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Honda Report


									      MAE 277
  Dr. Kemper Lewis
      Group 24

Project Manager- Bradley Cheetham

         Dennis Hoover

           Carl Javier

           Adam Cole

          Saaiba Ansari

     December 8th 2006
  Product – Honda Engine
                            Honda Accord Engine Executive Summary

Honda Motor Company has proven its value of many years of being in the automobile industry.
Honda engineers and manufactures have always produced a low cost high quality product that has
lasted well beyond the normally expected lifetime of a vehicle. However, there sometimes is a
problem or a defect that no one can really detect. Our group had a Honda Accord engine that had a
problem and wasn’t running correctly. We made it our job to figure out what went wrong with the
engine and why it wasn’t running the correct way.

The first part of the project was to look at the engine and figure out the best way to tear it apart in
the safest and easiest way possible, along with making sure that we could put it back together. The
group started by draining out the oil and fluids and started tearing the engine apart from the top
down. Starting with the intake and working our way down to the point where it was time to take the
head of the engine off. This is where we came across some problems.

After removing the head of the engine we noticed that one of the 4 cylinders had a lot more carbon
build up than the others and noticed why when we turned the head over. One of the exhaust valves
in the engine had lost a small chip out of the one side where it sealed against the head. This left a
gap for the gas to leak out as the engine went into the compression stroke. This means that the
violent vibration that occurred when the car was running was the loss of compression in one of the
cylinders. Having seen this we ventured further into the block of the engine tearing out pistons and
the crankshaft seeing if anything else was wrong.

Having found nothing else visibly wrong with the engine we concluded that the chipped valve was
the culprit of our problem. Knowing this we started making suggestions about how we could make
the engine design a little better. A few things that we noted were the manufacturing process of the
valves needed to be looked at closer to ensure 100% satisfaction while the valves are being used. A
few other things that we noticed were things such as the placement of the exhaust, the oil filter, and
the air intake, these things are better explained in Section 6.2.

                                  Table of contents

1. Before disassembling the engine
       1.1 Purpose
       1.2 Energy transformation
       1.3 Original status
       1.4 Pre-disassembly assumptions
2. Disassembling the engine
       2.1 Parts list and steps during disassembly
       2.2 Notes on disassembly
3. After disassembling the engine
       3.1 Component List
       3.2 Component analysis
               3.2.1 Intake Manifold
               3.2.2 Exhaust
               3.2.3 Piston cylinder
               3.2.4 Oil Pan
               3.2.5 Fasteners
               3.2.6 Valves
       3.3 CAD Representation of piston cylinder assembly
4. Assembly of the engine
       4.1 Steps and product description
       4.2 Problems/notes from assembly of engine
5. How an Internal Combustion engine works
       5.1 Energy Conversion
       5.2 Piston-Cylinder device
       5.3 Valves
6. After assembling the engine
       6.1 Ways to test product/components
               6.1.1 Engine mount/brackets
               6.1.2 Fuel efficiency
               6.1.3 Intake Manifold
       6.2 Overall recommendations for design
               6.2.1 Exhaust/intake
       6.3 Reflection and conclusion
7. Summary of group member contributions
       7.1 Saaiba Ansari
       7.2 Bradley Cheetham
       7.3 Adam Cole
       7.4 Dennis Hoover
       7.5 Carl Javier

1. Before disassembling the engine
           1.1 Purpose -The purpose of our product, a 1993 Honda Accord engine with 180,000 miles,
is to power an automobile. The engine takes in gasoline and outputs mechanical power used to
drive the tires of the car and power the cars electrical components.
           1.2 Energy transformations - The engine transforms chemical energy in the form of
gasoline into mechanical energy through internal combustion. The gasoline is sprayed into a piston
cylinder device into which a spark is introduced. This spark causes a small explosion. The small
explosion causes the gasses in the cylinder to expand and thus forces the piston downward. This
downward force is used to turn some kind of shaft to drive the car.
           1.3 Original Status - The engine did not run correctly, and was taken from the vehicle
because of this. The cause of this failure is unknown at the beginning of the project.
           1.4 Pre-disassembly assumptions - Just by looking at the engine and thinking about how
complex it is we are assuming it is made up of approximately 500-600 components total. We are
guessing these components are probably made of some combination of aluminum, steel, rubber, and

2. Disassembling the engine

2.1 Parts list and steps during disassembly table
      component           tool used        parts       description during disassembly
                          ratchet used
                          to remove 5
                          bolts, 6 in ex
      throttle body       12mm socket
  1   assembly            wrench                   1
                          12 mm
  2   Engine mounts       socket                   3    Held engine in car.
  3   vacuum line         pliers                   1   attached to throttle body assembly
      unknown sensor,     wrench w/
  4   intake manifold     sensor                   2
                          wrench w/                    inlet/outlet had a small punctured hole into the
  5   intake manifold     sensor                   1   intake valve, may have been cause of problem
                          12mm             1 w/
      manifold            wrench w/        10mm
  6   (exhaust shafts)    sensor           bolts
  7   valve cover         12mm socket            4     underneath bolts is washer w/ rubber seal
                          pliers, spark
  8   spark plugs         plug remover             4   1 came off easy, the other 3 are tight
      bolts to            15mm socket
  9   accessory           wrench                   3

     cover to timing
10   belt, 2 bolts      14mm                3
11   timing belt        scissor             1
                        10mm socket
12   bottom cover       wrench              3   does not come off, blocked by disk
                        10mm socket
13   oil dipstick       wrench              3
     lifter assembly,
     bolts on top of    12mm socket
14   motor head         wrench            18    head came off
     lifter assembly
15   link taken apart   hand                1   links taken apart
16   cam shaft          hand                1   control the lifter assembly links
     bolt on head
     underneath cam
17   shaft              14mm socket         1   wrench hammering method worked
18   oil pan                                    changed oil
     bolts on head of                           5 bolts on each side, to take off the head, bolts
     the motor,                                 are REALLY tight and hard to remove, one
     underneath cam                             ratchet broke, NOT EASY, 3 people standing on
19   shaft              14mm                9   motor to take bolts off
20   head               hand                1
21   head gasket        hand                1   underneath motor head
                        10mm socket             black, inside is oil intake, oily, lots of pipes, comes
22   oil pan            wrench              1   off like a hat off a head
     crank shaft
     holder, oil        4bolts, 14mm
23   distributor        socket              4   hammered, levered out
                        hammer,                 took four 4 tries to hammer out, connecting rod
24   piston             metal shaft         2   holder is tight
2.2 Notes on Disassembly
After taking apart the engine it became apparent that the reason the engine was performing poorly
was due to a loss of compression in one of the cylinders. This loss of compression appears to have
been caused by a valve which was deteriorated. This deterioration is most likely a manufacturing
error or defect. This is suggested because the remaining 15 valves were in fairly good condition
and showed no signs of deterioration. The engine could reasonably be repaired by replacing this
valve. However the engine we took apart was on its way to be recycled, so the group did not repair
the valve because of the complexity of the process and the lack of specialized tools to do so.

          3. After Disassembling the engine

          3.1 Component List

          Key- Ease of Removal                                                   Key - Manufacturing Process

          1-finger tight
          2-small initial force required                                      FS = Forming and Shaping
                                                                              MC = Metal Casting
          3-steady force required                                             DC= Die Casting
          4-additional force                                                  IM = Injection Molding

          5-nearly impossible (heavy duty equipment


                                                                                                          # of fasteners
                                                                      process used
                                      # of Parts


                                                                                                                                            ease of
                                                                                                                                type of
                Part                               Material
Section         Identification                     Type                               tool used

                                                                                        ratchet 6 in ex
                  throttle body                                                          12mm socket
                    assembly          1             aluminum        MC                      wrench        5                  bolt             2
                  vacuum line         1                                                      pliers                                           2
                throttle position
                     sensor           1            thermoplastic    DC
                                                                                       12mm wrench w/
                intake manifold       1             aluminum        MC                    sensor                                              2
                    exhaust                                                            12mm wrench w/
                    manifold          1             aluminum        MC                    sensor                                              2
                 cylinder head                                                                                              nuts and
                  cover (valve                                                                                               sealing
                     cover)           1            thermoplastic     IM                 12mm socket       8                grommets           2
                valve cover seal
                   and gasket         9               rubber       casting                  hand                                              1
                 engine mount         2                steel         MC

 head top:
Rocker arm
                    holders (in                                                         10mm socket                         bearing
                      series)         6                steel        MC                    wrench          12               cap bolts          3

                Intake rocker
                    shafts        5        steel       FS          hand           N/A      N/A        2
                wave washer       5        steel       FS          hand           N/A      N/A        2
                intake rocker
                     arm          8        steel       MC          hand           N/A      N/A        2
                    spring        5        steel       FS          hand           N/A      N/A        2
               exhaust rocker
                     shaft        1        steel       FS          hand           N/A      N/A        2
               exhaust rocker
                     arm          8        steel       MC           hand          N/A      N/A        2
                                                             pliers, spark plug
                 spark plug       4        steel       FS         remover         N/A      N/A        2

                                                               14mm socket
 Cylinder                               Aluminum            wrench, Heavy duty
  head          Cylinder head     1        alloy       MC       breaker bar       10       bolt       5

                Cylinder head                                                             gasket
                    gasket        1    thermoplastic   DC          hand            1     groove       1
                 intake valve     8        steel       FS      not removed        N/A      N/A
                exhaust valve     8        steel       FS      not removed        N/A      N/A

 timing belt
and balance
 shafts belt
                                                            14mm socket and
                upper cover       1     aluminum       MC      wrench             2        bolt       2
                 cover seal       1       rubber       FS       none              1       none        2
               Power steering
                     belt         1       rubber       FS       not present               none        N/A
               alternator belt    1       rubber       FS       not present               none        N/A
                   pulley         1        steel       FS      not removed        1     pulley bolt
                 camshaft         1        steel       FS          hand            1      holders     1
               camshaft lobes     15       steel       FS      not removed        N/A       N/A
                                                                                        1 adjusting
                 lower cover      1     aluminum       MC      not removed         6    nut, 5 bolt
               camshaft pulley    1        steel       MC      not removed         1        bolt      N/A
               tensioner spring   1        steel       FS      not removed        N/A       N/A       N/A
                                                                                          nut and
               belt tensioners    2        steel       FS      not removed        1        shaft      N/A
               balance shafts
               belt/sprockets             rubber       FS      not removed        N/A      N/A        N/A
                 timing belt      1       rubber       FS        scissor          N/A      N/A         1


                 cylinder              Aluminum    DC &
               tubes/head         1       alloy   Machined
                oil dipstick      1       steel
                                                                  10mm socket
                 oil pan          1    aluminum      MC             wrench         20       bolt        2
              main bearing
               cap bridge
               assembly                                          14mm socket and
                (pipes)           1    aluminum      MC              wrench        10        bolt        2
               crankshaft         1       steel      FS            not removed     N/A       N/A        N/A
                                                                 14mm socket and          bolt (2 for
               bearing cap        4      steel       MC              wrench        8        each)
                                                              not removed from              cap (1
             connecting rod       4       steel      MC             piston         4        each)       N/A
                                       Aluminum               hammer and metal           connecting
                  piston          4       alloy      FS             shaft           4        rod
               Piston rings       1                  FS         not removed        N/A       N/A        N/A
                 oil ring         1                  FS         not removed        N/A       N/A        N/A
             spacer/expander      1                  FS         not removed        N/A       N/A        N/A

Total #
parts                          123
Total #
fasteners                         95
Total # of
components                     218

       3.2 Component Analysis-

       3.2.1 - Intake Manifold-
              Function- Provide air to cylinder for combustion
              Material Analysis – Metal casting aluminum.
              Ergonomic analysis – Tapered to save space, easily removed.
              Design Change – Make out of heat resistant plastic because there is no need for aluminum
       on the intake manifold. The air entering this manifold would never be hotter than the engine
       compartment which has many plastic and rubber components

       3.2.2 - Exhaust-
              Function – Removes exhaust gasses from engine after combustion.
              Material analysis – Metal casting aluminum

          Ergonomic analysis – Wraps around front of the engine and under the oil pan. This location
of the exhaust makes removing the oil pan and accessing the oil filter a challenge. If this were
alternately placed on the back of the engine, with the intake on the front, the exhaust piping would
not interfere and the exhaust gasses could exit towards the back with less piping needed to wrap it
around the engine.
          Design change – This manifold and piping could be moved to the rear side of the engine for
the above stated reasons.

3.2.3 - Piston cylinder
          Overall analysis – Location where chemical to thermal to mechanical energy transfer occurs.
This is the heart of the engine.
          Function – Executes combustion and transfers energy to the crankshaft.
          Material analysis – Composted mostly of aluminum with thermoplastics and steel used for
seals, gaskets, and valves. This aluminum reduces the weight significantly.
          Ergonomic analysis – Designed to be compact but still offer ample displacement volume.
Steel is used for thermal resistance properties, long use, and to contain combustion while aluminum
is used to be lightweight and durable.

3.2.4 - Oil pan-
          Overall analysis – Oil plays vital part in engine.
          Function – Contains oil that is used to decrease energy loss to friction, prevent corrosion,
and allow components to move against each other for extended periods of time without
          Material analysis – Aluminum with 20 bolts.
          Ergonomic analysis – Aluminum is a heat resistant, durable material that also resists
puncturing. A total of 20 fasteners are used to ensure the pan fits to the engine with a seal that
prevents oil leakage.
          Improvements – High density plastic could be used to reduce manufacturing costs and

Above left – Bottom of engine block. Above right – oil pan.

3.2.5 - Fasteners
       Function – Keep engine parts connected and together. Also serve to resist shaking and
       Material analysis – Nuts and bolts were made of steel because steel has very good strength
and heat resistance.
       Improvement – Ionized aluminum bolts could be used to reduce the weight of the engine.
Although small, the weight of the bolts contributes to the engines weight. This improvement would
be expensive, but in the future such parts may come down in price and be more reasonable.

3.2.6 - Valves
       Overall analysis - This is the component on our engine that failed.
       Function – Valves are opened and closed by the CAM shaft. There are a total of 4 valves
per piston. The two inlet valves open to allow air in, the two exhaust valves open to allow the
exhaust out, and all four valves are closed to allow the piston to pressurize the gasses and
subsequently allow combustion to occur.
       Material analysis – The valves themselves are made of steel. Steel is used because it is heat
resistant and durable.

       Suggestions – Better quality assurance on the valves would prevent the deterioration that
was found on the valve in our engine. This engine had run for almost 190 thousand miles so it
performed decently. However, with better quality assurance the engine could have been driven well
past 200 thousand miles. We speculate that the cause of failure was a crack or factory defect that
was initially very small and insignificant, however after 190 thousand miles the defect resulted in a
component failure. Below photos: top left is the corroded valve and top right is a normal non-
corroded valve. The photo in the bottom left is of all of the valves.

3.3 CAD representation of piston cylinder assembly

4. Assembly of the engine

4.1 Steps and product description.
       See section 2.2. Assembly was reverse of disassembly.

4.2 Problems/notes from assembly of the engine
       The engine we took apart had been left out in the rain prior to our working on it. This caused
a few issues when it came to putting the engine back together. Furthermore, lack of appropriate
automotive tools also contributed to problems during reassembly. For one, there were certain
pieces, such as the Rocker arm assembly. That assembly actually proved one of the more difficult of
the pieces and ended as being impossible to reassemble. Not only did certain pieces have to fit back
onto a shaft in a specific order, but the fit was so tight that it took considerable man power just to
remove it in the first place. The pistons also refused to fit back in as part of the assembly. The end
pieces that attached them to the rotating shaft were nearly impossible to remove and reassembly was
completely impossible with our limited tool supply. We also had to cut off the timing belt to take
apart the engine in the first place. So timing the engine would have been impossible. More than that,
we didn’t have an appropriate torque wrench so we couldn’t really reattach most of the bolts in an
appropriate way. The grit, grime, rust, and other debris from an engine that had served for nearly
190,000 miles and had spent time out of the car and in the rain caused various problems around the
entire engine. As it was we did reassemble the majority of the engine. We got the head back on for
the most part minus some of the rocker arm assembly and reattached the oil pan with that assembly
in tact. The pistons were also placed back into the engine, though some of the assembly had to be
left out as the rings no longer fit around the piston heads. After it was put back together since the
engine was going to be used for scrap anyway, some of the ‘cooler’ pieces were removed to be kept
as souvenirs.

5. How an Internal Combustion engine works .

5.1 Energy conversion - The internal combustion engine (or ICE) works by converting stored
potential energy in a fuel into kinetic energy. The most popular fuels for ICEs are fossil fuels that

contain hydrocarbons that burn to produce a force. The engine then converts that force into a torque
on a shaft through a piston cylinder system.

5.2 Piston – Cylinder devices - Our particular engine has four cylinder piston systems all
connected to a shaft. This particular engine uses the four stroke method for combustion. Each
movement of the piston from one position to another is considered one stroke. So each piston
undergoes the following procedure: First, the piston moves from the up position to the down
position while the valves for fuel and air are opened to let fuel and air be sucked into the piston.
Then when the piston reaches the bottom the valves are closed and the piston starts its journey
upwards. As it moves up the air and fuel are compressed. Just as it passes the apex a spark plug
ignites the fuel and air mixture while it is under pressure to create a downward force, pushing the
piston down. Right as the piston moves past the bottom position the exhaust valves are opened and
as the piston moves up the burned fuel and air are pushed out of the cylinder. More than one piston
is necessary because pistons offset each other so that one piston helps provide power while another
piston is getting rid of exhaust or compressing.

5.3 Valves - The valves on our particular motor were controlled by a cam shaft. A cam shaft is a
shaft that the valves sit on. Where the valves are there are lobes. The cam shaft is connected to the
drive shaft so that when it is time for a valve to open the lobe pushes it open. The valves are on a
spring mechanism so that when the lobe isn’t forcing it open they automatically close.

5.4 Lubrication - Our engine is also cooled and lubricated by an oil system. The oil pan is on the
bottom of the engine block and holds the oil. There is a small suction system that pulls the oil out of
the pan and runs it through the engine which helps to lubricate and cool the engine. This is
important as the engine moves very quickly and would seize without oil. Also, since the engine is
powered by controlled explosions, it can get very hot. There is also a cooling system on most
internal combustion engines but that was not part of our project.

6. After assembling the engine.

6.1 Ways to test product/components

6.1.1 - Engine Mounts/brackets
       Using a static system the mounts could be tested for strength. This could be estimated, but
ultimately the required strength would have to account for weight of oil as well as vibrations caused
by piston/cylinder combustion. A basic model would have to assume the engine in static
equilibrium and thus would not be completely relevant if the engine were engaged.

6.1.2 - Fuel efficiency
       The thermal efficiency of the piston cylinder device could be calculated using
thermodynamic properties. In this case the efficiency of the engine could be improved using
estimates at first and later fine tuned using more precise models. This is very important because the
increase in efficiency of a very small amount ultimately would result in vast savings on energy.
Especially with an engine like the Honda engine we took apart which can easily be used for 200
thousand miles. Below is an example of what an increase in just .1 mile per gallon would result in.
Assumptions – Retail of 1993 Honda Accord (in 1993) $15,000.00 (
               fuel efficiency (average highway/city) =25 mpg (
               average cost of 1 gallon regular gas in 1993 – $1.10
                           gallon                 $1.10
200,000 miles .1mpg                 800 gallons            $880.00
                          25miles                 gallon
This savings is nearly 6% of the cost of the entire car. Thus it is obvious that efficiency is an
important thing to analyze.

6.1.3 - Intake manifold
       Our group suggested making this part out of plastic. Testing this would be important. In
order to test this material, testing would need to be done to find what temperatures the intake
manifold could withstand. For this testing estimates could be used because the exact temperatures it
would be subject to would vary greatly. As a result of this great variation the extremes would be
tested to insure the material could function properly.
6.2 Overall recommendations for design.

6.2.1 - Exhaust/Intake –
        Change – The locations of these could be switched, putting the exhaust on the backside of
the engine and the intake on the front. This would give greater access to the oil pan and would
facilitate the relocation of the oil filter. The current location is difficult to access.
        Why? – Honda engines are some of the best engines in the world and these small changes
could make them even better ergonomically designed.

6.3 Reflection and conclusion

The engine itself is very well built and uses aluminum for the block, head, pistons, and multiple
other parts. However the cam shaft and the crankshaft remain steel for strength issues and are the
heaviest of the components other than the block. The weight issue with the engine is relatively a
low concern because it really isn’t that heavy and it holds up to severe and long term use. There are
a few issues not with the components of the engine or the weight but the placement of some

Having a Honda accord in the group we went underneath and tried to access the oil filter and looked
at where the exhaust was, to see how big of a problem these things were. We noticed that the oil
filter was extremely difficult to get at, even if the car was on a car lift, and by moving the exhaust
out the back you allow the needed room on the engine to move the oil filter. This small change in
the design helps the mechanic and the do-it yourselfer who are going to be working on this engine,
making time in the shop shorter and safer for both parties.

The disassembly and reassembly processes were relatively easy except for the challenge of taking
out a few bolts. Although these few bolts broke a craftsman and another socket they were the only
challenging parts to remove. Honda has a very good engine that has proven itself year after hear.
For this reason, one of the hardest parts of this project was finding design suggestions. That being
said we feel that after careful consideration the recommendations in this report would serve to
perfect the Honda engine design even further.

7. Summary of group member contributions

7.1 Saaiba Ansari –
       CAD Rendering
       Graphic integration for report
       Report section 3.3

7.2 Bradley Cheetham –
       Group leader
       Compiled report – edited, formatted, and integrated various parts
       Report Sections 1, 3.2, 6.1, 6.2

7.3 Adam Cole –
       Presented Group Presentation
       Lead re-assembly team
       Report Sections 4, 5.

7.4 Dennis Hoover –
       Presented Group Presentation
       Chief engineer during both disassembly and reassembly
       Provided engine
       Executive summary and section 6.3

7.5 Carl Javier –
       Scribe during disassembly
       Sections 2, 3.1


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