Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Single Post

mooseheadm5 · 07-07-2009, 09:45 PM

I don't think you understand the way combustion works. For one, oxygen is not flammable. Period. It is an oxidizer. Next, extremely lean AFRs (leaner than about 22:1) can really only be achieved with charge stratification. You also don't seem to understand the mechanics of detonation and preignition. You are not going to be able to adequately control detonation. Detonation is very bad, as you have found. The pressure wave travels at the speed of sound in the compressed mixture and will scrub the boundary layer from the piston and cylinder walls. This can very quickly allow the piston surface to reach combustion temperature, which can exceed the melting point of aluminum. It can also crack the pistons, destroy the ring lands, and generally ruin your day. Adding heat sinks to the bottoms of the pistons will do more harm than good. You will likely end up pulling the motor again when they fly off. Any weight added to the backs of the pistons will definitely upset the balance of the engine and severly limit the maximum attainable RPMs. You may not like complex solutions, but what you are describing is incredibly complex and ineffective. In addition, removing the cat is harmful to the environment. To sum it all up:
What you are doing will damage the motor (again, if you persist.)
Removing the cat will increase emissions and is illegal in most, if not all, states. Even though you don't care, NOx emissions are harmful.
The amount of time you spend glued to the instrumentation to prevent detonation and overheating will likely cause a crash and amounts to reckless endangerment if you take this thing on a public highway.
And the best part, you will likely waste more resources trying to get this to work than you will save if you get it to work effectively enough to limp around without crashing. Every time you melt a piston you will waste all sorts of natural resources that are used to make and deliver the pistons, gaskets, engine oil (which you must change each time you experience a catastorphic engine failure) etc.
Essentially, if it were this "simple" to make it work, the OEMs would have done it already to cope with the stringent CAFE standards.
I strongly suggest you study some engineering texts before continuing.

07-07-2009, 09:45 PM	#31 (permalink)
mooseheadm5 EcoModding Lurker Join Date: Jul 2009 Location: earth Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	I don't think you understand the way combustion works. For one, oxygen is not flammable. Period. It is an oxidizer. Next, extremely lean AFRs (leaner than about 22:1) can really only be achieved with charge stratification. You also don't seem to understand the mechanics of detonation and preignition. You are not going to be able to adequately control detonation. Detonation is very bad, as you have found. The pressure wave travels at the speed of sound in the compressed mixture and will scrub the boundary layer from the piston and cylinder walls. This can very quickly allow the piston surface to reach combustion temperature, which can exceed the melting point of aluminum. It can also crack the pistons, destroy the ring lands, and generally ruin your day. Adding heat sinks to the bottoms of the pistons will do more harm than good. You will likely end up pulling the motor again when they fly off. Any weight added to the backs of the pistons will definitely upset the balance of the engine and severly limit the maximum attainable RPMs. You may not like complex solutions, but what you are describing is incredibly complex and ineffective. In addition, removing the cat is harmful to the environment. To sum it all up: What you are doing will damage the motor (again, if you persist.) Removing the cat will increase emissions and is illegal in most, if not all, states. Even though you don't care, NOx emissions are harmful. The amount of time you spend glued to the instrumentation to prevent detonation and overheating will likely cause a crash and amounts to reckless endangerment if you take this thing on a public highway. And the best part, you will likely waste more resources trying to get this to work than you will save if you get it to work effectively enough to limp around without crashing. Every time you melt a piston you will waste all sorts of natural resources that are used to make and deliver the pistons, gaskets, engine oil (which you must change each time you experience a catastorphic engine failure) etc. Essentially, if it were this "simple" to make it work, the OEMs would have done it already to cope with the stringent CAFE standards. I strongly suggest you study some engineering texts before continuing.