More Test flying of the New Cowling

Well this is a roll up of several days flying. I have flown 3 more flights or 1.7 hours since the last post. After the first flight I removed the cowling and checked everything over, all is well. As far as performance goes I pretty much end up at 143.5 MPH True Airspeed at 2700 RPM at 7.0 GPH at 5000 FT. I have tried the numbers now 4 different times and keep coming up with the same numbers. The plane is climbing out 2650 RPM. I may be under propped a bit and a friend of mine has offered to let me borrow his 76″ dia 66″ pitch pitch.

On another subject I have seen good numbers on the CHT’s no issues there however I have seen larger numbers on the Oil temps during Akro I have seen 210 which is 20 deg higher then I am used to at mod OAT’s so at this cold of temps I imagine i have some work to do on the oil cooler hood I already Knew this though.

As far as energy management the cowling really helps it allows me to pick up speed very quickly. I have noticed that if I push over to the 45 or less I will quick past through 170 to 180 which is great when flying out of maneuvers that cap out. I really notice cowling drag reduction during from base to final I am carrying way more speed then I usually do.

All in all I think it is a good mod some day I will try out the a different prop to see it that helps out but I will stick with what I have for now.

Flying time 1.7 hours total time since cowling mod 2.1 hours total time on the engine 87.0

Test Flying the New Cowling

Well this afternoon I as able to catch a test flight with the new cowling. First off everything went very well. Some temporary perf numbers…I say temporary because it was cold as all hell outside and it was pretty late and the sun was going down.

2700 RPM 32 Deg F OAT 3000 FT 143 MPH True A/S which is less then before but my fuel flow is down to 7.0-7.5 GPH from 8.5-9.0 GPH.

Fire walled (the speed was still building and so was the RPM so I backed off) 3300 RPM 195 MPH Straight and level. I will also explore this test point again as I was kinda in a hurry and just wanted to get a ball park figure.

Note: I was just quickly trying these points and I will go out and try them again in the future like I said I was just trying to get a feel for the the new cowling and what it was capable of. I am a little unsure of the true airspeed number and would like to go out and try that again. I can tell you the plane seemed nice and smooth and also seemed to climb well. The RPM seemed to want to run away on my a bit. It liked to run right around 2950 to 3000 RPM with excursion into the 3200 range. The CHT’s were right at 350 deg F. Oil temp was right at 180 deg F.

I will try this again after I take the cowl off to inspect everything make sure nothing is leaking. I will get back with some more concrete numbers as I get them.

Flight time today 0.3 hours Total time on Engine 85.3 hours total time on the cowl 0.3 hours

Finished up the cowling mod

I dug the foam and clay out of the now cured oil cooler hood.  This took a bit I used some acetone to help wipe the clay out of the fiberglass.  I then took some sand paper and sanded down the area where the engine mount could interface and I also sanded down where the SCAT duct attaches since it didn’t quite fit with the several layers of glass was added.   Did some last minute routing and securing of wires and hoses.  I reinstalled the oil cooler with the new hood which took some trimming to get to fit right.   I then double and triple checked everything and I then re-installed the cowl.  As soon as the I got the last screw in the cowl I heard some piter patter on the hangar roof it started raining so no test flight or ground run today.  Tomorrow is supposed to be cold windy and rainy so I guess the flight and ground run will have to wait.  Oh well.

Time spent today 3.5 hours total time spent 87.5 hours

More little things to clean up

I spent the day finishing off the mold for the oil cooler hood.  I was lucky and found the right size foam cylinder for the SCAT duct.  I used some clay to make the radius’s. Most of the time was spent making the oil dip stick door.  I used Tony’s (Wolf Aircraft) advice on utilizing the blank that I cut out for the door for the door itself.  This worked out great.  I added a shim on the piano hinge to make the top of the piano hinge sit flush with the top of the cowl.  I also added a piece of the 0.032 aluminum for the door to rest against and a place for the camlock fastener receptical.  Anyway I am really happy with the door and it is perfectly placed.  I went home later and glassed up the hood with a couple of layers.

Time spent 9 hours total time spent 84 hours

Nick Nack Clean up

So Now that I have completed major construction on my cowl i have a bunch of nick nacks to clean up to finish this project. Today I installed the 2 1/2″ SCAT flange in to the #4 cylinder baffle for the oil cooler. I cut the old oil cooler lines down to the new size and reinstalled them. I removed the old 90 deg + 45 AN fittings in the oil cooler and re-placed them with a 90 deg flare to NPT fitting. I drilled a new hole for the #2 and #4 cylinder ignition wires since the 2 1/2″ SCAT flange took the place of the old ignition wire hole. I drilled all the holes for the screw that hold the baffle seal on. I installed a hose clamp for the intake SCAT duct. I permanently installed the exhaust and I re-routed some wires. I have some more things to get done like build a hood for the oil cooler, install the baffle seal material. Permenently install the prop and make an oil cooler access door. But there is no reason why I couldn’t get that done this week and try to fly this sucker this weekend if the weather is good enough.

Time spent today 5.5 hours total time so far 75 hours.

Riviting the Cowling Piano Hinge

Tonight I finished up the major construction on the cowling by riviting the piano hinges to the cowling.  I started by setting up the countersink and countersinking the fiberglass.  I borrowed a friends pneumatic squeezer to squeeze the rivits.  That helped a ton and my hands thanked me for not having to hand sqeeze all those rivits. I re-installed the cowling and it looks great.  Just before I installed the cowling I made a template to mark the location of the dipstick door.  I traced it onto the cowling after install and when I have some time I will cut it out and install an aluminum door using some spare piano hinge.  All in all a good day

Time spent 2.5 hours total time spent 69.5 hours

Mounting the Cowling Permenently

Today I started off by trimming the spinner back about 3/16 – 1/4″ to help leave a gap between the cowling and the spinner.  I then set off to mount the cowling permanently.  I already have nut plates and holes drilled on the firewall so I needed to transfer them to the cowling.  The only way I can do with is all at once.  So I made 31 transfer tools out of aluminum strips with a rivit on each end and holes drilled on the other side.  I then used a flush screw to hold the transfer tools in each nut plate and use the top side of the transfer tools as a guide for my drill.  I drilled all 31 holes and then countersunk each of them for the tinnerman washers.  This took quite a while once completed the cowling was nice and strong and sitting perfectly where it should with the perfect gap between the spinner and the cowling.  In the last picture I have some paint touch up work to do taking this cowling on and off 100 time I had scratched the paint a little.  Lets be honest with my cowling to paint, my wheel pants to paint, gear legs to paint.  I have some painting projects .

Time spent today 7 hours total time spent 67 hours

Installing Spinner nutplates and screws

As the profile cutting is completed, I have the also important and scary drilling the holes for the screws that attach the spinner cone to the back and front plates.   I started with making sure that the spinner was on straight when it rotates I don’t want a wobbly spinner so I used a laser mounted to a tri-pod to make sure that it was centered.  I used cleco clamps to hold the spinner to the back plate while I adjusted.  It didn’t take much as it was restricted to move to much by the front spinner plate.  Once I was happy I need to figure out the screw spacing.  Evenly distributed 12 screws on the back plate and 7 screws on the front plate.  I figured that would be enough to keep it in place without putting a ridiculous amount of screws on the back.  I wanted less screws on the front so I thought 7 would be enough.  Wolf sent me 20 screws and nut plates so I had one spare.   I measured the distance with a string and subtracted 3/4″ on each side so 1.5″ total then divided that by one less then the number of screws so I would get the correct number of gaps not screw spacing. 6 screws = 5 gaps right! Just checking to make sure you were awake LOL!  I set the screw holes 3/4″ from the back of the back plate because I still need to trim about 3/16″ – 1/4″ off to make the spinner clear the cowling which needs to come forward a bit to make it fit better.   Anyway started with 3/32 drill bit and worked my way around the cowling drilling and clecoing.  I then removed the spinner and started installing the nut plates.  This is tedious and take awhile but I got all 19 nut plates installed and re-assembled.  I then re-installed the cowling to see how it looked and of course it looked great.  This whole process along with figuring out how to do it right the first time took forever as in 6 hours.

Time spent today 6 hours total time 60 hours