EPA/AA/CTAB-8 8-06
                        Technical Report
       Conversion of Methanol-Fueled 16-Valve, 4-Cylinder
           Engine to  Operation On Gaseous  H2/CO  Fuel  -
                         Interim Report
                      Gregory K.  Piotrowski
                            June  1988

     Technical  Reports  do  not  necessarily represent  final  EPA
decisions or positions.   They are  intended  to  present technical
analysis of  issues using  data which  are  currently  available.
The purpose in the release of such reports  is  to  facilitate  the
exchange of  technical  information and  to  inform the  public  of
technical developments which may form the basis for a final  EPA
decision, position or  regulatory action.

             U. S. Environmental Protection Agency
                  Office of Air and Radiation
                    Office of Mobile  Sources
              Emission Control Technology Division
           Control Technology and  Applications  Branch
                       2565 Plymouth  Road
                   Ann Arbor,  Michigan  48105

                        Table of Contents


 I.   Summary	    1

 II.  Introduction   	    1

 III. Discussion	    2

     A.    Engine Modifications   	    2

     B.    Fuel System	    8

     C.    Emissions Measurement  	  10

 IV.  Future Effort	15

     A.    New Emissions Tests:  M100 Fuel	15

     B.    Rebuild Continuous Emissions Measurement  .   .  15

     C.    Finish Camshaft Modification:  Test Engine   .  15

     D.    Develop Leanness Indicator   	  15

APPENDIX A - Test Engine Specifications  	  A-l

 I.   Summary

     Methanol  may be  catalytically decomposed  to  hydrogen and
 carbon  monoxide  (H2/CO) gas.   This gaseous  mixture may  be an
 ideal  cold start  assist for  an MIOO-fueled engine  as  well as
 serving to increase the  thermal  efficiency  of the engine during
 transient operation.

     The  work described in  this  interim  report  concerns the
 conversion  of  a  16-valve,  4-cylinder  light-duty  engine  to
 operation  on  a  mixture  of  H2/CO  gaseous  fuel.   This  engine
 will be evaluated on  emission  level  and lean  limit operation
 criteria for two fuels:  H2/CO gas  and M100 neat methanol.

     Modifications  to  the  engine  to  accommodate   the  gaseous
 fuel   are   discussed  and   a  description   of   the  specially
 constructed   fueling   system   is   provided.    The  emissions
 measurement  system  constructed  for  the  test  cell  is  also

 II.  Introduction

     Light-duty M100 neat  methanol-fueled engines are difficult
 to  start  and run  in  cold weather  because  of the  high  boiling
 point  of  methanol,  methanol's  high  heat of  vaporization  (5.5
 percent  of the  heat  of  combustion  compared  to  less  than  1
 percent for  gasoline), and  the  increased fuel  flow needed for
 methanol  (about  double  that  of  gasoline).   Gasoline-fueled
 engines  start  with  less difficulty  under  the  same conditions
 partly  because of  the  easily ignitable light ends  of  this  fuel
 such   as   butanes,   which   are   vaporized   at  relatively  low

     Methanol  may be  catalytically  decomposed  to  H2  and  CO
 gases.   Hydrogen's  higher  flame speed and  lower boiling  point
 may  make   it  an  ideal  cold  start  fuel.   The   nature  of  the
 decomposed  methanol  fuel  may  also  increase  engine  thermal
 efficiency and  reduce  emissions  measured as  hydrocarbons  (HC)
 below levels from similarly sized methanol-fueled engines.

     The  goal  of   this   project  is  to  modify  a  16-valve,
 4-cylinder  light-duty  engine  to  accept  a  mixture  of  H2/CO
 bottled gas,  and to evaluate this engine using two fuels:

     1.    H2/CO bottled gas; and
     2.    M100 (neat methanol).

     The criteria for evaluation is the engine's  ability to run
without driveability  problems  at  the  lean  limit  of  operation
 over several steady-state speed and load conditions.


 III. Discussion

     The  16-valve,  4-cylinder engine  used  in this  project was
 supplied  by  the  Nissan  Motor  Co.,  Ltd.   This  engine  was
 modified  for use on M100 neat  methanol prior  to its consignment
 to  the   U.S.  Environmental   Protection  Agency  (EPA);  engine
 specifications are provided in detail  in Appendix A.

     Several  modifications  to  the  engine  were  necessary  in
 order   to  operate   on  H2/CO  fuel;  these  modifications  are
 discussed below.   Included also  are discussions of  the bottled
 gas fueling system and emission measurement system.

     A.    Engine Modifications

     Methanol  can   be  dissociated   to  H2   and   CO  via  the

     CH3OH( , , 	2H2(g) + C0
                                       ... 3 
                                     Figure  1
                         Diagram of Valve Arrangement
                         For Individual Cylinder  -

                              H2/CO Fueling  System
   Conversion of 16-Valve,  4-Cylinder
   Engine to Operation On 112/CO  Fuel

                                          Hot to Scale
Drawn By:
                  Gregory K.  Piotrowski


     The hole in the assembly  left by  the  power valve slide was
 sealed   to  prevent   leakage  of   fuel  and   air.    A  metal
 impregnation technique  was  used to seal the  holes.   The sealed
 holes were then coated with a  layer of epoxy.

     Fuel  injectors  are not  used  to  feed  the  gaseous  state
 fuel.   The rail and  the individual  injectors  were  removed and
 3/8  inch  inside  diameter  stainless  steel  pipe  fittings  were
 used  in   their  place.   The   stainless  steel  fittings  were
 threaded  and the  insides of  the aluminum  injector  wells  were
 then threaded to accept  the fittings.

     Stock dual-overhead  camshafts were  used  by Nissan to equip
 the CA18DE test  engine  referred to in this paper.  A drawing of
 the  stock  intake-side camshaft  is presented  in Figure  2.   It
 was  necessary  to  redesign  the  intake  side  lobes in  order  to
 accommodate  the  air/fuel induction strategy  depicted  in Figure
 1  for   the gaseous  fuel.  Figure 2  also  presents  the proposed
 air/fuel lobe scheme for  the intake camshaft.

     Nissan  reported  that   the  valve  timing  events  for  the
 MIOO-modified  engine   were   similar   to  those  of  the  stock
 gasoline-fueled   version.     Valve    timing   was    measured
 independently,  however,  as  these  measurements were necessary as
 a  point of  reference   for  the  redesign  of   the  intake  side
 camshaft.  These measurements  are given in Table 1.  Table 2 is
 a summary of the intake valve events in  a stock (gasoline-
 fueled) engine  as well  as the measured  events from the modified

     It should be noted that a valve lift  of  .005  inch was  used
 to  denote valve-open  and  valve-closed events.   The  criteria
 Nissan  used  to  define  opening and  closing  was  not  available.
 There is  a substantial  difference, evident  in  Table  2, between
 the valve  timing information  provided  by Nissan and  the timing
 measured  by  EPA.   The  definition  of  what  constitutes  valve
 opening  may  explain  some  of   this  difference.   Also,  Nissan
 reported  that   the  engine  head  was  milled   to  increase  the
 compression ratio on the  modified  engine;  this  modification may
 also account  for some of the timing dif-ference.

     The  redesign  of the intake  camshaft  to  accommodate  H2/CO
 fueling  has  been  outsourced  to   General  Kinetics  Co.,  Inc.,
 Detroit,   Michigan.    A  summary  of    the   proposed   camshaft
 specifications  for  the  redesigned shaft is   given  in  Table  3.
 Timing  and design for the air  as well as  the  fuel  cams will be
 altered.   Air  valve  opening  will commence  at  15  crankshaft
 degrees before  top  dead center  (BTDC),  and will  close at  30
crankshaft degrees  after  bottom dead center  (ABDC).   Shortening
 the period during  which  the  air  intake valve  will be  open may
 necessitate decreasing  air  valve  lift;  this  dimension  has  not
yet been finalized.   Opening of  the  fuel valve will commence at
 15 degrees ABDC, and will close at approximately 65  BTDC,  for
 an open time of  100  crankshaft degrees.  The height of the  fuel
valve lift will  be  less  than or equal  to .200  inch.   Valve  head
diameter for both air and fuel valves  will be  similar  to  stock
 intake valve,  1.340  inch.

                                            Fuel Lobes
                                            Fioure 2
                               CA18DE Engine Intake
                                        Cam Lobes Indicated
         Conversion Of  16-Valve, 4-Cylinder
         Engine To Operation On H2/CO Fuel
                                                Not To Scale
Drawn By:
         Gregory K. Piotrowski


                             Table 1

        Current  Intake  Valve  Event Timing Measured  By EPA

Crankshaft Position                           Valve Lift
 7-1/2 degrees ATDC                   .005 inches

    15 degrees ATDC                   .020 inches

    24 degrees ATDC                   .050 inches

    35 degrees ATDC                   .100 inches

    59 degrees ATDC                   .200 inches

   129 degrees ATDC                   .332 inches (maximum lift)

    17 degrees ABDC                   .200 inches

    42 degrees ABDC                   .100 inches

53-1/2 degrees ABDC                   .050 inches

    65 degrees ABDC                   .020 inches

91-1/2 degrees ABDC                   .005 inches


                             Table 2

             Current Intake Camshaft Specifications

Cam height

Valve Lift

Valves open*
(crankshaft degrees)

Valves close*
     CA18DE Engine
1.5939  1.5951 inches

     .335 inches

      15 BTDC

      53 ABDC
Measured By EPA
On Test Engine
   .332 inches

    7.5 ATDC

   91.5 ABDC
     Indicates not measured by EPA.
     Lift  =   0.005   inches   measured  by  EPA;   criteria  not
     available for standard engine.
                             Table  3

             Proposed Intake  Camshaft  Specifications
Cam height

Valve lift

Valve head diameter

Valve opens*
(crankshaft degrees)

Valve closed*
(crankshaft degrees)

Total value event
       Air  Valve
 Less  than  1.59  inches

      .335  inches

     1.340  inches

       15  BTDC

       30  ABDC

   Fuel Valve

To be determined

  .200 inches

 1.340 inches

   15 ABDC

   65 BTDC

     Valve lift = 0.005 inches.


     A  buildup of  the gas  could  occur  in  the  engine  during
operation  due to  leakage past  the valve  stem seals  and from
blowby.  This  buildup  might  reach explosive  proportions  if the
crankcase  ventilation  system  is  unable  to  remove the  Hz  gas
quickly  enough.    To  prevent  the  accumulation  of  an  unsafe
concentration  of  explosive  gases  and  air,  the  engine  was
modified to  provide  a blanket of inert gas  where  this buildup
might occur.   A  valve cover  was   modified to  accept a connection
from a  bottle  of N2  gas.  A port  on  the valve cover  over the
exhaust  side  camshaft was  connected  to  the  room air  system
scrubber.  N2  gas at  2-4  SCFH will be admitted to the  engine
during  H2/CO  gas  operation.  This carrier  gas  will  mix with
and  dilute blowby,  also   providing  an  inert  atmosphere  which
will not promote  an  explosion.   This blowby/carrier gas mixture
will be exhausted  to  the scrubber;  the  line  which vents  the
crankcase  to  the combustion chambers will  be plugged,  ensuring
flow to the scrubber only.

     Several other  minor  modifications will  be made to  ensure
better  control of the  air/fuel  mixture from the  control room,
engine  start from  the  control  room, etc.   Further  major  engine
modifications may be made after testing on HZ/CO fuel begins.

     B.    Fuel System

     It  was  necessary to construct  a special fuel system  to
accommodate  the  fueling  of  the   test  engine with the  gaseous
blend.   A diagram of the system is provided in Figure 3.

     The H2/CO fuel  is  a gaseous  blend  with  a composition  of
66  and  34 volume  percent H2  and  CO  respectively.  This  fuel
is  stored  in compressed gas cylinders  ("T"  size)  at  1800-1850
psi.  A fuel  supply cylinder  will  be anchored  to a  concrete
safety  stop  outside  of  the  test  cell,  approximately 10  feet
from the cell  wall  during testing.  The  bottle,  fitted  with  a
regulator  and  pressure gauge, will be opened  by  a hand valve
prior to  testing.   The fuel line from the  bottle is  1/4-inch
stainless  steel  tubing,  22 feet  in length from bottle to cell

     The stainless  steel  fuel  line  enters the cell  through  a
hole  drilled  through  the   concrete  block  wall.    A   Gould
electrically controlled solenoid  valve is  located  in   the  line
immediately  after  the wall.   An  electrical  signal  from  an
acctuator in the  control room controls the opening  of the valve
to  accept  flow from either  of  two lines.   The first line  is
connected to the  fuel  supply while the second  extends from  an
N2  gas   source outside  the  cell.   This  N2  gas  is  used  to
purge the fuel lines in the cell   prior  to  and immediately after
testing.   A  shut-off  valve  in   the  purge line,  when  closed,
keeps N2 gas  out of  the  cell fuel lines  following  the  purge

Pressure Gauge
                         Test Cell Wall
      Electrically Actuated

      Solenoid Valve
                                                                 Shutoff Valve
    H2/CO Fuel
                                        N2 Purge
         To Scrubber
                                                    Conpressed Air  on
                        Pressure Gauge
                              Twin Bay Regulator
                            H2 Flame Arrestor
                                                                        Control Valve Assembly
      0-10 SCFM Flow Meter
                                          Figure 3
                              Fuel System for H2/CO Operation
     Conversion of 16-Valve, 4-Cylirder
     Engine to Operation On H2/CO Fuel

                                                Not To Scale
Drawn By:

     Gregory K. Piotrowski


     The  fuel  line from the cell wall to  a  fuel  flow regulator
measures  approximately 54-1/2  feet.   This regulator  is  a Twin
Bay  Model   TB-100.   Gas   flow  through  this   regulator   is
controlled  by a  flexible diaphragm.  The diaphragm  is  opened
proportionally  to  the pressure  exerted  by  a   <=i-ream  of  air
provided  by a tank  of compressed air;  the  pressure exerted  by
this  airstream is  controlled by  a  valve  located in  the cell
control room.

     H2/CO   fuel   flows   from  the  Twin  Bay  regulator  to  a
switching  valve.    This  valve  has  two   positions:    the  first
supplies  fuel  to  the  engine,  while  the  second  diverts  the gas
stream  to  the  scrubber  during  purging  of  the  test  cell fuel
lines.  During  testing,  the fuel will flow  from  the  valve to a
rotameter  calibrated  to  measure  0-10  SCFM.   The fuel  passes
through this gauge and then through a tee;  a  pressure gauge  in
the control  room  is operated by flow through this tee.

     The  final  stage  of  the fuel system supplies  the  gaseous
fuel to  the combustion chamber  ports.   From  the  tee mentioned
above, the  fuel passes to a  hydrogen  flame arrester.   The flame
arrester  is  located  immediately  upstream  from  a  cylindrical
plenum, this plenum serving as  a  header to four  flexible fuel
lines.  The fuel  lines are  connected to threaded fittings which
are screwed into  the fuel injection  ports in  the  valve  control
assembly.     H2/CO  fuel   is  then   directly  supplied  to  the
combustion  chambers by the opening of the fuel valves.

     C.     Emissions Measurement

     An emissions  measurement  system was  fabricated  for  the
test cell;  a flowchart of the system is given in Figure 4.

     Engine  exhaust passes  from  the  exhaust pipe  to a  2-1/2
inch  diameter  flexible  metal  tube.    This  tube  passes  the
exhaust  overhead  to  a   6-inch  rigid  tube  hung from  ceiling
supports.    The rigid tube delivers the exhaust to  a  Philco Ford
350  cfm  constant volume sampler  (CVS).  Total  length  of  the
flexible and rigid tube sections is 40 feet.

     A  gaseous   sample  line  and  electronic  ties   have  been
extended  through  the  cell  ceiling  and  connect  the  mechanical
CVS with  an electronic display  panel in  the cell  control  room.
A  fitting  in the sample  line at  the  control room enables  bag
sampling   at  this   point.    Analysis   of   bag  samples    is
accomplished  at   a  bank  of  analyzers located  in another  test
cell.   Emissions  measured as  hydrocarbons  (HC) are measured  on
Beckman model  400  flame  ionization  detector  (FID).    NOx level
determination   is   conducted   on   a    Beckman   model   951
chemiluminescent  NO/NOx  analyzer.   CO  is measured by infrared
technique  using a Horiba model A1A23  infrared analyzer.

                                              Exhaust Fran Engine
                                                 Water In
                           DNPH Cartridges
                                    Solenoid Valves
                                               Solenoid Valve
                                                                ^   Exchanger
                                                           Hater Out
Heated Manifold
                                                       iial Filters
                                      To Bag Sample Ports
                                               Figure  4
                                       Emissions Measurement System
          Conversion Of 16-Valve,  4-Cylinder
          Engine To Operation On H2/CO Fuel
Drawn By:
     Gregory K. Piotrowski
                                                 Not To Scale


     A  second  sample line  extends  from  the  CVS to  a heated
manifold.     This    manifold    contains    ports    for   three
dinitrophenylhydrazine-coated   (DNPH)  formaldehyde    sampling
cartridges.   Flow  to individual  cartridges  is   controlled  by
three   solenoid  valves   located  downstream  from   the  DNPH
cartridges.   The  hot sample  gas  flows through a  cartridge and
then to a heat exchanger where the gas is cooled to 21C.

     Flow for  the formaldehyde  sampling system is measured with
a  Porter  Mass Flow  Controller  calibrated  to  5  standard liters
per minute.   Gaseous sample  from  the heat  exchanger  flows past
a  solenoid valve  and  is pumped  through a  dual filtration system
to remove any water present in the sample.   The  pump  is a Cast
model  746A  with  a  maximum  rated  pressure  of  100 psig.   The
exhaust sample is then passed  through the  mass flowmeter where
sample  flowrate  is  determined;   an   electronic  gauge  in  the
control  room  is  wired  to  the  flowmeter   and   displays  both
flowrate  and  total  accumulated   volumetric  flow  through  a
selected DNPH  cartridge.

     Several  attempts were  made  to  characterize  the  emissions
profile of  the test engine when  it  was operated  on M100 fuel.
These test  results  will  be compared to emission levels measured
when  the   engine  is  fueled   with  H2/CO   to   quantify  any
reduction in emission levels due to the change of fuels.

     Nissan  has   requested  that  the  engine  not be  operated at
wide open  throttle  conditions  due to  poor  intake mixing.   We
therefore decided to measure emission over  four  speed and load
conditions that do  not  excessively burden the engine:  idle (no
load),   1600   rpm/30.8  ft-lb,  2400  rpm/40.5  ft-lb  and  3200
rpm/48.5 ft-lb respectively.

     Air/fuel  ratio  and injection  timing  may  be  varied through
the use of  a  rheostatically  equipped  control  panel  that Nissan
provided with  the engine.    Our  first attempts at  testing the
engine with  M100  fuel utilized  the same control  settings  that
the engine was equipped with upon  arrival at  EPA.   The air/fuel
ratio settings provided  by  the manufacturer were  fairly rich.
The engine  was warmed  to  steady-state conditions  and  tested
over  four  modes:   idle,  1600  rpm/30.8 ft-lb,   2400  ppm/40.5
ft-lb and 3200  rpm/43.4 ft-lb.   A/F ratio was measured  with an
NTK Micro  Oxivision  MO-1000  air/fuel  ratio  meter.   A/F  ratio
varied from  a low  of 4.67  at  1600  rpm  to  5.60  at  3200  rpm.
Ignition timing was 23  BTDC for all modes  tested.

     Fuel  consumption during  this  testing was excessively high;
we were unable  to determine  HC  and CO emissions  levels because
they were  offscale  on  the most  concentrated analyzer  ranges.
NOx emissions  were  so  low  as  to  be  unmeasurable during  this
testing,   however.  A problem  with the  solenoid valve  system


prevented  the  acquisition  of  good  formaldehyde  data.   The
overhead  pipe carrying exhaust from the  engine  to  the CVS also
developed several  leaks  at  critical  joints during this testing;
a  considerable  amount of fluid  leaked  from the exhaust system.
Testing was  finally halted during the  3200 rpm  mode  because a
severe backfire problem developed in the exhaust  system.

     This  testing  was repeated  using  the Micro Oxivision meter
as  a  guide  to leaning out engine A/F  ratio over the modes upon
which we  evaluated the engine.   The results of this testing are
given in Table 4.

     A/F ratio was  controlled  to near  stoichiometric conditions
for this  testing.   HC emissions  were very  low; at 2400 rpm/40.5
ft-lb  torque no  HC  were  detected.   The  bag  sampling  system
appeared  to  function normally  during  testing,  however.   NOx
emissions varied considerably from the  1600 rpm/30.8 ft-lb mode
to  the others tested.   Both NOx and formaldehyde emissions were
considerably  higher at  the 1600  rpm/30.8  ft-lb torque  point
compared  to  the   higher  speed/load   points.   Again,  engine
backfire problems curtailed testing at idle conditions.

     This testing  was again repeated;  results are  provided  in
Table  5.    A/F   ratios  for  this testing  were  held  to  ratios
similar   to   those  given   in   Table   4.   Engine   speed/load
conditions here given also approximated those given in Table 4.

     The  very high HC  emission  level at  the  1600  rpm  mode  in
Table 5 contrasts sharply with the .002  g/bhphr  figure from the
earlier testing.   CO  levels between the  two data sets are also
difficult to compare.   No CO was detected  in the  bag samples  at
idle  and  1600   rpm  conditions;  this  contrasts with the  .46
g/bhphr at  1600  rpm  recorded  earlier.   CO  levels  at  2400  and
3200  rpm  conditions from the later  testing increased  more than
three hundred percent from earlier levels.

     NOx  levels  indicate  differences   between emission  levels
determined  during   these  two  test  periods.   Results  from  the
later testing show much lower NOx levels  at  1600, 2400 and 3200
rpm than  those  from  the  tests  conducted  earlier.   HCHO  levels
remained approximately  the  same at  1600  rpm  between  the  data
sets;   again  no   HCHO   was  detected   at  2400  and  3200  rpm

     No  engine   operability problems  were  encountered  during
this  later  testing,  and  an  idle  test  was  conducted to measure
emission levels  at no-load  conditions.   Emissions are  expressed
as  g/hr  or mg/hr.   No  earlier  idle tests  were completed,  so
figures for comparison are not  available.

     Emission levels by pollutant vary considerably  between  the
data sets presented in  Tables  4  and 5.  While  these levels  may
be of  interest as a first approximation,  the variability  is  too
great   to  allow  for  a  reliable characterization  of  emission
levels  from  M100  operation.    Additional  testing   is   being
conducted in order  to  make this  characterization possible.

                                        Table 4
                         Emission Testing,  Nissan CA18DE Engine
                               M100  Fuel, First  Data Set
 Denotes none

6.35 30.22


Emission Testing, Nissan CA18DE
M100 Fuel, Second Data Set







     Denotes none detected.
*    g/hr
* *   mg/hr


 IV.  Future Effort

     This  document  is  an  interim  report  only;  a substantial
 amount  of  work remains to be  accomplished  on  this  project.  An
 outline  of some  of these  tasks  in given  below,  together with
 short comments  concerning  progress  being made toward completion
 of the work.

     A.    New  Emissions Tests:  M100 Fuel

     The  emission test  results provided in Tables  4  and 5 are
 inconclusive.   We are  currently retesting  the  engine  with M100
 fuel  to  obtain  a  reference  emissions  profile.   This testing
 will  be   redone   utilizing   two   separate   (bag  sampling  and
 continuous  sample) banks  of  HC  and NOx analyzers  in  order to
 improve the accuracy of  these  measurements.

     B.    Rebuild Continuous  Emissions Measurement System

     An  emissions  measurement system  capable  of  continuously
 measuring  HC  and  NOx  emissions  is present  in the  test  cell.
 This system  has  not been  operational because  of  analyzer pump
 problems.   New pumps  were  ordered  and  received;  this  analyzer
 system  is now  being  made  operational.   We  plan  to use  these
 analyzers  as  a  check  on  the bag  analysis system  for gaseous

     C.    Finish Camshaft Modification;  Test Engine

     The camshaft  redesign to  accommodate  the  fueling scheme in
 Figure  1  is  currently  underway.    After   this new   shaft  is
 designed and built, it will be installed on the test engine and
 evaluated.   The  need  for  any redesign  change should  be made
 apparent  during  this   evaluation;   any  succeeding  shaft  will
 incorporate these changes.

     D.    Develop Leanness Indicator

     The  testing  referred to  in  C, above,  has  as  its  goal the
 determination of  1)  the lean  limit,  at  certain speed  and load
 points,  of  the  test  engine  when  operated  on H2/CO gaseous
 fuel and  2) any improvement  in the  emissions  profile resulting
 from the  use  of  H2/CO  as  a  fuel.   In order  to  quantify the
 maximum   lean   limit   information   a   correlation   of  engine
 performance  with  increasingly  lean  operation  is  necessary.
 This correlation  could  be  done mechanically or  through the use
 of electronic data acquisition hardware.

     Our current  plan  is to  gather a magnetic  signal, convert
 it to a voltage and process the voltage  as  a  time  interval with
 reference to an  algorithm  that relates  crankshaft rotation time
 to engine  roughness.   Engine  roughness increases  as  the  lean
misfire  limit  is  approached,  hence a  quantifiable correlation
 should  be  possible.   If it  is  not possible  to determine  the
 lean misfire limit  electronically due  to equipment availability
problems,  etc.   a  mechanical  means  of making  this  determination
will be developed and used.


                           APPENDIX A

                   Test Engine Specifications

Basic engine designator


Cylinder arrangement


Combustion chamber

Bore x stroke

Compression ratio

Compression pressure

Fuel control system


Valve clearance

Idle speed

Engine oil


Air/fuel control

Spark advance control
Nissan Motor Co., LTD


1809 cc

4-cylinder, in-line

Dual-overhead camshaft

Pentroof design

83 mm x 83.6 mm


16.5 kg/square cm (350 rpm,

Electronically controlled fuel

EGR not used

0 mm (automatically adjusting)

750 rpm

Special formulation supplied by
Nissan for methanol engine

M100 neat methanol

Excess-air ratio may  be varied
from 2.0 to  0.5  by means  of an
external control

Ignition  timing   can  be  varied
from  0   BTDC  to  54  BTDC  by
means of an external control