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  #11  
Old 02-22-2016, 04:56 PM
scsmith scsmith is offline
 
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Default One thing to look for

When you borescope your cylinders, you should take a very close look at the valve guides as you turn the prop and make the valves open and close.
I linked a few pictures here not too long ago from a friend's Cirrus that had slightly loose guides on valves in 3 cylinders. It can be hard to see them move. My friend sprayed some light oil in the cylinders to make them shiny inside, and also some oil soaked into the pockets of the loose valve seats. When the valve closed, you could see light glint and a slight bit of oil squeeze-out when the valve seat moved.

My hunch is that this is more common than we know, because we don't look. A cylinder with a slightly loose valve seat might run a long time trouble-free. But in some cases, they get loose enough to fall out when the valve is open, then can bend the valve when it closes on the displaced seat.
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  #12  
Old 02-22-2016, 06:28 PM
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It appears these scopes are made in China (which is to be expected) by Able Device Co Ltd of Shenzhen.

http://www.ablescope.com/

http://ablescope.com/detail.aspx?cid=29

It also seems they sell direct on Ebay, by regular bidding and by Best Offer. I got one today for $99, with free shipping.

Thank you Cousin Horton
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  #13  
Old 02-22-2016, 10:43 PM
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erich weaver erich weaver is offline
 
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Default

Quote:
Originally Posted by donaziza View Post
This looks pretty interesting to me, but I'm no mechanic. Could one of you guys educate me a bit? I always thought one looked thru a borescope with the naked eye, but I guess here, you're plugging it in to your ipad or laptop, and then looking at the inside of your cylinder there?? Have I got it right? Not being a mechanic, I might not know exactly what I'm looking for inside a cylinder, but hey, no harm in just peeking every now and then. I might learn something.
Yes, view using a laptop or Anroid tablet, but NOT an iPad. Search the archived EAA webinars for the Mike Busch presentation on exhaust valves. He reviews the basics of what to look for and beware of, but the gist is that the exhaust valve is the smaller of the two valves and typically has a harsher appearance than the intake valve. The exhaust valve is much more likely to have a problem than the intake valves. You want a symmetrical color pattern on it. It's common and normal to have a reddish spot in the middle. What you don't want is uneven color around the edges of the valve where it rests on the valve seat. A greenish spot along the edge is evidence of a burnt spot where exhaust gas breakthrough has happened or is immenent, and where valve failure is certain to follow in the near future.

Erich
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  #14  
Old 02-23-2016, 01:26 AM
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erich weaver erich weaver is offline
 
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The Mike Busch webinar showing what healthy vs damaged exhaust valves look like can be found here:
http://www.eaavideo.org/video.aspx?v=3817526267001
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  #15  
Old 02-23-2016, 08:56 AM
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Steve N. Steve N. is offline
 
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Thank you Dan. Seven of them left.
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  #16  
Old 05-10-2016, 01:26 PM
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flyboy1963 flyboy1963 is offline
 
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Default same eBay purchase

Quote:
Originally Posted by DanH View Post
It appears these scopes are made in China (which is to be expected) by Able Device Co Ltd of Shenzhen.

http://www.ablescope.com/

http://ablescope.com/detail.aspx?cid=29

It also seems they sell direct on Ebay, by regular bidding and by Best Offer. I got one today for $99, with free shipping.

Thank you Cousin Horton
I also just bought one on eBay for $99 US, so you might be able to get them for a bit less than that!!!.
hopefully brighter and easier to get working on my Nexus tablet than my $40 flexible scope.....which will be for sale soon!

http://www.oasisscientific.com/store...ED_Lights.html
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Last edited by flyboy1963 : 05-10-2016 at 01:28 PM. Reason: add comment
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  #17  
Old 05-10-2016, 05:25 PM
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Jesse Jesse is offline
 
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I bought a package that included a Samsung tablet for about $250 and it works great.

By the way, I was able to inspected for the new service bulletin on an RV-9A with this borescope without removing any inspection panels or the aileron or pushrods. Makes a 15 minute job out of the SB.
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  #18  
Old 05-10-2016, 09:20 PM
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flyboy1963 flyboy1963 is offline
 
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Default whaaaaaaaaaaaaaaa?????

ok Jesse,
fessey up!

...exactly where did you stick your scope to see the front side of the spar?

( I'm not near the plane, so perhaps it's obvious when you're standing there!?!?)
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  #19  
Old 05-11-2016, 06:11 AM
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Jesse Jesse is offline
 
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Through the aileron pushrod hole. There was enough room to fit it through the hole, then, with the articulating head, you can see the spar. Easy peasy.
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Dynamic Prop Balancing, Prebuy Inspections, Condition Inspections, Repairs and Mods, Injector Tuning, Airframe, Engine, Panel Upgrades, Ferrying, etc.
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  #20  
Old 05-11-2016, 07:57 AM
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Aerosport1 Aerosport1 is offline
 
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I used the same Vividia VA-400 Borescope and went thru the same hole as Jesse
it worked great. Was also able to inspect the aft side of the spar.

Geoff
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