X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-vw0-f52.google.com ([209.85.212.52] verified) by logan.com (CommuniGate Pro SMTP 5.3.5) with ESMTP id 4217070 for flyrotary@lancaironline.net; Sat, 10 Apr 2010 17:35:04 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.212.52; envelope-from=rwstracy@gmail.com Received: by vws11 with SMTP id 11so1068080vws.25 for ; Sat, 10 Apr 2010 14:34:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:date :x-google-sender-auth:received:message-id:subject:from:to :content-type; bh=g32b7lf8fATc1QHMZdp+3+nCAXQjWwPUNry6Auswwh8=; b=uwxFpmx54u1LunNjED7GzG0s1PT9iv+hW7nGqhFBhJYOh9nE+tzK+HKiZyogf7uDeW hFqbvmc6TYDviK/fBQKsKDCEN4OTm9iyXDUD+fO8G3sejvSAizNomuLxOT8WUpLWJUW5 /nEA1jbtWDCZwrNbfbLl/AM4yHmecFEogsxk4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:date:x-google-sender-auth:message-id:subject :from:to:content-type; b=TuxH3epPM1X74wQFMWlYdUxNjnPAUOyDqa5AHmE72WJaSJHon/bZvy9A6h/Iu6TW9a vKl6TTTOiIAi9R9MQSqc1vqMbZKT5hrQC7KC4O6xgep3+TFvkjROcRGsjSeXJYvDcVQS +9ueOmUYOrXrjToqOg7guBgnRbjRqnWzRTUC8= MIME-Version: 1.0 Sender: rwstracy@gmail.com Received: by 10.220.163.72 with HTTP; Sat, 10 Apr 2010 14:34:28 -0700 (PDT) Date: Sat, 10 Apr 2010 17:34:28 -0400 X-Google-Sender-Auth: 8b24a6bbe34ebcd1 Received: by 10.220.107.95 with SMTP id a31mr892366vcp.206.1270935269062; Sat, 10 Apr 2010 14:34:29 -0700 (PDT) Message-ID: Subject: Re: Fuel Pressure sensor warning / crank sensor mounts From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=00c09f8e5bdf3eb91a0483e8ad97 --00c09f8e5bdf3eb91a0483e8ad97 Content-Type: text/plain; charset=ISO-8859-1 Just got done doing a final flight test on the RV-8 before Sun n Fun decision time. The battery had gone flat from being discharged to zero too many times by the Blue Mountain EFIS. It draws some power even when off. Replaced the battery yesterday with another Odessy 925 and the engine turned over smartly. Had just changed out the EC2 for an EC3 just because i felt the need to say I had personally flown it on a 20B. Also made a new mount for the RX-8 crank sensor. I had been getting an occasional high speed miss above 6200 rpm and suspected the problem might be the same as a customer's Continental AC engine that was equipped with an EC3. That turned out to be a resonant condition where the mount would vibrate above a certain rpm causing the distance between sensor and trigger wheel to vary enough to cause distortion of the signal. That caused the EC3 to lose sync momentarily. Making a very rigid mount cured the problem on the Cont. and my 20B. It's sweet at all rpms now. This might have been the problem on Mark Steitle's 20B as well. We thought it was the material it was made of but i'm not sure about that now. He also replaced his mount and the problem went away. Anyway, if you make your own crank sensor mount, make sure it is really rigid. The RV-8 flew perfectly on the test flight with only engine anomaly being a low fuel pressure reading. I knew it was an instrument problem because the engine wouldn't run if the fuel pressure was only 6 psi. Un-cowled the engine and heard a hissing noise coming from the fuel pressure sensor. There was a steady drip of fuel from the terminal end of the sensor. Why i didn't have an engine fire in flight I don't know. *SO, I can no longer recommend using the VDO pressure sensors for use on fuel systems.* Either an isolator must be used or a sensor rated for fuel exposure be installed. I've been using one on my -4 for >7 years with no problems. About 3 years ago VDO started putting a sticker in the pressure sensor package saying not to use them on fuel pressure applications. I suspect they changed something in the manufacturing process. I'll do some research on sensors and see if I can find a suitable replacement that doesn't cost a fortune. Anyone have a lead on sensor isolators? My transponder also decided it wasn't going to work this time. I recently had the instrument panel out for the EC3 change so I think it's an antenna connector or coax problem. Bummer. Too many last minute squawks to fix in time so will have to take the RV-4 to SnF :-( Tracy --00c09f8e5bdf3eb91a0483e8ad97 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
Just got done doing a final flight test on the RV-8 before Sun n Fun de= cision time.=A0 The battery had gone flat from being discharged to zero too= many times by the Blue Mountain EFIS.=A0 It draws some power even when off= .=A0 Replaced the battery yesterday with another Odessy 925 and the engine = turned over smartly.

=A0Had just changed out the EC2 for an EC3 just because i felt the need= to say I had personally flown it on a 20B.=A0

=A0Also made a new m= ount for the RX-8 crank sensor.=A0 I had been getting an occasional=A0 high= speed miss above 6200 rpm and suspected the problem might be the same as a= customer's Continental AC engine that was equipped with an EC3.=A0 Tha= t turned out to be a resonant condition where the mount would vibrate above= a certain rpm causing the distance between sensor and trigger wheel to var= y enough to cause distortion of the signal.=A0 That caused the EC3 to lose = sync momentarily.=A0 Making a very rigid mount cured the problem on the Con= t. and my 20B.=A0 It's sweet at all rpms now.=A0 This might have been t= he problem on Mark Steitle's 20B as well.=A0 We thought it was the mate= rial it was made of but i'm not sure about that now.=A0 He also replace= d his mount and the problem went away.=A0 Anyway, if you make your own cran= k sensor mount, make sure it is really rigid.

The RV-8 flew perfectly on the test flight with only engine anomaly bei= ng a low fuel pressure reading.=A0 I knew it was an instrument problem beca= use the engine wouldn't run if the fuel pressure was only 6 psi.=A0 Un-= cowled the engine and heard a hissing noise coming from the fuel pressure s= ensor.=A0 There was a steady drip of=A0 fuel from the terminal end of the s= ensor.=A0 Why i didn't have an engine fire in flight I don't know.= =A0 SO,=A0 I can no longer recommend using the VDO pressure sensors for = use on fuel systems.=A0 Either an isolator must be used or a sensor rat= ed for fuel exposure be installed.=A0 I've been using one on my -4 for = >7 years with no problems. =A0 About 3 years ago VDO started putting a s= ticker in the pressure sensor package saying not to use them on fuel pressu= re applications. =A0 I suspect they changed something in the manufacturing = process.=A0 I'll do some research on sensors and see if I can find a su= itable replacement that doesn't cost a fortune.=A0=A0 Anyone have a lea= d on sensor isolators?

My transponder also decided it wasn't going to work this time.=A0 I= recently had the instrument panel out for the EC3 change so I think it'= ;s an antenna connector or coax problem.

Bummer.=A0 Too many last mi= nute squawks to fix in time so will have to take the RV-4 to SnF :-(

Tracy
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