CK1

My Feedback: (60)

Didier what a great flight and the Zero looks fantastic. BTW , Which prop were you using on the recent video and what were your needle settings / rpms

Carlo Vangompel

Great flight Didier!!
Awesome sound, really love it!

Didier

Thank you very much. This was the 15th flight I guess. The first 4 flights I used a Biela 22x12x3 WW2 prop. But I did not like it all. To much revs and no speed. Now I use A Ramoser varioprop 25F with 22.7” 3 blades. Pitch adjusted around 14,5”. Engines revs around 5300 on ground and 6900 in air. This prop is so efficient. It pulls the Zero like a freight train. I hardly use full power. Only during vertical and loops. Needle settings: Around 5 turns on low and 4 on high.

CK1

My Feedback: (60)

It sounded perfect in the air . I'm not thrilled with the static rpms on the ground with the Biela 22x12x3 ww2 either. Too many revs on the ground will be me way too many unloaded in the air. I'll look into the Ramoser Vario prop system . I'm not sure if they have a US distributor .

darod07

Said news, my engine failed....
My last flight was week ago and there was no issue at all, I didn't hear any strange noise whatsoever. After flight I took my plane home and it was staying there untill yesterday when I went to the airfield again. After refuelling I wanted to prime engine but prop stucked after turning 180deg. Then I tried to turn clockwise but again it stucked after half turn. I removed spark plugs and looked at piston heads for any signs of loose metal particles but it looked ok. So I went home, put plane up side down but still something was blocking engine. When I put my plane vertically on to the nose and to the tail I tried again to turn propeller and....it turned freely all way around. I decided to open top cylinder to look at the crankcase and bingo: bottom part of piston head found broken with remainings in the crankcase.
This is so disappointing. Such a failure after just few flights.
Any ideas what might cause such a failure?

larry@coyotenet

My Feedback: (21)

Had one of our warbird guy's new 90 break a rod 6 min into first flight, bottom line is poor design.

CK1

My Feedback: (60)

It's difficult to determine a cause by only 2 photos but a guess would be that if the only detached part is the piston skirt that the skirt was either fatigued or was struck by something in the crankcase. I would venture a guess based on the aluminum content in the oil that there was some high speed piston chatter that fatigued the skirt and it failed .

irek

There may also be a defect in the material (aluminum)

darod07

Because engine is still under warranty I contacted local dealer and thoroughly described observed failure. Waiting for feedback from distributor representative.

Carlo Vangompel

Hi Didier,

Great setup you have with your Zero
I also bought a Ramoser varioprop 25F with 21.8" 3 blades for a FW 190
Since this is my first varioprop, can you give me some advice how to setup the prop?

Thanks!

jimkron

Darod,
That sucks. Engine should not break like that.
I assume you had it properly baffled.
Any idea what your RPMs in the sky were after prop unloading? Temps while flying?

jim

darod07

Sure it was baffled with cowl flaps fully opened during flight.
That day I made 2 flights only. Below are graphs from onboard telemetry. As you can see, it's obvious that failure happened during 2nd flight. I have also video from 2nd flight but I didn't notice anything suspicious.

1st flight


2nf flight



2nd flight video:

https://www.youtube.com/watch?v=IlDW...ature=youtu.be

Carlo Vangompel

Hi Darod,

The fact that you didn't notice anything during and after the flights means that the skirt was still on the piston during the last flight. However, I suppose that if you landed a few minutes later, you probably had a dead stick landing.
While cranking the engine before next flight, the skirt probably broke completely of the piston.
I guess you were lucky not to crash that plane...

Carlo

darod07

You are absolutely right...It was perfect timing. What is best that ground piston skirt blocked crankshaft. Otherwise I would fly again and probably crash plane during take off. I can stand damaging engine, I wouldn't stand damaging the plane.

Didier

That is terrible the engine broke. 😏
But lucky the plane is in one peace. If I look at your data the temp was rising to 160 degrees C. Is this the temp from the broken piston? Did you check the other cylinders as well?
I noticed in your data that the warm-up time of the engine is very short. I wait to go full power until the engine is at least 120 degree C. I don’t know of course if this was a contributing factor.

Didier

Hello Carlo.
This is my first Ramoser as wel. Just follow the instructions. I use 22,7” HS blades though and adjusted it around 5400 RPM on ground (6900) in air with a pitch around 14,5”. This seems to be perfect for the Zero. Hopefully the 21.8” gives enough load for the Saito 90. Good luck!! 👍

darod07

Temps are from top cylinder. I thought that it may be some minor issue that's why I opened only one cylinder. When I realized it's serious I mounted cylinder back, let service investigate what could cause cuch damage. I usually warm up my engines for abt 2 mins before flight, I had never failure of this nature.

su27flanker

Hi Guys,

I have an fg-90 in a Phonex Waco and I find the top cylinder gets super hot compared to the bottom cylinders, its to the point where I have to just about idle around the sky as the temps on the top cyl jump to 150 – 160deg not long being in the air. the bottom temps are much lower.

Is this a baffling issue? or the high temp is normal for this motor, I think it would keep climbing if I didn’t back off?

jimkron

What prop are you using? Baffles are a must for this engine. They should be about 25mm back from the front of the heat sink. This puts the baffles right around the engine center line. Make sure you have plenty of exit air out the back of cowl.

Dummy cowls are not the kind of baffles you need for the engine. I attached the baffles using some L brackets cut from aluminum.
Hope this helps,

jim

su27flanker

Thanks for your reply Jim, i'm running a master aircrew 24x12. I dont have any baffling, so hopefully it sounds like that might be the issue.

Where do you find the best mixture setting?
Reading this thread some people appear to be running approx 6 turns high speed and 4.5 on the low? much different from the manual (the manual stated settings seem to be quite lean?)

SJN

I also just installed my 84 in the Waco and test flew it with the cowl on no baffling....and it overheated. So I landed and removed the cowl and flew the rest of the day out.
This engine flew great in my baffled Yak 3U.

So it needs baffling in the waco.

jimkron

I've only done a break-in on the ground. Those are good starting points if you are unfamiliar. These engines are are pretty sensitive. The slightest adjustment could change performance. Weather, gas octane, type of oil, cowl on/off, even altitude can have an effect. My friend Ray lives in the mountains at 4500 feet. I live at sea level. Two slightly different settings. It takes some playing to get there, but here is where you want to be. Approximately, 1400 rpm at idle, 6000 on the ground, 6500+- unloaded in the air. Transition from high to low should be smooth and quick. Temps should stay between 200-250F...and the 250 should only be for a few seconds at full throttle. These are some basic numbers to consider if you want a long relationship with Miss Saito.

jim

jimkron

In terms of the Waco, baffles will help, but remember that air exiting the cowl is part of the equation. I'm still working through that challenge on my FW 190. Air exits are minimal.

jim

Carlo Vangompel

Hi Guys,

I want to use a Futaba SBS 01 TE sensor but I do not know where and how to mount his on the engine.
Any suggestions?

Carlo

CK1

My Feedback: (60)

The SBS 01 TE has a short thermal loop that is usually taped to electric motors . Usually a longer loop SBS 01 T is used at the base of a sparkplug.