Chapter 23 Engine, cowling, ect.
This chapter has previously shown the install with pics of a Renesis engine, but that will be changing to an install of a Lycoming HIO-360-D1A. The redrive issues for my Renesis install were fixed and then the EC3 programming failed for the "A" side and then the "B" side began to be erratic at high rpm. Since the EC3 is no longer being produced or supported (Real World Solutions, aka, Tracy Crook), then there was only one choice for me to make and that was to change engines. My Renesis will be marketed to an RX-8 driver and not a Cozy driver.
After having trouble with my computer for EFI for my Renesis, I decided to go with mechanical fuel injection system. The Lycoming HIO-360-D1A comes with a Bendix 7AA1 fuel controller that is mounted facing forward (for the Cozy). My controller needed to be replaced and so I went with an updated version from Airflow Performance. It comes with purge valve (with return line to the header tank) that will prevent problems with hot engine restarts. The kit that I am installing comes with a ram air/ alternate air setup. The ram air is off the main NACA scoop. on climb and cruise.
The Dynon system will give full engine monitoring on screen.
Here are the steps for my engine re-install. (subject to edit):
1. "Overhaul" the HIO-360-D1A
As a repairman, I am able to do this task and sign off on it, but that the case for my engine. Thanks to John Boatman, aircraft mechanic, I have been able to accomplish this step. The reason for the quotation marks on the word overhaul is that we left the intake guides alone and did not replace them. All four exhaust guides were replaced and rebored. This step took a lot of work, but in the end I have a dependable engine.
2.For "fuel" (injection system):
A. Airflow Performance FM-200 Fuel controller and Kit # 8000007
B. Rebuilt P/N LW-15473 mechanical fuel pump (high psi)
C. Check valve (50 psi rated) to allow the use of one of my Walbro high pressure electric "wet" fuel pumps as a boost pump that are located in my header tank (gravity fed 2.25 gallon tank)
3. For "fire":
A. Overhaul the two Bendix 1200 magnetos
B. New wiring harness from Contenental between the magnetos and the spark plugs
C. New SOS vibrator from Contenental for better engine starting.
4. New starter, Sky-Tec XLT
5. New alternator, Plane Power(ACS) 60 amp
6. Prop extension from Sabre
7. Prop from Cato
8. oil filter adapter(B&C) and new Vernatherm valve(oil flow thermostat)
9. Major modification of top and bottom engine cowlings
10. Install engine monitor module from Dynon and intall sensors on the Lycoming
1. Lower Cowling Lip
7. Top and Bottom Engine Cowling
The first step for making a lower cowling is to make the first four inches with the foam, before I place the fuse lip off the fuselage. The cowl lip is four inches wide, and the fuse lip is four inches wide, but two of those inches overlaps the fuselage. I microed on some foam blocks that overextended the contour. The scoop blocks are per plans and are added into this setup. I had already filled the bottom before this point so I sanded off the micro from the last 2.5 inches of the aft of the fuselage. I recommend this approach, because the final contour is already set and the sighting is much easier. I sighted down the sides of the fuselage to get a symmetrical taper of the cowling lip. I trimmed down and then looked from the nose of the plane, "peeking" left to right. Since a four ply BID layup (the main cowling layup) will be glassed on top of the aft two inches of the cowling lip, the aft two inches of the foam needed some additional taper. The last picture show the stepdown from the end of the fuselage to the foam. The cowling lip for the lower cowling was done as a 6 ply layup, on a plastic template (two ply BID-45 degree and two ply UND-in line-LT to RT, and then 2 more ply BID-45 degree). The fuse lip is a 4ply BID and so I trimmed to account for this. The addition of the UND on the cowling lip added some problem on the shaping, so you may choose to stick with the 4 ply BID. The second picture shows the gloss on the foam. I painted on epoxy and let it cure. The stiffening action is vital for the contouring of the transferred glass layup. I did this for the LE of the strakes also. Do not use blue masking tape. Use a premium tan masking tape and it will peel off. The tape is needed to prevent a dip in shape at the foam junctions, since micro is not used here and the outer lip would also have that dip with this technique. You have to clean the under side of the cowling lip to add some 1.5 by 2 inch 4 BID reinforcements for the nut plates. Later pics show the scoop lip and "upper part" construction.
In the first picture, the fuselage lip is on top and the cowling lip is below. I drilled the holes for the Ms24694-S51 screws before separating the two. The holes will be redrilled at several steps along the way, but the orientation will be set. The separation of the two layers was made easier by using the dremel to separate the part of the cowling lip that fit over the "wing root" rib from the main portion for the separation of the two pieces. I reattached it later. The extra glass that drooped down on the cowling lip is left that way to maintain shape until it is attached to the fuselage lip with the nut plates and machine screws (see pic below).
In the first picture, I had to "glass up" and so I used masking tape to hold the glass on the inner side of the scoop lip. Then I added a lip on the upper and side parts of the scoop "throat". The air will circulate through the cooling coils and then be directed to exit points at the aft of the wing root areas. The 200 m.p.h. wind must be directed to the coils and be made to slow down enough to do the heat transfer and then regain speed at the exit points. This involves pressure changes, ect. I read Tracy Crook's conversion book and I think that the Cozy platform can lead to better cooling conditions, since everything is forward of the propeller. To do all of that, I must contain the air flow in ducting along the whole way. Back to the pictures, there is a space between the sides of the scoop throat and the fuselage lip to allow the cowling lip to slide in place.
The last pic of the group shows the cowling lip screwed onto the fuselage lip with the MS21069L3 two lug anchors, aka nutplates. You may see the 4 ply BID reinforcement strips on the inner side of the fuse lip to the aft of the CS. The small bit of tan on that strip is some tan masking tape that has not been sanded off. I needed these reinforcement stips to lay down perfectly in the corner, so I placed masking tape instead of peel ply on the "bottom" side and with some ficro in the corner, I adapted the corner and then placed masking tape on the edge to the inner side of the fuse lip. After cure, I trial fitted the cowling lip again and it still fit well. I had a 1/4 space from the forward edge of the cowling lip to the CS/FW before these layups were placed. Also shown is the 1.5 inch wide 4 ply BID strips on the bottom of the cowling lip at the nutplate points. I used strips, because I wanted to maintain flexibility of the cowling lip to adapt to the fuse lip.
Now, back to the first picture. I clamped the two lips together. The original drilled holes were preserved in the cowling lip and redrilled after the reinforcement pads were placed, but the micro on the fuse lip obscured the holes there. So, I got out my 90 degree attachment for my drill and drilled from the inner side of the cowl lip to remake the holes in the fuse lip. I marked tick lines to exactly refit the lips back together. I trial fitted the machine screws through the two lips,and then I took off the cowl lip and attached the nutplates. See the second picture for that. I ordered the exact nutplates called for in the plans, but I chose to place 1/8th inch pop rivets from Lowes. So I screwed the nutplates onto the cowl lip and drilled the holes out to 1/8th inch and placed the pop rivets. They are very secure and it was easy to do.
In between the second and third pictures, I refitted the two lips and placed the machine screws (with the A3235-028-24A washers), but this time into the nutplates. I drew outlines with a pencil around the washers and took out every other machine screw/washer and recessed the fuse lip and replaced those and repeated the process with the rest.
Note: All reference to urathane soft foam is for the polyurathane soft foam.
2. Fire wall planning
Fire wall: You have a limited amount of space on the firewall that is available for mounting things after you exclude the space taken up by the engine mount points, aileron travel zone (and autopilot roll servo connector), electrical conduit exit areas, rudder pulleys, vent lines, fuel send and return lines and you see that it's a busy area. With the space left over, I need to mount the following:
have less "loose ends to tie up" with the Renesis choice, and for me that work out as less risk.
7. Top and Bottom Engine Cowling