What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

15hr report

akarmy

Well Known Member
I know I really enjoyed reading the early reports of phase I when a number of the rest of you were going through it, so here's my short update.

9 days, 15.2hrs of flying... WOW it's been awhile since I've flown this much.

As of now I think the engine is mostly broke in, the temps have stabilized and are generally below 400 when not climbing under full power. My hottest Cyl is #2 and it's always the hottest in most any situation. Have to start looking at some cutting down of the fin blockers in front of 1&2 since the rear Cyls are the coolest. In 15 hours I have added 1 quart of oil thus far, so it's using a bit, but not too much. The dual P-mags have been flawless thus far and start and run easily. The Catto prop seems pitched right, but it's hard to tell completely since I don't yet have the wheel pants installed.

The most distinctive thing that everyone keeps commenting on is how quiet this RV is. I am using the Vetterman 1.5" crossover pipe system with dual mufflers. That combined with the 3 blade Catto prop make for a very quiet plane both on the ground and in the air!

Only problems thus far was the oil door popping open on the first flight. I made it out of Aluminum and it flexed too much and the latch let go. I added some .063 angle heavily fluted to the underside and it's been fine ever since. The second thing was the exhaust hangers slipped off on one pipe causing a few min of anxiety as the pipe rubbed on the cooling ramp. Sounded like something was not right for sure and I quickly landed and found this when I de-cowled.

Untitled by akarmy, on Flickr

That's it for problems thus far. Just add gas and go!

So far I've been to 10,000ft, flown formation, completed the airspeeds, stall speeds, AOA calibration (a couple of times), G testing up to 4 g's. Basic aerobatics, loops, rolls, cuban 8's, Split S. and flown many hours of full rich 75%+ streaking around the local area to break in the engine.

Flying by akarmy, on Flickr

Landings... have been perfect! I love how the RV-8 lands. So easy for both wheel landings and 3-point. Once I got the AOA calibrated I can 3 point using the "donut" on the AOA pro display, and wheel land using the two bars of green for best glide speed. These speeds work out to 60kts for 3 point and 70kts for wheel landing. I've also taken it into my friends 1000ft grass strip using about 700ft. That was using the AOA, seems that I could slow a bit more to maybe 55kts on short final to shorten up the rollout.

Flying formation I noticed the Catto prop does provide quite a bit of braking effect when pulling to idle compared to my RV9A with a Sensenich metal prop. Some of that may be the shorter winged 8 vs 9A, but the prop seems to be helping as well. Still not like a CS prop, but not bad. I'm quite happy with the setup and especially the weight and balance.

Tucked in tight by akarmy, on Flickr

I had my Son help me and we balanced the prop with our EAA Chapter's Dynavibe. Took just a bolt and one small thin washer to get it balanced. Was nice to remove the remaining vibration from the system. It was already fairly smooth with the Catto 3-blade.

Flying by akarmy, on Flickr

My friend Linda-Lee is working on a custom canopy cover which is coming along nicely. We did a fitting the other day.

Flying by akarmy, on Flickr

There has been varied weather to fly in over the 9 days. It being fall in the NorthWest and all.

Flying by akarmy, on Flickr

Rainy days by akarmy, on Flickr

Flying by akarmy, on Flickr

I've spent a lot of time pulled up to the pumps over the last few days. Will be nice to start leaning things out and pulling back the speeds a bit.

Flying by akarmy, on Flickr

In summary the RV-8 is an amazing plane that is a blast to fly. Can't wait to continue to expand the envelope as I get more time on it. One of these days I'll get the wheel pants installed on a rainy day and then can post some final speed and climb numbers. Keep at it, it's totally worth it!

N898TT by akarmy, on Flickr
 
The second thing was the exhaust hangers slipped off on one pipe causing a few min of anxiety as the pipe rubbed on the cooling ramp.

Andy,

The solution to prevent this from happening again is to slightly flare the end of the stainless steel tube that go into the hose. When you apply the hose clamps to the tube, make sure the clamps are over the slightly flared ends of the tubes. The slight flare causes the exhaust hangars to be not easily separated from the rubber hose.

IMG_9416.JPG
 
If you have access to these (Parker Beading tool set), use 'em.
Otherwise flair like Mike says.

parkerbead.jpg
 
Andy, you look like a Borg with all that tech on your head!! :)

You better show up with that 8 at our next EAA meeting.

Darin
 
Wow! That engine sounds great! Reminds me of the big block throaty rumble from the muscle car era. (no coffee can muffles for me).
 
That's incredible! You keep that building pace flying it. Regarding those loose hose/hangers I used Dremel to notch the stainless for better rubber grip. Saw the trick on VAF maybe even on your RV9A site :D
 
A recommendation for your canopy cover. Add a "tail" to the front corner that comes down and covers the air intake.
 
Last edited:
I see a lot of people confuse/interchange the terms "heat muff" and "muffler"

Which do you have?

BOTH! :)

As can be seen here in a picture from Vetterman's page.

j45h7.jpg


both pipes have mufflers welded inline just behind the ball joint. Then the heat muff on one side and carb heat muff on the other are wrapped around the mufflers. Not only is it quiet, but you using just one heat muff the air coming out of the vent is VERY hot for cabin heat!
 
After two more of the tubes slipped out I finally pulled it all apart and made some mods.

Untitled by akarmy, on Flickr

I fully expect the tube to crack in half now from the shallow cuts I made in it to give it some tooth. :)
 
I've also been chasing leaks on the low pressure side of the brake system where the low pressure tubes go into the top of the master cylinders. This tube is a thin walled tube and the plans have you install a small hard plastic tube into the end to give the ferrel something to bit down on. It didn't work very well for me.

I found this part at Lowes in the plumbing area.

Untitled by akarmy, on Flickr

It has a much longer brass sleeve to install in the tube and seems to secure the connection better. Time will tell if it stops the leaks.
 
I don't think your exhaust hangers will slip anymore. I had the same problem initially but mine haven't moved since I flared them.

Here's an iPad pic from Friday. Great looking airplane!

Andy_RV8.JPG
 
34.5 hr update

Ok, winding down the initial test phase, have completed all of my planned testing except rear CG weights. Need to sandbag the seat / baggage area somehow...

Sunday was time to wrap up the load limit testing and aerobatics. First verified stalls again. Nice no issues. 54kts clean, 49kts with flaps. Then moving on to accelerated stalls, roll 90, 5.1 G pull, feels like you hit the rumble strip on the highway... thud thud thud thud, interesting, no break like my 9A had just stays in the tight turn and shakes like crazy as the stall comes on.

Loops, fine, all sorts of rolls, fine, Cuban 8, fine, split S, fine, hammer head... you know where this is going. :)

Nice vertical up line on the hammer, look right at the tip, look left at the tip, second look was too long, getting slow, kick full left now, slowly floating, engine dies, rotating 100 deg of the turn prop stops :) gliding straight down very quiet, and the engine spun up again as airspeed increased.

On to spins, Both left and right were very predictable, full stall first, then feed in full rudder. First turn either direction was slow and gentle as a maple leaf, second turn more like the new Dragon space rocket. It sure winds up after that first turn! Push forward and a little opposite rudder and it's flying again. Seems to loose about 1000ft in two turns. Was interesting looking at the EFIS data later showing -8000FPM at times on the flight.

Thanks to everyone for the tips previously I had no further mechanical issues. The exhaust has stayed in place after the flares.

I've also dialed back the PMAGS a bit for now by setting them at -2.4 offset to the A curve. This really helped out with high CHT at mid power bands. Now that I'm off the break-in oil I'll start dialing the advance back in, maybe to -1.2 and test for awhile to see how it goes. Thanks to Bill for talking with me about the various options. I really love the EICommander when flying with the PMAGS. I can't really imagine having dual PMAGS without this device to display and control them in realtime.

Next up is a bit of baffle work to make sure I'm maximizing any cooling air I have. I'm also going to try out a bent stick as I feel like its a bit of a forward reach with the straight one. Made worse since the Tosten grip angles forward a touch as well. Also going to add the slider latch system from Flyboy Accessories as I'm tired of having the canopy slide all the way back. And so it begins the life of upgrading RV parts and tweaking things. Sure is fun to be back in the RV game!
 
strakes...

Take a look at the tail during the high gee pull... the rumble is the tail shaking like a wet dog from separated flow at the root spoiled from the gear leg... do a search for strakes and follow up with Terry Burch at KAWO.
 
...
I've also dialed back the PMAGS a bit for now by setting them at -2.4 offset to the A curve. This really helped out with high CHT at mid power bands. Now that I'm off the break-in oil I'll start dialing the advance back in, maybe to -1.2 and test for awhile to see how it goes. Thanks to Bill for talking with me about the various options. I really love the EICommander when flying with the PMAGS. I can't really imagine having dual PMAGS without this device to display and control them in realtime.
...

You are more than welcome Andy! I was checking into to see if you bumped it back up as we discussed.

Let me know, if you have any more questions.

To those that follow this thread, the P-mag "A" curve (Jumper in for those of you who do not have an EICommander.) starts at roughly 26 degrees Before Top Dead Center at full power, such as takeoff or high power low level flight. As power drops off due to either throttle reduction or higher altitude, the P-mag will advance to its preset limit.

What Andy did by putting in a negative 2.4 offset was to reduce the timing to around 23.6 degrees BTDC. (The P-mags work in 1.4 degree increments.) This caused his CHT's to go down but his EGT's to go up because less of the mixture was burning in the cylinders and more "fire" was going out the exhaust. Yes, he might have lost some power but I doubt he noticed it.

The proper timing for any engine depends on many variables such as the cylinder head design, compression ratio, manifold pressure, etc. That's why a parallel valve (I)O-360 (180 HP) engine typically uses 25* BTDC and the angle valve IO-360 (200 HP) engine typically uses 20* BTDC. (Actual timing may differ depending on model, blah, blah, blah...)
 
Andy,
I had good luck using two cases of bottle water as ballast. One strapped to the rear passenger seat and one strapped down in the rear baggage compartment. No mess and you can drink it after testing!
Mike
 
Back
Top