The Biplane Forum > Biplane Builder's Forums > Starduster > Acroduster 2 vibration, low end aviation, etc. part 3



Help Support Biplane Forum by donating using the link above or becoming a Supporting Member.
Reply
 
Thread Tools Display Modes
Old 08-17-2017, 07:22 PM   #1
EAABipe40FF
Registered Users
BiP_SUPPORTER.png
 
EAABipe40FF's Avatar
 
Join Date: May 2009
Location: Springfield, WV
Posts: 4,100
Liked 752 Times on 597 Posts
Likes Given: 498

Default Acroduster 2 vibration, low end aviation, etc. part 3

( new thread getting away from that bottom feeding thing)


Update. Sensenich said they would probably ship the prop. back tomorrow. There was nothing wrong with the prop. except the damaged spot(as I expected), tracking and angle are fine. They had to reduce dia. by 1/4" (1/8"/blade)to maintain required tip profile.

Meanwhile I kept looking at the Wood Culver 74 X 50 that I tried on the Spezio which the O290 couldn't turn(like 1900 rpm static) . I figured after that it had relatively more pitch compared to a metal Sensenich. Anyway I bolted it on and it tracked ok so I tried it figuring static would be over 2700( Static is 2400 or so with the 74DM6 X 58)

Surprise, static was only 2550 rpm so why not try it out. I had thrown it on torqued but not indexed so this morning I installed it correctly and tried it out.

It worked fine. 2650 RPM in a 90 mph climb and cruise was about the same 120 IAS @ 2500 rpm.

Overall it is much smoother w/o that typical Sensenich roughness from 2100-2300 or so. That said, while overall less vibration it's still there?

If this was my first flight in the airplane I probably wouldn't take note of the vibration but that will no longer ever be how I react. I no longer take vibration as a norm. Just got a call from Sensenich and the prop will go out today and be here tomorrow. Probably won't do anymore until next week. My grandson is here and we are fishing and shooting.

Alas I can't use the wood prop anyway. With me and full fuel we are at the aft limit of GG.

My plan is to fly the repaired 74DM6 and see how bad the vibration is? Hopefully it's within a range that will give me confidence to go 15 min. (31 miles)north to Bedford for a dynamic balance. At least there is a decent valley most of the way. Then maybe the dynamic balance will tell me something, maybe point to the Lord mounts? At best the vibration will be cured and the oil filter clean in another few hours and I can go on with my life.

But frankly I'm spooked by the whole thing!

Thanks again for help and/or cautions,

Jack


__________________
Finished Spezio Tu-holer N92JM(Oct. 2011), AcroDuster 2- SA750 N22JM, first flight 12-14-15
2Cor5:17

Last edited by EAABipe40FF; 08-17-2017 at 07:25 PM.
EAABipe40FF is offline  
 
Reply With Quote
Old 08-17-2017, 07:30 PM   #2
EAABipe40FF
Registered Users
BiP_SUPPORTER.png
 
EAABipe40FF's Avatar
 
Join Date: May 2009
Location: Springfield, WV
Posts: 4,100
Liked 752 Times on 597 Posts
Likes Given: 498

Default

I am also using weights to help with arm strength. My inability to hold half of 40# when removing the %$#$# prop. has cost me $600. Add the dynamic balance and this bottom feeder may have a grand more in the game drawing to an inside straight.
Exactly where one on the low end(I dislike bottom feeder*) of the aviation spectrum doesn't want to be.



* I admit I started this bottom feeder nonsense. I thought it was somehow funny especially if linked to my adopted WV heritage. I'm finding it less funny...

Jack


__________________
Finished Spezio Tu-holer N92JM(Oct. 2011), AcroDuster 2- SA750 N22JM, first flight 12-14-15
2Cor5:17
EAABipe40FF is offline  
Dennis5678 Likes This 
Reply With Quote
Old 08-18-2017, 04:08 AM   #3
castleman
Registered Users
BiP_SUPPORTER.png
 
castleman's Avatar
 
Join Date: Jul 2012
Location: Anacortes, Wa
Posts: 1,251
Liked 294 Times on 209 Posts
Likes Given: 487

Default

I was a bottom feeder myself Jack. Sailboats. Much more profit considering the investment. AND no governing authority. But I did get smart and got out of it about 2007. First and last time I every made a good guess on the economic future of selling toys.

will
castleman is offline  
 
Reply With Quote
Old 08-18-2017, 12:37 PM   #4
EAABipe40FF
Registered Users
BiP_SUPPORTER.png
 
EAABipe40FF's Avatar
 
Join Date: May 2009
Location: Springfield, WV
Posts: 4,100
Liked 752 Times on 597 Posts
Likes Given: 498

Default

Yea.......... Me, I started putting money INTO vintage aircraft projects at exactly the wrong time. I'll never get my $ out of them but it's not that much and they have been exactly what I've needed to sustain me through my pain management. If not for the projects I would have probably been laying around feeling sorry for myself, eating pills and getting fat. Well I am too fat but no more Perocets.

Marcia and I both agree it's been money well spent but at some point you have to quit digging.
__________________
Finished Spezio Tu-holer N92JM(Oct. 2011), AcroDuster 2- SA750 N22JM, first flight 12-14-15
2Cor5:17

Last edited by EAABipe40FF; 08-18-2017 at 12:45 PM.
EAABipe40FF is offline  
 
Reply With Quote
Old 08-18-2017, 01:14 PM   #5
TFF1
Registered Users
 
Join Date: Apr 2010
Location: Memphis,TN
Posts: 2,588
Liked 418 Times on 325 Posts

Default

Keep after it. It's sad that engine mounts cost so much as changing them is the only way to know. If you can see a sag, I wonder if you can clock them 180 deg
TFF1 is offline  
 
Reply With Quote
Old 08-18-2017, 02:09 PM   #6
PittsDriver68
Registered Users
 
Join Date: Jan 2013
Location: NH
Posts: 3,595
Liked 916 Times on 658 Posts
Likes Given: 2

Default

A couple of suggestions.

You can use an engine hoist to lift your prop on and off. That's what I use to lift the 55lb Hartzell. Tie some webbing on either side of the hub and around the hook of the hoist. A friend uses a couple of old bungee rings with his hoist. Saves your back and shoulders if you do this regularly.

And yes you can swap the rubber engine mount halves around, upper to lower, forward to aft. One of my thriftier friends has been known to do that.

Best of luck,

Wes
PittsDriver68 is offline  
 
Reply With Quote
Old 08-18-2017, 03:28 PM   #7
EAABipe40FF
Registered Users
BiP_SUPPORTER.png
 
EAABipe40FF's Avatar
 
Join Date: May 2009
Location: Springfield, WV
Posts: 4,100
Liked 752 Times on 597 Posts
Likes Given: 498

Default

Good ideas. I don't really have trouble with the 35 # prop I just forgot how much it weighed and didn't prepare for it. That said there is an engine hoist and strap right there, better safe than sorry.

No signs of sag but that doesn't mean it isn't the mounts. I'm also thinking that these mounts might have been perfectly happy on the Comanche and then the push-pull I gave them might have invited an issue? They are such a B.... to change I wouldn't want to swap them for nothing.

When I first mounted the engine after building the mount I found it impossible to get the engine onto the mount that was attached to the airframe. I had to remove the mount, install it onto the engine and then hang the assembly onto the FW. It would even be harder now with everything else installed on the engine.

In the past I didn't have any particular problem with an engine with regular T1 mount. I think the 18 degree T2 mount is harder to get all 4 mounts aligned at once? Or maybe it was just me.

Whatever if it's the mounts, it has to be done,


Of coarse another option is the active "Balance Master" unit as suggested in my other thread although it likely won't "fix" bad mounts.

I hate chasing what might be a minor issue and spend a couple big ones for nothing or for nothing actually important. I feel like shoving the AD2 in the corner and play with the Spezio but letting the airplane sit is just asking for more headaches.

Oh well

One step at a time. Hang the repaired prop, fly and then decide what's next....

Thanks

Jack
__________________
Finished Spezio Tu-holer N92JM(Oct. 2011), AcroDuster 2- SA750 N22JM, first flight 12-14-15
2Cor5:17

Last edited by EAABipe40FF; 08-18-2017 at 03:33 PM.
EAABipe40FF is offline  
 
Reply With Quote
Old 08-22-2017, 01:00 PM   #8
EAABipe40FF
Registered Users
BiP_SUPPORTER.png
 
EAABipe40FF's Avatar
 
Join Date: May 2009
Location: Springfield, WV
Posts: 4,100
Liked 752 Times on 597 Posts
Likes Given: 498

Default

Update.

Flew with the repaired 74DM6 Sen. and no change. Still has vibration.

I think it may be the lord mounts but before I spend another 500 bucks on them and/or $400 for dynamic balance I'm going to do something that got lost in the vibration thing. Go ahead and do an oil analysis. A one time analysis may be definitive if something really bad is going on?

Meanwhile, put the biplane in the corner and move the Tu-holer up front and fly her for awhile as the Duster's problems are sorted out. Seems dump to keep putting money in a hole that's filling with water

Jack
__________________
Finished Spezio Tu-holer N92JM(Oct. 2011), AcroDuster 2- SA750 N22JM, first flight 12-14-15
2Cor5:17

Last edited by EAABipe40FF; 08-22-2017 at 02:35 PM.
EAABipe40FF is offline  
 
Reply With Quote
Old 08-22-2017, 03:32 PM   #9
airplanegeek
Registered Users
 
airplanegeek's Avatar
 
Join Date: Jan 2016
Posts: 250
Liked 77 Times on 52 Posts
Likes Given: 35

Default

i just finished an antique PA-15 annual with a lycoming o-145. engine ran fine, but shook bad at idle, and didn't seem to make full static rpm. i pulled it into the shop and told my guys to start looking.

45 minutes later i was summoned to the shop. #4 exhaust valve seat was about to fall out. Still maintained compression, but the valve wasn't opening but a smidgen.

that's my story for the day - enjoy!!

Moral of the story - I think you have an engine issue Jack.
__________________
- Kendall Horst -

keeping the dream alive - www.lancasteraero.com
https://www.facebook.com/LancasterAeroLLc
airplanegeek is offline  
2
People Like This 
Reply With Quote
Old 08-23-2017, 01:02 PM   #10
bneub
Registered Users
BiP_SUPPORTER.png
 
Join Date: Jun 2016
Location: Wray, CO
Posts: 49
Liked 13 Times on 8 Posts
Likes Given: 13

Default

I had a similar issue to Kendall.

I had my Cherokee prop balanced and it ran very smooth. Then it started making a little metal and the vibration slowly started coming back. The metal and vibration increased over the next two oil changes.

Here's the bad news from the bore scope...

Hopefully by next week I'll be back in the air but with a lighter wallet
IMG_0365.JPG   IMG_0364.JPG  
__________________
Brian
Skybolt rebuild in process...
From a friend - An airplane owner makes a boat owner look like a financial genius!
bneub is offline  
 
Reply With Quote
Old 08-23-2017, 03:04 PM   #11
TFF1
Registered Users
 
Join Date: Apr 2010
Location: Memphis,TN
Posts: 2,588
Liked 418 Times on 325 Posts

Default

You should be able to run it, pull the valve covers and pull the engine through and measures the valve lift on each cylinder. Lifters should stay up for a couple of turns. Opposite Intakes are on the same lobe . A friend has a 0-235 which is solid lifter. The pushrod AD was not done correctly and one of the pushrods collapsed like in the AD. It would mag check ok at 1700 rpm but low power because it lost a cylinder essentially at power. Shook a bit at full.
TFF1 is offline  
 
Reply With Quote
Old 08-23-2017, 03:36 PM   #12
airplanegeek
Registered Users
 
airplanegeek's Avatar
 
Join Date: Jan 2016
Posts: 250
Liked 77 Times on 52 Posts
Likes Given: 35

Default

It is an option but the mechanic will need seriously accurate set up to obtain good numbers out of that test.



Quote:
Originally Posted by TFF1 View Post
You should be able to run it, pull the valve covers and pull the engine through and measures the valve lift on each cylinder. Lifters should stay up for a couple of turns. Opposite Intakes are on the same lobe . A friend has a 0-235 which is solid lifter. The pushrod AD was not done correctly and one of the pushrods collapsed like in the AD. It would mag check ok at 1700 rpm but low power because it lost a cylinder essentially at power. Shook a bit at full.
__________________
- Kendall Horst -

keeping the dream alive - www.lancasteraero.com
https://www.facebook.com/LancasterAeroLLc
airplanegeek is offline  
 
Reply With Quote
Old 08-23-2017, 04:42 PM   #13
TFF1
Registered Users
 
Join Date: Apr 2010
Location: Memphis,TN
Posts: 2,588
Liked 418 Times on 325 Posts

Default

It's usually pretty visible when it's real bad. You can always pull the rocker, pull the hydraulic part of the lifter , and read direct. It's when one of the all cylinder engine monitors really are valuable.
TFF1 is offline  
 
Reply With Quote
Old 08-24-2017, 01:27 AM   #14
EAABipe40FF
Registered Users
BiP_SUPPORTER.png
 
EAABipe40FF's Avatar
 
Join Date: May 2009
Location: Springfield, WV
Posts: 4,100
Liked 752 Times on 597 Posts
Likes Given: 498

Default

Cam and lifters was my main concern. I pulled all 4 cylinders and inspected them and found no rust or pitting. I seriously doubt if that's my problem, first the metal is not typical for cam spall and 2nd, it usually takes more than 40 hours before performance suffers. So they say?

But then again, Could Be?

Jack


__________________
Finished Spezio Tu-holer N92JM(Oct. 2011), AcroDuster 2- SA750 N22JM, first flight 12-14-15
2Cor5:17
EAABipe40FF is offline  
 
Reply With Quote
Reply


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Re: 2-place canopy, vibration etc. EAABipe40FF Starduster 56 08-18-2017 02:58 PM
Acroduster 2 vibration, bottom feeding etc. Part 2 EAABipe40FF Starduster 10 08-17-2017 06:29 PM
Engine Vibration Dave Baxter Lycoming & Continental 38 08-03-2017 04:47 AM
Bipes, Lycs & Vibration larryM Skybolt Miscellaneous 6 06-26-2012 11:07 AM
Flying Wires Vibration Midco Steen Skybolt 6 12-26-2009 09:15 PM