X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail07.syd.optusnet.com.au ([211.29.132.188] verified) by logan.com (CommuniGate Pro SMTP 5.2.5) with ESMTPS id 3024444 for flyrotary@lancaironline.net; Sun, 13 Jul 2008 18:56:31 -0400 Received-SPF: pass receiver=logan.com; client-ip=211.29.132.188; envelope-from=lendich@optusnet.com.au Received: from george (d58-104-215-70.dsl.nsw.optusnet.com.au [58.104.215.70]) by mail07.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id m6DMtd5l015450 for ; Mon, 14 Jul 2008 08:55:45 +1000 Message-ID: <003501c8e53b$95e149e0$6400a8c0@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] pre-mix; great trip Date: Mon, 14 Jul 2008 08:55:39 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0030_01C8E58F.639F56D0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3198 X-Antivirus: avast! (VPS 080713-0, 13/07/2008), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0030_01C8E58F.639F56D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Al, Great report- great photo. I forget how many ounces you have in the US gallon ours is 128 oz to = the gallon which is too much. Tracy Crook used 1 oz to 1 gallon and found it too much. Ed Anderson uses 3/4 oz per gallon. Amsoil advises 100:1 Racing suggests .7 oz per US gallon. So I guess about 100:1 is the GO. George ( down under) Just returned from about 2500 nm trip. Engine ran great, including = flying over the Rockies west of Denver where I was briefly at about = 14,000 ft with density altitude of 16,500, and still had some throttle = to go. Generally cruising at 165 KTAS, 9.2 - 9.5 gph, about 5600 rpm. = Not bad for a 4-place airplane. OK, now for some technical stuff. You may recall I converted my 20B = over from pan oil injection to using premix. The main issue is the amount of 2-cycle oil that is ending up in the = oil pan. When mixing 1 oz/gal I found the pan oil level had gone up by = about 1 =BD quarts (from 6 =BD to 8) in about 15 hours of flying; and my = nice clear-amber 15-50 synthetic had become the dark blue-black color of = the SuperTech 2-cycle oil. Doing the math suggests that about 1/3 of the = pre-mix oil is ending up in the pan. That seems way out of line, and = although a suspect it is not harmful to the engine, I don't think it the = best lube for the re-drive. I changed the oil and reduced the amount of = pre-mix to =BE oz per gallon. I'll be surprised if there isn't still = some 2-cycle oil going into the pan. So. . ; suggestions? Use different brand 2-cycle? Further reduce = pre-mix amount? I'm wondering if the fact that my cruise coolant temp is now running = around 150F would result in more of the pre-mix to condense out than if = it was running at maybe 180F. Another thing I notice is a small amount of fuel is coming out of the = fuel vent. The only explanation I can come up with is foaming/bubbles = forming in the return line after the pressure regulator. This goes into = the 3-gallon sump tank and up the =BC" vent line. This may have been = occurring previously, and the fuel evaporated as it went back along the = surface; but now the blue 2-cycle oil is left behind to be quite visible = at the back of the cowl; but I suspect the pre-mix is exacerbating the = foaming.=20 I notice the plugs have less carbon than before, and the inside of the = exhaust exit is now very light grey. Al -------------------------------------------------------------------------= ----- -- Homepage: http://www.flyrotary.com/ Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0030_01C8E58F.639F56D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 Al, Great report- great = photo.
 I forget how many ounces you have = in the=20 US gallon ours is 128 oz to the gallon which is too = much.
 
Tracy Crook used 1 oz to 1 gallon and = found it too=20 much.
Ed Anderson uses 3/4 oz per = gallon.
Amsoil advises 100:1
Racing suggests .7 oz per US = gallon.
So I guess about 100:1 is the = GO.
George ( down under)

Just = returned from=20 about 2500 nm trip. Engine ran great, including flying over the=20 Rockies west of=20 Denver where I = was=20 briefly at about 14,000 ft with density altitude of 16,500, and still = had some=20 throttle to go. Generally cruising at 165 KTAS, 9.2 =96 9.5 gph, about = 5600 rpm.=20 Not bad for a 4-place airplane.

 

OK, now = for some=20 technical stuff.  You=20 may recall I converted my 20B over from pan oil injection to using=20 premix.

 

The main = issue is=20 the amount of 2-cycle oil that is ending up in the oil pan.  When = mixing=20 1 oz/gal I found the  pan oil level had gone up by about 1 =BD = quarts (from=20 6 =BD to 8) in about 15 hours of flying; and my nice clear-amber 15-50 = synthetic=20 had become the dark blue-black color of the SuperTech 2-cycle oil. = Doing the=20 math suggests that about 1/3 of the pre-mix oil is ending up in the = pan. =20 That seems way out of line, and although a suspect it is not harmful = to the=20 engine, I don=92t think it the best lube for the re-drive.  I = changed the=20 oil and reduced the amount of pre-mix to =BE oz per gallon.  = I=92ll be=20 surprised if there isn=92t still some 2-cycle oil going into the=20 pan.

 

So. . ;=20 suggestions?  Use different brand 2-cycle?  Further reduce = pre-mix=20 amount?

 

I=92m = wondering if=20 the fact that my cruise coolant temp is now running around 150F would = result=20 in more of the pre-mix to condense out than if it was running at maybe = 180F.

 

Another = thing I=20 notice is a small amount of fuel is coming out of the fuel vent.  = The=20 only explanation I can come up with is foaming/bubbles forming in the = return=20 line after the pressure regulator.  This goes into the 3-gallon = sump tank=20 and up the =BC=94 vent line.  This may have been occurring = previously, and=20 the fuel evaporated as it went back along the surface; but now the = blue=20 2-cycle oil is left behind to be quite visible at the back of the = cowl; but I=20 suspect the pre-mix is exacerbating the foaming.

 

I notice = the plugs=20 have less carbon than before, and the inside of the exhaust exit is = now very=20 light grey.

 

Al

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