, I Your Franklin engine is built with high quality materials and workmanship and is a sturdy piece of precision equipment. The service it gives depends much upon proper inspection and main­ tenance. This is t he owne rs ' r e R pon~ jb iii t Y and t he pur pose 0 f this booklet is to aid in the pl o ~ r c (J n~ and m(u nt pnunc f" of your Franklin engine. No attempt has been made to cover detailed technical informa­ tion in this handbook on mechanical construction, adjustments or repairs. ---+--­ WARRANTY Aircooled Motors, Inc. warrant s eac h new Franklin engine or new part manufactured by it against de l ects in material or workmanship under normal use, but its oblig(1 t i on under this war­ ranty is specifically limited to r opl C1("i ng or repairing at its factory any such engine or port wh ich :.11 (111 , wi t hin 90 days after delivery thereof to the originul pm CIl (lRl'r l1nd pr ior to 50 hours of operation. be returned to Ai r ~ oo l c d Mo tOIH, Inc., with its permission. transportation c ilur qcH prp poid, Gild wh i c h upon ex­ amination by Aircooled Motors, I nc., i s I.,h.' l e I mi II ~ I hy Ai rcooled Motors. Inc. to be defective . This warranty shall not apply to any such engines or parts which have been repaired or altered outside Aircooled Motors. Inc. factory is any way so to affect. in its judgement. its op­ eration. or which have been subjected to misuse. neglect. im­ proper maintenance or accident. or which shall have been opera­ ted at a speed exceeding the factory rated speed. Aircooled Motors. Inc. makes no warranty with respect to ignition apparatus. carburetors. instruments. trade accessories. or other equipment which it does not itself build or manufacture inasmuch as such equipment is usually guaranteed by the respec­ tive manufacturers thereof. The foregoing is the exclusive warranty made by Aircooled Motors. Inc. There are no other warranties expressed or i~lied. in fact or in law. made by Aircooled Motors. Inc. Ai rcoo Ied Motors, Inc. Syracuse 8, New York INDEX Page ENGINE SPECIFICATIONS 1 GENERAL CARE 9 INSPECTION PERIODS Twenty-Five Hour 10. 11 Fifty Hour 10. 11 One Hundred Hour 10. 11 Top Overhaul 13 Major Overhaul 13 MAINTENANCE 13 Magnetos 13 Model 6A4-lS0-B3 13 Magneto Point Setting 13 Magneto Timing 14 Model 6A4-16S-B3 18 Magneto Point Setting 18 Magneto Timing 18 Spark Plugs 20 Valve Rocker Adjustment 21 Carburetor Adjustment 22 PREPARATION FOR STARTING 6 RUNNING THE ENGINE 7 STARTING 6 STOPPING THE ENGINE 9 Figure 1 3/4 Front View of Franklin 335 ENGINE MODELS 6Aij-150-B3 & 831 6A~-165-83 SPECIFICATION NO. SPECIFICATION NO . 17569B 18403 This specification form describes briefly the Franklin aircraft six cylinder 335cu. in. displacement, direct drive, horizontally ~pposed engine for use on 80 octane aviation fuel. MODEL YODEL 6A4-150-D3 6A4 - 165 -B3 Rated Horsepower 150 165 Rated Speed 2600 2S00 Fuel - Min. Octane SO SO Compression Ratio 7.0:1 7.0:1 Oisplacemen t 335 335 Bore &Stroke 4~ x 3~ 4~ x 3~ Carburetor - Single MA3-SPA twbrvel MA4-5 Ignition - Dual Magneto Magneto Ignition-Timing 2SoB.T.C. 32 0 B.T.C. SAE 40 - Above 40 0 Oil - Grade SAE 20 - Below 40 0 Oil Capacity - Qts. B 8.8 Oil Temp. - Max. 230 0 F. 2300 F. Cylinder Head Temp. -Max. 500 0 F. 5200 F. Cylinder Barrel Temp ..Max. 300 0 F. 310 0 F. Engine Calibrcrtion Curves SO-138 SO-251 SO-142 SO-252 Engine Installation ~awing 17753 18400 Weight - Standard Engine, 318.6 1bs. 323.5 1bs. including oil cool­ er, starting motor, generator, carbure­ tor and magnetos. 1 ~·IJ!.L THROTTLF: PE:RF0RMANCE CURVES SEA LEVEL rERFORJWfCE lLANKl.1N IlUlItl. (,Al,-150-1l3 80 OCTANE FUll. FRANKLIN MODEL 6A4-150-BJ 80 OCTANE YUFJ. 1. '111 111.: 2600 RPII 7.011 COMP, RATIO 150 HP 2600 RPM 7.011 caD'. RATIO 160) 160 ... ~ ~ ~ I ~ \ 1 ;/' /\ 140 VI :;;­~ V ~.~ V ~ I ) /' ./ 14 1/' - / ~o n ~ r T. !lWEi' 1 ::.­ - ~ ~ L r-I-­ r-..... t.­ - - -­-­~~~~V- -- -/"V LJ -­ ~ &1 ,/ i R ---­ ~ '-..... V "", 75~ RATED POWER/",: [/fiF/ l.L 8 b/ I ].. / ....... ~ leO '\ I!l V :/ ,/ ~ fI;)' :. V V "'. 1\ III ./ .......... V It1 - - /Y -~ I~ V ~ .... '" !:J'" / V ( ./ /" ",-/ I \ 12 0 - - -j 1 o ~~ ~ 80 ~ /' :/ "..........­ v -­ ~ I FUlJ.. THRonLE / ~ /" V ~ lIl~oua ,/ -:7 "...., / ".......... no / / ",-/ ~ I60 / .........­ I I / 600 / ,~ ? I I-............ t--­ u r. T. BSFC I--­ r.. 100 en 40 :-- III I I--. ~ - I PROP LOAD BSFC . 00 1_1 - I 2800 2000 2200 2400 2600 3000 18 20 22 24 2b 28 ENGINE SPEED - RPM Absolute llanltold Pressure, In. bg. Full Throttle Performance Curves SA4-lS0-B3 Sea Level Performance SA4-.lS0-B3 .. 3 2 FULL THROTTLE Pl!:RFORKANCE CURVES F'RANKLIN ~'ODE:L 6A4-16 5-BJ 80 OCTANE FUEL SU LEnL PERPORlWfCI 165 HP 2800 RPU 7.011 COII.P. RATIO FRANKLIN KODEL 6A4-165-BJ 80 OCTAJIE FUEL 165 lIP 2800 RP1I 7.011 COIIF. RATIO r--- /' 160 VI 140 180 1Y~ ~ I 1/ T ...... 1 V ~ 0 /' "" u 150 / II ./ V V ?\ l.6O ~ , / / OJ ~ J ~V L 8 V ! V y V 120 A ~ L 1\ 1.40 ~u ~. I ~. !!l ~J Q:)' V ~ ~. \ o ~ ./V ;c ~ ~ ~ -.' I 0 V ' ... J u 5J ~TED~ pwm '/ fJ'j - - r2 ~ - - ~'ll ~ I- - I ~ - 130 ./V- ./ f..'" ./l2 / 120 S V V V / .! 'l ~ 1/ ~ / ~V ~ V I \ ~ V V V V 120 ~~ L ~ ~ ./ / 100 V V IV V VI-' J \ II /. ~ V ./ V -LIJ L V V VV V ~ / 110 / / .600 1 / V V-- FtJL TBRO tTLl ~ -- V -, .-- 80 ~ V- ~ V V V t:::-:;~ II F.T.~ t:::z Ul /' al / V L I'-.. V ,,/" ,,/ r--l ,/ I 100 .500 , ./" (ROP rAD---- ~FC V 60 II /' I I I ,/ 2000 2200 2400 2600 2800 3000 ENGINE SPEED - RPM I I 18 20 22 U. 26 28 Abeolute Ilan1told Pre.eure, In. bg. Full Throttle Performance Curves 6A4-165-B3 Sea Level Performance 6A4-165-B3 4 5 fails to crank the engine. the battery should be checked to see PREPARATION FOR STARTING if it is adequately charged. 1. Check to be sure that there is a sufficient quantity of both, \ CAUTION: It is important to lock the primer fuel and lubricating oil. The use of non-leaded gasoline of an , securely after using to prevent fuel leakaJe octane number never less than that specified for the engine into the induction system and improper op­ model is highly recommended. eration. 2. Check the operation of the engine controls for proper move­ Caution: If after the engine has started the oil pressure does ment and travel. These should consist of the throttle, mixture not immediately riSe the engine should be stopped and the cause control, carburetor heater, ignition switch, and etc. investigated. 3. Make sure that the fuel valves are in an ON position. Hot Engine - With the mixture control in the full rich position and the throttle closed. the engine should start immediately 4. Set the mixture control to the FULL RICH position. when cranked. No priming is necessary when the engine is hot 5. Check to see that the ignition switch is in the OFF position. regardless of the outside air temperature. 6. If the engine is cool or has not been operated for some Under no circumstances should the ,starter be operated continu­ time, the propeller should be pulled through by hand at least ously for more than 30 seconds consecutively ~n any two minute two full revolutions. The second revolution should be made as period. rapidly as possible to aspirate the maximum amount of fuel air mixture into the cylinders. As soon as the engine has started adjust the throttle to give a speed of approximately 900 rpm and maintain this speed for STARTING one or two minutes. Then raise ,the speed to approximately 1200 rpm and warm up the engine at least until the oil temperature I Cold Engine - At air temperatures of freezing or above. two or needle begins to rise. three strokes of the throttle should prime the engine suffic­ · 1 iently for easy starting. When the engine is cranked with the Before utilizing full power for takeoff it is advisable to starter'and with the throttle cracked slightly open, it should check the indivl.dual operation of each magneto. It is recom­ start immediately. At temperatures below freezing down to about mended that this check be made at approximately 85% of the rated 10°F. three strokes of the engine primer in addition to the rpm of the engine but since this requires nearly full throttle three strokes of the throttle should be used. After the engine under static conditions. the time for the check should be held to initially starts, occasional operation of the primer may be a minimum in order to insure against overheating and possible necessary during the first 30 seconds of operation. At tempera­ detonation. Single ignition rpm during the check should not be tures below 10°F., additional priming may be necessary. The mix­ more than 200 rpm below that of the dual ignition. ture control should be in the full rich position for all starting attempts. If the starter fails to turn the engine on the first \' RUNNING THE ENGINE or second try, the engine should be turned through by hand a few times with the ignition switch off.