So close but yet so far
07-11-2012, 02:08 PM
#1
Thread Starter
So close but yet so far
I have a hotspot ready to fly with my homebuilt 30.3 Phoenix engine. The engines been run many times on a test bed but my 1st attempt at some ground runs on the plane revealed a sick engine. Having stripped it, I found a broken fuel line inside the engine. Hooray a cheap fix. Today I tried it again and did several successful ground runs up and down the runway which showed it had stacks of power. I did two last static runs at 50% then 75% throttle to time the fuel consumption but during the 75% run, the tailpipe went redhot then it screeched to a halt (after I hit the kill).
Combustion chamber vaporisers melted, 1/3 of the inconnel exhaust guide vanes melted (a pig of an assembly to make and I also found the fuel pipe was again broken (the root cause?). Can prolonged static running do this damage?
Not sure whether to spend the time rebuilding the engine or simply polish it up as an ornament and save for a commercial one. Either way, I wont be joining the jet fliers club for quite some time.
Dave Windy Miller
Combustion chamber vaporisers melted, 1/3 of the inconnel exhaust guide vanes melted (a pig of an assembly to make and I also found the fuel pipe was again broken (the root cause?). Can prolonged static running do this damage?
Not sure whether to spend the time rebuilding the engine or simply polish it up as an ornament and save for a commercial one. Either way, I wont be joining the jet fliers club for quite some time.
Dave Windy Miller
07-11-2012, 04:04 PM
#3
Thread Starter
RE: So close but yet so far
Yep all 6 injectors tubes were fine and flowed the same amount. The main fuel line has a small 1/16" stainless tube take off for the front bearing which sheared off. This would dump fuel inside the engine near to the combustion chamber exit rather than through the vaporisers which is what I believed fried the back end.
My main driver is not only to fly jets but to fly the engine i spent years building. A few hours on and I can see myself working out how to repair it!
Dave
My main driver is not only to fly jets but to fly the engine i spent years building. A few hours on and I can see myself working out how to repair it!
Dave
07-11-2012, 05:42 PM
#4
My Feedback: (5)
RE: So close but yet so far
ORIGINAL: dave.windymiller
I have a hotspot ready to fly with my homebuilt 30.3 Phoenix engine. The engines been run many times on a test bed but my 1st attempt at some ground runs on the plane revealed a sick engine. Having stripped it, I found a broken fuel line inside the engine. Hooray a cheap fix. Today I tried it again and did several successful ground runs up and down the runway which showed it had stacks of power. I did two last static runs at 50% then 75% throttle to time the fuel consumption but during the 75% run, the tailpipe went redhot then it screeched to a halt (after I hit the kill).
Combustion chamber vaporisers melted, 1/3 of the inconnel exhaust guide vanes melted (a pig of an assembly to make and I also found the fuel pipe was again broken (the root cause?). Can prolonged static running do this damage?
Not sure whether to spend the time rebuilding the engine or simply polish it up as an ornament and save for a commercial one. Either way, I wont be joining the jet fliers club for quite some time.
Dave Windy Miller
I have a hotspot ready to fly with my homebuilt 30.3 Phoenix engine. The engines been run many times on a test bed but my 1st attempt at some ground runs on the plane revealed a sick engine. Having stripped it, I found a broken fuel line inside the engine. Hooray a cheap fix. Today I tried it again and did several successful ground runs up and down the runway which showed it had stacks of power. I did two last static runs at 50% then 75% throttle to time the fuel consumption but during the 75% run, the tailpipe went redhot then it screeched to a halt (after I hit the kill).
Combustion chamber vaporisers melted, 1/3 of the inconnel exhaust guide vanes melted (a pig of an assembly to make and I also found the fuel pipe was again broken (the root cause?). Can prolonged static running do this damage?
Not sure whether to spend the time rebuilding the engine or simply polish it up as an ornament and save for a commercial one. Either way, I wont be joining the jet fliers club for quite some time.
Dave Windy Miller
http://www.youtube.com/watch?v=qW1lu_6cFXY
07-12-2012, 10:33 AM
#5
Thread Starter
RE: So close but yet so far
Thanks for that one day mine will go like that. Having built the engine from scratch (not a kit) I know I can rebuild it and thankfully, the expensive bits are undamaged. It will fly dammit!!!
rgrds
Dave
rgrds
Dave
07-13-2012, 08:20 AM
#6
Join Date: Nov 2003
Location: Curitiba, Parana, BRAZIL
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RE: So close but yet so far
Honestly, did you ever seen a Phoenix turbine working properly for hours at full throttle? This engine is "different" as it uses a car turbo shaft among other details not to mention the designer didn´t sold the plans for long.
I have no doubt this engine may run properly after several hours of bench testing and development but this takes time and money.
IMHO if you want to fly, it is cheaper and better to buy a turbine in wich this development was already done. Believe me, you have a lot to learn and things to pay attention while flying a HS. you don´t need extra workload with the engine issues while learning to fly.
Also a good idea is to use the best landing gear legs available... the ones shown in the pic seems only good for takeoffs!
Best regards, Enrique.
I have no doubt this engine may run properly after several hours of bench testing and development but this takes time and money.
IMHO if you want to fly, it is cheaper and better to buy a turbine in wich this development was already done. Believe me, you have a lot to learn and things to pay attention while flying a HS. you don´t need extra workload with the engine issues while learning to fly.
Also a good idea is to use the best landing gear legs available... the ones shown in the pic seems only good for takeoffs!
Best regards, Enrique.
07-13-2012, 10:57 AM
#7
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RE: So close but yet so far
ORIGINAL: erbroens
IMHO if you want to fly, it is cheaper and better to buy a turbine in wich this development was already done. Believe me, you have a lot to learn and things to pay attention while flying a HS. you don´t need extra workload with the engine issues while learning to fly.
Best regards, Enrique.
IMHO if you want to fly, it is cheaper and better to buy a turbine in wich this development was already done. Believe me, you have a lot to learn and things to pay attention while flying a HS. you don´t need extra workload with the engine issues while learning to fly.
Best regards, Enrique.
Very good advice ....
Scott.
07-14-2012, 08:42 AM
#8
Thread Starter
RE: So close but yet so far
The plane is how i bought it and it now has trailing link oleos as well as many other mods.
I know what caused the problem (broken fuel line). Up until this issue (twice) it has been a reliable runner. Having invested the time building the engine I have to see it fly before I can polish it up and have it as an ornament. The longer term vision is with commercial engines.
Cheers
Dave
I know what caused the problem (broken fuel line). Up until this issue (twice) it has been a reliable runner. Having invested the time building the engine I have to see it fly before I can polish it up and have it as an ornament. The longer term vision is with commercial engines.
Cheers
Dave
07-16-2012, 09:32 AM
#9
RE: So close but yet so far
I applaud your perseverance.
In today's throw away world there are very few craftsmen left.
It is not always about the destination, sometimes it is the journey that is most fun.
I make a lot of parts in my basement that I know I can buy for less, and get faster, it is the challenge and sense of pride in a job well done that makes it worth it.
Good luck with getting it all sorted out.
Just a thought.
Since that internal line broke twice while taxiing, and runs fine stationary on the bench, is it possible that it just needs some support so that it can not move while bouncing across the ground?
In today's throw away world there are very few craftsmen left.
It is not always about the destination, sometimes it is the journey that is most fun.
I make a lot of parts in my basement that I know I can buy for less, and get faster, it is the challenge and sense of pride in a job well done that makes it worth it.
Good luck with getting it all sorted out.
Just a thought.
Since that internal line broke twice while taxiing, and runs fine stationary on the bench, is it possible that it just needs some support so that it can not move while bouncing across the ground?
07-16-2012, 03:21 PM
#10
Thread Starter
RE: So close but yet so far
Thanks for the encouragement and I agree flashing a credit card may make the journey shorter and smoother but im sticking to the scenic route!!
The first pipe broke as it was a 1/8" brass pipe that I had strained to fit a different position than originally designed. I replace this with a stainless tube bent to fit exactly. Off this tube is a lube tube 1/16" od for the front bearing but I also replaced this with stainless (very thin walled). I struggled to silver solder this to the main bearing housing and at one point overheated this thin tube. My metallurgy man at work confirmed that I seriously overheated it and whilst it looked and polished up ok it was structurally flawed leading to the fracture. Ive studied the data from the espiel fadec and it seemed that the problem started around 15-20 secs from the overheat shutdown.
Windy
The first pipe broke as it was a 1/8" brass pipe that I had strained to fit a different position than originally designed. I replace this with a stainless tube bent to fit exactly. Off this tube is a lube tube 1/16" od for the front bearing but I also replaced this with stainless (very thin walled). I struggled to silver solder this to the main bearing housing and at one point overheated this thin tube. My metallurgy man at work confirmed that I seriously overheated it and whilst it looked and polished up ok it was structurally flawed leading to the fracture. Ive studied the data from the espiel fadec and it seemed that the problem started around 15-20 secs from the overheat shutdown.
Windy
