X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from cdptpa-omtalb.mail.rr.com ([75.180.132.120] verified) by logan.com (CommuniGate Pro SMTP 5.2c4) with ESMTP id 2699751 for flyrotary@lancaironline.net; Wed, 30 Jan 2008 09:57:47 -0500 Received-SPF: pass receiver=logan.com; client-ip=75.180.132.120; envelope-from=eanderson@carolina.rr.com Received: from edward2 ([75.191.190.141]) by cdptpa-omta05.mail.rr.com with SMTP id <20080130145707.NJYR9785.cdptpa-omta05.mail.rr.com@edward2> for ; Wed, 30 Jan 2008 14:57:07 +0000 Message-ID: <000d01c86350$69d10a60$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Emailing: damage24.jpg Date: Wed, 30 Jan 2008 09:57:19 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_000A_01C86326.80B5E310" 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 This is a multi-part message in MIME format. ------=_NextPart_000_000A_01C86326.80B5E310 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I agree, Bill. While the example shown was not an aircraft rotor, I did indeed loose = the triangular bit of the apex seal during reassemble. It fell between = rotor and side housing into one of those lightening/balancing divots cut = into the rotor - Just my luck. If it had not fallen into the divot but = had simply got between the rotor and side housing, I doubt seriously = that the engine would have turned over at all. As, it was, it did turn = over, yes, with resistance - because I was in a hurry to get my aircraft = back from the unattended airport, I convinced my self the "resistance" = was just sign of a "good rebuild" with good solid compression. =20 Here are a few things that I should have paid attention to: 1. It took a bit of effort to hand turn the flywheel 2. While cranking it, was turning over slower than normal=20 3. When I fired it up it would not idle below 2000 rpm (obviously due = to the high resistance) 4. After the first hour of running everything was "normal" in that it = would now idle at lower rpm and the resistance was "gone" Of course by step 4 the hour of running apparently wore the seal piece = down and the rotor housing had already incurred the damage that the = friction caused - which later led to my rebuild while stuck in Louisiana = for 4 weeks. Clearly having a dial torque reading to compare would have helped. In = fact, Bruce Turrentine and several folks told me something was not right = - and I should have listened, but just in too much of hurry to get it = done and into the aircraft - so I got to do it again, correct this time = {:>) So your suggestion certainly has merit. Ed ----- Original Message -----=20 From: WRJJRS@aol.com=20 To: Rotary motors in aircraft=20 Sent: Wednesday, January 30, 2008 1:04 AM Subject: [FlyRotary] Re: Emailing: damage24.jpg Ed and group, This assembly problem is vexing. We really need to avoid these types = of foul up! When I built race cars and motorcycles the assembler = (usually me) would try to learn what kind of force it should require to = turn over a newly built engine. That is, how much friction to expect = when turning over a brand spanking new engine for the first time. = Cosworth even has a torque table that suggests you use a dial torque = wrench for that first rev or two. If you see higher than suspected = torque do not turn the engine over or even through the tight spot! = Learning these forces saved one of my best customers a completely = mangled engine! (Anecdote warning!) Guy M. my customer informed me that he would do the basic assembly of = the "long block" including putting on the head so all I would have to do = was time the cams. (Engine was a Kawasaki 900 with considerable = modification to run in an SCCA C sports racer.) Guy was an EXCELLENT = mechanic in his own right so I thought, "great that part is easy but = tedious so I won't have to do it." I installed the cams correctly, and = did the all important first revolution by hand. At TDC there was a very = small change in friction, that would have been easy to miss if I had not = been super familiar with that engine. Guy wanted to just run it, but I = wouldn't do it because that is where the engine has nearly no piston = movement for about 20 degrees. I made him pull the head and was super = glad I did. Guy had installed all four pistons reversed on the piston = pin. The large valve cut out was on the exhaust valve side rather than = the intake as was normal. The "tick" was the intake valve rubbing on the = side of the piston cutout! If we had started the engine it would have = run for a few seconds until the intake valves bent! We corrected the = problem, and thankfully the intakes were not even bent. Believe me we = checked. The result was a few hours lost rather than a destroyed engine. = We need to develop a data base here. So if you do a new build up, or = any build up for that matter, do us all a favor and put a dial torque = wrench on there and record your max turn over torque. Oh yea, do that = with the plugs out of course. On a rotary with plugs out you should get = a pretty even torque with no compression so if you get any spikes in = there you may want to pull it apart again before you do some serious = damage. Mistakes can happen even to very competent mechanics so it would = be a great help to everybody and might even save you some cash. Just a = good idea. My $0.02. Bill Jepson In a message dated 1/29/2008 7:32:20 AM Pacific Standard Time, = eanderson@carolina.rr.com writes: I agree, Bob, there is no way that apex seal could come out of its = recess without that part of the rotor being broken off. Those small = parts can be illusive, particularly when you turn the rotor upside down = to place it on the e shaft - make certain you use good Vaseline or = halomire stickum {:>). Ed -------------------------------------------------------------------------= ----- Start the year off right. Easy ways to stay in shape in the new year. ------=_NextPart_000_000A_01C86326.80B5E310 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I agree, Bill.
 
  While the example shown was not an aircraft = rotor, I=20 did indeed loose the triangular bit of the apex seal during = reassemble.  It=20 fell between rotor and side housing into one of those = lightening/balancing=20 divots cut into the rotor - Just my luck.  If it had not fallen = into the=20 divot but had simply got between the rotor and side housing, I doubt = seriously=20 that the engine would have turned over at all.  As, it was, it did = turn=20 over, yes, with resistance - because I was in a hurry to get my aircraft = back=20 from the unattended airport, I convinced my self the "resistance" was = just sign=20 of a "good rebuild" with good solid compression. 
 
Here are a few things that I should have paid = attention=20 to:
 
1.  It took a bit of effort to hand turn the=20 flywheel
2.  While cranking it, was turning over slower = than=20 normal
3.  When I fired it up it would not idle below = 2000 rpm=20 (obviously due to the high resistance)
4.  After the first hour of running everything = was=20 "normal" in that it would now idle at lower rpm and the resistance was=20 "gone"
 
Of course by step 4 the hour of running apparently = wore the=20 seal piece down and the rotor housing had already incurred the damage = that the=20 friction caused - which later led to my rebuild while stuck in Louisiana = for 4=20 weeks.
 
Clearly having a dial torque reading to compare = would have=20 helped.  In fact, Bruce Turrentine and several folks told me = something was=20 not right - and I should have listened, but just in too much of hurry to = get it=20 done and into the aircraft - so I got to do it again, correct this time=20 {:>)
 
So your suggestion certainly has merit.
 
Ed
 
 
----- Original Message -----
From:=20 WRJJRS@aol.com
Sent: Wednesday, January 30, = 2008 1:04=20 AM
Subject: [FlyRotary] Re: = Emailing:=20 damage24.jpg

Ed and group,
This assembly problem is vexing. We really need to avoid these = types of=20 foul up! When I built race cars and motorcycles the assembler (usually = me)=20 would try to learn what kind of force it should require to turn over a = newly=20 built engine. That is, how much friction to expect when turning over a = brand=20 spanking new engine for the first time. Cosworth even has a torque = table that=20 suggests you use a dial torque wrench for that first rev or two. If = you see=20 higher than suspected torque do not turn the engine over or even = through the=20 tight spot! Learning these forces saved one of my best customers a = completely=20 mangled engine! (Anecdote warning!)
 Guy M. my customer informed me that he would do = the basic=20 assembly of the "long block" including putting on the head so all = I would=20 have to do was time the cams. (Engine was a Kawasaki 900 with=20 considerable modification to run in an SCCA C sports = racer.) Guy was=20 an EXCELLENT mechanic in his own right so I thought, "great that part = is=20 easy but tedious so I won't have to do it." I installed the cams=20 correctly, and did the all important first revolution by hand. At TDC = there=20 was a very small change in friction, that would have been easy to miss = if I=20 had not been super familiar with that engine. Guy wanted to just run = it, but I=20 wouldn't do it because that is where the engine has nearly no = piston=20 movement for about 20 degrees. I made him pull the head and was = super=20 glad I did. Guy had installed all four pistons reversed on the = piston=20 pin. The large valve cut out was on the exhaust valve side rather than = the=20 intake as was normal. The "tick" was the intake valve rubbing on the = side of=20 the piston cutout! If we had started the engine it would have run for = a few=20 seconds until the intake valves bent! We corrected the problem, = and=20 thankfully the intakes were not even bent. Believe me we checked. The = result=20 was a few hours lost rather than a destroyed engine.
 We need to develop a data base here. So if you do a new = build up,=20 or any build up for that matter, do us all a favor and put a dial = torque=20 wrench on there and record your max turn over torque. Oh yea, do = that=20 with the plugs out of course. On a rotary with plugs out you = should get a=20 pretty even torque with no compression so if you get any spikes = in there=20 you may want to pull it apart again before you do some serious=20 damage. Mistakes can happen even to very competent mechanics so = it would=20 be a great help to everybody and might even save you some cash. = Just a=20 good idea. My $0.02.
Bill Jepson
 
In a message dated 1/29/2008 7:32:20 AM Pacific Standard Time,=20 eanderson@carolina.rr.com writes:
I agree, Bob, there is no way that apex seal = could=20 come out of its recess without that part of the rotor being broken=20 off.  Those small parts can be illusive, particularly when you = turn the=20 rotor upside down to place it on the e shaft - make certain you use = good=20 Vaseline or halomire stickum {:>).
 
Ed
 



Start the year off right. Easy ways to stay in shape in the new year.=20
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