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09-19-2010, 11:12 PM
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Join Date: Oct 2009
Location: Victoria, BC, Canada
Posts: 3,932
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Quote:
Originally Posted by rocketbob
Got some photos today in an email that showed the root cause of Relentless losing its prop ... Loss of oil pressure caused the prop to run away.
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Now that's what I call a runaway prop!
Are those photos you can share? I'd be interested...
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Rob Prior
1996 RV-6 "Tweety" C-FRBP (formerly N196RV)
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09-19-2010, 11:39 PM
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Join Date: Oct 2006
Location: Seattle, wa
Posts: 679
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Steel. You can get them at a hydraulic supply dealer.... Many of them in the bins say "china". I pass on those however.
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09-20-2010, 02:54 AM
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Join Date: Oct 2005
Location: Melbourne, Australia
Posts: 1,868
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Quote:
Originally Posted by Toobuilder
I rarely see anything BUT aluminum used in the oil cooler or engine case.
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Well that's true of most RVs, but that's simply because that's what Vans supplies with their FWF kits. As always Vans components are purely price driven. In the end it's cheaper (and easier) for builders to use what they have been given rather than discard their fittings and source the much more expensive AN steel fittings (virtually twice the price).
Personally I opted for steel. And thanks to RocketBob for the heads up.
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You’re only as good as your last landing 
Bob Barrow
RV7A
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09-20-2010, 04:48 AM
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Join Date: Jun 2008
Location: Charlottesville, VA
Posts: 801
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Thanks everyone for your replies. Based on everyone's input I decided to go with steel oil cooler fittings. The failure on Relentless sealed the deal. Thanks again.
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Jim Shannon
RV-8 N52VV
Charlottesville, VA
AFS 4500 EFIS & 3400 EFIS/EM
G430W - SL30 - G327 - G696 - G240
TT DigiFlight II VSVG w/pitch autotrim
VP-X Pro
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09-21-2010, 05:11 PM
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Join Date: Nov 2006
Location: Waco, Texas
Posts: 1,658
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Has anyone experienced corrosion when using steel fittings in an aluminum hole? I'm considering using steel fittings to terminate my hard aluminum lines at the firewall pass-thru. But I am a bit concerned about corrosion forming in the fuel line and going undetected for long enough for it to cause some serious problems.
Thanks,
Phil
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10-05-2010, 12:29 PM
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Join Date: Oct 2005
Location: Geneva, AL
Posts: 491
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General Consesus FWF
I'm getting ready to hang my engine and was reviewing this thread. Is the general consensus to use steel fittings in all the required places in the Accy case? If so, can one find the special fittings for the OP and FP lines in steel, or do you have to make them? I have them for the oil cooler, but just thought about the rest of them.
Thanks
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Paul Rose
RV-9A 91300
N417PR
SERFI 2013 Awards
Inspection Complete!!! 7/7/12
First Flight 7/22/12
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10-05-2010, 02:14 PM
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Join Date: Aug 2009
Location: Southern California
Posts: 882
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Not From a Broken Fitting!
Quote:
Originally Posted by rocketbob
Got some photos today in an email that showed the root cause of Relentless losing its prop was due to oil starvation from a broken aluminum AN fitting for one of the oil cooler lines on the accessory case. Loss of oil pressure caused the prop to run away.
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I should have rebutted the above statement sooner. I spoke to the crew chief for Relentless a couple of days after their spectacular engine failure. They DO NOT believe that the broken oil fitting in the back of the accessory case caused the failure. They have pretty strong evidence that the first failure was actually the oil filter mount casting (stock lycoming). They think that the filter mount failed from fatigue from the "G" loads and it and the filter fell onto the fitting/oil hose below it. The filter and the broken part of the aluminum casting were found somewhere out on one of the runways near the location where the oil loss was experienced. There was a witness mark on the filter where it was believed to have hit the oil fitting. Also note that they were using one of the "long" filters in this plane which would certainly increase the cantilevered loads on the filter mount.
Skylor
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10-05-2010, 03:09 PM
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Join Date: Oct 2005
Location: 08A
Posts: 9,500
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The crew chief is probably confused about the order of events. Failure of an oil filter casting due to flight G loads is unlikely. Failure due to the very high accelerations of a severe vibratory inbalance is quite possible:
http://www.relentlessairracing.com/z...&w=1905&h=1057
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Dan Horton
RV-8 SS
Barrett IO-390
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10-05-2010, 03:32 PM
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Join Date: Aug 2009
Location: Southern California
Posts: 882
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Quote:
Originally Posted by DanH
The crew chief is probably confused about the order of events. Failure of an oil filter casting due to flight G loads is unlikely. Failure due to the very high accelerations of a severe vibratory inbalance is quite possible:
http://www.relentlessairracing.com/z...&w=1905&h=1057
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Are you sure about that? The filter mount casting was pretty thin in one of the mounting bolt locations, and the broken casting showed some discoloration in that particular location as if there may have been a crack propagating for some time prior to the failure. Since the filter itself is cantilevered off of the mount and they were using the long filter, the mount would certainly see significant loads during in flight "G" loads.
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