Difference between revisions of "Group 29 - 5 HP IC Motor"

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(Disassembly Process)
(Product Testing and Analysis)
 
(27 intermediate revisions by one user not shown)
Line 18: Line 18:
 
==Introduction==
 
==Introduction==
  
This product was used to run a push mower.  It is powered by an internal combustion that is used to spin the blades. Based on the condition of its parts this engine will not run, but this has not been tested.  
+
This product was used to run a push mower.  It is powered by internal combustion that is used to spin the blades. Based on the condition of its parts this engine will not run, but this has not been tested.  
  
 
Group Members:
 
Group Members:
Line 26: Line 26:
 
Dan Leake - disassembly, wiki creation
 
Dan Leake - disassembly, wiki creation
  
Kyle Johnson - disassembly, reassembly
+
Kyle Johnson - disassembly, reassembly, wiki creation
  
 
Alex Lovallo - disassembly, reassembly, wiki creation, team leader
 
Alex Lovallo - disassembly, reassembly, wiki creation, team leader
Line 38: Line 38:
  
 
*Manufacturer: Tecumseh
 
*Manufacturer: Tecumseh
*Model Number:
+
 
 +
*Model Number: VS120 63063E
  
 
==Before Dissasembly==
 
==Before Dissasembly==
Line 97: Line 98:
 
|-
 
|-
 
| align="center" |9
 
| align="center" |9
| align="center" |Unscrew two 3/8” hexagonal head bolts (part 11) as well as two 8mm hexagonal head bolts (part 11a), then remove crank case cover (part 29) from engine block (part 37).
+
| align="center" |Unscrew two 3/8” hexagonal head bolts (part 11) as well as two 8mm hexagonal head bolts (part 11a), then remove fly wheel cover (part 12) from engine block (part 37).
 
| align="center" |Socket Wrench
 
| align="center" |Socket Wrench
 
| align="center" |Moderately Hard
 
| align="center" |Moderately Hard
Line 117: Line 118:
 
|-
 
|-
 
| align="center" |13
 
| align="center" |13
| align="center" |Removed Lock Spring off of Lock on Button
+
| align="center" |Unscrew eight ½” hexagonal head bolts (part 16) holding head onto engine block (part 37).
| align="center" |Flat-head Screwdriver
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |14
 
| align="center" |14
| align="center" |Removed Plastic Lock Washers off of Lock on Button
+
| align="center" |After removing screws pull off head (part 17) and head gasket (part 17a) from engine block (part 37).
| align="center" |Flat Head Screwdriver
+
| align="center" |By Hand
| align="center" |Moderately Difficult
+
| align="center" |Moderately Easy
 
|-
 
|-
 
| align="center" |15
 
| align="center" |15
| align="center" |Removed Switch Breaker off of Trigger Switch
+
| align="center" |Detach grounding wire from pickup coil (part 18.
| align="center" |By Hand
+
| align="center" |Screw Driver
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |16
 
| align="center" |16
| align="center" |Removed 2 Cord Clamp Screws off of Cord Clamp off of Casing
+
| align="center" |Unscrew two 5/16” hexagonal head bolts holding on pickup coil (part 18) then remove pickup coil as well as spark plug cord.
| align="center" |Phillips-head Screwdriver
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |17
 
| align="center" |17
| align="center" |Removed Red Motor Connecting Wire off of Spring Loaded Graphite
+
| align="center" |Remove pull string catch nut from fly wheel (part 19) using 19mm socket.
| align="center" |By Hand
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |18
 
| align="center" |18
| align="center" |Removed Black Motor Connecting Wire from Spring Loaded Graphite
+
| align="center" |Remove fly wheel (part 19).
| align="center" |By Hand
+
| align="center" |Hammer
| align="center" |Easy
+
| align="center" |Hard
 
|-
 
|-
 
| align="center" |19
 
| align="center" |19
| align="center" |Disassembled Spring Loaded Graphite Internals
+
| align="center" |Unscrew two 5/16” hexagonal head bolts holding on throttle plate, grounding wire and spring (all attached together: part 21).
| align="center" |By Hand
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |20
 
| align="center" |20
| align="center" |Removed Motor Screw From Casing
+
| align="center" |Unscrew two 5/16” bolts (part 22a) with nuts holding carburetor (part 22) to intake tube (part 23).
| align="center" |Philips-head Screwdriver
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |21
 
| align="center" |21
| align="center" |Removed Red Motor Connecting Wire From Armature
+
| align="center" |Unscrew two hexagonal head bolts (part 23a) holding intake tube and gasket (part 23) to engine block (part 37).
| align="center" |By Hand
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |22
 
| align="center" |22
| align="center" |Removed Black Motor Connecting Wire from Armature
+
| align="center" |Unscrew two 5/16” hexagonal head bolts (part 24a) then remove valve cover and gasket (part 24).
| align="center" |By Hand
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |23
 
| align="center" |23
| align="center" |Removed Metal Gear From 1/4in. Plate
+
| align="center" |Remove intake and exhaust valve (part 25), valve spring (part 25a) and valve clip (part 25b).
| align="center" |By Hand
+
| align="center" |Screw Driver
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |24
 
| align="center" |24
| align="center" |Removed 1/4in. Metal Plate from Armature Shaft With Rotar
+
| align="center" |Pry off drive pulley (part 26).
| align="center" |By Hand
+
| align="center" |Hammer and Screw Driver
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |25
 
| align="center" |25
| align="center" |Removed Small Metal Plate off of Armature Shaft With Rotar
+
| align="center" |Remove six 10mm hexagonal head bolts (part 27) from crank case cover (part 29).
| align="center" |By Hand
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |26
 
| align="center" |26
| align="center" |Removed Linear Oscillator from Metal Gear
+
| align="center" |Remove crank key (part 28) from crank shaft (part 33).
| align="center" |By Hand
+
| align="center" |Screw Driver
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |27
 
| align="center" |27
| align="center" |Removed Washer off of Gear from Metal Gear
+
| align="center" |Remove crank case cover (part 29) from engine block (part 37).
 
| align="center" |By Hand
 
| align="center" |By Hand
| align="center" |Easy
+
| align="center" |Moderately Easy
 
|-
 
|-
 
| align="center" |28
 
| align="center" |28
| align="center" |Removed Cylindrical Slider from Linear Oscillator
+
| align="center" |Pull out cam shaft (part 30) from engine block (part 37).
 
| align="center" |By Hand  
 
| align="center" |By Hand  
| align="center" |Easy
+
| align="center" |Moderately Easy
 
|-
 
|-
 
| align="center" |29
 
| align="center" |29
| align="center" |Removed Blade Changing Piece from Blade Changing Component
+
| align="center" |Remove valve lifters (part 31).
 
| align="center" |By Hand  
 
| align="center" |By Hand  
| align="center" |Difficult
+
| align="center" |Easy
 
|-
 
|-
 
| align="center" |30
 
| align="center" |30
| align="center" |Removed Blade Changing Spring from Blade Changing Component
+
| align="center" |Unscrew two ¼” hexagonal head bolts (part 32a) from connecting rod cap (part 32).
| align="center" |By Hand
+
| align="center" |Socket Wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |31
 
| align="center" |31
| align="center" |Removed Allen Wrench Screw from Blade Changing Component
+
| align="center" |Pull out crank shaft (part 33) from engine block (part 37).
 
| align="center" |3/32 Allen Wrench
 
| align="center" |3/32 Allen Wrench
| align="center" |Easy
+
| align="center" |Moderately Easy
 
|-
 
|-
 
| align="center" |32
 
| align="center" |32
| align="center" |Removed Blade Changing Component from Linear Oscillator
+
| align="center" |Remove connecting rod (part 34) that connects the crank shaft (part 33) to the piston  (part 36).
 
| align="center" |By Hand
 
| align="center" |By Hand
| align="center" |Easy
+
| align="center" |Hard
 
|-
 
|-
 
| align="center" |33
 
| align="center" |33
| align="center" |Removed Felt Piece from Linear Oscillator
+
| align="center" |Remove piston (part 36) from the engine block (part 37).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |34
 
| align="center" |34
| align="center" |Removed Cylindrical Slider 2 from Linear Oscillator
+
| align="center" |Remove the wrist pin along with the wrist pin clip (part 35).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 +
|-
 +
| align="center" |35
 +
| align="center" |Pried the piston rings (part 36a) off of the piston (part 36).  Two metal rings and an oil collector ring.
 +
| align="center" |Screw Driver
 +
| align="center" |Hard
 
|-
 
|-
 
|}
 
|}
Line 713: Line 719:
  
 
===CAD Models===
 
===CAD Models===
 +
{| border="1" align="center"
 +
! width="50"|Part #
 +
! width="75"|Component Name
 +
! width="75"|CAD Drawing
 +
|-
 +
| align="center"|1
 +
| align="center"|Piston Head
 +
| align="center"|[[Image:piston2008.jpg|center|thumb|150px]]
 +
|-
 +
| align="center"|2
 +
| align="center"|Compression Ring
 +
| align="center"|[[Image:pistonring.jpg|center|thumb|150px]]
 +
|-
 +
| align="center"|3
 +
| align="center"|Oil Ring
 +
| align="center"|[[Image:oilring.jpg|center|thumb|150px]]
 +
|-
 +
| align="center"|4
 +
| align="center"|Wrist Pin
 +
| align="center"|[[Image:wristpin.jpg|center|thumb|150px]]
 +
|-
 +
| align="center"|5
 +
| align="center"|Connecting Rod
 +
| align="center"|[[Image:connectingrod.jpg|center|thumb|150px]]
 +
|-
 +
| align="center"|6
 +
| align="center"|Connecting Rod Cap
 +
| align="center"|[[Image:rodcap.jpg|center|thumb|150px]]
 +
|-
 +
| align="center"|7
 +
| align="center"|Connecting Rod Cap Bolt
 +
| align="center"|[[Image:rodcapbolt.jpg|center|thumb|150px]]
 +
|-
 +
|-
 +
|}
 +
 +
  
 
===Assembly Process===
 
===Assembly Process===
Line 722: Line 765:
 
|-  
 
|-  
 
| align="center" |1
 
| align="center" |1
| align="center" |Remove 7 Phillips-head screws
+
| align="center" |Put the three piston rings (part 36a) onto the piston (part 36)
| align="center" |Phillips-head Screwdriver
+
| align="center" |By Hand
| align="center" |Easy, 1 Screw Quite Difficult
+
| align="center" |Easy
 
|-  
 
|-  
 
| align="center" |2
 
| align="center" |2
| align="center" |Removed Rip Fence Bolt to Saw Blade Locking Lever
+
| align="center" |Insert wrist pin (part 35) into piston and through connecting rod (part 34). Secure wrist pin to piston by inserting wrist pin clip.
 
| align="center" |By Hand
 
| align="center" |By Hand
| align="center" |Easy
+
| align="center" |Moderate
 
|-
 
|-
 
| align="center" |3
 
| align="center" |3
| align="center" |Removed Removed Dust Blower Angle off of Dust Blower
+
| align="center" |Insert connecting rod and piston into engine block (part 37).
 
| align="center" |By Hand
 
| align="center" |By Hand
| align="center" |Easy
+
| align="center" |Difficult-Piston rings needed compressed, did not have tool
 
|-  
 
|-  
 
| align="center" |4
 
| align="center" |4
| align="center" |Removed Dust Blower and Rip Fence off of Casing
+
| align="center" |Insert crankshaft (part 33) into engine block (part 37).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |5
 
| align="center" |5
| align="center" |Removed Rip Fence off of Casing
+
| align="center" |Attach connecting rod (part 34) to crankshaft (part 33), by means of connecting rod cap (part 32) and two ¼” hexagonal head bolts (part 32a).
| align="center" |By Hand
+
| align="center" |Socket wrench
| align="center" |Easy
+
| align="center" |Moderate-had to be aligned accordingly
 
|-
 
|-
 
| align="center" |6
 
| align="center" |6
| align="center" |Removed Plastic Blade Guard off of Casing
+
| align="center" |Insert valve lifters (part 31) into slots on inside of engine block (part 37).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |7
 
| align="center" |7
| align="center" |Removed Casing off of Casing
+
| align="center" |Insert intake and exhaust valves (part 25) into engine block (part 37) and then through valve springs (part 25a). Secure valve springs to valves with the valve clips (part 25b).
| align="center" |Philips-head Screwdriver
+
| align="center" |Flat-head Screwdriver and Pliers
| align="center" |Moderately Easy
+
| align="center" |Very Difficult-No spring compression tool.
 
|-
 
|-
 
| align="center" |8
 
| align="center" |8
| align="center" |Removed Gel Max Comfort Grip off of Casing
+
| align="center" |Place valve cover and gasket (part 24) onto engine block (part 37) enclosing the valve assembly. Secure cover with two 5/16” hexagonal head bolts (part 24a).
| align="center" |By Hand
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |9
 
| align="center" |9
| align="center" |Removed Shoe Plate Locking Gear off of Casing
+
| align="center" |Put cam shaft (part 30) into engine block (part 37) ensuring that it is in the proper position for correct timing.
 
| align="center" |By Hand
 
| align="center" |By Hand
| align="center" |Easy
+
| align="center" |Moderate
 
|-
 
|-
 
| align="center" |10
 
| align="center" |10
| align="center" |Removed Shoe Plate Locking Knob off of Casing
+
| align="center" |Slide cam shaft aligner (part 38) onto cam shaft (part 30).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |11
 
| align="center" |11
| align="center" |Removed Trigger Switch off of Casing
+
| align="center" |Attach crankcase cover (part 29) to engine block (part 37) using six 10mm hexagonal head bolts (part 27).
| align="center" |By Hand
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |12
 
| align="center" |12
| align="center" |Removed Lock on Button off of Trigger Switch
+
| align="center" |Insert crank key (part 28) into crank shaft (part 33).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |13
 
| align="center" |13
| align="center" |Removed Lock Spring off of Lock on Button
+
| align="center" |Slide drive pulley (part 26) onto crankshaft (part 33) and secure by hammering or pressing into position.
| align="center" |Flat-head Screwdriver
+
| align="center" |Hammer
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |14
 
| align="center" |14
| align="center" |Removed Plastic Lock Washers off of Lock on Button
+
| align="center" |Align head gasket (part 17a) onto engine block (part 37) and then align head (part 17) onto engine block.
| align="center" |Flat Head Screwdriver
+
| align="center" |By Hand
| align="center" |Moderately Difficult
+
| align="center" |Easy
 
|-
 
|-
 
| align="center" |15
 
| align="center" |15
| align="center" |Removed Switch Breaker off of Trigger Switch
+
| align="center" |Insert eight ½” hexagonal head bolts (part 16) through the head (part 17) and into engine block (part 37). Tighten bolts to secure head.
| align="center" |By Hand
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |16
 
| align="center" |16
| align="center" |Removed 2 Cord Clamp Screws off of Cord Clamp off of Casing
+
| align="center" |Insert spark plug (part 14) into engine block (part 37) and tighten using 21mm socket.
| align="center" |Phillips-head Screwdriver
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |17
 
| align="center" |17
| align="center" |Removed Red Motor Connecting Wire off of Spring Loaded Graphite
+
| align="center" |Attach intake tube and gasket (part 23) to engine block (part 37) with two hexagonal head bolts (part 23a).
| align="center" |By Hand
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |18
 
| align="center" |18
| align="center" |Removed Black Motor Connecting Wire from Spring Loaded Graphite
+
| align="center" |Attach carburetor (part 22) to intake tube (part 23) using two 5/16” bolts and nuts (part 22a)
| align="center" |By Hand
+
| align="center" |Wrench and socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |19
 
| align="center" |19
| align="center" |Disassembled Spring Loaded Graphite Internals
+
| align="center" |Attach muffler (part 15) to engine block (part 37) using two 11mm bolts.
| align="center" |By Hand
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |20
 
| align="center" |20
| align="center" |Removed Motor Screw From Casing
+
| align="center" |Attach throttle plate, grounding wire and spring (all attached together: part 21) to engine block (part 37) with two 5/16” hexagonal head bolts.
| align="center" |Philips-head Screwdriver
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |21
 
| align="center" |21
| align="center" |Removed Red Motor Connecting Wire From Armature
+
| align="center" |Slide fly wheel (part 20) onto crankshaft (part 33).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |22
 
| align="center" |22
| align="center" |Removed Black Motor Connecting Wire from Armature
+
| align="center" |Attach pull string catch nut (part 19) to fly wheel (part 20) using 19mm socket.
| align="center" |By Hand
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |23
 
| align="center" |23
| align="center" |Removed Metal Gear From 1/4in. Plate
+
| align="center" |Attach pickup coil (part 18) to engine block (part 37) using two 5/16” hexagonal head bolts then connect spark plug cord to spark plug (part 14).
| align="center" |By Hand
+
| align="center" |Socket wrench and by Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |24
 
| align="center" |24
| align="center" |Removed 1/4in. Metal Plate from Armature Shaft With Rotar
+
| align="center" |Attach grounding wire from pickup coil (part 18) to engine block (part 37) using a screw driver.
| align="center" |By Hand
+
| align="center" |Phillips-head screwdriver
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |25
 
| align="center" |25
| align="center" |Removed Small Metal Plate off of Armature Shaft With Rotar
+
| align="center" |Insert crank case ventilation tube (part 13) into engine block (part 37).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |26
 
| align="center" |26
| align="center" |Removed Linear Oscillator from Metal Gear
+
| align="center" |Attach fly wheel cover (part 12) to engine block (part 37) using two 3/8” hexagonal head bolts (part 11) as well as two 8mm hexagonal head bolts (part 11a).
| align="center" |By Hand
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |27
 
| align="center" |27
| align="center" |Removed Washer off of Gear from Metal Gear
+
| align="center" |Slide pull cord cover (part 10b) and pull cord (part 10) over end of crankshaft (part 33) and secure to fly wheel cover (part 12) using two ¼” hexagonal head bolts (part 10a).
| align="center" |By Hand
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |28
 
| align="center" |28
| align="center" |Removed Cylindrical Slider from Linear Oscillator
+
| align="center" |Insert dipstick tube (part 9) into engine block and secure to side of carburetor using one 8mm hexagonal head bolt.
| align="center" |By Hand  
+
| align="center" |By Hand and socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |29
 
| align="center" |29
| align="center" |Removed Blade Changing Piece from Blade Changing Component
+
| align="center" |Attach gas tank (part 8) to engine block (part 37) using three 8mm hexagonal head bolts (part 7).
| align="center" |By Hand
+
| align="center" |Socket wrench
| align="center" |Difficult
+
| align="center" |Easy
 
|-
 
|-
 
| align="center" |30
 
| align="center" |30
| align="center" |Removed Blade Changing Spring from Blade Changing Component
+
| align="center" |Connect gas line (part 22b) to gas tank (part 8) and carburetor (part 22).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |31
 
| align="center" |31
| align="center" |Removed Allen Wrench Screw from Blade Changing Component
+
| align="center" |Attach the air filter housing (part 6) to the carburetor (part 22), using two hexagonal head bolts (part 5).
| align="center" |3/32 Allen Wrench
+
| align="center" |Socket wrench
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |32
 
| align="center" |32
| align="center" |Removed Blade Changing Component from Linear Oscillator
+
| align="center" |Insert foam air filter and cardboard support (part 4) into air filter housing (part 6).
 
| align="center" |By Hand
 
| align="center" |By Hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |33
 
| align="center" |33
| align="center" |Removed Felt Piece from Linear Oscillator
+
| align="center" |Attach air filter cap (part 3) to air filter housing (part 6) by tightening one Phillips head screw.
| align="center" |By Hand
+
| align="center" |Phillips-head screwdriver
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
 
| align="center" |34
 
| align="center" |34
| align="center" |Removed Cylindrical Slider 2 from Linear Oscillator
+
| align="center" |Insert oil dipstick (part 2) into dipstick tube (part 9) and screw to tighten.
 
| align="center" |By Hand
 
| align="center" |By Hand
 +
| align="center" |Easy
 +
|-
 +
| align="center" |35
 +
| align="center" |Screw (clockwise) the gas cap (part 1) onto the gas tank (part 8).
 +
| align="center" |By hand
 
| align="center" |Easy
 
| align="center" |Easy
 
|-
 
|-
Line 900: Line 948:
  
 
===Product Testing and Analysis===
 
===Product Testing and Analysis===
 +
 +
Based on the nature of our product and the fact it has quite a few moving parts, fairly precise models would need to be made in order to evaluate the product.  In terms of various models that would need to be analyzed, analytical ones would be the most important and beneficial but graphical models would also be useful.  These graphical models can be in the form of CAD drawings, or 3D modeling such as Solid Works.  While these models are helpful the most important are the analytical models such as fatigue, power transmission, thermodynamic, stress/strain as well as others.  With our product being an engine many of these models need to be performed and analyzed before the engine is manufactured on a large scale.
 +
 +
Fatigue models would need to be performed on various parts of the engine such as the cylinder walls, pistons, piston rings as well as the engine block itself.  These are necessary because if some of these parts fail the whole engine could fail.  For example if any of the rings fail the engine could either lose compression or oil could leak into the combustion chamber and cause the engine to burn oil.  Also, power transmission models would need to be analyzed to look at how power is transferred from combustion to the pistons, then to the crank shaft then to the blades.  Along with the power transformations, possible power losses would need to be tested.  Thermodynamic/heat transfer models would also have to be tested and analyzed because our engine being internal combustion it creates a lot of heat.  The engine block itself has “fins” on it in an attempt to dissipate heat.  For engineers to know whether these fins properly dissipate heat or dissipate enough of it these models need to be looked at.  Fluid flow models, while not as important as the others would also need to be analyzed.  The only model that would need to be looked at would be the transfer of fuel from the tank to the carburetor.  A rubber hose connects these two components and would need to be tested to ensure proper flow as well as is there were possible restrictions such as a kink. 
 +
 +
Lastly and possibly the most important model that would need to be tested would be the materials stress/strain model.  There are various different components in our engine that are made of different materials.  Each of these components has a different use and some need to be able to handle certain stresses and strains.  For example, our engine block is made of cast iron.  This is so because with the engine block being internal combustion the block needs to be able to handle higher stresses and strains.  This piece as well as other various components needs to be tested numerous times and for long period of times in order to ensure that they do not fail under repeated use.  All of these models need to be fairly precise and when combined would provide a larger detailed model of how the whole engine may perform under hard repeated use.
  
 
===Process Comparison===
 
===Process Comparison===
Line 908: Line 962:
  
 
===Design Changes and Recommendations===
 
===Design Changes and Recommendations===
 +
 +
This motor is very heavy and would be exhausting to push around. One of the biggest things that could be done to improve this engine is to decrease the over all weight and the over all package size. Most of the materials could be lightened by using aluminum or some other alloy and still have the strength needed. Parts such as the gas tank could be redesigned to compact the entire package, other parts can be completely removed. The intake tube between the carburetor and the engine block can be taken out and the carburetor can be bolted directly to the block. This would reduce cost of manufacturing. Almost all of the rotating components could be reduced in weight this would allow the motor to reach operating speed faster, rev higher, and increase power by decreasing the rotating mass. The piston head and cylinder can be increased in diameter to increase displacement and increasing power. A switch to a fuel injection system would help improve fuel economy because the amount of fuel and the timing of fuel can be controlled. The muffler could be improved to have more baffels in it to make the engine quieter and more comfortable for the user. Air flow could be improved by porting the heads and using bigger valves, this would increase the power of the motor by making it easier for it to get the air and fuel in and out.
  
 
==References==
 
==References==
 +
 +
Four Stroke Engine. Retrieved November 3, 2008, from http://en.wikipedia.org/wiki/Otto_cycle#The_Otto_cycle.
 +
 +
Injection Molding. Retrieved november 13, 2008,  from http://en.wikipedia.org/wiki/Injection_molding.
 +
 +
Casting. Retrieved November 12, 2008, http://en.wikipedia.org/wiki/Casting
 +
 +
US Patent Database Search. Retrieved November 14-25  http://patft.uspto.gov/

Latest revision as of 15:20, 5 December 2008

Contents

Tecumseh 5 HP Engine

Wholeengine.jpg



Executive Summary

This wiki documents the the three phases of the analysis of a 5 Horsepower Tecumseh engine. This engine was originally used to power a push lawnmower, but the analysis below begins after it had been removed from the mower body, and covers only components of the engine.

The first phase of this project focused on the disassembly and analysis of the motor's condition. It was determined that this motor probably did not run due to a faulty piston ring. During the second phase group members cataloged and analyzed each of the approximately 38 total parts.

The final phase of the project involved reassembling the motor, and reflecting on its overall design. Based on the understanding of the engine during the previous phases recommendations are made regarding the design, manufacturing, use, and life-cycle of the engine.

Introduction

This product was used to run a push mower. It is powered by internal combustion that is used to spin the blades. Based on the condition of its parts this engine will not run, but this has not been tested.

Group Members:

Ian Kelsey - disassembly, reassembly, wiki creation

Dan Leake - disassembly, wiki creation

Kyle Johnson - disassembly, reassembly, wiki creation

Alex Lovallo - disassembly, reassembly, wiki creation, team leader

Sanket Chavan -


Product Description

  • 5 Horsepower Lawnmower Engine
  • Manufacturer: Tecumseh
  • Model Number: VS120 63063E

Before Dissasembly

Purpose and Operation

This 5 HP engine was used to power a pull start lawnmower. It was likely intended for urban or small yard use as it does not seem to have a drive system for its own locomotion. This engine once transformed chemical energy from combustion into linear kinetic energy using its piston. The connecting arm and crankshaft then converted this linear reciprocation motion into translational motion which could be used to power the mower blades directly, or may have been fed to the blades by a belt system.

It is possible that this engine will run as it does seem to have compression when the pull cord is pulled. While it is not possible for us to test this mower these is strong evidence that it will not run, or at least will only run for a short while until it breaks. The muffler of the engine is full of oil that will run out if it is tipped. This indicates that the piston rings may have failed and the engine is burning oil. Failed piston rings result in a lot of sediment build up from the burnt oil as well as increased piston friction which can significantly reduce the life of the engine. If enough heat builds up parts of the engine can melt rendering it inoperable.

Not including any fasteners it seems like that this engine will have roughly 40 parts. Viewing the exterior of the motor it is clear that plastic, and steel or iron have been used. Inside we expect to come across more iron, steel, rubber, and potentially some sort of textile.

Disassembly Process

Step Number Process Tool Level of Difficulty
1 Unscrew (counterclockwise) the gas cap (part 1) from the gas tank (part 8). By Hand Easy
2 Unscrew and remove oil dipstick (part 2) from dipstick tube (part 9). By Hand Easy
3 Remove air filter cap (part 3) from air filter housing (part 6) by unscrewing one phillips head screw. Screw Driver Easy
4 Take out foam air filter and cardboard support (part 4) from air filter housing (part 6). By Hand Easy
5 Unscrew two hexagonal head bolts (part 5) that are attaching the air filter housing (part 6) to the carburetor (part 22), then remove air filter housing. By Hand Easy
6 Unscrew three 8mm hexagonal head bolts (part 7) that are holding the gas tank (part 8) to engine block (part 37), then remove gas tank. Socket Wrench Easy
7 Unscrew one 8mm hexagonal head bolt and remove dipstick tube (part 9) from side of carburetor. Socket Wrench Moderately Easy
8 Unscrew two ¼” hexagonal head bolts (part 10a) then remove pull cord cover (part 10b) and pull cord (part 10). Socket Wrench Easy
9 Unscrew two 3/8” hexagonal head bolts (part 11) as well as two 8mm hexagonal head bolts (part 11a), then remove fly wheel cover (part 12) from engine block (part 37). Socket Wrench Moderately Hard
10 Removed crank case ventilation tube (part 13) from engine block (part 37). By Hand Moderately Easy
11 Unscrew and remove spark plug (part 14) from engine block using 21mm socket. Wrench Moderately Easy
12 Unscrew two 11mm bolts and remove muffler (part 15) from engine block (part 37). Socket Wrench Easy
13 Unscrew eight ½” hexagonal head bolts (part 16) holding head onto engine block (part 37). Socket Wrench Easy
14 After removing screws pull off head (part 17) and head gasket (part 17a) from engine block (part 37). By Hand Moderately Easy
15 Detach grounding wire from pickup coil (part 18. Screw Driver Easy
16 Unscrew two 5/16” hexagonal head bolts holding on pickup coil (part 18) then remove pickup coil as well as spark plug cord. Socket Wrench Easy
17 Remove pull string catch nut from fly wheel (part 19) using 19mm socket. Socket Wrench Easy
18 Remove fly wheel (part 19). Hammer Hard
19 Unscrew two 5/16” hexagonal head bolts holding on throttle plate, grounding wire and spring (all attached together: part 21). Socket Wrench Easy
20 Unscrew two 5/16” bolts (part 22a) with nuts holding carburetor (part 22) to intake tube (part 23). Socket Wrench Easy
21 Unscrew two hexagonal head bolts (part 23a) holding intake tube and gasket (part 23) to engine block (part 37). Socket Wrench Easy
22 Unscrew two 5/16” hexagonal head bolts (part 24a) then remove valve cover and gasket (part 24). Socket Wrench Easy
23 Remove intake and exhaust valve (part 25), valve spring (part 25a) and valve clip (part 25b). Screw Driver Easy
24 Pry off drive pulley (part 26). Hammer and Screw Driver Easy
25 Remove six 10mm hexagonal head bolts (part 27) from crank case cover (part 29). Socket Wrench Easy
26 Remove crank key (part 28) from crank shaft (part 33). Screw Driver Easy
27 Remove crank case cover (part 29) from engine block (part 37). By Hand Moderately Easy
28 Pull out cam shaft (part 30) from engine block (part 37). By Hand Moderately Easy
29 Remove valve lifters (part 31). By Hand Easy
30 Unscrew two ¼” hexagonal head bolts (part 32a) from connecting rod cap (part 32). Socket Wrench Easy
31 Pull out crank shaft (part 33) from engine block (part 37). 3/32 Allen Wrench Moderately Easy
32 Remove connecting rod (part 34) that connects the crank shaft (part 33) to the piston (part 36). By Hand Hard
33 Remove piston (part 36) from the engine block (part 37). By Hand Easy
34 Remove the wrist pin along with the wrist pin clip (part 35). By Hand Easy
35 Pried the piston rings (part 36a) off of the piston (part 36). Two metal rings and an oil collector ring. Screw Driver Hard

After Disassembly

Component List

Part # Component Name Quanity Material(s) Manufacturing Process Description of Function Image Physical Description
1 Gas Cap 1 Plastic Injection Molded To seal the gas tank, by means of interior threading and a rubber gasket, to prevent leakage but yet allow air to pass into the tank to allow the free flow of gas out of tank
DSC00042.jpg
Red Colored. Round with vertical ribs for grip, interior threading. Contains interior rubber ring to create seal
2 Oil dipstick 1 Plastic, Steel Injection Molded, Stamped Used to check oil level in engine
DSC00041.jpg
Long steel stick with round plastic cap
3 Air filter cap 1 Plastic Injection Molded Holds air filter into place on engine block
DSC00043.jpg
Plain top surface and the lower surface has ribs to secure the air filter
4 Air filter 2 Foam, Cardboard Chemicals are mixed then a gas in pumped in to create air bubbles Filters air coming into engine
DSC00044.jpg
Main filter made of foam with a cardboard support
5 Hex-head bolts 2 Steel Rolled steel stock then stamped head to shape Holds air filter and cover into place
DSC00047.jpg
Cylindrical with threads and hex shaped head
6 Air filter housing 1 Plastic Injection Molded Houses air filter. Allows the air from the surroundings to enter and lets filtered air flow to the carburetor
DSC00050.jpg
Rectangular with an inlet pipe on one end and an outlet at the other
7 Hex-head bolts 8mm 3 Steel Rolled steel stock then stamped head to shape Holds gas tank onto engine block
DSC00051.jpg
Cylindrical with threads and hex shaped head
8 Gas tank 1 Plastic Injection Molded Holds gas
DSC00052.jpg
Tank is plastic and is molded to fit side of motor and is flat on other side
9 Dip stick tube 1 Plastic Injection Molded Allows access for dipstick to travel into the crank case to check oil level
DSC00053.jpg
Funnel-like at the top with an extended pipe
10 Pull cord with handle 1 Nylon cord with plastic handle Nylon- Thin composite that is weaved into cord, Plastic- Injection molded Used to manually start the engine by rotating a pulley which in return rotates the crankshaft and initiating the combustion process
DSC00054.jpg
Durable nylon fiber cord that winds around the pulley with a plastic handle at other end
10a Hex-head bolts 2 Steel Nylon- Thin composite that is weaved into cord. Plastic- Injection molded Holds pull cord cover on
DSC00056.jpg
Cylindrical with threads and hex shaped head
10b Pull cord assembly 1 Steel and plastic Housing is stamped steel, plastic pulley is injection molded, and engagement mechanism is stamped and die cast Transfers energy from pull cord to crankshaft
DSC00054.jpg
Circular cover made of steel with striations, an inner pulley made of plastic, and a spring loaded metal engagement mechanism
11 Hex-head bolts 3/8" 2 Steel Rolled steel stock then stamped head to shape Holds on fly wheel cover
DSC00056.jpg
Cylindrical with threads and hex shaped head
11a Hex-head bolts 8mm 2 Steel Rolled steel stock then stamped head to shape Holds on fly wheel cover
DSC00057.jpg
Cylindrical with threads and hex shaped head
12 Metal fly wheel cover 1 Steel Sheet metal stamped into form, as well as holes punched into top Protects user from moving fly wheel as well as allows for ventilation
DSC00058.jpg
Steel sheet metal with holes to allow for air flow
13 Crank case ventilation tube 1 Rubber Extruded through a die and then cut into sections Allows oil vapor and pressure from crank case to be vented to the air filter to be sent through the combustion process
DSC00059.jpg
Rubber hose
14 Spark plug 1 Ceramic, copper, aluminum, glass Assembled from variety of manufactured components Creates spark to initiate combustion
DSC00060.jpg
Physical: cylindrical, hex shaped at base. Threaded at one end. Ceramic Coating over portion. One end has electrical connection to plug, the other end has electrodes to produce sparks
15 Muffler with two 11 mm bolts 1 Steel, muffler is two separate pieces welded together 2 pressed pieces of sheet metal, extruded steel rods then thread rolling The muffler reduces engine noise by creating a resonating chamber
DSC00061.jpg
Silver color, inlet pipe on one side, small outlet holes on other side
16 1/2" hex-head bolts 8 Steel Extruded steel rods then thread rolling Use threading to secure engine components together
DSC00062.jpg
Black, small threads for metal use, hex shaped drive hole
17 Head 1 Cast iron Die-cast then machined Radiates heat from engine, seals combustion chamber. Has 8 holes to attach to head, 1 hole to allow spark plug, and 2 small holes to attach an external component
DSC00063.jpg
Square plate with parallel fins. 11 holes
17a Head Gasket 1 Aluminum Layered punched aluminum Creates a seal between the head and the engine block.
DSC00064.jpg
Flat, square with holes for bolts
18 Pick-up coil with rubber housed cord 1 Steel, rubber Thin pieces or sheet metal that are rolled, vulcanized rubber process to create hose. Spray coated with sealant afterwards Produces high voltage output pulses for firing the associated spark plug
DSC00065.jpg
U-shaped bracket surrounding a black cube. Both have layered steel in the ends. Spark plug wire comes from rear. Small strip for attaching grounding wire. Has plastic spray coating to seal the back side
19 Nut, washer and pull string catch 1 Steel Stamped and machined steel.washers are stamped from sheet metal, nuts are extruded then cut and bored out Teeth on interior cause rotation of crank when pull string is pulled to start motor.
DSC00066.jpg
cup shaped steel piece. With teeth on inside. Hole in top center for affixing bolt
20 Fly wheel 1 Cast iron Die-cast then machined down to specs Rotates mounted magnet past pickup coil creating alternating magnetic field inducing current
DSC00067.jpg
Round in shape, has vertical fins, magnet on one side, counter balance on other
21 Two 5/16" bolts and washers, throttle control and grounding wire 1 Steel, copper wire Throttle components stamped from sheet metal and bent. extruded steel rods then thread rolling, washers stamped from sheet metal, copper wire extruded Throttle connected to butterfly valve to control gas input to combustion chamber. Throttle cable holds throttle open while in operation. When the cable is not under tension the throttle closes because of attached spring breaking the electrical connection to pick up coil. Preventing spark stopping engine
DSC00068.jpg
Flat plate with hinge and spring to throttle control and grounding wire
22 Carburetor 1 Cast iron, steel , rubber Portion is die cast iron, stamped steel, extruded rubber Carburetor controls mixture of gasoline and air flowing to the combustion chamber. Cylidrical shape filters the gasoline before combustion
DSC00071.jpg
Cylindrical with rubber primer on side. One input for gas, two holes for air flow. Throttle butterfly valve on interior. Wire arm attached to throttle
22a Nuts and bolts 2 Steel Extruded steel rods then thread rolling, nuts extruded then cut and bored Holds carburetor into place
DSC00073.jpg
5/16"
22b Gas line 1 Rubber gas line Extruded rubber hose Provides a path for gas to flow from tank to carburetor
DSC00072.jpg
Rubber hose
23 Intake tube with gasket 1 Cast Iron Die cast Iron Transports the air from the carburetor into the engine. Gasket prevents leakage in joint between tube and carburetor
DSC00075.jpg
L shaped tube, with 2 bolt flanges on each end. Gasket matches flange shape
23a 3/8" bolts with washers 2 Steel Extruded steel rods that are thread rolled, washers are punched out Fasten intake tube to carburetor and engine block
DSC00076.jpg
Bolts
24 Valve cover, valve gasket 1 Steel bolts, steel cover with plastic gasket Stamped steel and stamped plastic Seals valve train
DSC00077.jpg
Steel cover, plastic gasket
24a 5/16" bolts 2 Steel Extruded steel rods that are thread rolled Holds valve cover to engine block
DSC00078.jpg
Bolts
25 Valve 2 Steel Machined from solid stock One valve controls air/fuel intake into combustion chamber. Second valve controls exhaust out of chambers
DSC00080.jpg
Long cylinder and thing with flattened head. Filleted near head
25a Valve spring 2 Steel Coiled, hot wound, and hardened in form Holds valves shut until proper time
DSC00081.jpg
Spring
25b Valve spring clip 2 Steel Punched Secures spring to valve
DSC00082.jpg
Two diameters of ring on top of each other. Smaller diameter can fit inside of spring. Has slot in middle for valve stem to slip into
26 drive pulley 1 Steel Machined Connects to crank shaft to use engine power to drive belt
DSC00083.jpg
Hollow cylinder with groove around outside edge and key way through inside
27 10 mm bolts with washers 6 Steel Extruded steel rods that are thread rolled Attached crank case to the motor block
DSC00084.jpg
Bolts
28 Key from crank shaft 1 Steel Stamped Hold drive pulley in line with crank shaft so they rotate together
DSC00085.jpg
Small half cylinder cut along long axis
28a Crank case pins 2 Steel Cut steel bar Align crank case bolts holes with the blocks bolt holes
DSC00086.jpg
Short cylinders with rounded ends
29 Crank case cover 1 Cast iron Die cast iron then machined Holds parts and oil inside crank case.
DSC00087.jpg
Rounded shape with holes to affix to crank case, holes for aligning pins, holes in center for crank shaft. Interior cavity to hold and align camshaft and camshaft aligner
30 Cam shaft 1 Cast iron Die-cast then machined Powered by crank shaft, has gear and lobes sized to open and close valves at proper time
DSC00089.jpg
Shaft with two lobes, a central gear, smooth and cylindrical on both ends
31 Valve lifters 2 Steel Welded and Machined Steel Are pushed up by lobes of cam shaft. When pushed up they open the valves in the combustion chamber
DSC00090.jpg
Flat plate with cylindrical shaft attached
32 Connecting rod cap 1 Cast aluminum Cast and then machined Holds the connecting rod to the crank shaft
DSC00091.jpg
Semi-circular curved bar with a bolt hole on either end. Inner surface is machined . Inside of surface is machined to reduce friction
32a 1/4" hex-head bolts 2 Steel Extruded steel rods that are thread rolled Fasten connecting rod cap to connecting rod over crankshaft
DSC00092.jpg
Bolts
33 Crank shaft 1 Cast iron with machined parts Cast and then machined to specifications Translates reciprocating linear piston motion into rotation
DSC00097.jpg
Cylindrical shaft with an offset cylinder in the middle, has two counter weights near middle
33a Washer 1 Steel Punched To reduce friction on the crankshaft
Washerfromhell.jpg
Flat round ring made of steel
34 Connecting rod 1 Cast aluminum Cast the machined Connects the piston to the crankshaft transmitting the power
DSC00096.jpg
I shaped bar with circular hole on one end and semicircular groove on the other end that mirror the shaped of the connecting rod cap. Has a bolt hole on either side of the semi circular end to interface with the connecting rod
35 Wrist or gudgeon pin with a clip 1 Steel Pin is machined from solid stock, Clip is shaped and heated to hold form. Connects the piston to the connecting rod and provides a bearing for the connecting rod to pivot as it moves
DSC00094.jpg
Tube is a bored out cylinder and clip is shaped like a lowercase e
36 Piston 1 Aluminum Alloy Cast and machined to specifications. Transfers the force from combustion gas in the cylinder to the crankshaft via the connecting rod. Forces exhaust out of exhaust valve and draws the air fuel mixture into the combustion chamber. Compresses the air/fuel mixture pre-combustion
DSC00095.jpg
Cylindrical with flat plane on one end. Has lateral hole to allow wrist pin. Has grooves in side for piston rings and a hollowed interior to reduce mass
36a Piston Rings 3 steel and coated steel Punched steel, One ring has a spring coating along outside edge Seal the combustion chamber/ Support heat transfer from the piston to the cylinder wall/ Regulate engine oil consumption
DSC00093.jpg
Each ring has one gap. One ring is not solid steel but has a composite material insert
37 Engine block 1 Cast iron Die cast and machined to specifications Houses all of internal engine parts
DSC00099.jpg
Hollowed rectangle with fins
38 Cam shaft aligner 1 Plastic ring with stainless steel rod in it Machined steel, injection molded plastic Holds one end of the cam in place to insure that the teeth between the crankshaft gear and camshaft gear align
DSC00098.jpg
Plastic ring with extruded tube off one side with a steel insert in it

CAD Models

Part # Component Name CAD Drawing
1 Piston Head
Piston2008.jpg
2 Compression Ring
Pistonring.jpg
3 Oil Ring
Oilring.jpg
4 Wrist Pin
Wristpin.jpg
5 Connecting Rod
Connectingrod.jpg
6 Connecting Rod Cap
Rodcap.jpg
7 Connecting Rod Cap Bolt
Rodcapbolt.jpg


Assembly Process

Step Number Process Tool Level of Difficulty
1 Put the three piston rings (part 36a) onto the piston (part 36) By Hand Easy
2 Insert wrist pin (part 35) into piston and through connecting rod (part 34). Secure wrist pin to piston by inserting wrist pin clip. By Hand Moderate
3 Insert connecting rod and piston into engine block (part 37). By Hand Difficult-Piston rings needed compressed, did not have tool
4 Insert crankshaft (part 33) into engine block (part 37). By Hand Easy
5 Attach connecting rod (part 34) to crankshaft (part 33), by means of connecting rod cap (part 32) and two ¼” hexagonal head bolts (part 32a). Socket wrench Moderate-had to be aligned accordingly
6 Insert valve lifters (part 31) into slots on inside of engine block (part 37). By Hand Easy
7 Insert intake and exhaust valves (part 25) into engine block (part 37) and then through valve springs (part 25a). Secure valve springs to valves with the valve clips (part 25b). Flat-head Screwdriver and Pliers Very Difficult-No spring compression tool.
8 Place valve cover and gasket (part 24) onto engine block (part 37) enclosing the valve assembly. Secure cover with two 5/16” hexagonal head bolts (part 24a). Socket wrench Easy
9 Put cam shaft (part 30) into engine block (part 37) ensuring that it is in the proper position for correct timing. By Hand Moderate
10 Slide cam shaft aligner (part 38) onto cam shaft (part 30). By Hand Easy
11 Attach crankcase cover (part 29) to engine block (part 37) using six 10mm hexagonal head bolts (part 27). Socket wrench Easy
12 Insert crank key (part 28) into crank shaft (part 33). By Hand Easy
13 Slide drive pulley (part 26) onto crankshaft (part 33) and secure by hammering or pressing into position. Hammer Easy
14 Align head gasket (part 17a) onto engine block (part 37) and then align head (part 17) onto engine block. By Hand Easy
15 Insert eight ½” hexagonal head bolts (part 16) through the head (part 17) and into engine block (part 37). Tighten bolts to secure head. Socket wrench Easy
16 Insert spark plug (part 14) into engine block (part 37) and tighten using 21mm socket. Socket wrench Easy
17 Attach intake tube and gasket (part 23) to engine block (part 37) with two hexagonal head bolts (part 23a). Socket wrench Easy
18 Attach carburetor (part 22) to intake tube (part 23) using two 5/16” bolts and nuts (part 22a) Wrench and socket wrench Easy
19 Attach muffler (part 15) to engine block (part 37) using two 11mm bolts. Socket wrench Easy
20 Attach throttle plate, grounding wire and spring (all attached together: part 21) to engine block (part 37) with two 5/16” hexagonal head bolts. Socket wrench Easy
21 Slide fly wheel (part 20) onto crankshaft (part 33). By Hand Easy
22 Attach pull string catch nut (part 19) to fly wheel (part 20) using 19mm socket. Socket wrench Easy
23 Attach pickup coil (part 18) to engine block (part 37) using two 5/16” hexagonal head bolts then connect spark plug cord to spark plug (part 14). Socket wrench and by Hand Easy
24 Attach grounding wire from pickup coil (part 18) to engine block (part 37) using a screw driver. Phillips-head screwdriver Easy
25 Insert crank case ventilation tube (part 13) into engine block (part 37). By Hand Easy
26 Attach fly wheel cover (part 12) to engine block (part 37) using two 3/8” hexagonal head bolts (part 11) as well as two 8mm hexagonal head bolts (part 11a). Socket wrench Easy
27 Slide pull cord cover (part 10b) and pull cord (part 10) over end of crankshaft (part 33) and secure to fly wheel cover (part 12) using two ¼” hexagonal head bolts (part 10a). Socket wrench Easy
28 Insert dipstick tube (part 9) into engine block and secure to side of carburetor using one 8mm hexagonal head bolt. By Hand and socket wrench Easy
29 Attach gas tank (part 8) to engine block (part 37) using three 8mm hexagonal head bolts (part 7). Socket wrench Easy
30 Connect gas line (part 22b) to gas tank (part 8) and carburetor (part 22). By Hand Easy
31 Attach the air filter housing (part 6) to the carburetor (part 22), using two hexagonal head bolts (part 5). Socket wrench Easy
32 Insert foam air filter and cardboard support (part 4) into air filter housing (part 6). By Hand Easy
33 Attach air filter cap (part 3) to air filter housing (part 6) by tightening one Phillips head screw. Phillips-head screwdriver Easy
34 Insert oil dipstick (part 2) into dipstick tube (part 9) and screw to tighten. By Hand Easy
35 Screw (clockwise) the gas cap (part 1) onto the gas tank (part 8). By hand Easy

After Assembly

Engine Operation

This engine was designed as a small 4-stroke engine, which was most likely used to power a push mower. The operation of this product begins initially with the startup. This is done when the operator presses the primer bulb a few times, which causes gas to be forced into the carburetor and also removing any air in the fuel line. The operator then proceeds to manually pull the draw string, which is indirectly attached to the crankshaft by a clutch mechanism. When the clutch is engaged during startup, the crankshaft is forced to rotate, initiating the four stroke cycle. This means that there are four necessary steps or strokes needed to complete a cycle. These four strokes are the intake, compression, power and exhaust. The process begins when air is drawn through the air filter, where it then travels through the intake tube into the carburetor. When the air reaches the carburetor, gas is released through small jets, causing atomization to guarantee a saturated mixture of air and fuel. This mixture is regulated by the carburetor which is dependent upon the users desired operation speed. This is done by using a throttle valve to control the air flow. The mixture is then drawn into the engine through the intake valve during the intake stroke. The intake valve is controlled by the camshaft, which is driven by the crankshaft. The valve opens during the intake stroke, which starts with the piston at top dead center (TDC), meaning that the piston is at a position that is the farthest away from the crankshaft. The piston then starts traveling towards the crankshaft drawing the air-fuel mixture into the combustion chamber. When the piston reaches bottom dead center (BDC), meaning that the piston is at its closest position to the crankshaft, the intake valve closes. This is then the beginning of the compression stroke, during which the piston returns to TDC. The fuel-air mixture is compressed during this stroke to raise its temperature closer to its ignition point. When the piston reaches TDC for the second time, the power stroke is initiated. The piston then begins its return to BDC, when just passed TDC, a spark is generated from the spark plug. Spark is generated by a permanent magnet on the flywheel that rotates past a pickup coil. The spark then causes the mixture to combust, causing it to vaporize. The burning of the gas results in an increase of temperature, which causes the gas to expand. The expansion increases the pressure in the combustion chamber, which forces the piston back toward the crankshaft. When the piston reaches BDC for the second time it begins the exhaust stroke. The piston is then driven back towards TDC due to the rotational momentum of the crankshaft. As the piston returns to TDC the exhaust valve opens allowing the remaining gases to be forced out of the chamber. As the piston reaches TDC, the exhaust valve closes and the cycle repeats itself.

Product Testing and Analysis

Based on the nature of our product and the fact it has quite a few moving parts, fairly precise models would need to be made in order to evaluate the product. In terms of various models that would need to be analyzed, analytical ones would be the most important and beneficial but graphical models would also be useful. These graphical models can be in the form of CAD drawings, or 3D modeling such as Solid Works. While these models are helpful the most important are the analytical models such as fatigue, power transmission, thermodynamic, stress/strain as well as others. With our product being an engine many of these models need to be performed and analyzed before the engine is manufactured on a large scale.

Fatigue models would need to be performed on various parts of the engine such as the cylinder walls, pistons, piston rings as well as the engine block itself. These are necessary because if some of these parts fail the whole engine could fail. For example if any of the rings fail the engine could either lose compression or oil could leak into the combustion chamber and cause the engine to burn oil. Also, power transmission models would need to be analyzed to look at how power is transferred from combustion to the pistons, then to the crank shaft then to the blades. Along with the power transformations, possible power losses would need to be tested. Thermodynamic/heat transfer models would also have to be tested and analyzed because our engine being internal combustion it creates a lot of heat. The engine block itself has “fins” on it in an attempt to dissipate heat. For engineers to know whether these fins properly dissipate heat or dissipate enough of it these models need to be looked at. Fluid flow models, while not as important as the others would also need to be analyzed. The only model that would need to be looked at would be the transfer of fuel from the tank to the carburetor. A rubber hose connects these two components and would need to be tested to ensure proper flow as well as is there were possible restrictions such as a kink.

Lastly and possibly the most important model that would need to be tested would be the materials stress/strain model. There are various different components in our engine that are made of different materials. Each of these components has a different use and some need to be able to handle certain stresses and strains. For example, our engine block is made of cast iron. This is so because with the engine block being internal combustion the block needs to be able to handle higher stresses and strains. This piece as well as other various components needs to be tested numerous times and for long period of times in order to ensure that they do not fail under repeated use. All of these models need to be fairly precise and when combined would provide a larger detailed model of how the whole engine may perform under hard repeated use.

Process Comparison

The assembly of this engine was nearly the reverse of the disassembly and went much more smoothly.Using our disassembly directions it was much easier to find the proper socket sizes to apply to each fastener. The only notable difference was during the assembly of the valve springs. While removing the valve clips was very simple inserting them was much more difficult. The valve clips attach the valve springs to the valves. Reinserting them requires either a valve spring compressor tool or two sets of hands.

Besides the difficulty with the valve springs the assembly was much easier than the reassembly. At times the disassembly required the use of brute force and in some situations multiple hammers to remove components that had become firmly attached over the last 2 - 3 decades. Since these natural adhesives had been overcome and cleaned away the assembly went smoothly and was completed in 2.5 hours.

Design Changes and Recommendations

This motor is very heavy and would be exhausting to push around. One of the biggest things that could be done to improve this engine is to decrease the over all weight and the over all package size. Most of the materials could be lightened by using aluminum or some other alloy and still have the strength needed. Parts such as the gas tank could be redesigned to compact the entire package, other parts can be completely removed. The intake tube between the carburetor and the engine block can be taken out and the carburetor can be bolted directly to the block. This would reduce cost of manufacturing. Almost all of the rotating components could be reduced in weight this would allow the motor to reach operating speed faster, rev higher, and increase power by decreasing the rotating mass. The piston head and cylinder can be increased in diameter to increase displacement and increasing power. A switch to a fuel injection system would help improve fuel economy because the amount of fuel and the timing of fuel can be controlled. The muffler could be improved to have more baffels in it to make the engine quieter and more comfortable for the user. Air flow could be improved by porting the heads and using bigger valves, this would increase the power of the motor by making it easier for it to get the air and fuel in and out.

References

Four Stroke Engine. Retrieved November 3, 2008, from http://en.wikipedia.org/wiki/Otto_cycle#The_Otto_cycle.

Injection Molding. Retrieved november 13, 2008, from http://en.wikipedia.org/wiki/Injection_molding.

Casting. Retrieved November 12, 2008, http://en.wikipedia.org/wiki/Casting

US Patent Database Search. Retrieved November 14-25 http://patft.uspto.gov/