Injector Sizing: not dumb questions at all

[Gary Derian]

In my opinion, I think the Oberg injectors are just the ticket for a 2
stroke where you have to inject fuel after the exhaust port closes.  On a 4
stroke, however, the gains will be small if any because there is ample time
to mix during the compression stroke.

Gary Derian <gderian at cybergate.net>

>For something that impressed me as very much as being a peek into the
>future, take a peek at the web site that Stuart Baly called our attention
>to over the weekend, amid the smoke. "www.orbeng.com.au". Their stuff would
>appear to offer the best yet. Their financial data appear to indicate that
>people like Siemens, Daimler, and Bosch agree with this assessment. The
>neatest thing about it is that I see no reason not to stab the Orbital air
>assisted injectors (the actual fuel injectors, which, in turn, plug into
>them,  are standard stuff) into the existing bungs on an existing TPI
>engine and go from there. One would have twice as many drivers, (one for
>fuel injectors, one for air valves) but hey--I hear Sandy already has some
>grey hairs! Orbital claims maximum droplet size of 8 microns coming out of
>the injector. Obviously, if these units can direct inject, they are quick
>enough to match injection with inhale in a TPI system without resorting to
>staged injectors. The Orbital air injectors are in production in Michigan,
>and available through the Mercury Marine parts system, as (that) Merc has
>had engines (their DFI-200) in production using them for two years!!!!!
>(All I know SO FAR!!)
>
>Anybody out there care to place a wager on how much improvement in: torque,
>power, and BSFC would be seen with this type of a conversion on an
>otherwise same TPI engine???? (Tom--I've got first dibs on any bets against
>improvements.)
>
>Regards, Greg
>