rhtrudder

Thoughts on using anti puncture goo in aircraft tyres, planning on some trips away , don’t need flats, anyone tried this 

Would there be any benefit of spraying inox inside the wings and fus to help with any corrosion, aluminum aircraft 

Okay if my problem is from the prop would it be noticeable below 5000 but smooth out above or would it be through the whole rev range

Has anyone fitted one to the flywheel end, looks easy enough, do you think it would make a difference, my plane has a noticeable vibration under 5000 feel it through the cabin support, I realize the engines run like a thrashing machine up at cruise, you only have to take you headsets off, so it may be just what it is, 

On 15/6/2018 at 9:52 PM, smokeybear said:

I have been bringing in the Balancers for some years, they do a fantastic job and I believe extend the life of the gearbox & engine as well the reduced vibration throughout the airframe reducing  fatigue.

 

I have Balancers on hand for

 

Rotax 912/914 

 

Rotax 503 flywheel 

 

Rotax 582 & Lycoming on order.

 

 

Hi are you still bringing in the balancers 

1 hour ago, RFguy said:

was the pilot the original builder ? Otherwise up to the original builder to do the test flying and V speeds, and the new owner to trust but verify......

 

Not the original builder 

Just found out the pilot was a local boy from Tongala,I took him up a couple of years ago for his first flight, he was very keen and soon had his instructors ticket and was possibly on his way to a commercial, looks like his brother and cousin were lost as well, I think he had relatives in the area I guess that’s why all the orbits, he had only just taken over the plane , sad times. 

I thought the bristell was aluminum, but it looks like fiberglass the way the fire took hold

What’s the safest detergent to use on a aluminum plane, I figure ph neutral, but should keep away from phosphate , most of the auto cleaners have sodium in some form, a lot to choose from 

In the past if I have left one off I could barely notice the difference but not now , both sides the same, feels like it will cut out, I’ve never come across this information before, can drop up to 500, at 4000 , just found out the 914 runs one side a bit more advanced , I guess to help with detonation, read somewhere the earths off the cdi and coils can corrode, just cleaned them up , fly tomorrow and hope my imagination was the trouble all along 

Still trying to figure out my engine, switch between the mags below 4000 not much drop, up in cruise, above 5000, the is a big drop on both sides, I know the ignition systems are separate from each other but is there something common to effect both 

Planning a trip from northern Victoria heading up north along the darling , still in the planning stages, anyone welcome to tag along, Greg 

On 28/5/2024 at 6:36 PM, facthunter said:

Watch how they stop when shut down. A good motor will bounce back off compression.  Nev

Don’t think my 914 has bounced back, maybe something to do with the reduction gearing 

On 29/5/2024 at 12:49 PM, F10 said:

Yes I wonder about that? You seem to get all these cylinder head mods, power flow exhaust systems and bored out barrels for more power... But the bottom end, crankshaft and journal bearings or conrod big ends are never mentioned? Are they able to handle the higher power output? I feel engine life/reliability may be shortened. 

I guess that’s why the the hot up mobs offer to weld up the crankshaft to take the strain of the extra power, I think I will leave it standard 

True, the 914 is a 80hp with a turbo, low compression on start up , HP comes up when over 30 on the map gauge 

25 minutes ago, F10 said:

Not sure why Lycomings are coming up in a Rotax 914 chat? My Rotax 912 ULP is running on condition. These are things I have found out/experienced with leak-downs. Firstly, it is a pretty good check, but it is not as bullet proof as some think. If you have any doubts, a borescope look tells you a lot! It will show valve condition, signs of valve heat stress, will show. and valve seating health, very often the cause of low compression. A borescope will also show health of cylinder walls. It is a pretty reliable check and will tell you of pending problems, whereas a leak-down is a snapshot health check. I have head a good borescope, one that can look in all directions are around $300. A good investment? I think so. 

 

Having said that, one thing I found was getting the engine up to a reasonable temperature is important. I recently replaced my Bolley prop, during my last annual. The old one had been on the aircraft for 10 odd years and was showing signs of corrosion. In for a penny, in for a pound, replacing the hub and blades, cost only slightly more than keeping the old blades. After running the engine for a while, to check static RPM and vibration levels, we carried out a compression check. The engine returned figures of 77/80, 78/80, which a new engine would. Doing a leak-down with a hot engine makes a difference, although taking out hot spark plugs is good juggling practice!

 

As I recall my leak-down minimum is 65/70. Certainly anything under 65 is a worry, but it could be just a badly seating valve. A borescope will tell you that before you do anything expensive. There are crafty tricks out there, to also grind and re-seat valves, without removing the cylinder head! 

How many hrs on your engine 

6 minutes ago, F10 said:

Not sure why Lycomings are coming up in a Rotax 914 chat? My Rotax 912 ULP is running on condition. These are things I have found out/experienced with leak-downs. Firstly, it is a pretty good check, but it is not as bullet proof as some think. If you have any doubts, a borescope look tells you a lot! It will show valve condition, signs of valve heat stress, will show. and valve seating health, very often the cause of low compression. A borescope will also show health of cylinder walls. It is a pretty reliable check and will tell you of pending problems, whereas a leak-down is a snapshot health check. I have head a good borescope, one that can look in all directions are around $300. A good investment? I think so. 

 

Having said that, one thing I found was getting the engine up to a reasonable temperature is important. I recently replaced my Bolley prop, during my last annual. The old one had been on the aircraft for 10 odd years and was showing signs of corrosion. In for a penny, in for a pound, replacing the hub and blades, cost only slightly more than keeping the old blades. After running the engine for a while, to check static RPM and vibration levels, we carried out a compression check. The engine returned figures of 77/80, 78/80, which a new engine would. Doing a leak-down with a hot engine makes a difference, although taking out hot spark plugs is good juggling practice!

 

As I recall my leak-down minimum is 65/70. Certainly anything under 65 is a worry, but it could be just a badly seating valve. A borescope will tell you that before you do anything expensive. There are crafty tricks out there, to also grind and re-seat valves, without removing the cylinder head! 

Worst cylinder was no 2, left front, could definitely hear bubbling in the oil tank, so I reckon the valves are good, 70/80 , the bore scope sounds a good idea but I’m not sure I’d know what I would be looking at, wonder if just a set of rings would make a difference, read that the bores hardly wear, hard as a cats head, found on eBay a full set of pistons and cylinders only 95hrs, $1200 plus freight from the US

could be a scam but might be worth the gamble.

23 hours ago, skippydiesel said:

Go with Wal's advice.

 

You may as well keep using while operating perimeters are all in the green.

 

If not already, keep a log of oil added against hours flown - when oil added starts to approach Ly/Con normal consumption, might be time to consider your options.

 

May be instructive to do the leak down cold & hot.  Do cold, then go fly, to get engine well heat soaked and do the test again.

Would it be possible to replace the pistons and rings and maybe valve guides give the old cylinders a hone and go again, I reckon the bottom end looks solid, could be a cheap way out although I have out jewed myself in the past with mixed results 

Only private flying, having trouble trying to justify over $50K on a replacement so I guess I keep up the service and hope for the best, worked okay so far , Wally tells me plenty have well over 3000 up

• Over 1900 hrs on my engine, no 2 always felt a bit soft in compression when flipping over the prop, leak down showed 70/80 , rest about 75/80 , going past the rings , should this be a concern or just keep flying, engine doesn’t use any more oil than usual 

Thanks 

Maybe end up going through the week 

Hi anyone flown the VFR track through Nowra , I’ll be heading south, wondering if it’s easy enough, Greg 

At around 4500 revs my engine definitely has increased vibration ,below 4000 and above 5000 it’s good , I think I come across this in another thread, it’s fitted with a O2 sensor so I know the mixture is correct, prop been balanced,  could this be harmonics , has anyone else come across this 

Quote

 

Noticed a soft compression one one cylinder so ran through a leak down test sat the gauge on 80 , three read 77psi but the sick one was down to 75 psi , I guess not a lot of difference, could hear a faint bubble in the oil tank , engine has 1850 hrs up, would a set of rings an a hone fix this , back in my 2 stroke days rebored to get everything round , engine is a 914