Diesel World – October 2019

(Jacob Rumans) #1
Oilenginesweredividedintothreegeneralcategories:lowcom-
pression,mediumcompressionandhighcompression(laterknown
astheDiesel).In reviewingperiodliterature,wecanfurtherdefine
thataslowcompressionengineshavingcompressionpressuresof
about 70 to 150 psi(approximately5:1to8:1CR).Mediumcom-
pressionengineswerebetween 150 and 250 psi(uptoa 13:1CR,
orso).Nearing 500 psiandoverwasconsideredhighcompres-
sion.Theoldmanualssaytobea “true”diesel,thecompression
pressuremarkwas 500 psi.Asuseof“diesel”becamecommonto
describethehighcompressionoilengine,themediumcompres-
sionenginesbecame“semi-diesels.”Lowcompressionoilengines
technicallyaren’tsemi-dieselsusingthatolddefinition,butover
theyearstheyhavebeenlumpedintothatcategory.

Fairbanks-Morse(F-M)wasalreadyanoldmanufacturingcompany
whentheydesignedandbeganbuildinginternalcombustion
enginesin 1893.Theirgasolineenginesquicklyestablishedanen-
viablereputation,andtheirexistingdistributionsystemanddealer
networkenabledthemtohitthegroundrunningin theenginemar-
ket.By1912,theyalsohadanoilengineoftheirown,andit went
onthemarketin 1913astheTypeY, StyleH (for“Horizontal”).It
wasa variationofa hot-bulb,low-compressionoilenginethatwas
builtthrough1914.

F-Mmovedtowarda truedieselbyupdatingtheirTypeY, StyleH
linein 1915withanimprovedcombustionchambercalleda “hot-
head.”Someenginesalsohadtheinjectormovedfromthesideto
thetopofthecombustionchamber.Thisevolutionretainedsome
aspectsofthehot-bulbsetup,butwithanincreasein compres-
sion(toabout 150 psi),theenginecouldbettersustainignition
viacompression.It wasanearlyvariationofthewhatwenowcall
indirectinjection,withfuelbeinginjectedintoa separatechamber
connectedtoa smallerchamberabovethepiston.Commonlycalled
theY-H,it wasa singlecylinderhorizontalenginethatwaseventu-
allyofferedin a rangeof10,15, 20 and 25 horsepowerwithan
assortmentofboresandstrokes.

Thetrickypartoflowandmediumcompressionoilengineswasstart
up.Theydidn’tgenerateenoughcompressiontoself-ignitetheoil
untilthecombustionchamberwasveryhot.“Firingup”theseearly
enginesrequiredrealfire!Withhot-bulbengines,a kerosenetorch
wasusetoheattheoutsideofthebulbbeforetheenginewasspun
over.Thehot-headhada hollowstudthatprotrudedoutsidethe
combustionchamberandwasheatedviathetorch.Ona moder-
atelytemperateday,gettingenoughheatintotheenginecouldtake
10 minutes.Ona colddayit tookevenlonger.Oncetheenginewas
wellwarmedup,theexternalheatcouldberemoved.Someofthe
surfaceignitionenginesthatremainedonthemarketa longwhile
wereupdatedwithelectricglowplugstoreplacethefire.

TheTypeY enginesexpandedtoa multi-cylinderrangein 1914
withtheTypeY, StyleV (for“Vertical,”commonlycalledtheY-V).
It wasofferedin twoboreandstrokedimensions: 12 x 15inches
and 14 x 17inches. Compressionwasabout 265 psiandthey
useda hot-headdesign.Thesmallerboreengineswereoffered
in one-tothree-cylindersinline,making37.5hppercylinder.The
largerenginewasbuiltwithone-tofour-cylindersinlinemaking 50
horsepowerpercylinderat 257 rpm.Continualimprovementsin
theirnearly 10 yearsofproductionbroughtthosenumbersupa bit.

ThelateY-HandY-Venginesweretruesemi-diesels,butin 1924
F-Mdebutedtheirfirstfulldiesel:theY-VA.It wasalsoofferedin
smallandlargedisplacements,buta sixcylinderwasaddedtothe
largedisplacementline.Thoughsimilarin architecturetotheY-V,
theY-VAhadmanyimprovements—mostnotablya increasein
compressiontoabout 500 psi.Maximumpowerstayedlargelythe
sameastheY-V,butbyincreasingtherpmsupto 75 horsepower
percylinderwasoffered.In 1925,theY-VAwouldmorphintothe
Model32A.Withcontinuingimprovements,theModel 32 wouldbe
offeredintothe1950s—mostlyusedaslargestationaryengines
drivinggeneratorsorpumps.

VINTAGESMOKE 1923 FAIRBANKS-MORSEY-VSEMI-DIESEL

This 1923 Fairbanks-MorseY-Vsemi-dieselenginebelongsto theTri-StateGasEngineandTractorAssociation
andhasbeena partof theirlivinghistorycollectionsince1981.It makes 100 horsepowerat 257rpmandabout2,044
lbs-ftof torqueat thatrpm.Boreandstrokeare 14 by 17 inches.It’snolightweight,tippingthescalesat 26,000pounds
withtheflywheel.It wasoriginallyusedat a brickfactoryin Brownstown,Indiana,andwasin regularuseinto1946.It was
restoredto runningconditionbytheTri-Stategroupin 1982.

Forgivethegasengine!TheY-VstartswithcompressedairandtheTri-Stategangusesa vintageF-MModelZ , 2-hp
enginewitha F-MTypeE direct-driven,single-cylinderaircompressorto supplyairpressure.ManybigFairbanksengines
areseenwithanaccompanyingF-Mcompressorsetup.F-Mdevelopedtheirowncompressorsin 1921,andthisonehas
a 3 x 3.5inchboreandstrokeandcouldgenerateupto 250psi.

SEMI-DIESEL


126 OCTOBER I 2019 • DIESEL WORLD http://www.dieselworldmag.com

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