RV-7 N117TR

[crabandy]

Thanks Kurt, hopefully the Wx will cooperate!

I did find several places that needed some more silicone on my baffling around the top engine mount bolts and on the case inboard of the oil cooler.

It doesn't take much pressure to push the metal baffling around the rocker covers out to create a leak because of the limited screws holding it to the head. I loosened them up and put a bead of silicone around each head to seal any potential gaps. My initial results are inconclusive so far, temps seem to be running about the same, any benefits are masked by different ambient temps etc. I was expecting 5-10 degree improvement, we'll see.

[crabandy]

My experience with the magic shrinking air filter, this was after 31 hours tach time. You can see the sharpie marks of the original filter size on the bottom of the FAB. I've got an email out to K&N now, we'll see what their response is.



New filter:


No cracks on the Carb to Fab plate but my .032 angle brace did crack and break, I make a new foot out of .063. We'll see what happens, probably break the topside now. I'm thinking there's a wholelota shakin going on down here.
http://i1137.photobucket.com/albums/...psq3jhubzz.jpg


Found something new in 3 hours since the last time the cowl was off, pretty sure I didn't miss it at the oil change. The clamps didn't seem too tight, I loosened the clamps and repositioned the muff on the end pieces. We'll see how she holds.


I put some packing tape along the rub line of the baffling material on the bottom of the top cowl. I found that my baffle material was sealing well except where the material overlapped it wasn't contacting the cowling for about 1/4 inch because of the doubled up material. I put a dab of RTV to hopefully fill the gap and smooth the transition at the seams, I put on the top cowling and let the RTV skin over about 45 minutes. Then I went flying to hopefully squish things in place. We'll see next time I pull the cowl.



I also cut 1/4 inch off the cowling exit, initial test show slightly cooler but need more flights to know for sure.

[crabandy]

Installed Saber Manufacturing's heaviest crush plate, I lost my note but if I remember correctly it weighed 19 lbs 4 oz. The 7 inch bolts were about 1 ounce more than the 6 inch bolts. The original crush plate was about 20 oz, so somewhere around 18 lbs 6 oz on the nose more than the standard crush plate. Defenitely changed the flying characteristics, a little more nose heavy than I'ld like it solo but will probably be much nicer when flying with 2 aboard.



I computed the theoretical new empty W&B, but I want to verify the new W&B with the "real" empty airplane. I only have 3 five gallon gas cans so I had to (twist my arm) burn about 4 gallons of gas checking out the local grass strips.


Good news is my fuel guages are accurate in flight, fuel flow/totalizer is accurate with 100LL. With Mogas my fuel flow/totalizer will show about 25-30% than it actually burns. I'm glad I made the fuel drain valve for my draining my tanks.


My left fuel drain didn't drip but was always moist with fuel, extended sumping of fuel didn't fix it so I thought I needed a new o-ring. Turns out it had some red fuzz wrapped around the o-ring, same red fuzz I found in my fuel filter. I believe this fuzz was leftover from red shop rags used to clean up the inside of the tank after I did the fuel pickup service bulletin.


I used a cleco clamp to hold it open to clean the quick drain.

[crabandy]

All that weight really adds up, I started at 1038 lbs and ended up at 1079 after the landoll ring/heavy crush plate/gear fairings/portable radio and intercom. My new CG is 79.77, with 180 lb me and a 200 lb aerobatic instructor and zero gas the CG is 84.38. Whew just inside the aft aerobatic limit of 84.5, 23.5 gallons of gas puts me right at the aerobatic gross limit of 1600 lbs and moves the CG to 83.99.
Since the tanks were empty it was a good time to calibrate the fuel gauges for the ground on the G3X, now my gauges should read correctly in the air and on the ground. I also noted how many gallons per inch in the tanks for a dipstick type gauge.
My wife suggested we fly to lunch (YES!!!!), so we checked out Kingsley field's Hangar Kafe (MO9) halfway between Joplin and Springfield Missouri. Great food stop and great prices!



Mr. Kingsley seems to be a Minneapolis Moline fan and one was mowing when we arrived.


I got some screen shots running LOP, but left the cards in the airplane. Hope to post them soon.

[crabandy]

LOP screen shot from the other day, with the throttle pulled back my EGT/CHT spreads really even out. 8000 feet density altitude, around 85 F on the ground. 50-80 * LOP, my EGT's peak right about 1450. With the increased OAT's I haven't noticed the decreased CHT's of 330 I was seeing at 40* OAT.


With the mid 80's my CHT's/oil temp has been on the rise. I believe I did a decent job at sealing with the baffles etc, any tweaks I've done to the baffle sealing didn't show any noticeable difference. Thanks to others on VAF I decided to make a cowling exit bump/ramp.
Stock exit.


I used poster board to make a template, and used an old oil field pipe to shape a curve into the .017 stainless.


A small break in the top to match the angle of the engine mount about finishes it off.



A strip of .063 holds it together at the top with nutplates and a couple of adel clamps.


A peek from underneath, I think the exit is actually smaller but way smoother. You can see the flap of baffle material I used to seal the space between my exit ramp and the engine control cables.

[crabandy]

First test flights with the exit ramp are very encouraging, OAT's were down to the mid 50's but I was seeing much cooler CHT's than before. Taxi operations seem to be 40-50* cooler. I had numerous shutdown/startups today, usually I see 410 on #4 CHT on a heat soaked climbout at 125 IAS. #4 cylinder is my leanest cylinder by at least 100 *F EGT, all my other cylinders were cooler as well from 350-375ish on the heat soaked climbout. I also had my first aerobatic lesson today, 4000-6000 density altitiude around 75 ish% power with CHT's from 326-375 and oil temps 170-180's. I consistently saw 210-230* CHT's after landing, I've never seen them that low.
I did notice a deeper exhaust sound and some vibration in the floor after adding the ramp. Not sure if it's the ramp or positioning the exhaust stacks after adding the ramp.
I plan on extending the stainless steel aft on the belly and extending the exit of the cowl to semi-match the slipstream flow as depicted from the -G testing done previously.

[crabandy]

I met a great bunch of guys at K81 for lunch today, my aerobatic instructor was breaking-in the new 90 on this Luscombe. 11-13 inches of manifold pressure and 95 knts IAS seemed to work well, until we had to descend to pattern altitude than I was at idle.


My RV next to his Pitts nestled in the hangar.


I have to say the first aerobatic lesson was right up there with the first flight in my RV. First he wanted to see my aileron rolls, then he took the controls for a loop. My head was spinning for 30 seconds after the first loop, after verbal cues where to look and feeling the pressures on the stick/pedals on the second one I was hooked! Next was barrel rolls, my favorite maneuver so far! He also introduced cloverleafs and humptybumps and several other manuevers I've forgotten.

After I made a pit stop at OWI I went back up to practice loops and barrel rolls, both my instructor said I should practice solo before our next lesson. Long way to go but it's so much fun, what an airplane!

[crabandy]

Finally back to more airplane stuff, I've been posting my cowling exit ramp/bump on this post.

http://www.vansairforce.com/communit...ight=exit+bump

2nd try on my upper intersection fairings, I tried the expensive frog tape to make the tape removal easier. I projected the trailing edge of the gear leg fairing onto the belly skin, I measured that point reference the stiffeners to place the aft radius.

I used RTV to glue some 1/4" inch foam to both sides of my .063 aluminum radius pieces. I then RTV'ed and taped the pieces in place behind the gear leg fairings. The first time I just taped the .063 aluminum in place but it moved as I was forming the clay. I'm thinking I can easily sand the foam at the edges and the extra surface area and RTV should hold them in place. The clay should cover most of the foam and RTV.

[crabandy]

A little sanding on the foam and 3 hours of smushing clay yielded my shape, I tried to make the frontal area slightly smaller and sharper (instead of curvy). The front curve follows the leading edge of the gearleg fairing higher than before. The trailing edge is slightly longer.



I sprayed a layer of paint over the clay for a smooth surface to apply wax to, I ended up putting packing tape over the clay and then wax. Last time I used nothing and the clay was semi embedded in the fiberglass.

New glass.



I redesigned the split line for fairing removal. I made the split line under the fuse and aft of the gear leg fairing trailing edge so no split line is seen from the top and the aft curve is solid. I left a piece of plastic between the split line for removal after it cured.



I hate spending hours removing the packing tape from the airplane so I tried frog tape as the base layer before the clay and packing tape. Worked very well, stuck well and removed very easy with little to no residue. It was expensive $10 for the big roll but it's like paying myself $5/hr to remove residue.

[crabandy]

Family, work, Oshkosh = busy busy busy!

I was able to finish pinhole filling, priming and reattaching the wheel fairings several days ago. I think my sanding gets a little too anal and I broke through the epoxy cost ting I a few places and still have a few pinholes. Oh well, practice makes perfect.

Lower transition fairings faired into the pants, I still have to massage a paint gap but getting closer.



I added a screw to the aft upper intersection fairings by drilling and tapping the lower fuse and stringer.