X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from ms-smtp-04.southeast.rr.com ([24.25.9.103] verified) by logan.com (CommuniGate Pro SMTP 5.1.11) with ESMTP id 2287649 for flyrotary@lancaironline.net; Mon, 27 Aug 2007 13:58:29 -0400 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-04.southeast.rr.com (8.13.6/8.13.6) with SMTP id l7RHvWxE010521; Mon, 27 Aug 2007 13:57:33 -0400 (EDT) Message-ID: <001301c7e8d3$dc30d600$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" Cc: "Tracy Crook" References: Subject: Friction was [FlyRotary] Re: Latest 20B testing Date: Mon, 27 Aug 2007 13:58:22 -0400 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C7E8B2.54B3F110" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MIMEOLE: Produced By Microsoft MimeOLE V6.00.2900.3138 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0010_01C7E8B2.54B3F110 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Glad to hear you are getting the "bug" worked out, Tracy. I presume the = increased loudness was not due to it being in the hangar verse outside = {:>) Great to hear the non-return fuel system is working as expected. Will = want to know the details at some point. Boy, I hope you are right about the friction. One more rotor would, of = course, increase that friction feel, but I figure your arm should be = able extrapolate between 2 and 3 rotors. Certainly hope its not a seal = out of place. I personally don't think it is and here is my rationale. First, When my apex seal (slightly misplaced to the side of the rotor) = incident happened, I would have not been able to turn the engine over = had it not fallen into one of the milled "lightening" holes in the rotor = (what are the odds?). Without falling into that hole, It would have had = so much pressure friction that I am certain I would not have been able = to turn it. It was hard as it was.=20 The second indication was that my engine would not run/idle below 2000 = rpm (due to the friction) until after about 1 hour of run time - by = which time the misplaced apex seal was probably worn into dust (and the = damage already done). =20 I don't recall the friction before and after the run, I do know it was = high before the run and it seems like it was still high after the run - = but, don't hold me to that. But, if your engine has no problem at low rpm idle, then its likely = that is not the problem. Also if you have more than 1 hour run time it = would probably have worn that seal down by now - but I've been wrong = before. I'll be keeping my fingers crossed for you. The only good news if you = do decide you have to tear it down, it that you are home rather than in = a dilapidated garage in the middle of a Louisiana summer with no rotor = parts within 600 miles {:>) Best Regards Ed ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Monday, August 27, 2007 10:28 AM Subject: [FlyRotary] Re: Latest 20B testing Finally got a moment to report on the RV-8 progress. I have about 2.5 = hours of ground testing over the last month or so on the 20B RV-8 with = mixed results. The Bluemountain stuff is working great and the display = is crisp & bright in daylight as advertised. Very pleased so far.=20 The first attempted engine start after installing all the = instrumentation resulted in a loud bang followed by the sound of = dripping liquid (I was inside the hangar). The other 'first start' at = last year's rotary roundup fly-in was with no instrumentation and the = engine temporarily 'hot-wired' for the demo. Climbing out of the = cockpit, I found gas dripping from the exhaust pipe into a sizable = puddle on the floor. Note to self--- Perform all first starts outside = in the future.=20 Problem turned out to be a misfire on one of the injector disable = switches causing always on injectors. After correcting that and = clearing the flooded engine, the engine started immediately and I = thought the engine sounded much louder than last year's engine run. = Before I had just the exhaust header on with no muffler or tail pipe and = the engine was surprisingly quiet. I had added the rest of the exhaust = system up to but not including the under belly muffler. I thought this = might make it even quieter than it was before but the opposite was true. = When throttled up to 24" manifold pressure the sound is powerful and = defening. I will need something bigger than my golf cart with chocked = wheels to test it at higher power. At 25" Hg and 5000 RPM It jumps the = chocks and the RV-8 starts dragging it down the runway even though the = cart parking brakes are on. =20 Having no vapor lock problems so far with the non-circulating fuel = rail scheme. I used a remote fuel pressure regulator near the pumps = (inside cockpit) so the fuel goes only one way to the fuel rails with no = return. Return is from the regulator to fuel tank. This arrangement is = used on most late model cars and vapor lock does not seem to be a = problem. On my Mazda Tribute I do notice that on a hot start on a hot = day there can be a momentary stumble from vapor in the rail but it = clears immediately.=20 Not sure why but this engine seems much more critical in mixture = tuning than any of the 13Bs I've run. The mixture control only has = about 70 deg. range where the mixture is OK which is about half the = range I have on other engines. The 20B injectors are about the only = variable I can think of that could affect this. =20 Cooling is surprisingly good. On a 90+ degree day the coolant = stabilizes at 200 F and oil at 185. This is much cooler than my RV-4 on = extended ground runs. =20 The bad news is engine friction that I notice when pulling the prop = through compression cycles. BTW, with only a little experience you can = gauge the relative health of a rotary with just a few pulls of the prop = through all 6 (or 9 on 20B) compression cycles. When cold this 20B feels = close to normal for what I would expect on a freshly overhauled engine = considering it has one more rotor than my 13Bs. But when it's hot the = internal friction is much higher. When switched off after a run, the = prop stops quite abruptly. Immediately afterward, it will not rebound = from a quick pull into compression after releasing the prop. Hot starts = are very sluggish and sometimes not possible with the tiny battery I'm = using. I keep hoping this will change after break in but so far it = doesn't look good. OTOH, the Renesis took a full 40 - 50 hours to break = in. I do NOT want to open this engine again but it may be necessary. I = keep having nightmares of Ed's ordeal with an engine that felt very = similar to this. Time will tell. lots more things to test before making = that decision.=20 Tracy ------=_NextPart_000_0010_01C7E8B2.54B3F110 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Glad to hear you are getting the "bug" worked = out,=20 Tracy.  I presume the increased loudness was not due to it being in = the=20 hangar verse outside {:>)
 
Great to hear the non-return fuel system is = working as=20 expected.  Will want to know the details at some = point.
 
Boy, I hope you are right about the = friction.  One=20 more rotor would, of course, increase that friction  feel, but I = figure=20 your arm should be able  extrapolate between 2 and 3 = rotors. =20 Certainly hope its not a seal out of place.  I personally don't = think it is=20 and here is my rationale.
 
First, When my apex seal (slightly misplaced to = the side=20 of the rotor) incident happened, I would have not been able to turn the = engine=20 over had it not fallen into one of the milled "lightening" holes in the = rotor=20 (what are the odds?).  Without falling into that hole, It would = have had so=20 much pressure friction that I am certain I would not have been able to = turn=20 it.  It was hard as it was. 
 
 The second indication was that my engine = would not=20 run/idle below 2000 rpm (due to the friction) until after about 1 hour = of run=20 time - by which time the misplaced apex seal was probably worn into dust = (and=20 the damage already done). 
 
I don't recall the friction before and after the = run, I do=20 know it was high before the run and it seems like it was still high = after the=20 run - but, don't hold me to that.
 
But,  if your engine has no problem at low = rpm idle,=20 then its likely that is not the problem.  Also if you have more = than 1=20 hour run time it would probably have worn that seal down = by now -=20 but I've been wrong before.
 
I'll be keeping my fingers  crossed for = you. =20 The only good news if you do decide you have to tear it down, it that = you are=20 home rather than in a dilapidated garage in the middle of a Louisiana = summer=20 with no rotor parts within 600 miles {:>)
 
Best Regards
 
Ed
----- Original Message -----
From:=20 Tracy=20 Crook
Sent: Monday, August 27, 2007 = 10:28=20 AM
Subject: [FlyRotary] Re: Latest = 20B=20 testing

 
Finally got a moment to report on the RV-8 progress.  I have = about=20 2.5 hours of ground testing over the last month or so on the 20B RV-8 = with=20 mixed results.  The Bluemountain stuff is working great and the = display=20 is crisp & bright in daylight as advertised.  Very pleased so = far.=20
 
The first attempted engine start after installing all the = instrumentation=20 resulted in a loud bang followed by the sound of dripping liquid (I = was inside=20 the hangar).  The other 'first start' at last year's rotary = roundup=20 fly-in was with no instrumentation and the engine temporarily = 'hot-wired'=20 for the demo.  Climbing out of the cockpit, I found gas dripping = from the=20 exhaust pipe into a sizable puddle on the floor.  Note to=20 self---   Perform all first starts outside in the future. =
 
Problem turned out to be a misfire on one of the injector disable = switches causing always on injectors.  After correcting that and = clearing=20 the flooded engine, the engine started immediately and I thought the = engine=20 sounded much louder than last year's engine run.  Before I = had just=20 the exhaust header on with no muffler or tail pipe and the engine was=20 surprisingly quiet.   I had added the rest of the exhaust = system up=20 to but not including the under belly muffler.   I thought = this might=20 make it even quieter than it was before but the opposite was=20 true.  When throttled up to 24" manifold pressure the sound = is=20 powerful and defening. I will need something bigger than my golf cart = with=20 chocked wheels to test it at higher power.  At 25" Hg and = 5000=20 RPM It jumps the chocks and the RV-8 starts dragging it down = the=20 runway even though the cart parking brakes = are on.  =20
 
Having no vapor lock problems so far with the non-circulating = fuel rail=20 scheme.  I used a remote fuel pressure regulator near the pumps = (inside=20 cockpit) so the fuel goes only one way to the fuel rails with no = return. =20 Return is from the regulator to fuel tank.  This arrangement is = used on=20 most late model cars and vapor lock does not seem to be a = problem.  On my=20 Mazda Tribute I do notice that on a hot start on a hot day = there can be a=20 momentary stumble from vapor in the rail but it clears immediately. =
 
Not sure why but this engine seems much more critical in mixture = tuning=20 than any of the 13Bs I've run.  The mixture control = only has=20 about 70 deg. range where the mixture is OK which is about half = the range=20 I have on other engines.  The 20B injectors are about the only = variable I=20 can think of that could affect this. 
 
Cooling is surprisingly good.  On a 90+ degree day the = coolant=20 stabilizes at 200 F and oil at 185.  This is much cooler than my = RV-4 on=20 extended ground runs. 
 
The bad news is engine friction that I notice when pulling the = prop=20 through compression cycles.  BTW, with only a little experience = you can=20 gauge the relative health of a rotary with just a few pulls of the = prop=20 through all 6 (or 9 on 20B) compression cycles. When cold this=20 20B feels close to normal for what I would expect on a = freshly=20 overhauled engine considering it has one more rotor than my=20 13Bs.  But when it's hot the internal friction is much=20 higher.  When switched off after a run, the prop stops quite=20 abruptly. Immediately afterward,  it will not rebound = from a=20 quick pull into compression after releasing the prop.  Hot = starts=20 are very sluggish and sometimes not possible with the tiny battery I'm = using. I keep hoping this will change after break in but so far = it=20 doesn't look good.  OTOH, the Renesis took a full 40 - 50 hours = to break=20 in.  I do NOT want to open this engine again but it may be=20 necessary.  I keep having nightmares of Ed's ordeal with an = engine that=20 felt very similar to this.  Time will tell. lots more things to = test=20 before making that decision.
 
Tracy
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