In Chamber Testing

[NoDOHC]

The curve is ugly, but I like the timing! You should be about peak power at this point (12-18 degrees ATDC for peak pressure).

Keep up the good work! (Try not to hurt your engine, I don't know how safe it is to run a turbo at optimal ignition timing. Most turbo cars I have seen run REALLY retarded.

[Barry Bordes]

Originally Posted by NoDOHC

The curve is ugly, but I like the timing! You should be about peak power at this point (12-18 degrees ATDC for peak pressure).

Keep up the good work! (Try not to hurt your engine, I don't know how safe it is to run a turbo at optimal ignition timing. Most turbo cars I have seen run REALLY retarded.

Notice that this is not the pressure chart but the burn rate. It is ugly but fairly typical. There seems to be a wave cycle of burning.

The proper term for what is happening is probably auto-ignition.

I think Honda has the answer with their two stroke experiments into Active Radical Combustion.

“When the spark plug fires and ignites the fuel mixture, some of the fuel is isolated from the resulting flame by the exhaust still in the cylinder, and does not burn. What Honda has done is to develop a way to ignite all the fuel in the cylinder by using the properties of auto-ignition, and has termed this process Activated Radical Combustion. This title is derived from the way fuel actually ignites. When the fuel is brought to the right pressure and temperature, the molecules break down into what are known as active radical molecules. These are highly unstable chemical compounds which are an intermediate step in the actual combustion reaction. When hot exhaust gas remains in the cylinder, it contains a small percentage of active radical molecules; when these are combined with the incoming fuel charge, the resulting mixture begins to auto-ignite at lower temperature that a pure gasoline/air mixture. What we currently associate with auto-ignition is engine knock, a phenomenon that occurs when the fuel ignites before the spark plug fires, while the piston is still on the up-stroke”

I am working with a Gorilla (Jonathan) and a Trout2 (Jack) on this project.

The real question may be… do we try to eliminate the reversion causing auto ignition or try to control this new ignition source with some type of valve?

Thanks for your input, we learn together,
Barry