than a cooler air would. Diesel power unless i'm missing something I had nos on my moped when you was still riding your bigwheel. Jeff

 

[Diesel power]

Assuming that your nitrous is in check(not to much) wouldnt its cooling effect delay the peak temp time, therefore delaying ignition(fake timing retard)? Hope this makes sense!

on the intake stoke yes a lot. say the temp to ignite diesel is 600* the average opperating temp is 900, you add nos and it goes down to 750, still ignitable right?

Now on the exh side it usally runs 1500* with nos it runs 1650* because it is completely burning all the fuel, is that a bad thing......NO! because you have cooled the intake charge somuch you allowed the piston to thermally prepare for a higher exh event..... make sence.. wanna reduce the EGT's more? add more nos......but make sure there are no restrictions on the exhaust side first(small turbine housing)......

 

[McRat]

Assuming that your nitrous is in check(not to much) wouldnt its cooling effect delay the peak temp time, therefore delaying ignition(fake timing retard)? Hope this makes sense!

No, because the air must be "just hot enough" before you inject fuel, then the fuel increases the temp to burn more fuel. If the air is hotter than needed, all is good.

 

[Diesel power]

You still say the same. Its not more air than you would have with a higher boost. The hotter air (more boost) imho would cause more problems than a cooler air would. Diesel power unless i'm missing something I had nos on my moped when you was still riding your bigwheel. Jeff

Your missing the point!

nos has way more oxygen in it (36%) and it's a sub zero liquid(-120*)

 

[Turbo Buick 6]

And to bring it back on topic, aluminum atoms when exposed to high oxygen levels, at high pressures and temperatures, ignites. Atmospheric oxygen is usually not enough to burn aluminum, unlike magnesium (it's chemical cousin). But add a catalyst like nitrous, and the pressure/temp required goes down.

I agree, but my question is does this apply to aluminum oxide? Aluminum oxide melts at around 3600F and if it is not cleaned off befor welding the aluminum melts but the oxide doesn't and it looks like a skin over the puddle. I only ask this because if the oxide would make the pistons more durable we could oxidize the top of them to help protect them.

 

[camomax]

No, because the air must be "just hot enough" before you inject fuel, then the fuel increases the temp to burn more fuel. If the air is hotter than needed, all is good.

Sorry to continue off thread, but Im confused. Does injection begin before or after peak temp?

 

[Diesel power]

I have agree, but my question is does this apply to aluminum oxide? Aluminum oxide melts at around 3600F and if it is not cleaned off befor welding the aluminum melts but the oxide doesn't and it looks like a skin over the puddle. I only ask this because if the oxide would make the pistons more durable we could oxidize the top of them to help protect them.

Theroetically yes as it would be a barrier of some sort, but oxidation is deterioration, so let use something similar ceramic coating............:cool2:

 

[Diesel power]

Sorry to continue off thread, but Im confused. Does injection begin before or after peak temp?

injection starts before TDC otherwise ther would be nothing to compress but air.

 

[Osubeaver]

I only ask this because if the oxide would make the pistons more durable we could oxidize the top of them to help protect them.

That would be anodizing right? Don't see any anodized pistons..... wonder if there is a reason.

My guess is that it wouldn't do much.

 

[Turbo Buick 6]

Theroetically yes as it would be a barrier of some sort, but oxidation is deterioration, so let use something similar ceramic coating............:cool2:

Maybe ceramic would be better but I'm just trying to look at something else (pretty much free and can be done at home). Plus ceramic can flake off where oxidation won't....unless you get to an extreem coating of it.

If it would help even the slightest bit it would be worth it for someone who otherwise wouldn't coat their pistons.

 

[Turbo Buick 6]

That would be anodizing right? Don't see any anodized pistons..... wonder if there is a reason.

My guess is that it wouldn't do much.

not really, aluminum oxide is aluminums version of rust.

 

[Stingpuller]

nos

I guess i'm done. Its just because someone said so. Pat, your the smart guy(the most education) :hug:here but unless there is melting pistons I still don't see aluminum oxide in the camber. I just think some try to over think some things and not do so with a open mind. I just a dumb hillybilly who does things(tears sh## up) to try and learn. I was hoping someone could give me a good reason why it would change the flame front. Now if someone would say piston bowl shape, injector angle, pressure id have to think about it but not just because thats how it is. Jeff P.S. sorry for the rants but its winter time and i need to get out more.

 

[camomax]

injection starts before TDC otherwise ther would be nothing to compress but air.

I understand it starts before TDC, Im talking about peak ignition temperature. Is temp achieved and then injection, or can injection begin before ignition temp is reached? Thanks for the help, I wont invade this thread again.

 

[McRat]

I guess i'm done. Its just because someone said so. Pat, your the smart guy(the most education) :hug:here but unless there is melting pistons I still don't see aluminum oxide in the camber. I just think some try to over think some things and not do so with a open mind. I just a dumb hillybilly who does things(tears sh## up) to try and learn. I was hoping someone could give me a good reason why it would change the flame front. Now if someone would say piston bowl shape, injector angle, pressure id have to think about it but not just because thats how it is. Jeff P.S. sorry for the rants but its winter time and i need to get out more.

All aluminum has a layer of aluminum oxide on it, and that's why it's pretty hard to burn. It happens in seconds once you cut it. But it is a prime ingredient in military flares and solid rocket engines. Don't confuse melting with igniting. Aluminum doesn't have to melt to ignite.

 

[Osubeaver]

not really, aluminum oxide is aluminums version of rust.

Huh?

What am I missing here?

Aluminum forms it's own oxide layer basically instantly in the normal atmosphere. You know this as a welder. That's the black stuff you see on your rags and brushes as you clean aluminum to weld it, and the skin on the puddle if you don't get it off. Duh. Don't need to tell you that.

Anodizing increases the thickness of that layer. That really isn't up for debate. Or are you saying there is some other process to oxidize aluminum that should be used or invented? Like a non-crystallene type or something?

Not being an ass, really wondering.

 

[Diesel power]

I understand it starts before TDC, Im talking about peak ignition temperature. Is temp achieved and then injection, or can injection begin before ignition temp is reached? Thanks for the help, I wont invade this thread again.

Hey i dont mind your questions at all, it's those that dont appreciate/listento the answers i give that i would rather not help.


Peak cylinder psi is going to be achieved after ignition which would be after TDC( perfect world)(correctly tuned)

Some engines which are not tuned correctly will have PCP before TDC sadly thats reality.

assuming we are talking about an engine that be injected with nos this is a real word result

 

[McRat]

I understand it starts before TDC, Im talking about peak ignition temperature. Is temp achieved and then injection, or can injection begin before ignition temp is reached? Thanks for the help, I wont invade this thread again.

If you inject fuel before the air is hot enough, the fuel (120deg) cools down the air to less than the ignition temperature before it can ignite. If the piston is still going up, it can heat the mixture more, then finally ignite all at once near TDC, and you hear a "knock" which is diesel rattle.

 

[Turbo Buick 6]

Huh?

What am I missing here?

Aluminum forms it's own oxide layer basically instantly in the normal atmosphere. You know this as a welder. That's the black stuff you see on your rags and brushes as you clean aluminum to weld it, and the skin on the puddle if you don't get it off. Duh. Don't need to tell you that.

Anodizing increases the thickness of that layer. That really isn't up for debate. Or are you saying there is some other process to oxidize aluminum that should be used or invented?

Not being an ass, really wondering.

I should have phrased that differently. You are correct about anodizing being oxide, but most people think of anodizing as coloring because they use different types of dyes to color the oxide. I would not play with the dyes as you don't know what they could do. But I would be intested to see what plain annodizing could do for us.

 

[Osubeaver]

I should have phrased that differently. You are correct about anodizing being oxide, but most people think of anodizing as coloring because they use different types of dyes to color the oxide. I would not play with the dyes as you don't know what they could do. But I would be intested to see what plain annodizing could do for us.

Right, and it was an honest question from me. Anodizing does produce a different type of oxide coating than the normally occuring oxide (that's why it will accept die I think). But I'm no plating expert.

ETA: I guess "structure" woudl be a better word than "type"

 

[McRat]

I believe the problem with anodize is that it expands at a different rate than aluminum does, so for applications of 400 deg or higher, it's not recommended since it can flake. With normal oxidizing, it happens at a microscopic level, so you get some aluminum oxide dust on you when you handle it. When it's heavy anodize, it's different.

Or so I remember.