Orbital Combustion Co ... Injector Deposits

[Shannow]

http://orbeng.com.au/download-document/319-2001-01-2030-presentation.html

For those not familiar with Sarich, he "developed" the orbital engine in the '80s. Doomed to failure, it was a mass of sealing surfaces that could never work (IMO) as a production vehicle.

But it DID make him come up with a novel injection system, which is being used increasingly around the places. Uses both fuel and air for atomisation/stratification purposes.

Here's a paper on the injector tip deposits that they have been experiencing, including charts of specific emissions increases with time.

Precis view (note, it's injector deposits)
* It's the fuel, not the oil;
* fuel wetted paths show less deposits;
* aromatics in fuel are contributors (Shell V-Power should be good);
* additives can help;
* additives can make it worse.

 

[d00df00d]

Originally Posted By: Shannow
* aromatics in fuel are contributors (Shell V-Power should be good);

Why Shell V-Power in particular?

 

[Shannow]

At least down here, they created Shell V-power as a high density fuel, i.e. more btu/gallon....stating that they dropped the aromatic content.

 

[Silk]

I think Sarich's patents stopped development of the direct injection 2 stroke. Other companies were working on it, and stopped when he tied up all the patents around it.

 

[A_Harman]

I worked with Orbital on a project about 4-5 years ago. We were combining their air-assisted injection system with Eaton's dual-lift valvetrain technology for a Chinese auto manufacturer. Even though the DI 2-stroke didn't catch on, Orbital has continued to develop their injection system.