Group 7 - GM 2.2L 4-Cyl Engine Gate 4

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This is the final documented gate of our project. In this section we will be reassembling our engine and documenting the process, along with our final management review and suggestions for design revisions at the system level.


To return to Group 7's main page click here: Group 7 Main Page
To go back to gate 1 click here:  :Gate 1: Project Planning
To go back to gate 2 click here:  :Gate 2: Product Dissection
To go back to gate 3 click here:  :Gate 3: Product Analysis


Critical Project Review

During the finale of this project, our group has faced virtually no challenges. We all work very well together. We have figured out the best ways to split up work and have gotten better at getting our work done ahead of time. Our collaboration with Group 18 went smoothly as well. We determined a plan for the reassemble and it proved to be efficient. Group 18 started the reassemble one day with the assistance of one of our team members. The next day we completed the task with a group 18 member. This plan worked very well because we did not have too many people working on the engine at once. Overall our group had no problems during this task.

Product Reassembly

This section of the gate provides Group 7 and 18's step by step process for reassembling the engine. In reassembling our engine we have defined an ease of reassembly metric as discussed in the table below:

Ease of Re-assembly Metrics Group 7
Level Description
1 No tools or very little tools required, one person needed
2 Some basic tools required, very basic thinking, one person needed
3 Some basic tools required, some critical/applied thought process, one-two people needed
4 More complex tools/process, difficult to assemble, one to two people with moderate physical strain
5 Very complex/high degree of difficulty, two or more people with high physical strain/tactility or would require some other equipment



We found that level 5 was only used once throughout our entire process for the valve springs.

The following table outlines Group 7 and 18's reassembly process step-by-step, highlighting the primary part/parts involved with each step, along with the specific tools required and the number of bolts/nuts/screws and appropriate sizes involved in reassembly. Adam Lawyer of Group 7 observed Group 18's progress on Wednesday, and Yong Chi Lim of Group 18 observed Group 7's progress on Thursday.
The steps completed by each group are as follows:
Steps 1-15: Group 18, Wednesday
Steps 16-36: Group 7, Thursday

GM 2.2L 4-CYLINDER INLINE ENGINE ASSEMBLY PROCESS
Step # Step Overview Tools Fasteners Ease of Assembly Instruction Picture/Video
1 Piston Rings None None 1 Carefully ease piston rings back into pistons by aligning grooves properly. Group7 pistonrings.jpg
2 Pistons into Engine Block Mallet, flat head screwdrivers None 2-3 Since the piston rings were removed this step will require multiple people. Using the flat head screwdrivers, have 1-2 people the multiple rings in place while another gently taps the piston into the each slot in the engine block as shown. Video here: http://www.youtube.com/watch?v=O5AfH-PitIk
3 Crankshaft Timing Gear 4-5" hex key, pliers 3 smaller bolts, 2 round fasteners/side, 3 hex bolts 3 This step requires two people. First screw in surrounding hex bolts. Then have one person hold gear while screwing in 3 smaller bolts using hex key. Use pliers to tighten around. Group7 timinggear.jpg
4 Connecting Rod Bearing Mallet N/A 1 Gently tap connecting rod bearings into connecting rods. Group7 crbearing.jpg
5 Crankshaft into main engine block/casing None None 2 Align connecting rods through bottom of block appropriately.
*Align curves in crankshaft with each connecting rod to allow for smooth fit; place in.
Crank thatshaft.jpg
6 Connecting Rod Clamp 1/2" drive ratchet, 14mm socket wrench 14mm bolts, ribbed fasteners 3 Initially tighten bolts and fasteners by hand; use drive ratchet and socket wrench to tighten all in appropriate holes. Group7 crodclamp.jpg
7 Camshaft None None 1 Insert camshaft in slot on side of engine block as shown Group7 camshaftpic.jpg
8 Timing gear chain/wheel Mallet. Bolt from wheel 3 Maneuver chain around wheel by hand until aligned. Tap wheel into place on side of engine block gently with a mallet. <b>Replace center bolt that holds in the wheel by hand Group7 gearchainwheel.jpg
9 Crankshaft clamps 1/2" drive ratchet, 15mm socket wrench 8 15mm bolts (2 per clamp x 4 clamps) 2 Fasten in bolts initially by hand, then use ratchet/socket wrench to tighten. Cclamps.jpg
10 Oil Pump Assembly <Tools here> Small black bolts 3 *Screw top oil pump section containing spring/screen in w/small black screws on side.
Mount on top in required section on engine block, align as shown in video.
Group7 opumpassembly.jpg
Video Here:
http://www.youtube.com/watch?v=ixcRobuSY5Y
11 Oil Pan 10mm socket wrench, 1/4" drive ratchet Small black bolts 1 Place oil pan on top of internal engine, replace using same screws. Opan.jpg
12 Water Pump 13mm socket wrench, 3/8" drive ratchet Various nuts and bolts 1 Replace in slot by screwing in open spot where it fits. May require 2 people to hold water pump in place. Group7 waterpump.jpg
13 Thermostat housing 13mm socket wrench, 3/8" drive ratchet 2 bolts,13mm 1 Screw back into slot; part and placement are shown in photo Group7 tstathousing.jpg
14 Camshaft pulley 15mm socket wrench, 1/2" drive ratchet 15 mm bolt 1 Screw bolt back in; may require two people Group7 cshaftpulley.jpg
15 Valve springs/locks/rods Large wrench, mallet/hammer N/A 4-5 Insert valve rods through bottom of valve housing. Place spring on top, gently initially tap top piece in place. Apply pressure using large wrench as shown in video to depress spring. Gently tap in small locking pieces until secure Video here:
http://youtu.be/GfuMYeOWbHw
16 Push Rod Seats None None 1 Insert in line with proper holes in engine block Pichere.jpg
17 Push Rod Guides(4) 10mm socket wrench, ¼” drive ratchet 8 bolts, 10mm 2 Replace 2 bolts per push rod guide as shown G7 prguides.jpg
18 Valve Spring Housing 15mm socket wrench, 3/8” drive ratchet 10 bolts, 15mm 2 Set valve spring housing atop the engine block w/block flipped upside down as shown; place the bolts with wrench/ratchet Group7 valvehouse.jpg
19 Push Rods(6) None None 1 Insert aligned with push rod guides/seats through openings in valve housing Group7 pushrods.jpg
20 Rocker Arms(6) 10 mm socket wrench, ¼” drive ratchet 8 bolts, 10mm 2 Replace rocker arms on top of push rods using socket wrench and bolts Group7 rockerarms.jpg
21 Engine Head/Valve Housing Cover 10mm socket wrench, ¼” drive ratchet 6 bolts, 10mm 2 Replace cover on top of valve housing with bolts Engine cover head.jpg
22 Spark Plugs None None 1 Insert individually into holes on side of engine block as shown <B>Spark Plug Photo:
Group7 plug.jpg
Placement:
Group7 splugs.jpg
23 Oil Temperature Sensor 9mm socket wrench, 1/4” drive ratchet 9mm bolt 1 Replace in proper hole as shown, screw in 9mm bolt Group7 otempsenor.jpg
24 Exhaust manifold/oxygen sensors attached 13mm crescent wrench 4 hex nuts, 13mm 1 Mount manifold on side of engine block and replace the 4 hex nuts, tightening with crescent wrench. Eman.jpg
25 Oil pressure sensor 9mm crescent wrench 9mm bolt 1 Replace in proper hole on side of engine block as shown Group7 opsensor.jpg
26 Temperature Sensor None None 1 Tighten in with hands in proper spot on engine block Group7 tempsensor.jpg
27 Flywheel/Beltwheel 13,18mm socket wrenches; ½”,3/8” drive ratchets 3 bolts(13mm), 1 18mm bolt, washer 2 Replace belt wheel as shown atop harmonic balancer; screw in the 3 13mm bolts, then replace 18mm bolt with washer Group7 flywheel.jpg
28 Distributor Mounting Bracket 8mm socket wrench, ¼” drive ratchet 7 bolts (8mm) 2 Screw in mounting bracket on side of engine block Mbracket.jpg
29 Ignition Coil/distributor 13mm socket wrench, 3/8” drive ratchet 3 mounting bolts (13mm) 2 Screw in atop mounting bracket with wrench/ratchet; picture shows ignition coil/distributor being re-attached on top of mounting bracket on side of engine block The mounting bracket referred to in the photo is from step 28:
Group7 ignition.jpg
30 Mounting Bracket 13mm socket wrench, 3/8” drive ratchet 4 bolts(13mm) 2 Replace mounting bracket on side of engine block by replacing bolts and tightening Group7 mbracket.jpg
31 Coolant Tube 13mm,15mm crescent wrenches, hammer 2 hex nuts, 13mm/15mm 3 Insert rubber end of coolant tube into proper hole on front of engine block and use hammer to secure it in. Replace the 13mm and 15mm hex nuts, tighten with appropriate crescent wrenches Group7 ctube.jpg
32 Purge Solenoid 15mm socket wrench, ½” drive ratchet 15mm bolt 1 Replace 1 bolt and insert in proper spot on engine block as shown in photo Group7 psolenoid.jpg
33 Throttle Body into Intake Manifold 10mm socket wrench, ¼” drive ratchet 4 bolts(10mm) 2 Screw in bolts initially w/fingers as shown, tighten with socket wrench Group7 tbody.jpg
34 Fuel Rail Assembly into Intake Manifold 8mm socket wrench, ¼” drive ratchet 2 mounting bolts(8mm) 2 Replace bolts in manifold as shown Group7 frassembly.jpg
35 Intake Assembly onto Engine Block 13mm socket wrench, 3/8” drive ratchet, 13mm crescent wrench 3 standoff bolts(13mm),2 mounting bolts(13mm),2hex nuts (13mm) 3 Replace bolts on side of engine block as shown; connect sensor wire Group7 iassembly eblock.jpg
36 Dipstick Tube 16mm socket wrench, ½” drive ratchet 16mm bolt 1 Screw in as shown and insert tube Group7 dtube.jpg

ORIGINAL ASSEMBLY VS OUR ASSEMBLY
Some parts such as the springs in the valve spring housing were not assembled how it was done for the sake of this project; for original assembly, heavier machinery would be required to properly apply the right amount of pressure for the valve springs to be securely locked in on the housing. It's likely that the piston rings, in step 1, were placed in by machine. The rest of the steps were likely assembled very closely to how we did it, though likely not in the same order, just the same fasteners/tools.

Design Revisions

This section of the gate highlights our group's recommended design revisions at the system level. These revisions are based on our knowledge of the product, with the intent of improving one or more critical aspects of the product.

REVISION I: Dry Sump Oil System

Photo: (link:http://www.stockcarracing.com/techarticles/scrp_0710_dry_sump_oil_system/photo_01.html)
DRY SUMP OIL SYSTEM SHEMATIC
Drysump.jpg

    Recommended Change: One change to the engine could be to install a dry sump oil system in which the oil pan is removed from the engine. With this change, the oil leaves the tank and goes directly to the dry sump pump. After the dry sump pump, the oil is filtered and then cooled. The cooled oil is run through the engine and then returned to the pump through scavenge lines. From here, the oil returns to the oil tank and then the process repeats as shown in the diagram above. Due to this change, The engine would be thinner allowing the engine to sit lower in the car. This lowers the center of gravity of the car and improves the performance of the vehicle.
    Improvements: In this system, the oil pan is removed which leaves more room for other parts. The dry sump system uses a flat pan called a scavenger pan. This pan "scavenges" the oil in the engine and several hoses return oil pressure.
    Potential Disadvantages:There are two pumps that are required for this system. One scavenges the oil and one is used for pressure. Both pumps are driven by a belt. These systems are used in aircraft and race cars, but have not been rigorously tested in everyday cars. The dry sump system is expensive compared to the current system.
    Factors Addressed: With this change, there will be environmental advantages. The cars will use less oil than a conventional car. This would make fossil fuels last longer. The societal impact would be that cars would improve proformance which would lead to a desire for this type of engine system.

REVISION II: Cylinder Deactivation/Engine Auto Start-Stop Combo

Example Cylinder Deactivation Video for 4-Cylinder engine in Volkswagen: http://www.youtube.com/watch?v=yxjGTBF-dVY

    Recommended Change: Cylinder deactivation is a process used generally in larger engines that could be applied to our engine to help conserve fuel by essentially shutting down cylinders. This occurs under low stress situations, when the engine in only using around thirty percent of its peak power. This is because at that point, the engine has to work to draw air through the throttle valve. By shutting down some of the cylinders you essentially force the throttle valve to be open further and can build up more pressure in the cylinders, allowing for a more efficient power stroke.
    Cylinder deactivation works by a combination of processes. A computer is used to sense the pressure the user puts on the acceleration pedals and can therefore adjust the number of cylinders based on how hard the user is or is not accelerating. As in the 4-cylinder Volkswagen video shown, the cam is then shifted along the camshaft. This is to prevent intake or exhaust from occurring and therefore shuts down the cylinders not in use.
    Engine auto start-stop is a similar feature to cylinder deactivation and is mainly seen in hybrid cars today. This technology allows the engine to completely shut off at idle. It works in conjunction with the engine, the battery and an electric generator and starter. When a vehicle is braking, the electric generator sends a signal that shuts the engine off. When the driver then steps on the accelerator, the electric starter re-ignites the engine by using stored energy from the battery.

    Improvements: The combination of these technologies reduce environmental impact by lowering wasted gas and energy and improving fuel efficiency.
    Potential Disadvantages: The implementation of both of these technologies would increase the price of the engine, but the increased fuel efficiency over time would balance it out; the cost would still be less than a hybrid engine overall. Cylinder deactivation generally isn't used in smaller engines so it would have to be tested.
    Factors Addressed: This revision addresses environmental concerns by limiting wasted gas and energy. It addresses societal concerns by improving efficiency, which would be more appealing to a consumer.

REVISION III: Vehicle Accessory Power

    Recommended Change: Currently our engine powers its accessories by using a serpentine belt and the belt wheel, as shown in fig. A. Together they receive torque from the crankshaft and then transmit that power throughout the cars other systems. By using a beltless system such as that in the Toyota Prius, electric motors would power the cars accessories. The current design on our engine does not have electric motors built into it. Therefore when eliminating the serpentine belt, the electric motors would have to be added. In other implementations of this system, the electric motors are generally run through processes like regenerative breaking, simply because a cars battery alone would not be able to power the motors. Regenerative brakes allow the car to collect excess kinetic energy that would otherwise be lost to heat through friction. While this would increase the price of the vehicle, it would also lower maintenance costs because belts would not have to be replaced. Also, using a beltless system increases the fuel efficiency of the vehicle, lowering its environmental impact.
    Improvements: There would be fewer parts to manufacture in the engine, and the engine could use more of its power to drive the vehicle, increasing overall efficiency.
    Potential Disadvantages: These revisions would result in additional changes to the vehicle, which would raise vehicle price and modify manufacturing processes. It would also be necessary to conduct additional consumer research and cost analysis before going ahead with these revisions to ensure that they are in fact feasible for our target audience.
    Factors Addressed: Once the manufacturing is modified/studies are carried out, this revision would eventually create an economic impact since there would be fewer overall parts. The environmental impact created by the engine would be lowered since the engine is using more of its potential power.

FIGURE A: CURRENT BELT SYSTEM IMAGE
Fig a: Figa.jpg