Mailing List flyrotary@lancaironline.net Message #28856
From: george lendich <lendich@optusnet.com.au>
Subject: Re: [FlyRotary] Re: Eccentric Shaft Position Sensor
Date: Sat, 31 Dec 2005 10:02:24 +1000
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Al,
What CAM are we talking about here.
However could a back-up be somehow placed on a flywheel - just thinking out loud.
George (down under)
 
FWIW, I track Subaru fail rates. The crank sensor fails 1 per 200k hours estimated.  Which sounds ok, but isn't the best rate. It is trivial fail rate though, as the ECM has design features which determine sensor has failed, flags owner, then uses cam sensor. This is a big part of the reason there are never (virtually) vehicle shut downs. Pretty ingenious failure mode actually....the engine is difficult to start if one of those sensors fails, yet runs great. They use irregular pulse intervals for each of the sensors, making it easy to self diagnose.
 
We've been discussing these design advantages for years on the newsgroup. It's good to hear it results in design requests. I've heard of at least three aircraft crank sensor failures. Two were custom wiring failure, crash resulted. One was actual sensor. All of these had aftermarket ECM's ...so engine stopped. I look forward to when the aftermarket ecm's take advantage of these safety techniques.
 

-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
 
 
 
On Thu, 29 Dec 2005 11:15:57 -0500 "Tracy Crook" <lors01@msn.com> writes:
Not a stupid question at all.  Nothing special about the sensor but note that it is a variable reluctance sensor, not Hall effect.  Most any VR type will work but some are more reliable than others.  The Subaru does not have a good track record based on the number of Soob flyers who have had failures and asked me to make dual pickup versions for the EJ-2x & EG-33 engines.  I have not heard of a Mazda sensor failing but that is of course no guarantee that it can't happen. 
 
Do be sure to check the polarity of any VR sensor used.  The output should swing positive as the tooth moves toward it and negative as it moves away.
 
Spent yesterday configuring my oil system on the RV-8.  I should have heeded Rusty's warning on those "Easy push-on oil line fittings"  The Summit description says "no more busted knuckles trying to assemble oil lines".  Ha!  I'm an FAA "standard 170 lb pilot" but that is not enough force to put on those blasted fittings.  Anyone know a trick to make them easier to put on? 
 
Tracy (finally getting my XM weather activated)
----- Original Message -----
Sent: Thursday, December 29, 2005 9:39 AM
Subject: [FlyRotary] Re: Eccentric Shaft Position Sensor

Kelly Troyer wrote:

>
>     > > Ken,
>     > > Hit the junkyards........1999-2002 Mazda Protege "Camshaft
>     Sensor"
>     > > is the same part number as the 1993-95 RX7 eccentric shaft
>     sensor....
>     > > Rock Auto price had best price of $81.00 that I
>     found.......Get the
>     > > connector from the donor car harness with the sensor !!
>     > > --
>     > > Kelly Troyer
>     > > Dyke Delta/13B/RD1C/EC2
>     > >
>     >
>     > Guy on eBay is letting them go for $40.
>
Tracy, I don't really expect you to know such trivia, but it can't hurt
to ask.  The eBay  store with the RX-8 crankshaft sensor has a bunch of
other models, so for as little as $5.  Is there anything special about
this particular model, or is it just a hall effect sensor?  Some of the
other model numbers looked like they had long mounting arms that would
make installation in an RX-7 series a tad easier.

--
         ,|"|"|,                                    |
----===<{{(oQo)}}>===----        Dyke Delta         |
        o|  d  |o          www.ernest.isa-geek.org  |

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-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html
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