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Re: Fuel system anomaly video [1 Attachment]
Matthew Curcio
So last night I figured I would check the float height. I did and it seemed fine. I bent it up just a bit and while I was down there putting it on I figured I mine as well bend the vent up a little to like someone had mentioned. I took off and flew around
and I could not get the engine to run rough. I decided to bend it down even more to get it further away from the fuselage but still at the same angle and after 1.5 hours of flying today it is stills fine. The weird vacuum bubbling looking sensation in the
sight glass did not occur - except one time. I was diving and got up to 200 and it started to occur but didn't start tuning rough. My theory now is that there is a low pressure area behind the bottom of the cowl and it migrates back further the faster you
go or some kind of weird airflow going on at least. I'm thinking that at some point I would like to locate the vent nearby where the pitot is. That should prevent this issue from ever occurring against. I've now got 2 hours on it without this issue. I'm still
not confident in it but I feel like I'm on to something.
On Sep 10, 2017, at 8:29 PM, jay@... [Q-LIST] <Q-LIST@...> wrote:
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Re: Jon Finley
Jon Finley
Ryan, if you don't have the Ellipse issues of Contact! Magazine you should get them from Pat. They are VERY good!
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Re: Jon Finley
Jon Finley
Hi Ryan,
I did a lot of prop theory research a decade ago - read everything I could find. However; I am no expert. Thanks to Pat Panzera for connecting me with Paul. Everything he wrote and said about prop design made sense to me. I believe it was also proven in the air by those that took the time to construct what he designed. Sadly, that was a very significant effort. Especially significant since one should expect to carve three or more props to nail it down. This may not be true if all of the components are fairly well know (HP & drag curves). Paul was interested in my setup as I was running very high prop rpm (3500) and was very noisy. The first Ellipse prop I built (Paul designed) showed signs of being massively better than the modified warp drive prop I had been using. However; it was over pitched. I cannot remember the exact details now - something like 20 mph faster at cruise a cruise rpm several hundred less than normal. Of course, being down on rpm meant that climb suffered terribly. Paul modified the design and I carved a second prop. I made it as far as some ground testing with that prop but no further due to life issues. Jon
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Re: Jon Finley
oops, sorry, it was a Lycoming O-235, not Continental. Pat
On Sun, Sep 10, 2017 at 9:23 PM, ryan goodman elboy0712@... [Q-LIST] <Q-LIST@...> wrote:
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Re: Jon Finley
ryan goodman
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Re: Airport Closed - Hurricane.
This is going to be the biggest $ damage ever. FL is a wreck! Mike
On Sep 10, 2017 8:53 PM, "Mike Dwyer" <q2pilot@...> wrote:
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Re: Airport Closed - Hurricane.
Wind is blowing near 80 mph gusts. Will be this way for 5 hours. Looks like the eye is going to pass well east of us and I think the hangar will not get flooded with the wind this direction. Lost power at 6:30pm so it's just flat dark and windy! Will be curious to see what the place looks like in the morning! Mike Q200 N3QP
On Sep 10, 2017 8:30 PM, "jay@... [Q-LIST]" <Q-LIST@...> wrote:
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Re: Airport Closed - Hurricane.
John ten
Good Luck, Mike.
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Re: Airport Closed - Hurricane.
John ten
Good Luck, Mike.
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Re: Airport Closed - Hurricane.
Wishing you the best, Mike. Nature is interesting, sometimes too much so. Hang on tight.
Cheers, Jay Scheevel
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Re: Fuel system anomaly video
Matthew,
I suspect a slightly different problem. Once you enter high speed level line of flight, there is a low pressure area that migrates to an area near the top rear of the canopy, where the canopy frame meets the seat back bulkhead. This is usually not an airtight seal. See the red area in the attached picture (low pressure). When you are at lower speed and a higher angle of attack, this same low pressure area is closer to the front of the canopy where plex is a solid piece and is consequently airtight. I suspect that when you reach 140-ish the low pressure area serves to de-pressurize your cabin through the crack between the canopy and the bulkhead. My thought is that the top of your fuel sight gauge (main tank) is in communication with the cabin pressure. If there is a small crack in the gauge tube inside the tank, then the low pressure in the cabin could draw air through the crack and into the standing fuel gauge column, showing up as bubbles. Regardless of the source of the bubbles (could be "boiling" fuel as previously suggested), such communication will tend to depressurize your tanks, and may be sufficient to overwhelm the ram air tube, especially if the ram is poorly positioned. If I am correct, I think the only thing to do would be to install a fuel pump downstream of the header that can be used as needed to send pressurized fuel directly to the carb. The long term fix would be to install gauges that do not communicate with cabin pressure, so the ram air will be more effective. My two cents. Cheers, Jay Scheevel, Tri-Q, still building.
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Re: Fuel system anomaly video
Are you using Ethanol based fuel? If so, STOP. Could something be heating your fuel line? Is you fuel line metal and near the exhast? Mike
On Sun, Sep 10, 2017 at 10:33 AM, Matthew Curcio mlcurcio89@... [Q-LIST] <Q-LIST@...> wrote:
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Re: Jon Finley
It was during one of the AWESOME Livermore tandem wing gatherings. I invited Paul to join us, so he flew in with his highly modified Lancair 235 - which was powered by a stock Continental O-235. Jim's O-200 is more than stock so they're "close enough" in power, but Jim couldn't use a spinner - accounting for a few mph lost.
On Sep 10, 2017 1:06 PM, "logistics_engineering@... [Q-LIST]" <Q-LIST@...> wrote:
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Re: Jon Finley
No, he took off his plane to let me try it out.
Jim Patillo N46JP - Q200
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Re: Airport Closed - Hurricane.
I just saw some video of the local beaches and Tampa Bay. The water is being sucked out! As long as the Hurricane stays to the east of us the hangar should stay dry. As long as we have power I will be posting video from the house hourly on my youtube channel. Don't have much else to do... Mike n Liz
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Re: Jon Finley
ryan goodman
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Re: Jon Finley
On Sep 10, 2017 12:30 PM, "logistics_engineering@... [Q-LIST]" <Q-LIST@...> wrote:
Tom Aberle's Phantom. Smoked the biplane class for 3-4 years in a row, going faster each time. Started with a three blade Elippse prop, and is now running 4 blades. Last year he didn't run Reno, but he's there thus year with his Elippse prop. Pat
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Re: Jon Finley
Paul Lipps was a friend of mine and let me use the Ellipse prop off his Lancair for testing on my Q200.
It was proven at Reno that his props would increase speed. Don't recall the name of the race plane but it went significantly faster with Paul's prop on it. Paul's prop was a 62/78 and was a little to much for my 120HP Q but I did pick up several knots, just didn't make enough rpm to produce the HP to go really really fast. I wanted to have a 60/72 made but Paul wasn't making them. I asked Craig to make one for me but he wanted 3k to do it because of the complex mfg. I didn't persue it further after Paul died. Jim Patillo N46JP Q200
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Re: Jon Finley
ryan goodman
No didn't find a used one. And not really thinking of carving my own. Though I'll admit the idea crossed my mind. My buddy has a cnc machine so........ That said; I think it's mostly an interest from a curiosity perspective. The experimental community tends to be full of folks who love to talk about what doesn't work, or what is common knowledge, that they themselves have picked up over the years and preach as gospel. To me that may be true often and yet still wrong under certain conditions. Because of this I think that the mentality may stifle innovations and potentially great leaps forward. So, when I come across things that show someone breaking down walls(even small or partial victories) against conventional "truths", it really piques my interest and I want to know more. I'm am engineer, so numbers and explanations why kind of calm my anxiety in this experimental world. There's a lot of builders out there who do amazing things just on the things the community "knows to be true" with little engineering knowledge at all. I think that's wonderful, but it still leaves me seeking an explanation. I don't do well pushing the "I believe" button. I need to know why. So for me, it's an exercise in finding out which parts of Paul's design broke convention and worked, and which parts just made for canon fodder. And I want to know why.......sorry for the long reply, but I felt it necessary to explain my pursuit of this. /Ryan
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Re: Fuel system anomaly video
Earnest Martin <MartinErni@...>
Matthew, If you can run full power in a nose up position but not level or nose down your vent may be in a low pressure area when you level off and the fuselage AOA changes. I chased that for weeks after changing the cowl exit which affected the pressure aft of the firewall. The pressure may be so low in the tanks that the fuel is changing from liquid
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to gas (bubbling). Earnest Martin 40 Glen Cove Drive Arden NC 28704-3219 828-230-5378 martinerni@...
On Sep 10, 2017, at 11:51 AM, Paul Fisher rv7a.n18pf@... [Q-LIST] <Q-LIST@...> wrote:
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