SCROLLBAC
SCROLL
Iftheductlengthexceeds5feet,increaseductsize30
percent.Usenomorethantwo90degreeradius-type
(notsquare-type)elbowsifitisnecessarytochange
airflowdirection.Whena ductisusedbetweenthe
scrolldischargeandtheoutletvent,itsunobstructed
airflowareamustbeatleastaslargeasthescroll
discharge.Thecross-sectionalareaoftheductmust
beincreasedifairflowisrestrictedbybends,long
runs,
screensortheexhaustpipe.Exhaustpipes
runninginsideVacu-Floductsshouldbecoveredwith
asbestostape.
WARNING\ Thesafetyscreenusedtocoverventsmustbe
••irii™««—I
1/4-inch
meshorlargertopermitsufficientair
flow,andmustbecommensuratewithsafetystandardsfor
hazardousmovingpartstoavoidpersonalcontact.Providea short
canvassectionbetweentheengineairoutletandtheexternalduct
oropening,toabsorbvibration.Ifoperationincoldweatheris
likely,installinga shutterintheairoutletisadvisable.Coldweather
cancauseovercoolingifairflowisnotregulated.
EXHAUST
^ARNJINGJExhaustgasesaretoxic.Provideanadequate
exhaustsystemtoproperlyexpelexhaust
gases.Checkexhaustsystemregularlyforleaks.Ensurethat
exhaustmanifoldsaresecureandnotwarped.Besuretheunitis
wellventilated.
FIGURE2. VACU-FLOSCROLL
POSITIONS
Shoulda vacu-floenginechronicallyoverheat,the
mostlikelysourcesoftheproblemare:
1.
Airinletisobstructedortoosmalltoallowproper
ventilation.
2.
Airdischargeopeningispartiallyblockedby
externalductsorexhaustsystems.
3.Recirculationofheatedairintofreshairinlet.
Thevacu-floinstallationpermitsgreaterfreedomin
choiceoflocatingtheairinletandoutletopenings,
andpermitstheuseofa compartmentonlyslightly
largerthantheengineitself.
60
Theareaoftheairinletmustbeatleast/TWsquare
inches.Ifa filter,grille,orlouversareuseflTtheinlet
openingmustbeincreasedaccordingly.Theair
outletopeningshouldbelocatedasclosetothe
engineaspossible.
Usea lengthofflexibletubingbetweentheengine
exhaustoutletandanyrigidpipingtoabsorbengine
vibration.
Shieldthelineifitpassesthrougha
combustiblewallorpartition.Ifturnsarenecessary,
usesweepingtype(longradius)elbows.Increaseone
pipesize(frommanifoldoutletsize)foreachad-
ditionaltenfeetinlength.Locatetheoutletawayfrom
theairintake.
CARBURETOR
AIRINTAKE
Properengineefficiencydependsupona supplyof
freshairtothecarburetor.Underspecialconditions,
itmaybenecessarytomovetheaircleaneroffthe
engine,usinga longerconnectionhoseasnecessary.
Forextremelydustyordirtyconditions,installa
specialheavydutyaircleaner.
FUEL
SYSTEM
Theengineuseseithera diaphragmorpulsating
diaphragmtypefuelpump.Thefuelpumphasa 1/8-
inchpipethreadedinlet,fittedwitha
1/4-inch
inverted
flaretubefitting.If
a
solidwalllineisused,forma loop
intheline,orinstalla sectionofflexiblefuelhose,to
absorbvibration.Ifa linewitha pipethreadendis
used,
removetheflaretypefittingfromthefuelpump
inlet.
