DOCUMENT RESUME

ED 099 544 CE 002 630

AUTHOR Jacobs, Clinton O.TITLE Effectiveness of Prepared Instruction Units in

Teaching the Principles of Internal Combustion EngineOperation and Maintenance. Technical Bulletin No.192.

INSTITUTION Arizona Univ., Tucson. Dept. of AgriculturalEducation.

REPORT NO Tech-Bull-192PUB DATE Jan 72NOTE 16p.; Photographs are not reproducible

EDRS PRICEDESCRIPTORS

MF-$0.75 HC-$1.50 PLUS POSTAGE*Course Evaluation; *Engines; Evaluation Methods;*Program Effectiveness; Unit Plan

ABSTRACTThe report is an evaluation of the effectiveness of

the 12 instructional units developed around the use of theBriggs-Stratton Model 80302, 3HP, 8 cu. in. displacement enginehaving a fuel induction system similar in construction to farmtractor types. The evaluation procedure used was the "one-groupPre-test and Post-test" research method. The evaluation instrumentused in the testing program consisted of 45 selected multiple choicequestions drawn from the original 60 questions used in the pilottesting program. In general, there was an overall improvement frompretest to posttest in a student's performance indicating thatinstructional material was effective. Lists of student referenceliterature, basic tool sets, secondary tool sets, special laboratoryequipment, the evaluation instrument, and a nine-item bibliographyconclude the document. (Author/BP)

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Effectiveness of Prepared Instructional Units

In Teaching the Principles of

Internal Combustion Engine

Operation and Maintenance

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Agricultural Experiment Station

The University of Arizona

Tucson

Technical Bulletin 192

Effectiveness of Prepared Instruction Units

In Teaching The Principles of Internal Combustion

Engine Operation and Maintenance

A RESEARCH PROJECT

Of THE

DEPARTMENT Of AGRICULTURAL EDUCATION

CLINTON 0. JACOBS

Project Leader

AGRICULTURAL EXPERIMENT STATION

UNIVERSITY OF ARIZONA

TUCSON, ARIZONA

TECHNICAL BULLETIN 192

21/2M JANUARY 1912

3

Introduction

The economic magnitude whichthe internal combustion enginecontributes to the production ofagricultural products and servicesin the United States is tremendous.Likewise, the emphasis by depart-ments of agriculture in vocational,secondary and technical schools inoffering pre-employment trainingin Agricultural Power probablyexceeds any other instructionalarea in agricultural mechanization.

During the past ten years, thesmall single-cylinder, air-cooledengine has been universally ac-cepted by departments of agricul-ture in vocational schools to pro-vide students a "hands-on" oppor-tunity to learn basic principles ofinternal combustion engine °peva-tion, care and maintenance.

The reasons for this acceptanceare (1) manufacturers of small en-gines have provided new enginesto schools at an attractive price,hence the cost per student is com-paratively low in contrast to mak-ing available "hands-on" experi-ences by other methods; (2) thegrowth of the small engine manu-facturing and utilization industry(an estimated 9.4 million units ofless than 15 hp were produced in1970)' has provided occupationalopportunities for graduates insales, service and repair busines-ses; (3) the subject matter associ-ated with small engine instructionis considered to possess elementswhich are common and transfer-able to most types of present dayinternal combustion engines.

Purpose of the StudyIn the past five years, numerous

instructional units treating thesubject of internal combustion en-gines have been developed by vo-cational agricultural educators invarious states, some of which havebeen published for distribution.

Because teachers of vocationalagriculture in Arizona ranked inservice training in small gasolineengines as a much needed area, astaff study was initiated to (1) de-velop an instructional resourceunit in the internal combustion en-gines for Arizona using the small

single-cylinder, air-cooled engineas a teaching model and (2) to eval-uate the effectiveness of the unitsby conducting a testing service forcooperating teachers.

A review of literature revealedonly one other study which hadbeen conducted to determine theeffectiveness of instructional unitsin small internal combustion en-gines. 2

In the study, the following hypo-theses were tested:

1. There was no change in theresponse of students basedupon pre-test and post-testscores after having receivedinstruction using the resourceunit.

2. Whether teachers }lore hadin-service training in the useof the equipment and re-source unit had no effect up-on the performance of stu-dents involved in the testingprogram.

3. The time of the school yearwhen the instruction was con-ducted had no effect upon thechange in student responsebased upon test score infor-mation.

Development ofResource Unit

Instructional units published bydepartments of agricultural educa-tion of Pennsylvania3 and Miss-ouri4 were utilized to determinecontent and equipment whichmight be desirable for a resourceunit. In addition, manufacturer'sliterature was reviewed to deter-mine equipment and materialsneeded. Also, student referenceliterature was chosen based uponavailability, depth of subject mat-ter, and cost.

The resource unit content wasdeveloped around the use of theBriggs-Stratton Model 80302, 3 HP,8 cu. in. displacement engine hav-:Lig a fuel induction system similarin constructions' to farm tractortypes (Figure 1).

One new engine was recom-mended for each two students.

Twelve units of instruction wereidentified as necessary to meet theobjective of providing sufficient

subject matter to teach the princi-ples of internal combustion engineoperation, care and maintenanceand subsequently provide valuable

Figure 1 Itecommended Engine Briggs-:Stratton Model 80302

facts related to tractor engine op-erating principles. The units devel-oped were as folloWs:

I. Principles of InternalCombustion Engines

II. Identification andFunction a EngineParts

III. Definition of TermsIV. Valve and Ignition

TimingV. Fuel Induction

CarburetionVI. Magneto Ignition

VII. Spark PlugsVIII. Taking Accurate

MeasurementsIX. Using the Torque

WrenchX. Maintenance and

Repair TechniquesXI. Governors

XII. Daily Service andOperation

From the above units, a teacher'smanual was developed which pro-vided unit outlines, teaching tech-niques and answers to questions.*A student's manual also was pro-vided which identified referencepage numbers specific to the listedquestions for student study. Refer-ence literature and student's textswhich were recommended are il-lustrated in Appendix I.

It was suggested that teachersprovide the recommended refer-

1. George H. Seferovich. Power Outdoor Equipment: More and More Market: Lawn/Garden/Outdoor Living, June 1970, p. 12, 13, 32, 33.2. Lewis C. Ayers. "The Development and Evaluation of a Unit of Instruction on Small Gasoline Engines". Thesis, M.E. 1967, The

Pennsylvania State University University Park, Pennsylvania.3. Lewis C. Ayers, H. J. Hoerner and L. P. Grant, Smell Gasoline Engine, Student Handbook, Teacher Education Series Vol. 10

No. 4(3). 1969, The Pennsylvania State University. University Park. Pennsylvania, 76 pages.4. Curtis R. Weston, L. Bays, G. Shinn. and R. Lindhart, Internal Combustion Engine, Department of Agricultural Education, Uni-

versity of Missouri, Columbia, February, 1967. 107 pages.'For information on how to obtain a complete copy of the teacher's resource unit, contact the Agricultural Education Department.

University of Arizona, Tucson, Arizona 85721.

Page 1

8

ences in sufficient numbers to sup-ply one copy for each student inthe largest class.

One engine was considered to bea work station. A recommendedlist of basic tools for each enginewas developed in cooperation withSnap-On Tool Corporation andBriggs-Stratton Company repre-sentatives (see Appendix II). Asecondary list of tools, one set foreach three engines, also was re-commended (see Appendix III).

Suggested special laboratoryequipment for instructor use,which included timing disc, gra-duated cylinder, torque wrenchadapter, and other special equip-ment, is illustrated in AppendixIV.

A method to control loss of partsand tools as students progressedthrough the program of engine dis-assembly and reassembly was con-sidered essential. Thus, a storagebox was developed as illustrated inFigure 2 to serve as a work stationand a method of permitting stu-dents assigned to the station to re-tain control of hardware by beingable to lock the box after eachclass activity.

In-Service TeacherTraining and Pilot

TestingAn intensive two-day workshop

for 18 teachers of vocational agri-culture was conducted by the auth-or during the 1968 Christmasschool vacation period using theresource units and recommendedequipment.

The Briggs-Stratton Corporationand Snap-On Tools Corporationprovided representatives to assistwith the practical instruction anddonated use of tools and equip-

Figure 2. Suggested Work Station andStorage

ment. All twelve instructional un-its were taught during the trainingsessions. One engine of the recom-mended model was provided foreach two teachers.

Besides performing the recom-mended steps of procedure to dis-assemble, study the working parts,take measurements, reassemble,and operate the engine, the teach-ers were instructed in operatingprinciples and teaching techniques.

Six teachers from this groupagreed to pilot test the resourceunits for purposes of evaluatingthe response of students to the sub-ject matter during the 1969 springterm. The pilot testing includedthe administration of a written ex-amination of 60 selected multiple-choice questions on a pre-test topost-test basis to a total of 86students.

In addition, teachers were askedto submit recommendations to im-prove the resource units. As a re-sult, minor changes and correctionswere made in both the teacher'sand student's manuals.

Method of ProcedureDuring the summer of 1969, the

revised resource unit in InternalCombustion Engines, includingteacher's and student's manuals,were published and disseminatedto all teachers of vocational agri-culture in the State of Arizona.

Prior to the start of the fallsemester, 1969, fourteen teachersrepresenting 218 students indicateda willingness to cooperate in a test-ing program.

Design of the study was basedupon the "one-group Pre-test toPost-test" research method.5 Inthis process, the dependent varia-ble was measured before the inde-pendent variable was applied, afterwhich the amount of change wascomputed.

The evaluative instrument used

in the testing program (see Ap-pendix V) consisted of 45 selectedmultiple choice questions drawnfrom the original 60 questions usedin the pilot testing program. Thereduction in number of questionsfrom 60 to 45 was based upon theteachers' recomendations that thetest was too long and that severalof the questions did not sufficientlytest subject matter drawn from theresource unit.

Test questions and pages werenot numbered and the order ofcollating the five sheets was var-ied, thus providing a more equalopportunity for retaining the dis-criminatory p o w e r of eachquestion.

From the fourteen cooperatingschools, 218 usable students re-sponses to the test were receivedand manually scored. For purposesof evaluating the strengths andweaknesses in the twelve units ofinstruction, the responses to indi-vidual questions were entered onIBM punch cards according tothree subject matter areas. Thesewere (1) Principles of Engine Op-eration, (2) Fuel Induction andIgnition and (3) Engine Repair.

Profile information on each stu-dent regarding age, intelligencequotient number, number of yearsfarming experience and the num-ber of years enrolled in vocationalagriculture courses was collectedfor the purpose of determiningwhether these data would providecorrelative relationships to testresponses. Also the number ofyears of experience in teaching vo-cational agriculture was identifiedfor each of the fourteen teachers.

Analysis of DataThe primary objective of this

study was to determine the amountof change in understanding whichstudents exhibited for the princi-ples of internal combustion en-gines as a result of having been in-

5. Debold E. Van Dalen and M. J. Meyer. Understanding Educational Research, MeGraw-Hill, Inc.. 1966. pp. 230-232.

Page 2

volved in instruction using thesmall engine as a teaching modeland the resource unit as an instruc-tional guide.

The principle concern was to de-termine whether there was a sig-nificant change in understandingfrom pre- to post-test results andwhether the observed differenceswere of such a magnitude that thechange could not be attributed tochance factors or sampling varia-tions.

Test Instrument Evaluation

The importance of the data re-ported in this study which con-cerned the effect of a prepared re-source unit on instruction in theint-,,inal combustion engines forh'g'i school students is directlyri ated to the performance of thein:. rument used to collect the data.A; previously reported, the instru-

ot consisted o f 45 multiple-noice items in a written examina-tion which was administered as apre- and post-test.

The test items used were screen-ed from 60 items used in the pilottesting program.

From the data gathered in thisstudy, it was possible to obtainseveral descriptive performancecriteria relative to the test instru-ment. As illustrated in Table 1, thetest was calculated to have a re-liablity coefficient of .86. Reliabili-ty refers to the internal consist-ency of test scores within onemeasurement.

Using t h e Kuder-Richardson,Formula 20 method, a reliabilitycoefficient was calculated in orderto obtain a stability indicator ofthe test performance.'

A high degree of confidence inreliability is indicated by a largenumerical coefficient. Coefficientsin the .80's - .90's are commonlyreported for standardized tests ofaptitude and achievement admin-istered within a fixed time period.

Because the testing programused in this evaluation involved atime spread of 6 to 8 weeks, it isbelieved that the test instrumentused had an acceptable degree ofreliability based upon a coefficientcalculated to be .86.

A measure of difficulty also isan indication of the reliability of atest. A test should be neither tooeasy nor too difficult to avoidlow reliability of scores. A com-posite test score which approaches

TABLE 1

SELECTED FACTORS FOR DETERMINING THE EFFECTIVENESSOF A 45 ITEM EVALUATION INSTRUMENT'

EVALUATIVE FACTORReliability (Correlation coefficient)Difficulty (Average Score)Discriminatory Power CoefficientMeanStandard Deviation

1 Post-test data analysis used

NUMERICAL DATA.8656%

.119 to .72925.25 items

7.6

TABLE 2

DISCRIMINATORY POWER COEFFICIENT CHARACTERISTIC OF THE45 ITEM TEST INSTRUMENT IN INTERNAL COMBUSTION ENGINES

COEFFICIENT RANGE BYCATEGORIES

NUMBER OFTEST ITEMS

PER CENTITEMS

.0 .20 3 6.5

.21 .50 29 64.5

.51 .80 13 29.0.81 1.00 0 0.0

Total 45 100.0

TABLE 3

COMPARATIVE DIFFEREN:.:E BETWEEN MEAN CORRECT RESPONSESON PRE-TEST AND POST-TEST BY AREAS OF SUBJECT MATTER

AND COMBINED SCORES (N = 218)

SUBJECT MATTER NO. MEAN CORRECT TESTAREAS OF TEST QUESTIONS SCORE RESULTS

Pre-test Post-test DifferencePrinciples, Internal

Combustion Engine 20 09.138 11.830 02.692 7.851Fuel Induction and

Ignition 16 05.628 08.638 03.010 11.193Engine Repair 9 03.358 04.780 01.422 8.157Overall Scores

Combined Areas 45 18.124 25.248 07.124 10.612

t* 1.960 at .05 level2.592 at .01 level3.291 at .001 level

df == 434

the 50 per cent mark is an indicatorof a desirable level of difficulty.The value calculated for this in-strument was 56 per cent.

A third measure used to evaluatethe effectiveness of the test instru-ment was to determine the degreeto which each test item was capableof discriminating between pupilsof high and low achievement. Thediscriminating power of each testitem obtained for this study indi-cated coefficents ranging from .119to .729. Table 2 shows the coeffici-ents by number of test items whenarranged according to four meffic-ient range categories.

From this data it can be seenthat three of the test items weredetermined to have discriminatorypower of .20 coefficent or less.Twenty-nine items or 64.5 per centho i discriminatory power of .21 -.50, while thirteen items (29 percent) had a coefficient range of .51-

.80. There were no items havingvery high, (.80-1.00) discriminatorypower.

Generally, the range of .21 - .50coefficient is considered to indicateaverage acceptability while a .51 -.80 range is ranked very good tooutstanding in discriminating pow-er. From this data, it is believedthat the evaluative instrumentgenerally had the ability to satis-factorily discriminate between theperformance of low and highachievers since 93.5 per cent of theitems ranked in the average to out-standing coefficent rating.

The three test items that werefound to be low in coefficient werereviewed to determine whetherthere was a possibility that theitems were poorly worded, failedto be answered by instructionalinformation in the resource unit,or were mechanically poor. It wasconcluded that the items were not

t. Norman E. Gronlund, Measurement and Evaluation In Teaching, MacMillan Co., New York, pp. 133.

Page 3 6

TABLE 4

ANALYSIS OF VARIANCE OF MEAN DIFFERENCE IN PRE-TESTAND POST-TEST PERFORMANCE OF STUDENTS PASED UPON

IN-SERVICE TRAINING STATUS OF TEAC. IERS(N = 2181

SUBJECT MirTER MEAN DIFFERENCE - PRE-TES r to POST TESTAREAS OF TEST

Principles ofInternal CombustionEngine Operation

Fuel Induction andIgnition 2.291

Students ofTeachersReceiving noTraining

N 79

Students ofTeachersReceivingTraining

N 139

2.220 2.957

Engine RepairOverall Scores

Combined Areas

3.4170.506 1.942

5.025 8.317

F'' 2.74 @ .1 level3.89 @ .05 level

--: 6.76 @ .01 leveldf = 1 and 216

MeanScore

Difference

F*

.729 2.84

1.126 7.431.436 24.84

3.292 14.59

TABLE 5

ANALYSIS OF VARIANCE BY QUARTERS OF SCHOOL YEARIN WHICH SUBJECT MATTER WAS TAUGHT

(N = 218)MEAN DIFFERENCE, PER CENT OFQUESTIONS ANSWERED CORRECTLY:PRE-TEST TO POST-TEST

SUBJECT MATTERAREAS OF TEST

SCHOOL YEAR QUARTERS

FirstN 8

SecondN -,- 22

Third FourthN 117 N = 71

F*

Principles ofInternal CombustionEngine Operation 24.40 5.95 14.60 11.65 2.40

Fuel Induction andIgnition 22.65 18.50 21.40 14.18 2:49

Engine Repair 26.30 12.20 21.58 6.28 7.29

Overall ScoresCombined Areas 24 20 13.42 18.40 11.40 5.15

F* = 2.65 Q .05 level3.88 @ .01 level

df 3 and 214

inferior in .:uality and substanceand should be retained for futuretesting programs.

When the reliability value of .86.the degree of difficulty of 56 percent, and the discriminating pow-er data were interrelated for com-parison, the 45-item test was foundto possess characteristics descrip-tive of a desirable evaluative in-strument for determining the ef-fectiveness of the instructionalresource unit concerning the in-ternal combustion engine.

Change in Understanding

ResultsWhen the data for this study

were compared on overall testscore mean difference in response.there was determined to be an in-crease of 39.3 per cent in under-

standing by the 218 students whowere involved in the internal com-bustion engine instructional unit.

A comparison of the mean num-ber of correct responses betweenpre-test and post-test by areas ofsubject matter is shown in Table3. Also included is the computedFisher's test values of observeddifference in mean test score be-tween subject matter areas andcombined scores. In all three sub-ject matter areas and combinedscores, there was sufficient evi-dence to refute the hypothesis ofno sufficient difference at the.001 level of 3.291 at 434 degreesof freedom.

Effect of In-Service TrainingIt was anticipated that one of

the factors which n contrib-ute to a difference in N. formance

Page 4 7

of students on the post-test wouldbe whether the teacher had re-ceived in-service training on howto utilize the resource unit prior tohis being involved in the testingprogram. As shown in Table 4,there was sufficient evidence at the.01 level of significance to rejectthe hypothesis that there was nodifference in performance of 79students whose teachers had notreceived training, compared to 139students whose teachers had re-ceived training when compared tooverall scores of all subject mat-ter areas.

The computed mean score dif-ference of 3.292 represents a 65'4greater increase in student under-standing when the teacher had re-ceived inservice training.

Contributing to the highly sig-nificant results on overall testscores for trained teachers werethe subject matter areas of FuelInduction and Ignition and EngineRepairs with F values of 7.43 and24.84, respectively.

The area of Principles of In-ternal Combustion Engine Opera-tion showed a mean difference of7.29 in score increase for thetrained teacher, which was signifi-cant at the .1 level.

Based upon the performance ofstudents' response to test ques-tions, the data indicates that thegreatest effect of inservice trainingwas obtained in the areas of FuelInduction and Ignition and EngineRepair.

Apparently, all teachers weregenerally more informed in prin-ciples of engine operation, com-pared to their knowledge in theother subject' matter areas basedupon student performance.

Effect of Time in School Year

A second variable which wastested for its effect as a factorwhich might contribute to studentperformance was the time in theschool year when the instructionalunits were taught. As shown inTable 5, there was a significantdifference in the F value at the.01 level to indicate that time inthe school year had an influenceon the mean difference in correctscores a student would attain, es-pecially in the Engine Repair Areaand overall results.

The reasons for this differencemay be due to (1) the variation inthe number of (N) students in-volved by quarters and (2) thetendency to run out of time duringthe second and fourth quarters ofa school year. when the conse-

TABLE 6

CORRELATION COEFFICIENCIES FOR SIX VARIABLESWITH OVERALL SCORES ON PRE-TEST AND POST-TEST

(N = 82)

VARIABLEPRE-TESTSCORES

(r)

POST-TESTSCORES

(r)Student's Age .1001 .0312Student's I.Q. .4266 .5019Student's Farm Experience, .1411 .0284

No. YearsStudent's Vocational Agriculture .2202 .2822

Experience, No. YearsExperienced Teacher .0015 .1824Teacher Received In-Service .03578 .1767

Training

quence that students may havebeen rushed through the instruc-tional information without com-plete understanding. The lattermay attribute to the generallylower mean difference in per centof questions answered correctly,(see Table 5) in the second andfourth quarters.

Correlation Factor Relations

Product-moment correlation co-efficient (r) relationship were com-puted for six variables and areshown in Table 6. The variablestested for relationship to perform-ance on pre- and post-test scoreswere (1) age of student, (2) I.Q. ofstudent, (3) number of years whichthe student had farm experience,(4) number of years vocational ag-riculture schooling, (5) whether theteacher was experienced, and (6)whether the teacher had receivedinservice training.

The evaluation was made using82 observations because sufficientdata was not available to use theremaining 136.

All correlation coefficient rela-tionships (r) were found to be verylow with the exception of "studentI.Q." which indicated low to mod-erate relation in both pre- andpost-test performance.

The relationship between I.Q.and verbal performance is associ-ated closely with what is expectedsince r's usually run .40 - .60 inthese areas. It also is believedthat the positive r relationshipswhich were computed for all sixfactors have significance even ifthe numerical value is low. Thetendency for r to have a highvalue in post-test scores in thevariables of students having had"more experience in Vocat;onalAgriculture", a more "experiencedteacher", and "teachers having re-

ceived inservice training", followswhat generally could be expected.

Summary andConclusions

It was generally observed thatteachers and students have enthu-siastically received t h e smallsingle-cylinder, four-cycle, air-cooled gasoline engine as a modelfor teaching the operation, care,and maintenance of internal com-bustion engines.

The change of 39.3 per cent in-crease in understanding from pre-to post-test scores on a writtenexamination of 45 multiple-choicequestions was considered to be anencouraging insight related to theperformance of the resource unit

When the mean difference innumber of correct responses be-tween pre- and post-test scores wascompared, the computed t valueindicated that the difference inscore was significant at the .001level. When compared by area ofsubject matter, namely Principlesof Internal Combustion Engines.Fuel Induction and Ignition andEngine Repair, each area was de-termined to have a significant dif-ference in mean correct responsesfrom pre- to post-test when evalu-ated by t at the .001 level.

Whether the students of teacherswho had received inservice train-ing in the use of small engineequipment and resource units hadmore correct responses in meanpre- to post-test score differencewas determined to be not signifi-cantly different when F was com-pared at the .05 level.

There were indications that stu-dents of trained teachers did betterin the units of instruction relatedto principles of internal combus-

tion engines when F was comparedat the .1 level of significance.

Time of the year in which theunits were taught had a significanteffect upon the overall test scoreperformance when F was com-pared at the .01 level. Generally,students had a greater per cent ofmean correct responses in the firstand third quarter of the schoolyear than in the second and fourthquarters.

Very low but positive product-moment correlation (r) relation-ship existed between six factorscompared upon. pre- and post-testscores. The greatest change be-tween pre- and post-test relation-ships (although low) were for thefollowing variables: (1) Teacherhad received inservice training, (2)Teacher was experienced, and (3,Student had previous experience inVocational Agriculture.

Intelligence quotient of the stu-dent had low to moderate relationship to performance.

The evaluation instrument usedin this study had high level ofreliability and discriminatory pow-er when used as an insaument tomeasure performance of studentswhen taught principles of internalcombustion engine operation andmaintenance using the preparedresource unit.

RecommendationsThe high motivational factor

which instruction in the subject ofinternal combustion engines modelapparently possesses for both stu-dents and teachers using the smallengine as an instructional modelshould be exploited and perfectedto the greatest possible degree ofrefinement. Continued research innew methods and techniquesshould be explored continually todetermine the effectiveness of thevarious processes.

Use of the "One-Group Pre-testPost-test" technique as a re-searc'' tool to determine the effec-tiveness of the instructional pro-cess to measure change inunderstanding is recommended forteachers as a self-evaluationtechnique.

Additional studies should beconducted to design instructionalmaterial in small engines whichwill determine how effectivelystudents are able to transfer know-ledge of subject matter in the smallengines to farm tractor engineoperation, care, and maintenance.

a. Henry E. Garrett.Statistics In Psychology and Education, Longm.s, Green and Company. New York, 5th Edition. 1058, pp.175-177.

Page 5 8

S

Appendix IStudent Reference Literature

00 (4'

ASOVI

0%* NOINSOMIN ULLSTIN WO IT .

READ

USECARE-

. Ose

.7.-As. 7

M.o.PRIMING .40 MAINIIMAPKI

MOOIIIMSIInx

th,OC pots?00 6111./

8D,On to BO Qia" to 11197

CON

IIESI CAM AVA11,161,1

FARM TRACTORSB ANC

OPIINATION. MKS r

+4 .'"'".6 e 41:ix?fiff'.:1 , . tO:". 61

- - 4,r4

-*".°: it' 11; .t *.'".-fiy'at

'210kittS1 -

A

Literature

asersumoca

Farm Tractors, Engineering Bulletin FT53-A.National 4-1-1 Supply Service, 1968.

Repair Instructions III, MS 4750-48. Briggs-Stratton Corporation.Ge..neral Theories of Operation, MS-3553-24

Briggs-Stratton Corporation.Illustrated Parts List, MS-4255-108. Briggs-

Stratton Corporation.Operating & Maintenance Instructions, Form No. 27842-108,

Briggs-Stratton Corporation.,rque Manual, P. A. Sturtevant Co,

vlow to Read, Use, and Care for Micrometers, L.S.Starrett Co.

No cost in quantities for largest class.

Page 7

Cost per Copy$1.00

*

*

$1.00

Appendix IIBasic Tool Set BS118

(One set recommended per engine)

S

lip

II

ItemNo. CostTool Size1 Hammer, plastic tip 1/2 lb. $5.262 Screw driver, Phillips No. 2 x 4 1.322 Screw driver, standard tip 1/4 x 4 1.89

2 Screw driver, cabinet 3/16 x 3 1.47

3 Pliers, needle nose 6 inch 4.21

4 Pliers, pump 6 inch 3.01

5 Gauge, feeler .0015-.025, 25 leaf 2.63

6 Gauge, spark plug 1.37

7 Ratchet '4H" drive 6.53

8 Extension 3" x 34{" drive 1.92

9 Socket 7/16" x 3,;i" drive 1.05

9 Socket 1/2" x :!ii" drive 1.05

9 Socket x :!i4" drive 1.47

9 Socket 3'4" x :!W' drive 2.06

10 Hex Nut Driver 1/4" 1.9-

11 Wrench 5/16" :V 1.83

11 Wrench 38" - 7/16" 1.96

11 Wrench 7/16- 2.06

12 Punch, starting 1.68

13 Spark tester 1.65

14 Plug gauge, breaker point plunger .45

14 Plug gauge, valve guide 2.15

15 Valve spring ,:ompressor 2.25

16 Puller, flywh.2e1 .50

17 Compressor, diston ring .95

18 Clutch wrench 1.85

19 Holder, flywheel 3.35

20 Piston ring expander 2.80

21 Piston land wear gauge ,50

Total Basic Tool Kit. each $43.88

Page 8 1.0

Appendix IllSecondary Tool Set BS108

(One set recommended for each three engines)

1.0.4171111111101:*

I

g -

1

AMC AP-

Bey 1011AMX

ItemNo.1

234567

89

10

ToolDial Indicator SetMicrometer, outsideMicrometer, outsideAllen Wrench SetWrench, Torque meterCylinder Compression GaugeTelescoping GaugeTelescoping GaugeSmall Hole Gaurr,eTachometer, dial type, direct

reading Stewart-Warner Model 757-W

Size

0-12-3

0-600 in. lb.0-300 lbs.2 1 /8 " - 31/2-

3/4" - 11/4'..200-.300

Total Secondary Tool Kit

Cost$15.39

16.4021.153.71

49.1120.53

6.354.704.00

12.70

$154.04

Page 9

1.1

ItemNo.

1

2

3

4

5

6

7

A

No.Each

1 ea.

1 ea.

1 ea.

2 ea.

1 ea.

1 ea.

1 ea.

Appendix IV

Special Laboratory Equipment(For Instructor)

Item

Sleeve, oil seal installation, shopconstructed

Test Spark Plug, 3/16" gap (substitutefor BS 19051 spark tester), shopconstructed

Battery Dry Cell, 6 volt LanternTest Leads with Alligator Clips, shop

constructed

Timing Leads, Circle (360°) Protractor,Post No. 1532A-6

Torque Wrench Adapter, 4 inch, ShopConstructed

Graduated Cylinder, 50 nil plastic base

Page 10

Cost

.80

.50

1.25

2.00

TOTAL COST $4.55

Appendix VEvaluation Instrument

QUESTION: Which of the follow-ing positions of crankshaft rotationis the exhaust valve of a four-cycleengine starting to open?

a.bcd

a.

b.

C.

d.

QUESTION: How many valveswill normally be in the block of afour-cycle, one cylinder gasolineengine?

a 1

b 2c 3d 4

QUESTION: What is the name ofthe device in spark ignition enginethat mixes gasoline and air in theproper proportions?

abc

d

chokecylindercarburetorgovernor

QUESTION: Size of an internalcombustion engine is usually ex-pressed in

a weight in poundsb compression

pressurec piston displacementd torque output

QUESTION: The magneto systemof most gasoline engines generatesan electric spark by

a the incorporationof a small battery

b the rapid opening& closing of points

c a condenser of theproper capacity

d magnets movingpast the armaturepoles

QUESTION: Which of the follow-ing describes the secondary wind-ing of an ignition coil?

a.

b

_c.

d.

many turnsvy wirea few turnsvy wirea few turnswiremany turnswire

of hea-

of hea-

of fine

of fine

QUESTION: A governor acting onthe principal of centrifugal forceis known as the

a_b.

d

vacuum typeventuri typemechanical typepiston type

QUESTION: Which of theis not a part of the ignition coil?

a.bc.d

corecondenserprimary windingsecondary winding

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J.1...11

QUESTION: The "compression ra-tio" in a given size of engino iscontrolled by the design of the en-gine. This could be altered bywhich one of the following?

a advance the sparkand clean carbonfrom the valves

b increase the intakevalve in length anddiameter

c. install a super-charger and use arich fuel mixture

_d change the volumeof the combustionchamber by usinga thicker cylinderhead gasket.

QUESTION: The micrometer pic-tured below is set to read:

a 2.381b 2.376c 2.316d. 3.351

QUESTION: Which would be areason for honing a cylinder tooversize?

a vertical scoreb flat

.001" taper.d. .001" out-of-round

QUESTION: Which of the follow-ing is equal to a torque wrenchreading of 60 foot-pounds?

a 720 inch-poundsb 180 yard-poundsc 60 millimeters-

gramd 210 meter-grams

QUESTION: Which one of the fol-lowing spark plug appearancesmost clearly indicates the possibil-ity of too "rich" a fuel mixture?

a dry or damp blacksoot on insulatoror shell

b. burned and badlyeroded electrode

c light tan or browninsulator

d black, wet depositson insulator andshell

QUESTION: Which of these aircleaners can be cleaned with soapand water?

a metallic meshb dry-type paperc oil bathd polyurethene

QUESTION: Which type of gaugeshould ordinarily be used tc mea-sure magneto air gap?

a inside calipersb. outside caliperse flat thicknessd round wire

QUESTION: One of the reasonsfor adjusting valve clearance of anengine is to

a

b

d

make valves openfurtherkeep valves coolerplace valves in timeincrease compres-sion

QUESTION: When a condensor ischecked for capacity, the unit ofmeasure is

a.bc.d

ohmsvoltsresistancefarads

QUESTION: A condenser is mostactively functioning

a when the breakerpoints open

b when the breakerpoints close

c after the spark plugfires

d when the primarycoil stops function-ing

QUESTION: The combustion pres-sure of a gasoline engine cylinderis greatest when the piston is lo-cated

a at bottom dead cen-ter

b several degreespast bottom deadcenter

c at dead centerd a few degrees past

top dead centerQUESTION: Secondary voltagesin a small gasoline engine may beas high as

a 15 voltsb 150 voltsc 1,500 voltsd 10,000 volts

QUESTION: Diesel engines aredistinguished from other types ofinternal-combust:;:n engines bytheir use of

a

b

c

d

the four-stroke cy-cle onlyignition by heat ofcompressionvery low compres-sioil ratioair blast fuel injec-tion

QUESTION: Richness or leannessof mixtures burned in an engine isreferred to as

a.

cd

octane of fuelolatility of fuel

air-fuel ratiovapor being burned

QUESTION: In a two-cycle enginehow many complete revolutionsmust the crankshaft make to com-plete one cycle?

a oneb twoc threed four

QUESTION: What part of the ig-nition system controls the timecurrent flows to the spark plug?

ab.cde

induction coilignition coilbreaker assemblylead wirecore

QUESTION: What is the constrict-ed area of a carburetor that is de-signed to it Tease the velocity ofthe air?

a tunnelb venturic air foild valve

QUESTION: In order to operatesuccessfully every engine musthave at least three primary func-tional systems. These are

__a. magneto, sparkplug and condenser

___b. spark plug, breakerpoints, and com-pressioncompression, fueland magneto

_________d. compression, fueland ignition

QUESTION: Diesel and gasolineengines differ mainly in their

____a. fuel systems andignition methodsfuel systems andcylinder blocks

___c. fuel systems andcylinder assemblies

____d. ignition methodsand cylinder as-semblies

QUESTION: A two-cycle chainsaw engine will be expected tohave the following type carbure-tor

floatinjectiondiaphramrotary

Page 12 14

QUESTION: In comparing two-cy-cle vs. four-cycle engines, which ofthe following is the most accuratestatement?

a a four-cycle andtwo-cycle engine ofthe same horsepow-er will be of ap-proximately equalweight.a two-cycle enginewill start fasterand easier.a two-cycle enginewill normally runsmoother than afour-cycle.

d. a two-cycle engineis simpler in con-struction and de-sign

QUESTION: One cylinder gaso-line engines operate at a compres-sion ratio of about

a 6 to 1b 9 to 1c 12 to 1d 15 io 1

QUESTION: Which of the follow-ing spark plug insulator descrip-tions best indicates a "hot" sparkplug?

a longb thin

_______c thickd short

QUESTION: As breaker pointswear, timing of a spark ignitionengine will be:

a advancedb retarded

_________c. no change in timing.d. wear only effects

RPMQUESTION: If a piston displaced6 volumes in the cylinder, the com-pression ratio of the engine is

a 5:1b. 6:1c. 7:1d 8:1

QUESTION: When fastening thecylinder head of a small engine tothe block, which of the followingprocedures should be followed?

rotate each of thehead bolts one-quarter turn

b. use a socket wrenchwith a handle 12inches long

c. tighten the boltsevenly followingproper order

_d. tighten down thebolt nearest themuffler port beforetightening the oth-ers

QUESTION: The angle or surfaceof the valve seat should matchwhat part of the valve?

a. faceb headc margind dish

QUESTION: The normal wear onmost cylinders is greatest near the

a valve chamberb top of the cylinderc center of the bored bottom of the bore

QUESTION: What should be donewhen crankshaft end-play is insuf-ficient?

a use a thicker mag-neto plate

b use special bush-ings on the crank-shaft

c use additional endplate gasket

d replace the crank-shaft

QUESTION: The float level in asmall gasoline engine carburetor isset to manual specifications with a

a rulerb feeler gaugec micrometerd depth gauge

QUESTION: A machine whichconverts heat of burning gases intorotating movement is referred toas a:

a prime moverb motorc blast furnaced heat engine

QUESTION: Stroke of the pistonis expressed in: .

a inches of movementin the cylinderdegrees of crank-shaft rotation

c pounds of force ex-erted on flywheel

d torque valve inounces

QUESTION: Which of the follow-ing type engines does not take anair-fuel mixture into the cylinderon the intake stroke.

a external combus-tion

b spark - ignitionc compression - igni-

tiond vacuum - ignition

QUESTION: When the connectingrod is in exact parallel alignmentwith the crankshaft throw, the pis-ton is said to be positioned on:

a dead centerb power strokec bore sightd 360 degree align-

ment

Page 13

QUESTION: The reference to theexact time that ignition sparkoccurs during engine operation isexpressed in:

_a. speed of lightb degrees of crank-

shaft rotationc angle of connecting

rodd seconds between

electric discharges

QUESTION: The relationship ofthe crankshaft gear to the cam-shaft gear is such if the crank gearhas 16 teeth the cam gear willhave:

a 16 teethb 21 teethc. 26 teethd 32 teeth

QUESTION: Which of the follow-ing mechanisms causes the valveof a four-cycle engine to be liftedfrom its seat?

a wedgeb guidec springd cam

Bibliography

Ayers, Lewis C., "The Development and Evaluation of a Unit of Instruction on Small Gasoline Engines," The-sis, M. E. 1967. The Pennsylvania State University, University Park.

Ayers, Lewis C., M. J. Hoerner, and L. P. Grant. Smal! Gasoline Engine, Student Handbook. Teacher Educa-tion Series Vol. 10, No. 4(s), 1969. The Pennsylvania State University, University Park, 76 pages.

Garrett, Henry E. Statistics in Psychology and Education, Longmans, Green and Company, New York. 5thedition, 1958, pp. 175-177.

Gronlund, Norman E., Measurement and Evaluation in Teaching, MacMillan New York, 1968. pp. 83-211.Hoerner, Thomas. Tools, Equipment and Reference Materials for a Gasoline Engine Teaching Unit for Eligh

School Agriculture. The Agricultural Education Department, The Pennsylvania State University,1967, 8 pages.

Hoerner, Thomas and Russell Johnson. "Instructional Materials for a Gasoline Engine Unit." The Agricul-tural Education Magazine, Vol. 39 No. 3, September 1966, pp. 58-59.

Seferovich, George H. Power Outdoor Equipment." More and More Market. Lawn/Garden/Outdoor Living,June 1970, pp. 12, 13, 32, 33.

VanDalen, Debold B. and M. J. Meyer, Understanding Educational Research, McGraw-Hill, Inc., 1966, pp. 230-232.

Weston, Curtis R., Lyndon Bays, Glen Shinn and Richard Lindhardt. Instructional Combustion Engines, De-partment of Agricultural Education, University of Missouri, Columbia, February, 1967. 107 pages_

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