Return-Path: Received: from mail.viclink.com ([66.129.220.6] verified) by logan.com (CommuniGate Pro SMTP 4.2) with ESMTP id 350312 for flyrotary@lancaironline.net; Tue, 03 Aug 2004 09:03:23 -0400 Received-SPF: none receiver=logan.com; client-ip=66.129.220.6; envelope-from=pjmick@viclink.com Received: from viclink.com (p186.AS1.viclink.com [66.129.192.186]) by mail.viclink.com (8.11.7/8.11.7) with ESMTP id i73D2mY33519 for ; Tue, 3 Aug 2004 06:02:49 -0700 (PDT) Message-ID: <410F8C88.3000701@viclink.com> Date: Tue, 03 Aug 2004 06:00:56 -0700 From: Perry Mick User-Agent: Mozilla/5.0 (Windows; U; Win95; en-US; rv:1.0.1) Gecko/20020823 Netscape/7.0 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Rotary motors in aircraft Subject: Re: [FlyRotary] Re: Oil injection, and more References: Content-Type: multipart/alternative; boundary="------------020900030702010601020906" X-RAVMilter-Version: 8.4.3(snapshot 20030217) (mail.viclink.com) --------------020900030702010601020906 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Al Gietzen wrote: > > > It is my understanding (from David Atkins) is that the spring on the > metering pump forces the control to 'Low' position. Since this is a > critcal issue if relying upon the metered system for seal lubrication > I (we) would be forever grateful if someone would verify which way is > which. > > > > On a related subject, a posting on the ACRE list follows: > > Dave Atkins claims the apex seal oil metering system does not work over > > 8000 feet. He also claims the engine will run up to three months in > automotive service with no apex seal oil whatsoever. We have some > verification of that as George Graham flew his airplane from Tennessee > to New York state while forgetting to mix two cycle oil with the fuel. > > > > If it be true, then that also is a bit of a critical piece of > information. But 'why'? The driving force for the metering system oil > flow (as best I can figure out) is the pressure differential between > the ambient atmospheric and the pressure in the combustion chamber > during the intake cycle. This would suggest that for a NA engine > there would always be some pressure to drive the flow. > > > > And it is consistent that the metering control lever should be at > lowest flow for closed throttle position (greatest pressure > differential), and highest flow position for open throttle position > (lowest pressure differential). I'd guess there is the presumption > that the lubrication requirement is only a function of RPM, and not > power output, and the metering control level is for compensation of > the changes in pressure differential. > > > > Al > Al, I just went out and checked it on my RX-7, and I was wrong. The spring forces the pump to the minimum flow. Sorry for the erroneous statement earlier. Like I said in a previous message, I premix 2-stroke with the fuel, and just leave the minimal metering pump flow as a backup, and it puts the oil right on the apex seal, which surely is more effective than relying only on just the dispersed two-stroke oil. The idea of running ONLY with premix has always made me a little nervous so I wasn't willing to remove the stock system completely. Even with it set to minimal flow you can see the oil moving in the tubes. For my first 200 hours I flew with the stock system and did not add oil to the gas. I don't think I buy that statement that the metering pump quits working above 8000'. Perry --------------020900030702010601020906 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Al Gietzen wrote:

It is my understanding (from David Atkins) is that the spring on the metering pump forces the control to ‘Low’ position. Since this is a critcal issue if relying upon the metered system for seal lubrication I (we) would be forever grateful if someone would verify which way is which.

On a related subject, a posting on the ACRE list follows:

Dave Atkins claims the apex seal oil metering system does not work over

8000 feet. He also claims the engine will run up to three months in automotive service with no apex seal oil whatsoever. We have some verification of that as George Graham flew his airplane from Tennessee to New York state while forgetting to mix two cycle oil with the fuel.

If it be true, then that also is a bit of a critical piece of information. But ‘why’? The driving force for the metering system oil flow (as best I can figure out) is the pressure differential between the ambient atmospheric and the pressure in the combustion chamber during the intake cycle. This would suggest that for a NA engine there would always be some pressure to drive the flow.

And it is consistent that the metering control lever should be at lowest flow for closed throttle position (greatest pressure differential), and highest flow position for open throttle position (lowest pressure differential). I’d guess there is the presumption that the lubrication requirement is only a function of RPM, and not power output, and the metering control level is for compensation of the changes in pressure differential.

Al

Al, I just went out and checked it on my RX-7, and I was wrong. The spring forces the pump to the minimum flow. Sorry for the erroneous statement earlier. Like I said in a previous message, I premix 2-stroke with the fuel, and just leave the minimal metering pump flow as a backup, and it puts the oil right on the apex seal, which surely is more effective than relying only on just the dispersed two-stroke oil. The idea of running ONLY with premix has always made me a little nervous so I wasn't willing to remove the stock system completely. Even with it set to minimal flow you can see the oil moving in the tubes.
For my first 200 hours I flew with the stock system and did not add oil to the gas.
I don't think I buy that statement that the metering pump quits working above 8000'.

Perry

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