[Diy_efi] Re: Diy_efi Digest, Vol 21, Issue 19

[Mike]

At 04:00 AM 11/24/06, you wrote:

>I wonder, would it be feasible to install such a
>device downstream of a regular port injector to
>improve mixture homogeneity, especially when cold or
>at small engine loads?  I think it might bear
>considering if there's a way to install one in a
>manifold a few inches downstream without compromising airflow...

When engine is cold there is substantial condensation of fuel vapours
on cylinder walls. Eaton gmbh designed ultrasonic (horn)
shaped fuel injectors over 20 years ago (I must dig up the article),
and I referenced them in my EFI thesis in 1982 for uni, at that time
they had a limited number of prototypes and wouldnt sell any. They
were expecting to go into production but dont know what happened.
The fuel economy gains were alleged up to 20% or better depending on
conditions. Makes a lot of sense to maximise atomisation and reducing
in droplet size assuming you could also achieve good distribution
and manifold injection may not be ideal in that latter aspect. The direct
piezo injector type as used on latest bmw biturbo engines seems to
offer an excellent fuel economy for an engine capable of 225Kw on
tap without noticeable turbo lag, something like 7L/100Kms country
for a 3L. Have been offered a test drive by my friendly dealer and have
the full brochure if anyone wants me to up upload any 4mpixel scans
of any pages to an ftp server, I'll include the price list ;-)

Heres the link for the direct piezo injectors for that car:-

http://www.siemensvdo.com/press/releases/powertrain/2006/SV_200604_002_e.htm







Regards from


Mike
Perth, Western Australia
VK/VL Commodore Fuse Rail panel that wont warp, twist or melt, guaranteed  !
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