Main Title |
91 RON-increased compression ratio engine demonstration / |
Author |
Godici, Patrick, E. ;
Liljedahl, Douglas R. ;
Terry., Jerry L.
|
Other Authors |
|
CORP Author |
Environmental Protection Agency, Ann Arbor, Mich. Emission Control Technology Div.; Exxon Research and Engineering Co., Linden, NJ. Products Research Div.; |
Publisher |
United States Environmental Protection Agency, |
Year Published |
1978 |
Report Number |
EPA 460/3-78-009 |
Stock Number |
PB-289 959 |
OCLC Number |
52465215 |
Subjects |
Accelerometers ;
Automobiles--Fuel consumption
|
Internet Access |
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
EKBD |
EPA-460/3-78-009 |
|
Research Triangle Park Library/RTP, NC |
10/26/2011 |
ELBD ARCHIVE |
EPA 460-3-78-009 |
Received from HQ |
AWBERC Library/Cincinnati,OH |
10/04/2023 |
NTIS |
PB-289 959 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
Collation |
iii, 617 pages : illustrations ; 28 cm |
Abstract |
A 1975 California model automobile with an 8:1 C.R. 350 CID
engine was modified by increasing the compression ratio to 9:1 which
resulted in improved fuel economy. The higher NOx emissions were reduced
to the base level by substituting a back pressure-controlled EGR unit
for the original valve and increasing the EGR flow. Four approaches
were tried in an engine dynamometer installation to lower the octane
requirement of the 9:1 C.R. engine. These were (1) increase turbulence
by increasing the squish area, (2) use dual spark plug ignition to minimize
flame travel time, (3) use aluminum heads to obtain better heat
transfer, and (4) use knock sensor-actuated spark retard to temporarily
de-tune the engine when knock occurs. Of these, the latter approach
showed the most promise and was installed in the vehicle to control
the level of detonation in the modified 9:1 C.R. vehicle.
The knock sensor (accelerometer) is attached to one of the
cylinder heads of the engine. When knock occurs, the vibration is
picked up by the sensor, the signal is filtered to remove some of the
engine background noise, and the knock pulse is detected. When the
amplitude of the detected knock signal exceeds a threshold value, the
spark timing is retarded. When no knocking is detected over a waiting
period, the timing is advanced back to its normal schedule. Using this
system, the vehicle's octane requirement can be lowered several numbers
with some performance debit, i.e., slower acceleration times. |
Notes |
"EPA 460/3-78-009"--Cover "September 1978"--Cover Project officer: Robert Wagner. "EPA contract no. 68-03-2162." |