RPM, spray angle, bowl design

Sometimes I really hate how serious this "sport" has become.:aiwebs_027: Remember when it was just a bunch of guys beatin' the crap out of there pickup just to see how far they could drag crap across the field all in the name of fun?:poke:
 
with a very large port volume, would the engine be under vacuum momentarily, in low/off idle rpms? Since their is less restriction at the heads, air would take longer to pressurize equaling less air being forced into the motor. Yes larger port volume will flow more air, but where does the line get drawn between velocity and pressure vs. volume and flow?
 
DirtyMaxx03 said:
with a very large port volume, would the engine be under vacuum momentarily, in low/off idle rpms? Since their is less restriction at the heads, air would take longer to pressurize equaling less air being forced into the motor. Yes larger port volume will flow more air, but where does the line get drawn between velocity and pressure vs. volume and flow?
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No, to have a vacuum you'd have to have something for the engine to draw "against" for the lack of a better way to say it.

Even a turbo not making "boost" it is still not enough restriction to cause a vacuum condition.


That's my best attempt to not look stupid in this thread!
Chris
 
well i guess what i said was stupid, because if a diesel is running there will always be more air coming out of the cylinder after combustion then whats going in.
 
Didn't mean you were stupid...Sorry about that. Was trying not to sound dumb in my explanation.

Chris
 
@ idle a diesel makes a tremendous amount of vaccumb, due to the internal design and high sealing qualities.

ever put your hand/paper/book close to the engine air inlet @ idle??--not smart


The head flow is great and all , but one must understand that the head flow is STILL limited to camshaft design and specs, and after this the valve size and bore/ stroke config plays there parts after this.

In a running engine,
Head flow is limited to camshaft design,
camshaft design is limited to valve size
Valve size is limited to bore
Among many other areas in the air path this should get the wheels turning.

Diesel engine building, is NOT a one step process, there are many systems, and components that need to be adressed for optimal effiecency.
 
DIESEL_POWER said:
@ idle a diesel makes a tremendous amount of vaccumb, due to the internal design and high sealing qualities.

ever put your hand/paper/book close to the engine air inlet @ idle??--not smart


The head flow is great and all , but one must understand that the head flow is STILL limited to camshaft design and specs, and after this the valve size and bore/ stroke config plays there parts after this.

In a running engine,
Head flow is limited to camshaft design,
camshaft design is limited to valve size
Valve size is limited to bore
Among many other areas in the air path this should get the wheels turning.

Diesel engine building, is NOT a one step process, there are many systems, and components that need to be adressed for optimal effiecency.
Click to expand...

In order to put my hand close to the engine air inlet, I would need to remove my IC pipe. Then of coarse there is going to be vacuum. I'm saying with the IC boot and everything intact is there still vacuum at idle. Or is there still a very small amount of pressurized air in the intake tract?
 
DIESEL_POWER said:
@ idle a diesel makes a tremendous amount of vaccumb, due to the internal design and high sealing qualities.

ever put your hand/paper/book close to the engine air inlet @ idle??--not smart
Click to expand...

Do us all a favor and connect a vacuum gauge to a running turbo'd engine with all piping connected and report back to us a vacuum reading.

Even a turbo'd engine without piping, you still essentially have a NA engine, so of course it is going to pull vaccum. :poke:
 
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DIESEL_POWER said:
@ idle a diesel makes a tremendous amount of vaccumb, due to the internal design and high sealing qualities.

ever put your hand/paper/book close to the engine air inlet @ idle??--not smart


The head flow is great and all , but one must understand that the head flow is STILL limited to camshaft design and specs, and after this the valve size and bore/ stroke config plays there parts after this.

In a running engine,
Head flow is limited to camshaft design,
camshaft design is limited to valve size
Valve size is limited to bore
Among many other areas in the air path this should get the wheels turning.

Diesel engine building, is NOT a one step process, there are many systems, and components that need to be adressed for optimal effiecency.
Click to expand...

This is just a quick FYI from me to you. If i ever ask anymore questions or anything like that and you respond, i want you to know, whatever you say is automatically null and void hendering your reply useless due to your reputation and alot of the things i've read that you've posted.
 
duck_04 said:
Do us all a favor and connect a vacuum gauge to a running turbo'd engine with all piping connected and report back to us a vacuum reading.

Even a turbo'd engine without piping, you still essentially have a NA engine, so of course it is going to pull vaccum. :poke:
Click to expand...


LOL You are simply not paying Wade the respect he deserves. Wade was kicking up a notch there and your making him look like a fool......LOL
 
there is measurable vaccumb @ the turbo inlet FYI. No need to take everything apart to check vaccumb, sorry if i sounded like that was the case.
 
DIESEL_POWER said:
@ idle a diesel makes a tremendous amount of vaccumb, due to the internal design and high sealing qualities.

ever put your hand/paper/book close to the engine air inlet @ idle??--not smart


The head flow is great and all , but one must understand that the head flow is STILL limited to camshaft design and specs, and after this the valve size and bore/ stroke config plays there parts after this.

In a running engine,
Head flow is limited to camshaft design,
camshaft design is limited to valve size
Valve size is limited to bore
Among many other areas in the air path this should get the wheels turning.

Diesel engine building, is NOT a one step process, there are many systems, and components that need to be adressed for optimal effiecency.
Click to expand...


YOU ARE A DUMB FUKK!

That is all
Chris
 
DIESEL_POWER said:
there is measurable vaccumb @ the turbo inlet FYI. No need to take everything apart to check vaccumb, sorry if i sounded like that was the case.
Click to expand...

Yeah dumbass, a compressor wheel is supposed to do that. Thats not engine vacuum! :bang
 
There are generally two accepted methods from what I have seen, no one can conclusively say one is better than the other; wide vs narrow cone angle. The wide angle produces a bit more hp, yet the narrow angle produces a bit more torque.

Overall I see a greater movement toward wide shallow piston bowls, flatter cone angles while attempting to retain as much fuel in the bowl as possible and keep liquid fuel off the top ring. A wider angle allows the fuel to mix more quickly with oxygen, and aids in efficiency at high RPM, but to decrease burn time enough to really alter much, a high volatility fuel would be much more effective.

Rule restrictions keep a pretty tight grip on what is allowed in the pulling world, as they should. If any market will find or be able to use less timing with a different fuel I believe it will be seen in the drag racing side of things. But again the results and requirements are the same as the first paragraph, horsepower vs torque.
 
It is impossible in any engine without throttle plates to create a substantial amount of vacuum. At idle, you "might" have 1" of vacuum.
 
Smokem said:
There are generally two accepted methods from what I have seen, no one can conclusively say one is better than the other; wide vs narrow cone angle. The wide angle produces a bit more hp, yet the narrow angle produces a bit more torque.

Overall I see a greater movement toward wide shallow piston bowls, flatter cone angles while attempting to retain as much fuel in the bowl as possible and keep liquid fuel off the top ring. A wider angle allows the fuel to mix more quickly with oxygen, and aids in efficiency at high RPM, but to decrease burn time enough to really alter much, a high volatility fuel would be much more effective.

Rule restrictions keep a pretty tight grip on what is allowed in the pulling world, as they should. If any market will find or be able to use less timing with a different fuel I believe it will be seen in the drag racing side of things. But again the results and requirements are the same as the first paragraph, horsepower vs torque.
Click to expand...


this is correct, back in 2007-2008 we implimented a duramax piston like this, first of it's kind. it works when the rest of the build is configured to utilize the different burn charcteristics the piston design has.
 
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