First Test Flights: Unexpected Results 

Thanks for this video, Scott. Nice to see you're flying again.

Glad you are back in the air. You have worked very hard on your airplane!

Maybe the new prop is causing the cylinder temp issue?

Biggest impacts to cooling are timing and mixture not (within reason) airflow. Since the fuel nozzles bleed to outside air pressure, increasing air pressure at the bleed makes a leaner & hotter cylinder

Scott, You truly are a Perfectionist. You leave nothing to chance.

Nice job! On the cowling!

Great video. With high CHTs, especially after maintenance, double check your ignition timing. Good idea getting the baffling buttoned up as well.

black spots on prop are likely exhaust condensation... same you see coming out a car tailpipe

All great stuff ! Seems like one can of worms just leads to another lol doing a great job sorting it out ! Thanks for the content 👍

A very exciting episode. May Elias be always with you!

Great video! Make sure the hot air can get out

Nice job on the go around!

Thanks for the content, Scott... I very much enjoy watching your channel. I have wanted to own and fly a Long EZ since I was a kid. I got my private.. single engine land in th lat 80's, but only have time in Cessna 150, 152, and 172 aircraft. I never got too fly in any pusher aircraft at all... I am living vicariously through watching you fly the Cozy!!! Thanks again!

TIL "grazing mode" alternate title: "a series of baffling problems"

Is the new prop dissimilar in pitch and size than the previous one? Different loading, thus thrust and rpm may be causing the temp to rise higher than previous. One simple test would be to put the original prop back on an try that? Johnston's baby oil may also help get the prop clean - it works with car exhausts :)

NACA duct, good idea. I had a 1" inlet, 3" long side and blew a ton of air. Do you have somewhere for the cabin air to get out? Stainless clamp, safety wire it? We have small loops welded to the exhaust pipes that have a stranded stainless wire attached to the engine. If the pipe breaks off it can't get to the prop. I'll be following your CHT saga as mine are doing the same thing on a Velocity and I've tried everything to fix it! I wonder if another plate on your diffuser could direct the airflow at the cys?

doesn't the glare coming off the top of your instrument panel bother you? glare panels are usually black...

Oh yeah, finally lovin the test flight, get the cylinders to cool down a bit, maybe some disappointment, but you'll figure it out.

I've been really enjoying your vids! Simply LOVE the Cozy and Long EZ's. Keep doing what you love for as long as you can and God Bless my friend!

Regarding the high CHTs, is there a way you can check that the indicated temperatures are correct?

Lol, I said "nice" when you landed and then a second later you said it the same way.

Theory on your cooling: if I remember from your previous videos your cabin heat dumps (What could be cooling) air into the low pressure side of your baffling when in the off position and thus reducing the differential pressure below and above your cylinders. Consider sealing that off to collect data. I bet your cabin heat and cooling issues are intertwined.

I would put some type of safety wire on those hose clamps on your exhaust, just a suggestion?

Great progress great vid, Why do people Vocal Fry on VHF?

A couple of observations if I may? Firstly if you want something air cooled cool, supply air directly to it. Secondly, imagine that cowl contents on the outside of your aircraft. Would that arrangement provide acceptable airflow outside the aircraft? If not you might want to ask why putting it inside a cowling would make any difference? The air paths inside that cowl are chaotic and indirect, to say the least.

A safety wire on the hose clamp would be a good idea.

You definitely had two blast of white smoke on startup. Could that have caused the splatter on the prop? Good looking aircraft

I power my cameras from a standalone power pack. I have found it to be a game changer. I found the GoPro to be sensitive to low amps (not surprisingly). I chose a power pack, problem solved. I can also get the cameras going early (before aircraft power on) and just forget about it.

After the work you've done along with the new air scoop, I can't help but feel that the exit pressure from the engine must be too high causing air stagnation. Is the exit area from the cowling greater than the air intake area?

Awab brand hose clamps are much better clamps. They are used in the marine industry. They cost a bit more but worth every penny.

Thinking about your cooling issue. The blades on the new prop have little airfoil near the hub. May not produce enough suction power to cool.

I noticed something pertaining to your fox on the prop. When you were talking about the screw clamp being missing I noticed black what looked like exhaust on the bottom of the pipe that the clamp came from. It looks like spatter from the engine. Carbon or oil from maybe an issue with a cylinder. You may want to check that !!!! Better safe then an oh shit moment! Just saying

First time viewer. Is it possible to fly the old prop agan? Those temperatures are not too hot.

You need to safety wire those clamps because they will loosen up.

Put the old prop Back on and check CHT’s

Check mixture cable? maybe running leaner than indicated?

There is a NACA/ NASA document, available from Cranfield Repository, indicating NACA Air Intakes are not the best. Blessings +

I have an idea Scott. Could you take a reversible shop vac.... And fabricating adapter to fit over the lower air intake where your diffuser is and in the hangar turn it on and have it blow air into the diffuser and go around to the engine compartment and see how the air is behaving as it blows up through the engine compartment? I figured that might be a way to view the aerodynamic behavior of the airflow without possibly having to fly the airplane who knows?.... Maybe it might reveal something. Just an idea

Hard to get it up when the OAT is 46

Remove the blast heat. Check intake leaks. Verify mechanical engine timing then ignition timing. Verify oil cooler and varistat. Did I see a zip tie on an intake tube? Your very calm👈🐱👍

What a cool airplane, Nice video :) I am new to this with airplanes and aircraft. i will start my ppl training this fall. But one thing I have noticed when I look around here on youtube and all the flight videos is that the finish on the construction in the engine compartment looks like it would be built in kindergarten. cables hoses hanging here and there. crooked and twisted. Everything looks so amateurish. Junk buildings. even on factory-built pipes or cessnas, the same junk building. Do you not have greater requirements in aviation. This is what you have to get used to. Not that it scares me but I just wonder if it is this standard overall on small airplanes. :) Happy flying to all. see u in the air later on hopefully if i get my ppl :)

If your cylinder head temperatures (CHT) are too high on those two cylinders, why do you continue to fly? Is it high, just not alarmingly high? Not trolling you, I really don't know and am curious. Thanks!

I may be wrong, but the clamps on the exhaust look like regular hose clamps, not sure if they are rated for high temperatures. Normal high temp exhaust clamps are a T bolt style. Just a thought. Fly safe!!

The best way to to increase engine cooling is NOT to worry so much about the intake section, BUT look into the exit and make it an EXTRACTION rather than a FLOW. PULLING air is far more effective than FORCING air. Forcing air creates abnormal chamber pressures. Extracting air creates a LOW PRESSURE system and reduces the air temperature while it works. One way to do this is with a modified exhaust system that helps drive the air our of the engine compartment. Work on that.

Did you read: 'Des couacs chez les canards'? -Kwaks among ducks There is an english translation in the site 'Homebuilt Aircraft and kitplanes' Blessings +

Not being able to see from here but wondering if there is any mounting between the two exhaust pipes. Heat & vibration would allow the distance between them to change and allow the clamp to loosen if there is no attachment to each other nearby. Also, I always avoid using worm clamps whenever possible because of their tendency to come loose, especially when not clamping something that has no resiliency (rubber, silicone, etc.) Also - temperature readings will change with supply voltage changes. Possibly your recent repairs to the electrical system created a change to your readings. I'd do a back-up / proof test by placing a sensor in a cup of heated water alongside a trusted mechanical thermometer. Maybe there is an adjustment/correction ability built-in to the system?

- Cool. Some more debugging, but it seems to be flying pretty well. Smooth landing at the end.

How about temperature sending units or guages ? 👨‍✈️Also, is OIL temperature normal

Yo, that hose clamp that went through the prop. I’m sure there’s a ton of heat on the exhaust pipe, especially right near that bend, if the clamp was very tight I can imagine it getting super hot and just letting go I suppose. I wonder if there are hose clamps specifically made for high heat scenarios.

I thought in the previous video, it was said if the heat isn’t going into the cabin, then it’s being dumped on the engine….. could be the cause of the engine temp issues.

Are you allowed to fly with the engine cowling off?

Verry nice flight after all the work you did. Does your plane have the bottom air brake flap? I didn't hear you deploy it. Thanks and I love following your journey....

I doubt you’ll get any benefit from a new duct unless it’s a straight ram, because the issue is pressure difference front to back. Work at sealing up the nose, foam blocks can go on the elevator opening. A boot over the nose gear actuator. Once you don’t have the same pitot pressure up front, the heater will cook you out of the airplane

What field you flying from?

Just a thought about cooling but may be some where some how the air can't leave quick enough for proper flow. Love the videos and thank you for them.

I would have someone while you do a 70% run-up for about 2mins, use a IR temperature reader, and confirm you gauge readings. It possible its NOT a correct reading, and the gauge needs to be calibrated.

Yo scott do you get nervous doing a test flight after a long break and maintenance like this? Whats the feeling like going down the runway after making all these repairs and getting the plane back up in the sky after months?

Hi Scott, Enjoy your videos. Were you provided the plans for your Cozy when you purchased it? It looks like you are missing some of the baffling on your lower cowl as per the plans although it's hard to see in the video. It also looks like as per the plans you are missing your interior cylinder baffles that butt up against the engine case. Might help with the cooling.

from outside the velocity-canard - pusher seam to be the best plane concept and save because of his stol caracteristic...why this concept is the only one...so many new aircrafts on the market, now one builds this ruton concept ???

Wait is there a choke or something in there? You mentioned ‘leaning the mixture to not foul the plugs’.

Or have somebody fabricate a cowling made of heavy duty screen material

Is that 15 seconds plus of cranking the starter to start normal? Is best practice to never allow an engine to not be run up to operating temp for more than a week if possible? That's a general rule of thumb in terms of automotive 4 cycle gas or diesel engines. Does a 3 blade prop's 50%ish more resistance make more work for the engine? I was very nervous after that 15+sec cranking to start. But I'm completely unfamiliar with piston aviation.

Wow - that high pitch when you play at fast speed is kinda miserable. If you need help editing let me know.

What is your fuel flow?

Weiman Ceramic and Glass Cooktop cleaner works good for cleaning props. 100LL would probably dissolve that stuff too.

Is there a Cozy Owner’s Club that you belong to? These types of clubs are great for brainstorming with when faced with such problems as overheating cylinders and cabin heating issues.

I can't wait to find out why the cylinders are so hot.

I think 2200 static rpm full throttle at your elevation is too low. That's probably 6 inches of MP over square. Is the 0 360 rated for that? I know 0 320s were good for about 5.

Try WD40 to remove the prop splatters...

for the splatter, try olive oil to remove it (i know, but it may work)

Safety wire anyone?

A left field idea. Stevefranseen is probably correct. What if its 5 pounds of air with a 10 pound air requirement? Pop up top scoops on the top cowling? I don´t know I am not an aviation guy. You now have more air running to the heater, and another duct for your old hot cylinder. This is totally not taking into account, High pressure side, low pressure side, etc. But, the cylinders are on top. What if you treat bottom air as a thing, and top air as a thing. Then make that adjustable so you don´t run too cold in cold weather. It may be totally no bueno. Basically your issue was the wife is cold and one hot cylinder. That may not fit at all, I don´t have a good idea of how the high pressure side, low pressure side works. But, Brute Force Cooling may work without disrupting what you have going on in the lower segment. Or, it may be impossible due to high side, low side? You tell me? Plus you get algorithm up for comments. I figured you might have high RPM alternator output magnetic issues with the wiring, Maybe... This is unexpected. But... Like I was saying. IDK, the scoops may draw from air for the prop to bite? Again, you tell me. Left field is to do course adjustment, as in course sand paper vice fine sandpaper. You seem to be stuck with fine adjustment. You may just need more airflow where you need it. Also, maybe cowl flaps rearward facing on the top? Find an HVAC Person and have them look at it? They might just look and say "Well obviously its..." while punching buttons on their calculator. Maybe it exhaust side and not supply side? If I could make one critique, you do chains of "This IS this. and This IS that." I recommend you do more "This MIGHT be this. Or this MAY be that." or you build a mental Jenga tower. Nothing is anything until its shown to be that. Not theory. You know where I am coming from on that. Again, I like how you do risk management on doing what is more or less "Green Field" stuff. Its advice, to be taken as such. You are the one strapping your backside in it and doing the final "Go, No Go" Gauge testing. This is just pass forward on that sort of development cycle in other fields. What you fixed is what was making it work before? Now its too air tight? It was obviously in some sort of balance. Call an HVAC guy and barter a ride for an opinion. Plus its makes for good video etc. The clamps,. x2 clams less tight, if its vibration breaking? Hope its helpful, that's the idea. Jamie out.

Isn't this the type of plane John Denver was killed in. Not for poor piloting skills but for poor placement of fuel tank switching lever.

Ty raps are cheap, use more on your engine wiring.