---------------------------------------------------------- Rocket-List Digest Archive --- Total Messages Posted Sat 12/08/12: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 02:21 PM - HRII Fuel Pump Vent Clearance (viperpilot) 2. 03:27 PM - Re: HRII Fuel Pump Vent Clearance (Stuart Hutchison) 3. 03:29 PM - Re: HRII Fuel Pump Vent Clearance (Hr2pilot) 4. 04:08 PM - Re: HRII Fuel Pump Vent Clearance (viperpilot) ________________________________ Message 1 _____________________________________ Time: 02:21:00 PM PST US Subject: Rocket-List: HRII Fuel Pump Vent Clearance From: "viperpilot" I am finally returning my ship to flying status, having been aground for upgrades and fixes following a prop strike nearly a year ago. Mounting the IO-540 with new elastic mounts has changed the clearance at the back of the engine a bit. The engine-mounted fuel pump drain is uncomfortably close to the firewall. The firewall has been dimpled inward a bit to increase clearance during the previous engine installation, but additional dimpling does not appear to be available due to the proximity of a vertical structural member on the cockpit side of the firewall. 1. Does anyone know of a method to increase clearance between the firewall and the fuel pump drain? 2. I have seen a few drain elbows of other aircraft that look to be smaller (or at least project aft less than the AN832-type fitting). Are these available or are they custom made from an AN832-4? 3. Vans notes that the threads on the Lycoming fuel pump are "special" and that NPT threads will not work--does that note apply to the vent drain? 4. I assume that the vent drain only comes into play if there is a rupture in the fuel pump diaphram. In that case, one is looking for fuel or oil coming from the vent drain as a major clue that the fuel pump is about to fail. Is that an accurate statement? Any assistance or comment would be greatly appreciated. Thanks, Randy Sage Peachtree City, GA Read this topic online here: http://forums.matronics.com/viewtopic.php?p=390071#390071 ________________________________ Message 2 _____________________________________ Time: 03:27:57 PM PST US From: "Stuart Hutchison" Subject: RE: Rocket-List: HRII Fuel Pump Vent Clearance G'day Randy, The vent thread is tapered and I'm pretty sure it's NPT. The other fittings are straight thread, sealed by O-ring. I used a lathe, but the link shows one option. I ground the JB Weld flat of course. http://www.mykitlog.com/users/display_log.php?user=RockFLY&project=797&categ ory=5584&log=131278&row=53 As you say, this should only vent fuel if the diaphragm is failing ... the intent is to stop fuel entering the crankcase through the hole where the actuator arm penetrates (top side of the diaphragm). Kind regards, Stu F1 Rocket VH-FLY http://www.mykitlog.com/RockFLY www.teamrocketaircraft.com -----Original Message----- From: owner-rocket-list-server@matronics.com [mailto:owner-rocket-list-server@matronics.com] On Behalf Of viperpilot Sent: Sunday, December 09, 2012 9:21 AM Subject: Rocket-List: HRII Fuel Pump Vent Clearance I am finally returning my ship to flying status, having been aground for upgrades and fixes following a prop strike nearly a year ago. Mounting the IO-540 with new elastic mounts has changed the clearance at the back of the engine a bit. The engine-mounted fuel pump drain is uncomfortably close to the firewall. The firewall has been dimpled inward a bit to increase clearance during the previous engine installation, but additional dimpling does not appear to be available due to the proximity of a vertical structural member on the cockpit side of the firewall. 1. Does anyone know of a method to increase clearance between the firewall and the fuel pump drain? 2. I have seen a few drain elbows of other aircraft that look to be smaller (or at least project aft less than the AN832-type fitting). Are these available or are they custom made from an AN832-4? 3. Vans notes that the threads on the Lycoming fuel pump are "special" and that NPT threads will not work--does that note apply to the vent drain? 4. I assume that the vent drain only comes into play if there is a rupture in the fuel pump diaphram. In that case, one is looking for fuel or oil coming from the vent drain as a major clue that the fuel pump is about to fail. Is that an accurate statement? Any assistance or comment would be greatly appreciated. Thanks, Randy Sage Peachtree City, GA Read this topic online here: http://forums.matronics.com/viewtopic.php?p=390071#390071 ________________________________ Message 3 _____________________________________ Time: 03:29:11 PM PST US Subject: Re: Rocket-List: HRII Fuel Pump Vent Clearance From: Hr2pilot Do away with the fitting Sent from my iPhone On Dec 8, 2012, at 2:20 PM, "viperpilot" wrote: > > I am finally returning my ship to flying status, having been aground for upgrades and fixes following a prop strike nearly a year ago. Mounting the IO-540 with new elastic mounts has changed the clearance at the back of the engine a bit. The engine-mounted fuel pump drain is uncomfortably close to the firewall. The firewall has been dimpled inward a bit to increase clearance during the previous engine installation, but additional dimpling does not appear to be available due to the proximity of a vertical structural member on the cockpit side of the firewall. > > 1. Does anyone know of a method to increase clearance between the firewall and the fuel pump drain? > 2. I have seen a few drain elbows of other aircraft that look to be smaller (or at least project aft less than the AN832-type fitting). Are these available or are they custom made from an AN832-4? > 3. Vans notes that the threads on the Lycoming fuel pump are "special" and that NPT threads will not work--does that note apply to the vent drain? > 4. I assume that the vent drain only comes into play if there is a rupture in the fuel pump diaphram. In that case, one is looking for fuel or oil coming from the vent drain as a major clue that the fuel pump is about to fail. Is that an accurate statement? > > Any assistance or comment would be greatly appreciated. > > Thanks, > Randy Sage > Peachtree City, GA > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=390071#390071 > > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 04:08:44 PM PST US Subject: Rocket-List: Re: HRII Fuel Pump Vent Clearance From: "viperpilot" Thanks guys! Stuart's solution is certainly the most elegant, but simply removing the fitting would seem to work also, as there should be no fuel coming out of the port if all is well inside the fuel pump. Seems like the only reason to have the drain line is to make it easier to ID the problem and I am sure the FAA required it for certification. Thanks, Randy Read this topic online here: http://forums.matronics.com/viewtopic.php?p=390080#390080 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message rocket-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Rocket-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/rocket-list Browse Digests http://www.matronics.com/digest/rocket-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.