W“Urrmm RIM’BORT ORIGINALLYISSUED August 1944 As Advance Confidential Report E4H03

~ 6 MAR @

NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

w“urrmm RIM’BORT ORIGINALLYISSUED August 1944 as Advance Confidential Report E4H03

ENGINE AND INSPECTION TESTS OF METHYL tert-BUTYL ETHER

AS A COMPONENT OF AVIATION FUEL

By Henry C. Barnett, Carl L. Meyer and Anthony W. Jones

Aircraft Engine Research Laborato~ Cleveland, Ohio

NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were pre- viously held under a security status but are now unclassified. Some of these reports were not tech- nically edited. All have been reproduced without change in order to expedite general distribution,

E-214

5 ..- ..- .——-...... —. —---—.—..-. I 1 31176013541735 —.——. .—

EAq Am Ho. E4E03

HATIOXALAlm80RY caaaTTEE FoRAmOltAmm8

. . . . AUVANOEOO~REPORT “ —.

ImlmlrEAHo ImPl!mIo.w!mms cm Mlg!EYL.—ixn!t-mru E!mm A8tA CCMPONENT~ AVIATIOIVFUl!Z“

. . SUMARY “ The suitabilityof methyltert-butyl”etheras a omponent of aviationfuel fran oonaldera~m of knock-llmltedperformance testseud laboratoryinapectlontestswas Investigated.Knook- llmltedperformancedata were obtainedfrom tests on the 17,6 engine urder supercharged ooditdona with fuel blends containing10 ad 20 percentmethyltert-butyl ether. Blemh were testeda% engine speedsof 1800 ti~O rpu and Inlet-airtemperaturesof 1500 ad 250°F. Kixmk-limltedperformanoe data for the bleds were oompered with slmllardata for AH-F-28(MO grade)cd AN-F-29 (140-P)avla- tlon fuels.

Knmk-limltedperformanoe data were also obtainedon a full- scalealrm@’t-en@ne oylitierwith a blendoontalning10 pement rmthyltert-butylether. Testsweremade at an enginespeedaF 2000~—ti an inlet-ah tmuperatureof 210°F aml also at an enginespeed of 2500rpm ani an inlet-al??temperatureof 250°F. Inepeotlondata for two bletis oontalnlng methyl tert-butyl ether were mupered.with data for AH-I’-28and AN=3’-29f=.

The followlngresultswere obtainedIn this tivestlgation: At all renditionsexamined,data frcxuboth mall-scale and full- mele enginesImlloatedthatmethyltert-butylether is a eatla- faotoryblendlngagentfcm hproving’m- anl rloh-mirtureknook- llmlted.performance.hepeotlm data indloated*t the amount or methyltert-butylether that oan be addedto aviationfuels will.be lM~&i by the effeots of the etheron the specified heat of oombustion. It was estimatedthat a 10-peraent addition of this ether will deorekse-the-heat of mmbustion of an aviationfuel 1 to 2 pemerrt. The additionof mthyl tert-butyletherto the base blerxlsdid not seriously lower the ~T.M. diatill@lon temperatures. EACA AcR Ho. E4H03

..”. . . “ ImmixmIolf .. .“ Supercharged te8temade by the she~ DevelopmentCcqmyj the EthylGasollneCorporation,the Army Air Forces,Materiel Command, ml the NACA have Imilcatodthatmethyltert-butyletherhas better antIlmockcharacteristicsthan currenta=ion fuels In the ccqlete range of fusl-atiratios. F%r this reasonadditionaltestswere conductedat the AircraftEngineResesrchLaboratcry of the NACA betweenA~il 1943 euilJ&umary1944 to provideinformationon the effectof enginespeedand i@et -ah temperatureon blendsof methyl tmt-butyl etherwith aviationblbdlng stooks. Partlculercon- =ration was givento the possibilitiesof usingthis materialto increasethe lean-mixtureas well as the rich-mlxtme knock-limlted performanceof aviation fuel.

Small-scale-enginet@s were made with fuelspreparedby blendlngvariouE concentrations of methyltmt-butyl etherwith aviation.alkylateblendingagent,straight~r=m borgasoline,or referencefuel. The eri+tnedata for these fuels were compared with data obtainedfor two currentaviatioafuels, Knock-lUzitedper- formancedata were also obtainedIn a fti- scaleaircraft-engine cyl~er on a reference-fuelblord contalniagmethyl tert-butyl ether.

Results of all teste are presentedin staniardknook-limited performance curvesd in tabularform. Inspectiondata were. obtainedon severalblefis for comparisonwith standsmimilitary . aviationfuels.

APPARATUS AND TIST CONDITIONS

Fuel blendsmyi impectlon data. - Small-scale-engine tests of the followingblendswere --

Blend Ccqlposition

A 60 percent 72-octane straight-run motor fuel plus 40 percent91-octAneaviational~late bleniingagent . plus 4 ml TZL pm gallon ,- B 90 percent blend A plti 10 peroent(methyltert-butyl etherplus 4 ml TEL per gal)

c SO.perqent S-2 referenoe fuel plus 20 percentM-3 reference fuel plus 4 ml TEL per gd.lon lfAcA AoR Ho. E4H03

Bled (hmpot!ltioli . D “80 “peroent““”-‘-blend“ ‘-C. plus‘-. 20p--”’peument‘(met&l tiaiziyl ether plus 4 nilTEL per gal)

E AH-F-28 (130 grade) aviation fuel

r AH-IT-29(MO-P). aviationfuel

G 80 peroent blexd R plus 20 ~rmmt methyl tert-butyl ether

FulJ.-8mJ.e-engim tests were made on the followingblemis:

Bleti Ccmlpoaitlon

H 85 peroent S-3 referenoe fuel plus 15 pement M-3 refer- tmoe fuel plus 4 ml TEL per gallon

I 90 pement bletiH plus 10 peroent(methyltert-butyl etherplus 4 ml TEL per gal.)

Inepoctiondata consistingof tetraethyl-leadooncentrathne, apeciflo @?avitles,Reid vapor~essures, heatsof cmbuetion, d A.8.T.M.diatillationewere determinedfor bletieB, E, I’,- G.

Small-scald-e nginetests.- Small-scale-enginetestswere made on the 17.6 engine desoribedin refercince1. All testswith this englnowere knook-limltedand were made at the fol.lowingconditions:

~inespeed, m ...... 1800.2700 Ccmtpmeeionratio...... 7.0 Inlet-coolant temperatum,% ...... 250 Inlet-air tmperature, OF...... HO. 250 Spark advanoe, deg B.T.C...... 40

.Full-soale-&@ne tests.- Khock-llmitedperformanoe data were obtained on an R-1820G200 csylimler.A detaileddesorlptionof the engineinetalLation is inoludedin referenoe2. All fulJ.-scale- englnetestsweremade at the following cotiitione, 8s recmmmted by the Comdinating Researoh Counoil:

mgineqeed,r pa...... 2000.2500 Compressionratio...... 7.3 Inlet-airtemperature,%’...... 210.250 Spark advanoe,deg B.T.C...... 20/20

. . 4 1 MACAAcRnrc*E4M3

The oocl~-air.flaw was @ to give a rear spark-plug-bushlrg temperature of 365° F at a fuel-alr ratio of 0.10 @ a brake mean effmtdve preggmra .0$,140.paprds per aqwre inch.

EWULXS ~ .DISCUSSIOl!l.

Stnall-Eloale-FmgineData .

Accuracyof result~&- At interva@, throughout the test program “thh 17.6 engineo~eraticmwas checkedwith S-2 roforencefwl at an engine ape= of 2700 r-pmand an inlet-alr temperature of 250° F. Data for ~ee represeptativ~.testscoveringqn.operatingperiodof 17 days : are presentedin fIgurei.

Reference—. .——.%.s19.— - Fhcck-llmited performance curves for S-2 refor- enoe fuel pi .us vanoue cfincentrat ions of tetraet~ ~1 let~ are shown at three sets of engineco~itlons in figtm 2. Tho pmfomance numbers correspomilngto the coacentrations of totraotl@ lead m-e givenon the figure.,These curveswere used for ratingother K.enisin terms of perfcrmanoenumlmrs. me d~t~ fcm imilcatodeycifis fuel cnn- sumptions i~.icetathat the fuel corazmptIon at bIlvfu;i-airratio is not depemianton th~ knock-limitedinlet-airprea Hue.

Service-=e fuels.-.The reed% o# tests on AN-7?-28 and Mi-I’-~ticn~~=&-e presented in figure 3. Tbcm fuels were testedfor comparisonwith preparedblondsccntcd.ni~~mthyl tert-butylether.

Em?lne perfcmmrm of blmls. - The effect of lnkt-air temperature and ergineepeed ~i~ She Lmck-+ited purfom=ncc of bl~ilds A ad B is bhnwhin figu:g4.” Comparisonof the lL~_mk-limited~orfcrm- ance cul’ve=of Bi&ndA ad A.EI...F:26fuel showsth~t ble:”fiA in apprcxi- matedyFe@raedntatlte”c*6urrsntaviationgasollae. T_aeme%kyl tert-butylethedizcreased~he bock ~imlt of t% base fuel c,verthe .=lote Psi@ C? fuel-atiratios,as shownby comparingbl~m:sA @ B h flgum 4. This feet is of particularInterestbec~.use:d?tho need of fu=lbledlng agentsthat-willincreasethe kncck-l~-xted performanceat leanmi@ur6s as well as at rich mixturesunderall “ engineoperatI@ “cotiltIons..The additionof the etherdid not . Increasethe Indicatedspe.clficfuel consumptionexceptIn the lean regionfor the cotiitionsshownin figure4(c); the loweringof the heat of combustionby a 10-percentqddltionof ether,however,was estdmated*a be ap@rbx’lniatelj1 to.2.perOeptand.consequmtlylies withinthe ekpbrlmbntal.aobtiaoyof the data. ,.. ! . . . -. .,...... -. . . .

I . .

w40AAoRlro. E4Hb3” “ “ 5

Results that were obtained with blerdeCsd. Dereehownln figure 5. In this case the galne In knook-limltedperformance . . caused ‘bY W additia & 20 merczetitetherwore quite appreolable - sgti app6aredover the wilolerangaof fuel-& rati;slnwoO- tdgated. Thesedata Ix@ioatethat the use of methyltert-butyl ether& an avlatlonblemilngagentwill resultIn u~weaee In the book llmit ov6r a wl.derange of smglne oozdltions. Che&gee In the Idloated epotffo fuel ooneuurptlonattrlbutabloto the additionof etherare not~ceableIn both the rioh aal leanregloms. b The effeotof adding20 percentof methyltert-butylotherto AWW29 fuel is shownby blade F @ G In flgv&=. This addltlon of etherreduoedthe tetraothyl-leadcontentfimn 4 ml per gallonto 3.4 ml.per gaUon. The gainshere were not eo great 8s wore obtained when 20 peroentof the methyltert-butyletherwas addedto bled C (fig.5) but againthe lnoreae~ietsd over the ccmrpleterange of .. fuel-atrratloe. The i@loated speolfiofuel ooneumption showed (withinthe aoouraoy.of.* data)an inoreaeeby the additionof etherfor fuel-airratioslowerthau O.065;fm a oonetaxrkkmook- llmltedmean effootive preesure,howevor,the etherblendhad a lowerindioatedspeoif10 fuel ooneumption than pure A&F-29 fuel. Table I giveethe eetlmatedperformancenumbersat various fuel-airratiosfrom 0.065to ().10.Theseperformanoe numberewere determlnodfrom a oauparlsonof the knook-llmitedperformanceourvee for fuel bluhdswith the lmock-llmltedperformanoe ourveef= S-2 referencefuel preeontodIn figure2. TableeII and III eumarlzo temperaturead speedsensitivitiesof the.blondsteetodin the 17.6 engine;eeneitivitloeare expressedas percentageInoreasee In indicatedmean effeotivepressurefor a given ohangoIn engine Oditione .

lhl.1-Smle-Engim Data Knook-llmitedperfmmanoe teetemade in tho full-soale-engine oyliMer are presentedIn fIgure7. Data for the baee fuel (blondH) are mmpsred with the performanoo of ble~,.Ioontainlng10 peroent methyl tert-butyl ether.

The Inoreasein knook-limltedpower qaueodby the additionof 10 peroentetherwas very similarto the gain deterxulnedIn the emall-eoale-engl~toets,as shownIn tableI. Data for the ldi- oatedepooif10 fuel ooneumptlon(fig.7) show a sllqhtlnoreaseIn fuel oonsucaptionat lean fuel-alr ratioe.

—. -—. . .

InspectionData .. -, ., ;, . . .- :.. Inspectiondata for blendsII,~,”R!.,and G are mesehted h “ “ . tableIV. l’uelprep=qd by adding20 @eroentmetml tert-butyl@her to JUJ-F-29.(bled G) met alJ.the epeoiflcatlonrequlr=nts presented - with the exoeptIon of heat of cabuetton. ~eti 3 oontalning10 per- oentethermet thd specifIoation llmits. b this ease,houeverlthe heat of ccmbuetionwas not detmuined.

The data presentedIn tableIV idicate that the amountof ether whloh‘canbe addedto aviationfuelswill be limitedby the effeot@ of the ether.on the speoifledheat of oaubtitlon. Althoughthe additionof mthyl tert-butyl~etherto t@e base bleds lowei?edthe .~ distillationtemperature,this effeotshouldoffer no serious.. llmi~ tathn to the use of the ether”In aviationfuels. ,J ..

SUIMARY OF R15ULTS “

Resultsobtainedfl?omInspection tests and small- and fuU-scele- englne knock-limlted perfomanoe tests on blends containing methyl “ tert-butyl ether were as follows: . 1. At all conditions examined, both smalJ-scale-and fuKl-soale- englnedata l@ioated thatmethyltert-butylether is a satisfactory blend- agentf& Improvinglean-~ rioh-mixtureknook-limlted performance.

2. Inspectiondata itilcatedthat the amountof methyltert-butyl etherthat mu be addedto aviationfuelswill be llmltedby= effeds of the ether on the specifled heat of combustion, It was estimatedthat a 10-peroentaddition of this ether will.deorease the heat of oabustion of an aviationgasollne1 to 2 peroent.

3. The addition of methyltert-butyletherto the base blends . did not seriously lower the A.S~M. distillatlontemperatures.

AlroraftEngineResearchLaboratory, NationalAdvismy Comdttee for Aeronautics, Cleveland, Ohio. NACA Am No. E4H03 7

. .,. , .1. iimett ;’ Henry “C.;‘d 6iOU@, hu@s-W. , &.:’ ‘“~~eZ’&d- Euglne -ok Teats of Methyl tert-Butyl v. No. If4Hlo,1944. I 2. Jones,&Mmny W.,.and Bull,ArthurW.: Mck-L~t* p=f~- anoe of Pure B@rocerbona ELefiedwith a BaaeFuel In a Full- SoaleAlroraft-Er@ne Cylinder. I - JE@t p~~~ ~ Oleflne. EAcA Am No. E4E25, 1944. . .

,. .- —— I

8 EAcA AcR No. E4H03.

!l!4HLEI - ISTWUED ~CE RUMBlR8FROM T=TS OH TWO EMG~ AllDA!lVARIOTE~INE CONDITIONS herformanoenumbersfram 17.6 engine eslilmatedfixaufig. “2;. prfarmano e nmbers frcm full-male engine eetimated fraa fig. 7; all num~s below 100 representthe percentagepower baaed on 100 peroentpowerwith S-2 referenoefuel.] . . —. 1. Fuel-air rat10~ . 0.065 0.075 0.08 .0.09 0.10 r~l ble~ak ——— L7.6 engine;enginespeed,2700w inlet-airtemperature,150°F — —- A “. 85 94 101 --iiF 10 B 95 MO U2 3.30 145 c 100 107 109 115 115 D 148 152 156 >160 >160 E 86 92 98 Uo r124 F 89 97 105 121 133 ----- ——107 120 _l-146 .7.6 engine; engine speed, 2700 rpm; Inlet-alrtemperature,250°F A 100 100 103 106 111 B 105 108 112 1.15 120 c 118 122 123 121 D 155 154 153 154 ~ :: E 103 106 F 105 ~~ ~i! X6 engine;enginespeed,1800—— rp; inlet-alr.-— temperature,150°Y A 101 110 —n3 118 I 121 B 106 121 131 137 I 137 c. 112 113 113 114 114 D 156 >160 >160 >160 >160 E 104 113 123 132 133 — F 110 121 137 142 142 Full-scaleengine;engineepeed,2000 rpm; Inlet-alrtem erature 210° F H I _zm8 I :: I :X& Full-aoaleengine;engines&ed, 2500 rp; inlet-airtemperature2 0 F H . —.. I— ggl-=-r ~~?%! i R. kmoomposltionof fuel blenis,see pp. 2-3. NationalAdvlmry Cammlttee far Aeronautics EA&A Am No.’ E4H03 9

.,. . .W.ll ~.m cEnTAm ImREA8E m IPmIcA!KDMEAN’nwmmvE ERm3uRm F(JRAN INCREME @ EMG13t2SPEED 1’RCM1600”.RPM”TO”2760 RPM NM n?mr-m !mMPmA1’uRE0F150° R’FORTHE 17.61RKHllE ......

, . A.- 7.6 - .qs~oo 6.3 16 16 .. . . B 4.5 3.5 33 . 16 . .c 5.7 1o:7” 12.7 16 Is D o .“4.0 6.5 11 17 E 4.0 . . -3.2 -1;$? 1.5 10 F -2 . -8.8 -7.1 0 7 b %’or exposition of fuel ble&S, see pp. 2-3. . .

TAELE III - PEROENl?AGE~E IN lllDICATEDMEAN EWB?M2TIVE-~ .FURADKREASE OF INIJQ!-AIRTEMPERATUREFROM 250°F TO 150°F AT AN ENGINESPEEDCM’2700RPMFOR TEE17.61!llUlXE . . \ ,:=”< 09065. . 0.075 ‘gm 0909 0.10 A 34 .. 40 40 35 20 B 44 . 39 34 30 23 c 32 24 “18 14 9 D 42 34 33 29 22 E 32 30 23 22 20 F ,.. 35 29 29 27 21 . %’= oc@osltlon”o*fuel bletis, see pp. 2-3. 3

National Advisory Ccmnnlttee for Aeronautics .- ., ..

~. ..- ,- . --- -. . —. .

10 llAcA Am moo E4B03

IAN-F-28 I Fuel ble~a apaGifi- ~ , E F G oationa I — I. Tetraethyllead,~& , 4.0 4.1 4.1 4.2 b3.4’ Speoific gravity at 60° F ‘------0:710 0,718 0.736 0.739 Reid vaporpreaaure 7.0 6.7 6.3 6.3 6.6 ——.2~/W in. -----118,360118,260117,650 —Heat of oanbuation,—. Btu/lb 1.la ,700 I —— .—.A.S.T.M.diatil.lationdata Mtmentage Temperature evapmatad - ?F o ------m llo llo 10 167 145 20 --.-.- 154 169 146 30 ------163 166 164 161 40 167 169 163 196 175 50 221 178 203 212 185 60“ ---.-- 191 220 229 “200 70 .---.- 206 232 244 217 80 ------219 252 262 240 90 293 236 276 264 275 End point 356 2!34 315 334 319 —- —- Reaiduejperoent 1.5 1.0 .1.0 Loaa, percent 1.5 1.0 .2 ——

%r oampoaltionoffuel bletia,eee pp. 2-3. %atimated value. NationalAdviaomyCamuittee for Aeronautlca F i“l CA ACR No. EUH03 m ,.. NATIONAL ADVISWtY COMMITTEE FOR AERONATUICS

I I I

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o D Cl\ u / ‘ A Engine speed, .2700 rpm [ ( Inlet-air temperature, 250° F 9-3: -!,-. — , # # 111 1u .05 .06 .07 .0s .09 .10 .11 .12 Fuel-air ratio Figure 1. - ~eok tests on .%2 reference fuel. 17.6 engine; engine speed, 27~ m; Inlet-air tarnperature, 2500 F; inlet-coolant temperature, 250 F; spark adv-ce, )#0 ~.~.c.; compression ratio, 7.0. Fig. 2a NACA ACR NO. E4H03 60 CCMMITTEE FOR AERONAUTICS

[ ❑ ,

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: Performance Fuel number o s-2 100 0 5-2 + o.~ ml TEL 115 260 0 s-2 + 1.26 ml TEL 1 0 A S-2 + 2.81 ml TEL 1 v v v %2 + 5.76 ml TEL :6; v

v/ 240 3 / A

( % / w 220 / y / / {. / /

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(a) Engtne speed, 2700 rpm; inlet-air temperature, 1500 F. Figure 2. - Knock-limited performance of reference fuels. 17.6 engine; spark advance, 40° B.T.C.; compression ratio, 7.0; inlet-coolant temperature, 250° F. Fuel-alr ratio (b) Engine speed, 2700 rpm; inlet-al. temperature, 250° F. Figure 2. - Continued. 2C NACA ACR NO. E4H03 60

zN- ---- I I I I I 0 I ❑ 5-2+o. [4 I 0s-2+1.--- I I I I 1 1/ 1 1 [ 1 “-C. >.(” j,,- -— [ A I . I I I d LK llll.OJ’+I II ILL---I

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/ d + J E I 1 1 1 I I I 1 I 1 A A- I F81#I I I I -1/’Tk-Tl I 30 >

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S-3 120 .05 .06 .07 .08 .09 .10 .11 .12 Fuel-air ratio (a) Engine speed, 2700 rpm; inlet-air temperature, 150° F. Figure 3. - Knock-limited performance of AN-F-28 and AH-F-29 fuels. 17.6 engine; spark adwince, 40° B.T.C.; cornprmeslon ratio, 7.0; inlet-coolant temperature, 250 F.

1—II mmmmm ,mmm-mm,,nnnmnnm ,,,, ....——-...,-, —,,.. . ., . . .. Fig. 3b NACA ACR NO. EqH03 NATIONAL ADVISCN?Y COMMITTEE FOR AERONATUICS

.- :. fit ?:30 .bJm ~: e

~ - ! / !2 $ :.6 ❑ / 0 Blend E - AN-F-28 (lJO grade): . c< ~ t ❑ Blend F - AN-F-29 (14c-P) 3 /L ,/ 220 “5 /p 7

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< 180 D d .

~ ~ 160 : : +

: 140 E

120 A /

100

1 S-3 ao- ... . — .05 .06 .07 .08 .10 .11 .12 Fuel-aii”%atio (b) Engine speed, 2700 rpm; inlet-air temperature, 250° F. Figure 3, - Continued. NAC~ ACR NO. E4H03 Fig. 3C . , r NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS l“’’I’’’’””l’””’”l ”””l1””””1”””1”””lm n 2. au r !- ! !J ~% rl-1.-.! I I

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+ 140 -

: x

120 -

S-3: 100 .05 .06 .07 .08 .09 .10 .11 .12 .13 Fuel-air ratio (c) Engine speed, 1800 rpm; inlet-air temperature, 150° F. Figure 3. - Concluded. Fig. 4a NACA ACR NO. E4H03 60 MAIIOMAL ADVISORY COMMITTEE FOR AERONAUTICS

50- — — — J’ n Q 40- t .Q \

Jo :

P/ o Blend A - 60s straight run + 40$ av~atlon D alkylate + 4 ml TEL/gal

o Blend B - 90$ blend A + 1~ (MTII ether / ; : + 4 ml TEL\gal) ,> 7 3 2 : 2 - 0

: - 6 I--t+ : -

/ .=- > ?ko :.5 . / ~ ) , AN-F- 29 u / ---- 4 d ~ .?20:.4 / 0/ ‘, .- - ‘-. AN-F..- .2& / ‘ / /d, Y / -L1 / / 3 200 - / / / /’, ‘ / . / a / : /, 180 / / ~/

/ J ‘ / ‘i /, i 160 / d 1 / (/ ‘( \ $ // P }! / 140 / (I / , \\ % -“- o

120 “ S-3: L ,t, , 1111 ,,,, 1I11 .05 .06 .07 .08 .09 .10 .11 .12 Fuel-air ratio

(a) Engine 5Peed. 2700 rPm; inlet-air temperature, 150° F. Figure 4. - Effect of methyl tert-butyl ether on knock-lim:ted performance of aviation-fuel blendln stoc~17.6 engine. spark advance, ~0° S.T. C.; compression ratio, 7.0: inlet-coo f ant temperature, 2506 F. NACA ACR NO. EUH03 Fig. 4b 60* 1- NATIONAL ADVISCRY COMMITTEE FOR AERONATUICS 2

50 : 0 -— ~

A / ~ ‘ 40 : / k

~o - \

20 : 0 Blend A - 60$ straight run + 40$ aviation H alkylate + b ml TEL\gal

o Blend B - 90% blend A + 10% (MTB ether + 4 ml TEL\gal) 240 . 0 6 /

/ ‘ 220 J ~

~ ~ -

lgo ~ // / / // ,/

160

v/ /

140 - //

120 / / // / / / C* / [ \ + 100 - \ ~“ T- —~- ~ ~ ‘

3-3 80 ..... , , ,,, 1,t1 1111 11II .05 .06 .07 .0s .09 ,10 ,11 .12 Fuel-air ratio (b) Engine speed, 2700 rpm; inlet-alr temperature, 2500 F. Figure b. - Continued. —— —

Fi 9- ~c NACA ACR No. E4H03 J NATIONAL ADVISORY 0 COMMITTEE FOR AERONATUICS — 50 -

n 9 40 ~ /

Jo “ —

8 1 & 20

7 “

/ D : 6 n - $ . / Y d - /

❑ Blend A - 60,$ straight run + 40$ aviation I 2 5 alkylate + b ml TEL/gal 2 - ❑ / o Blend B - 90,$blend A+ 10$ (!4TB ether u 7 + 4 ml TEL/gal) o 4 220 L

/ \ . / \ AN. F-7q 200 / / / o — / / \ / )“ / \ \ 180 / / /’=’/ ‘ > AN-F >6 / / . , 0 < u ; .+ 160 - / // / / // f /

140 — \q \ / \ 3 n\ -~ / / 120 \ & “-

3-3: 100-n,,, ,, , , ,1I, t ,, 1111 1111 t111 1I1I .05 .06 ,07 .08 .09 .10 .11 .12 Fuel-air ratio (c) Engine speed, 1800 rpm; inlet-air temperature, 150° F. Figure k. - Concluded. NACA.ACR tiOO ELIH03 Fig. 5a

70 r NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS A k &-

60 - / 7 k ‘A ;; 4!9% b ‘

;$ Y < 0 Q c. 50 :..4 .+- Ew a 2: i: 0 Ou 40 F / ‘ 2k x

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2gc

260

240 d O Blend C - 80$ S-2 + 20,%M-3 + b ml TEL/gnl: . A z A A Blend D - gO% blend C + 20% (MTB ether + L+ml TEL/gal) : 220 .0 .-l ~ A / [ \ ❑ . L [ * 200 n ~. -o : 4 E ) ~ ; : 0 18P

160

A <1 0 140 \

s-> 120 , , ,,,, ,, I 11 1I1I .05 .06 .07 .08 .0? .10 .11 .:2 Fuel-airratio

(a) %nglne speed, 2700 rpm; inlet-alr!emperriture,150° F. knock-llm!ted performanceof Figure 5. - Effect of methyl tert-butylether on referencefuel base blend.~G engine; ‘ga;:adv=ce’ ‘“B”T”C.; compre’810n ratio, 7.o; Inlet-coolanttemperature,30

..— ...... — ——— .———- ...-.. ! !.!. !.-!-... 1. .! . . I . . .,. —-.— , 1 , , , I 1 , , 1 1 , I I r r 1 1 t 1 , , 1 , 1 1 I 1 r 1 t r I , 1 , I 1 1 , 1 1 , , , , 1 1 I , n , , , 1 , I I , 1 r 1 1 1 , , , I I -. NATIONAL ADVISORY Q’ CCMMITTEE FOR AERONAUTICS: .

tJO% S-2 + 20% M-3 + ! ml TEL/gal . .8

l-l

Engine speed, 2TO0 rpm Inlet-air temperature, 150° F .4 3-3 - 111I 111I 1II1 1,11 I,mI ,1,I ,1I1 1111 1111 1III 111I 1111 111, 1 1 , 1 1 1 t 1 1 1 1 I I I 1 1 .05 .06 .07 . oi3 .09 .10 .11 .12 ‘Ill 4= Fuel-air ratio = (a) Concluded. 0’ Figure 5. - Continued. cd I J

3C)

260 / r OBlend C - 80$ s-2 + 20% M-3 + 4 ml TEL/gal / L ./ I go$ blend C + 20$ (MTB ether I

240

220

~ 16o v 0 z

-..,

L v

120 /

/ \ 1 I / I I 1

100

(b) Engine speed, 2700 rpm; inlet-air temperature, 250° F. Flgfuw 5. - Continued. , 9 , 1 8 I m , , I , 1 , , , , , , , , , , , 1 1 , , , , , , , , 1 I a I , r , 1 , I r , 1 , , , , , , , , , , , I , , I , , , , , , NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS - .9 -

0 t

/ .8 “ OBlend C - /30%S-2 + 20% M-> + 4ml TEL/gal / A Blend D - gO% blend C + 20% (MTB ether + 4 ml TEL/gal) ! .7 - g P d

/ .5 .

Engine speed, 2700 rpm Inlet-airtemperature,2b0° F / .4 “ > S-3 - m , , 111 11an n11h 1, n1 119, a, #, #B1 1 1 1 # 1 # 1 1 I 1 1 1 t I 1 1 I 1 1 1 1 1 1 * n I 1 1 m n 1 I I 1 1 1 1 I a .05 .06 .07 .0$ .09 .10 - .11 .12 Fuel-airratio (b) Concluded. Figure 5. - Continued. NACA ACR NO. EUH03 Fig. 5C NATIONAL ADVIS(3?Y COMMITTEE FOR AERONATUICS 60 *_ _A 4 A ~ : ~. / di ;? 50 c :2 e; k 0..4 ~ - :. Is: ~ A - Az 4: L A ~k % 30

OBlend C - gO% 9-2 + 20% M-3 + 4 ml T2Vgal A Blend D - .50%blend C + 20$ (MTB ether + 4 ml,TEL/gal)

260

2ko / ;

; 220 , .+ i A e / : .+ ; 200 ) ~ : .-l , ) ~ * v : 5 160 q > A : / - s 160 A / A

140 ? ,

9-3 120 f.... ~~ a , 1m, ,, 111I 1,,, II It .05 .06 .07 .08 .09 .10 .11 .12 Fuel-air ratio (c) Engine speed, 1800 rpm: inlet-air temperature, 1500 F. Flgurc 5. = oont~~ed, n

, r r , , , , , , , r , , , , T , , r-, r , r , , 1 I 1 , r , , 1 1 , , , 1 , , , 1 r 1 , T 1 ! 1 NATIONAL ADVISORY COMMITTEE FOR AERONAU TICS: ●9 -

.8 A

O Blend C - 80% S-2 + 20% M-3 + 4 ml TEL/gal

A Blend D - 80% blend C + 20% (MTB ether h + 4 ml TEL/gal) : ●7 - ~ A .

.5 :

A r Engine speed, 1~00 rpm

Inlet-air temperature, 150° F .4 “

9-3 : a? 1 I , 1 , # 1 1 1 1 1 1 a I 1 1 1 I m n , , a a n 1 1 1 , # , 1 1 , I 1 , , 1 1 1 1 t 1 I 1 , o 1 111, I 1 1 1111 , , a1 n1I 1 . .05 .06 ,07 ● 0s ● 09 .10 .11 .12 I Fuel-air ratio (c) Concluded. I Fl@u’e 5. - Concluded. NACA ACR tiO. E4H03 F/a. 6 NATIONAL ADVISCRY 60 CoMM’TTEE ‘OR ‘ERONATu’cs ‘

.&W . 5 u“ :40 c1 a h a

30 --g

2 : / / 280 ~ -

240

220

P o /’ 200 / / / / / ltto / / A { Engine speed, 2700 rpm Inlet-air temperature, 1500 F 160 // o / /

\ / t I 140 \ / \ / \ / \ / S-3 120 .05 .06 .07 .06 .09 .10 .11 .12 . Fuel-alr ratio Figure 6. - Effect of methyl tert-butyl ether on knook-limlted performance Of fuel AN-F-29. 17.6 engine; engine speed, ~Q rw; spark advance, [email protected].; cowresslon ratio, 7.o; Inlet-alr temperature, 150 0 F; inlet-coolant temperature, 250° F. I Fig. 7a NACA ACR Noo EVH:03

60 1. NATIONAL AOVISORY COMMITTEE FOR AERONAUTICS * ~ + - L A 5

b < D 6 / d -

A \ ‘ss — ~ ‘ / f

x \ . ~ ~ 4 * ~ 7 / ------d

/ 7

6 (

5 / F / / w 5 ~ - / ~ .4 / W“ m A + A 0“ 3* 4 / ,

240 3 d / / /A f’” ~ ---CM 6 / /’ / / “

220 A / /

k / / - ---’ / / x , . ❑ * / / { r . — ‘ . A A /“ / / 0 / / + 0 0 \ / Fuel Performance ---+-/ / number r\ P ‘ d 0 9-J 100 / + S-J + o.~ ml TEL 115 \ / . s-~ + 1.25 ml TEL l~o o s-J + 2.0 ml TEL 138 0 BlendH - ~~,%S-3 + 15% M-3 + k ml TEL/gal 14C / A Blend I - 90% blend H + 10% (MTB ether o + O ml TEL/Ezal)

\ 12C \ / ‘

53-6( loci ,,. . 05 .06 .07 .Og .’09 .10 .11 .12 .13 Fuel-air-ratio fa) x- S-S 2~ X’PEI;inl@-air temperature, 21@ F. . Fl@re 7* - Bffeot of methyl Y1 ether on hook-limitedperformanceof

refemnme fuelbase WenL Fall-wtle-exwinecylinder;spark advanoe~ 2@ B.T.C.j Ocmpmgsion ratio# 7.3;ooolimg air eet to give rear spark-plug-boarntemperature’ of 363 F at 140 kmep and 0.10fuel-airratio. I NACA ACR NO. E4H03 Fig. 7b :& + NATIONAL ADVISORY J? :OMMI TTEE FOR AERONAUTICS d < ~ ; \ .pJ ~ - ~ “ .: m & / k / / / Y / : * c% h40 / y .-l / : / : 0- ● .5 8 : 30- \ / ---’ @ { ~ * 1+ A z 20 .7 z 6 / ,&3CXJ.6 !4 x : M d . 0 :

260 C@& ❑ / c A x /

240 z , / 2 % . u / H : 0 + 22a < / ~ / / ~ . / ; / / / / / d 7 /0 ~ x / \ / : 20C / / / EJ / / , ~ x 3 \ Y / P ~ 2 \ J / 0 Fuel Performmce ~ ltlo. / / number / 0 s-~ 100 \ \ / / + 9-Y + 0.5 ml TEL 115 / x s-~ + 1.25 ml TEL 130 ❑ S-3 + 2.@ ml TEL 136 0 / OBlend H - 85%9-3+ 15% M-3 + 4 ml TEL\gal 160 / “ “end 1- ?“f ::e%;;.p ‘m’ “her \ yo < /

14C o

j3-6] l?n .05 .06 .07 . 0s .09 .10 .11 .12 .1> Fuel-air ratio . (b) Engine @peed, 25OO rpm; inlet-air temperature, 250° F. Figure 7. - Concluded. llllllllllflfliti~wlmlll~ 3 117601354 1785