marine engine FI

[Stuart Hastings]

> At 05:00 11/10/99 -0400, DIY_EFI Digest wrote:
> >Or - altitude could be faked out by reading the MAP while the engine is 
> >stopped.  Then you could account for it.  Of course this assumes that the 
> >car is stopped every once in awhile (probbaly a reasonable thing).  I know 
> >for a fact that some outboard marine engine controllers do this.

Marine FI can probably get away with this, unless you run your boat
down (or up) the side of a mountain with the engine running.
"Over the falls," perhaps :-) ?

> Outboard engines are FI???? Wow!! Things have changed in the past 5 years.
> Why would they do this? Manufacturers are still putting ECUs in the engine
> bay of cars. This is a pretty nasty place for electronics. I can see the
> reason for putting FI in cars as it improves fuel ecconomy and power along
> with controling the fuel so that it doesn't clog the CAT. But why on a
> small outboard engine? Surely you would want to keep the thing as simple as
> possible using NO electronics as Sea water isn't electronics freindly by
> any means.

Marine two-stroke engines have aroused the Federal EPA, and they're on
a ten-year program of gradually tightening emissions through 2006.

EPA looked at off-road engines, and decided that marine engines were
the next logical target. They catagorized marine engines as diesel,
two-cycle, and four-cycle. I didn't pay attention to what they did
about diesels (probably nothing at this time). However, they noticed
that carbureted two-cycle engines passed 25-30% of their fuel directly
out their exhaust.

The technology employed to fix this is DFI; injecting fuel directly
into the cylinder, after the piston has risen enough to close the
exhaust port. Mercury uses a system they licensed from Orbital (of
Australia), OMC bought a company named Ficht (of Germany), and Yamaha
has developed their own. As I recall, Ficht uses a special injector
that develops about 450psi, Orbital uses ~90psi mixed with a blast of
compressed air, and Yamaha uses ~700psi. There are some explanatory
websites:

	www.mercurymarine.com
	www.orbeng.com.au
	www.omc-online.com

I haven't looked at Yamaha's web site; they may not have a writeup
yet, as I don't think they've shipped yet.

Curiously, while DFI reduces oil consumption, it doesn't really
address the oil-emission question. Apparently EPA agrees this is not a
major pollution issue at this time. Manufactures are quick to tout the
reduced fuel consumption of DFI, and many satisfied customers agree
it's real.

EPA has purposely avoided any smog regulations for four-stroke marine
engines, with the expressed intent of encouraging their use. Since the
existing marinized car engines were emitting about 25% of the smog
(measured in grams/kW/hour) of carbureted two-strokes, this sort of
makes sense. As I understand it, a 2006-compliant two-stroke is almost
as clean as an unregulated 4bbl SBC, neglecting the oil issue.

Since DFI is expensive, and the law requires a gradual cleanup, large
marine engines (>100HP) are being converted one-at-a-time to DFI, and
smaller engines to four-stroke. Marine two-stroke ECUs seem to be
relatively up-to-date, with proprietary laptop connections and flash
memories.

The wild card is the California Air Resources Board. They've enacted
much stricter standards than the Federal EPA, and no two-cycle
manufacturer has agreed to meet them yet.

stuart hastings