Mark Hubelbank

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0353 Fuel pump modification, To allow the use of AN fittings, the fuel pump top was removed, the fuel lines were drilled out and tapped for 1/8 NPT. Be very careful to flush out all metal chips. 0354 Although it is often recommended that the gasolator be in the lowest place in the fuel system to let water drain to it, this is fundamentally violated by the required location of the fuel selector valve which is higher than the bottom of the wing tanks. The real purpose of the gasolator is to capture water before it gets to the engine. 0363 Firewall parts location, The airbox was mounded so the waste air could flow directly down. This required a U in the cable. The extra friction from the additional bends does not effect operation
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0397 The carb fuel coupling was modified by removing the barb at the end. Then a standard threaded fitting was drilled out to 0.250 to snugly fit over the original fitting. 0405 The fitting on the carb and the threaded fitting were then cut so the carb fitting would come too almost the end of the new threaded fitting. The two were soldered together. A propane torch was used. Be careful not to heat the body of the carb. 0406 Get all surfaces very clean with a fine sandpaper and use flux (not acid) before soldering.
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0414 Fuel flow sensor, Not shown in this picture is the extra support under the fuel flow sensor to take the strain off the elbow on the fuel pump. Although this violates some of the rules in mounting fuel flow sensors (length of straight lines), it works perfectly with the engine fuel pump and reads slightly high when the electric pump is on 0415 Fuel selector valve 0417 Finally all surrounding areas were masked with tape and epoxy weld was used to add strength to the joint. Clean all surfaces with paint thinner before applying the epoxy. Flush out the whole system with paint thinner when finished.
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0418 Cabin side of firewall 0419 Fuel lines from selector 0431 Panel made from turbocad files available from mhubel@nemon.com
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0438 Flex fuel lines to engine pump, All flexable fuel lines were factory assembled AE466 with built in fire sleeve 0440 Fuel line from right wing 0455 An extra block was inserted into the flap arm to insure that it would not deform when the bolt was tightened. The hole for the bolt was drilled through the block.
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0456 Right flap adjustment bracket shown prior to the final connecting strap being bolted in. The bracket is made of 1/8 material. 0457 Mounting blocks for the right flap adjustment bracket. The one closest to the arm has one bolt thought the torque rod and another over a slot cut in the bracket to provide a clamping action. 0473 Union in fuel line to wing, Putting a union at this location makes it much easier to remove the section of line between the wing and cabin.
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N708HU 0613 Mounting bracket for mixture cable 0618 Bottom view of mixture cable and bracket
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0623 Side view of Mixture cable and bracket 0643 Block drilled at 30 degree angle for throttle cable. A set screw is used in a tapped hole on the side to lock the cable in place. 0646 Forward end of spring added to balance elevator weight. Spring is mcmaster.com 9640K234
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0648 Forward end of elevator spring 0653 engine side view of duel throttle lever arm support. This was not used with the 1 inch outlet extension as the engine mount did not provide space. This duel throttle system was latter replaced with a direct action system. 0658 Top view of duel throttle cable bracket. Not used with one inch extension.
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0660 Side view of duel throttle lever arm in full throttle position. Not used with one inch extension. Note washers between all moving surfaces. 0662 Duel throttle lever arm in idle position. 0666 Tube on intake showing vertical plate. This version of the tube was 2 inches long. The one used in the final assembly was 1.25 inches long.
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0670 A 2.25 inch dia by 1.25 long tube was held in place on the intake side of the carb by a block of phenolic and 4 set screws. Inside the tube a single vertical piece of aluminum was riveted using counter sunk 3/32 rivets. This reduced the angular airflow problems caused by the sharp bend in the intake hose. 0674 Primer cable lever arm shown in "pulled" position. 0677 Connecting tube with one inch extension.
0946 1004 1008
0946 TBI-40-3 mounted on the Jabiru 3300. A 2 inch thick spacer box is between the engine and the TBI. This replaces the Bing carb flange. 1004 Side view of the TBI-40 with spacer box. Also shown is one end ot the tuel throttle bracket. One cable exits on this side the other cable is on the opposit end of the TBI. 1008 Throttle linkage end of the TBI showing second throttle cable. This cable housing moves with the linkage. The center line is fixed. Also shown is the bracket and cable for the mixture control.
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1049 The original AN6 fittings and hose have been replaced with AN10 parts. Additionally, the oil filter adapter was replaced. 1054 A cover for the center consol was made out of the same material used for the seat cushions. It was cut to shape using a paper template of the console. 1059 Snaps are used along all edges of the console cover to hold it in place.
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1056 The section covering the control stick was made using two overlapping pieces of double thickness spandex. Each piece was the full width of the opening and was attached to the cover at the ends and one side. The forward end of the spandex is held in place by a piece of plastic and two snaps. Sewing this is difficult, at the aft end, one is going through 4 layers of spandex and two layers 1061 The finished cover showing the control stick coming through the overlapping spandex sections. 1065 The wire with the brade on it is pushed into the mag over the pin. The end is then covered with RTV sealer and with 1/2 inch heat shrink tubing. Finally it is secured with tie wraps. The final assembly should have a resistance of 11-15K ohm.
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1066 intake hose now is closer to vertical (about 30 degrees to the left) resulting in more even EGT values 1069 The more vertical intake hose results in a long U shaped hose with two right angle bends. Note the cover on the air box is reversed and the air intake to the air box is now interior air. 1070 For the replacement mag wire magnecor wire (electrosports 70 ss25 200T) was stripped so about 0.5 inch of the core shows and 0.5 inch of the outter black layer is removed.
1071 1072 1091
1071 To make a good contact 2.5 inches of the braided shield of RG58 wire was removed to use as a contact. 1072 The core of the Magnecor wire is folded back and the braid is wraped over it. The rest of the braid is folded and twisted up to take up the space from the end of the pin in the mag to the bottom of the hole. 1091 bearing pressed into test plate showing tool made to press it in without touching the inner race. The bearing is a McMaster 57155K16 and the hole was reamed out with a McMaster 3087A54 reamer.
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1094 Drilling out the holes in the existing brackets required a close fitting right angle drill. 1095 One of the bearings shown pressed into the bracket. 1096 A spacer made to bear tightly on the inner race of the bearing. The bolt is an AN3 and the spacers were made out of bronze bearing stock. McMaster parts 2934T31 and 6391K124 were used.
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1146 The bottom view of the adapter box between the TBI-40-3 carb and the engine. It was made out of 2 x 4 inch aluminum tube with 0.25 inch walls. 1149 this mixing plate was put in the adapter box. the air flow was forced down through the holes at the bottom and back up to the engine. This significantly improved mixing and eliminated one very high EGT. There is some power loss but it was not measured in a careful before and after manner. The improved mixing appears to compensate for some of the reduced air flow so the total power 1184 Viking in crate. Planks were used to slide the crate off the trailer and on to the ground.
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1185 Viking in packing 1186 Viking on shipping base 1187 Viking on shipping base
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1210 2 Engine mount showing 1.5 inch spacer (McMaster). Also shown is the additional stiffener to take some of the vertical load off the spacer. 1210 3 Engine mount with additional spacers and support brackets. The engine was moved forward 1.5 inches for better W&B. 1210 4 Picking up engine from shipping position.
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1210 5 Engine being lowered into place 1210 1 engine mount rubber held in place with fender washers. 1201 Hole saw modified (was 1.25 inch). Saw cut short with grinder and bent hacksaw blade put inside. Drill replaced with rod. A short right angle air drill was used to clear the limited space. Note, McMaster sells a tool like this ready to use.
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1204 step drill with stop washer and cork protection to make 5/8 inch hole for tank fitting. Washer drilled out large enough so most of the 5/8 step shows. 1206 tank fitting in place. A 1/8 inch hole was drilled first through the rib and tank. It was then opened up to 1/4, Then the modified hole saw made the rib hole. Finally the step drill made the 5/8 hole in the tank. 1208 Steel tool used to tighten the tank fitting. A cut off open wrench could have been used also.
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1209 tank fitting, McMaster Carr 8682T21. Note flats filed so it can be held with 13 mm open end while tightening the nut. A fibre washer was made for the inside and it was coated on both sides with a non-slip gasket forming material. Note that this must be put inside the tank with the threaded portion extending out. The fitting was fed in using the wire and plastic hole covers through the fuel filler 1210 The fuel selector valve with an4 (return) and an6 (feed) fittings attached. note the use of right angle and 45 degree fittings to make all the fittings point in the right direction. These are available at McMaster Carr. It should be noted that this valve is only made to work with up to 0.060 panels. I had a 0.110 panel and had to make up a replacement mounting plate. 1212 End of tank showing addition of return line
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1215 Fuel selector showing feed and return lines to fuel tanks. 1218 Fuel pumps were mounted forward of the Firewall. To avoid having high pressure pumps inside the cabin and the required overflow pans the pumps were mounted on the engine side of the firewall. Temperatures have been measured and the air temperature at the pumps has never been seen to be more than 20 F higher than ambient. Additionally the temperature of the fuel was measured by using a thermocouple tightly attached to the pressure regulator and the temperature was never more than one degree different from the tank temperature. There would appear tha 1220 Heater core with additional gasket material showing. This was 1/16 inch material to both provide a seal and adjust the spacing. The core was from a 1995 Geo Metro (Spectra 94758). It is designed for 1/2 inch hose.
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1222 test of hose for use as vacuum line. The external pressure was raised to 100 PSI without any reduction of the inner diameter of the hose. The hose was from http://www.hrpworld.com and the part number is BL-6103 1225 adapter for oil temp and pressure sensors. Note hole in adapter is not big enough for the sensor. It is possible to put the temperature sensor on the side hole but that would not put it directly in the flow of oil and possibly produce a false temperature reading. 1227 adaoter removed and mostly cleaned. Note three holes in block. Only two line up with holes in adapter. The bottom of the hole which the temperature sensor is threaded into was enlarged. If done on a drill press a very short drill should be used to minimize bending, and the hole should be drilled very slowly.
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1228 gasket being made up to expose all holes which are supported by adapter and completely cover unused hole. 1229 Adapter with sensors in place with gasket and additional gasket sealer to insure a good seal. 1230 steel block drilled and cut to make it easier to crimp #4 wire lugs.
1232 1238 N708HU_WB
1232 added additional circuit breakers to power the ECU and fuel pumps 1238 The top cowling will be held on with Camlock fasteners. Weight and balance after installing Viking engine Mar 5, 2013. Oil and coolant weights were measured before engine start so are approximate. Another test will be posted with post engine start numbers.
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1345 Viking Engine valve cover leak fix. Edge of valve cover showing modification to allow Honda gasket to cover the arc in the casting which the original valve cover design did not fully cover. The cut was done with a Dremel using a combination of various sizes of cutoff wheels and Dremel 9901 Tungsten Carbide Cutter. I erred on the side of not removing too much rather than risking unrepairable damage to the cover. 1346 Valve cover addition showing area machined in block to allow the Honda gasket to cover an arc in the casting. Note that the edges of this had to be chamfered to allow it to clear the fuel injector mount and the length has to be limited so it will not hit a rounded section of the valve cover or get in the way of the fuel injector plug. The cutout was made using a Dremmel cutoff disk mounted in a drill press. 1348 valve cover edge showing the area where the material needs to be milled down to allow the extension to be added. This was done with a Dremmel cutoff wheel by mounting the Dremmel in a holder and slowly lowering it as it was passed over the area to be removed.
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1349 Added block for the valve cover of the Viking engine. The block is attached with JB Weld cement and the two screws (4-40) shown. The screw heads were bedded with more JB Weld to seal them. If you can weld aluminum and then machine the result this would look nicer. 1350 Finally a small block was made to fill up the section of the slot which is no longer used. This helps hold up the gasket. Although it stays in place by itself, held in by the gasket, one could cement it in place with JB Weld. 1351 The manifold end of the Viking duel throttle arrangement is shown. The lower throttle cable is from the left side and the upper one is the wire from the right side. Note the offset. One could also make the bracket holding the cables so no offset was required.
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1352 See 1353 for a full description of this. It is the Throttle linkage end of the duel throttle update. 1353 Throttle end of the Viking duel throttle update. The original rod end bearing was replaced with a McMaster 60645K311. Also a star lock washer was placed between the right angle bracket and the rod end to stop rotation. This arrangement works only if the plastic tank supplied by Viking is replaced with a right angle hose. The plane has been flown in hot weather (95F) and no change in cooling was seen. One may have to place some protection on the hose as the throttle cable moves and may touch the hose. 1359 Honda Fuel line from the Viking with the hose pulled back showing the crack in the steel line at the point the metal was cold worked. See image 1360 and 1369 for a fix for this.
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1360 The Viking Honda fuel line was cut back to the first "barb" and a McMaster 5182K808 fitting was used. This fitting is designed for use with steel tubing, is rated for 3280PSI at 1200F (with stainless steel). Since the exact type of steel used for the fuel rail is not known this needs to be derated but there is a 78:1 safety margin so this appears to be very conservative. To further reduce the stress, the hose was clamped to the engine. 1366 708HU ECU which replaces the Viking ECU. This is one of the first 3 prototypes. Unless others request these units, it will be used as shown. If more were made, the black relay can be eliminated, different connectors would be used, and all jumpers (these were there by design) would be eliminated. In this version the MAP sensors are under the board. 1369 Engine wiring harness for the N708HU version of the ECU. There are no splices in the cable. All wires go to the ECU connectors. Wires which leave the main bundle are protected by two layers, first a layer of heat shrink tubing, then a wrap of small diameter spiral wrap. A;so shown is the support used for the fuel hose. The bracket was made out of 0.090 thick Aluminum.
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1373 N708HU ECU status display. At this time the display has been programed to show RPM, fuel flow, Manifold pressure, coolant temp, ambient temp, oxygen sensor output (AFR). Other things could be added (oil temp/pressure?). This is a Digikey NHD-0216K3Z-FL-GBW-V3-ND ($19.75) 1381 Fuel pump arrangement modified to use the Walbro 255 pumps. The pumps were fitted with AN6 adapters. This required washers under the adapters. These are now available with the adapters. All connections are AN6 except for the return line which is all AN4. Note the 0.5 ohm resistor mounted next to the backup pump to reduce the voltage slightly. Without this, the flow is at the upper limit of the regulator. The voltage on the primary pump is controlled by the ECU. 1404 Dynon roll servo mounted behind the seats and connected to the torque bar with a push rod
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1413 Thermostat replacement assembly also showing the reducing hose used to connect to the radiator. It was a 1.25 to 1 inch 45 degree elbow. For clearance the temperature sender was also replaced with a shorter unit purchased from Dynon. Since the ECU is the 708HU unit, it can be programmed to accept a range of senders. Also note that the cabin heat is connected to the fitting below. This is important to provide some flow when the engine is cold. See picture 1416 for more details. 1416 An alternate thermostat and cabin heat arrangement are shown. The origional thermostat was replaced with a Meziere WN0071 housing with a 1 inch OD tube welded to the side of the intake. The outlet is then plumbed using a 1.25 inch to 1 inch reducing 45 degree elbow. The thermostat element is a 180 degree chevy unit. The bleed stopper was removed leaving a fixed 1/8 inch bleed hole. This allows the thermostat to sample the temperature as the engine warms up. The cabin heat is connected using a bent pipe and rubber hose sections. This also provides a continuous bypass. 1419 The ECU enclosure was made using an off the shelf box. The ECU is slid into the bottom slot and cutouts are made for the connectors. While the dimensions are shown on the forum drawing, drilling a series of hold along the center line, then opening them up to 3/8 inch and filing the resulting slot smooth works reasonably well. Four holes can be drilled in the bottom and used to mount the enclosure. Note the top can be slid off to do this. About 3/4 inch in from the corners is a good location. Using round or pan head screws should provide good clearance to the bottom of the board.
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1424 The ECU is shown with the hose connected to the MAP sensors. With the proper hose, no clamp is required. A piece of velcro was placed on top of the relays to hold the hose in place. The hose on the center of the T can be routed to either end of the box depending on how the MAP line is routed in the aircraft. 1433 The least expensive way to make a through panel fitting for the MAP hose is to use the supplied 1/8 to 1/8 nipple. Drill a hole in the panel just large enough to allow it to pass but not for the ring in the center. Then make a bracket with a similar hole to hold the nipple in place. Alternatively one can use a pre-made through hole nipple from McMaster 5058K116 1434 If one is using a armored line with AN3 fittings for the MAP line, then this shows using an McMaster 50745K25. It is shown soldered to a piece of copper salvaged from a section 5/8 copper pipe flattened out. This will be trimmed and screwed to the ECU enclosure.
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1438 The 708HU ECU Revision B1 1439 The air intake was changed so that it uses the air box on the oil cooler. A K&R filter was put between the oil cooler air box and the added air box for the engine air intake. 1444 A hole was made in the cowling to allow access to the dipstick. A standard hole plug was used to cover the hole in flight.
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1452 Although not required on a fuel injected engine, a ECT probe was put in the muffler. This temperature measurement is well removed from the exhaust valves but it still is a usable measurement. In this installation the cruse temperature is 1200 F +/- 50. When the AFR probe (O2 sensor) is unusable because of leaded avgas, this can be used as a backup to verify that the mixture is not significantly off. 1463 the partly complete regulator installation. 1464 Original regulator from the Viking installation. It is a 3 BAR regulator. The closest replacement seemed to be from a BMS 1997 318 but that unit had a larger diameter rim so it will not fit. Of note is that the BMW unit appeared to be much more solidly made.
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1467 Replacement regulator installation using regulator from SummitRacing.com The regulator was part AEI-13109 and the following parts were used: AER-FBM5282 adapter (2) FRA-499206-BL 90 deg (1) MRF-MP-3071 #6 plig-1/8 pipe (1) EAR-91616ERL 6 Female to 1/8 pipe (1) EAR-AT934106ERL fitting (1) FRA-4981003-BL male-female adapter (2) #6 Female-Female union (2) ECU2687 Test jig used to simulate an engine and verify that each output of the ECU is operating. ECU1917 To make the harness lay out the locations of junctions and end points on a piece of wood. Use nails or screws to hold the positions and allow the wires to be bent over or tied to. Insure that there is enough extra on the ends so that they can be trimmed for the connectors.
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ECU1921 Closeup of the template used to make the harness. Note that the wrap was put over each group of wires exiting from the harness before the wrap was put over the whole harness. If all one color wire is to be used(like white), extra labeling is needed to be sure wires are not mixed up. 1472 At times a smell of fuel could be detected in the cockpit. It was found that fuel could wick up through the treads of the fuel filler assembly. From there it was pulled into the cockpit through the holes for fuel lines. This does not have tapered threads so it can not provide a good seal like a NPT assembly. To seal it, an O ring was added. Although there is not a serface really designed for the O ring, it does seal very well and it eliminated all traces of fuel odor. 1487 N708HU and myself at the B18 ice runway on Alton Bay NH
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1494 N708HU at the ice runway B18 1497 A busy day at B18 4018 Departure from B18