X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail11.syd.optusnet.com.au ([211.29.132.192] verified) by logan.com (CommuniGate Pro SMTP 5.1.12) with ESMTPS id 2342703 for flyrotary@lancaironline.net; Thu, 20 Sep 2007 17:55:54 -0400 Received-SPF: none receiver=logan.com; client-ip=211.29.132.192; envelope-from=lendich@optusnet.com.au Received: from george (d198-142-113-254.dsl.nsw.optusnet.com.au [198.142.113.254]) by mail11.syd.optusnet.com.au (8.13.1/8.13.1) with SMTP id l8KLt5id011775 for ; Fri, 21 Sep 2007 07:55:07 +1000 Message-ID: <002401c7fbd0$ecb76600$fe718ec6@george> From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Fw: [FlyRotary] Re: TDC Date: Fri, 21 Sep 2007 07:55:12 +1000 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0021_01C7FC24.BCE38CC0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2180 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180 X-Antivirus: avast! (VPS 0657-0, 12/12/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_0021_01C7FC24.BCE38CC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks Ed! Some of the questions I ask are for setting-up my single rotor = demonstrator and others are just ignorance. So now on the single rotor the No 1. housing ( front/our back/ pulley = end) - is superimposed on number two, however the keyway slot is now 180 = degrees ( opposite side) from the 2 rotor placement (because of = balancing requirements). So I guess I will have to set my timing marks = 180 degrees on the opposite side of the pulleys - as per Lynn's = descriptions/ instructions. However as I'm driving the rear rotor ( now the front as well), I was = wondering why we take the timing from the front rotor, when the timing = is 180 degrees, it could be from either end. Question:- Does the timing pick-up have two timings marks, one on either = side of the wheel? I don't seem to recall seeing that ! Confused - me too! George ( down under) This message failed its original transmission attempt, so here goes = again Ed ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Wednesday, September 19, 2007 7:40 PM Subject: Re: [FlyRotary] Re: TDC George, if you are talking about the ignition sequence for a two = rotor, there is a combustion event every 180 degrees of the e shaft = rotation. So one complete cycle of a rotor face =3D 180 deg of e shaft = rotation. 6 faces * 180 =3D 1080 deg e shaft rotation for all six faces = to fire. The six faces are therefore 180 deg apart (eshaft reference). IF face = #1 of rotor #1 fires at 25 deg BTDC then the next face on rotor #2 will = fire 180 degrees later, then 180 degrees later the face #2 on the #1 = rotor will fire. Then 180 degrees later the #2 face on rotor #2 will = fire etc. So to answer your question, ALL Faces fire the leading spark plug = 25Deg BTDC for their respective cycle. But if you want to know where the = nth face fires relative to the first face firing, the answer is the = nth rotor face fires at (n-1)*180 deg + 25Deg later - where n is the = face number in question. Remember the firing faces will alternate from = rotor to rotor.=20 So the second face, n=3D 2 fires at (2-1)*180 + 25 =3D 205 deg (using = the first face firing at 25 BTDC). The third face, n=3D 3 fires at = (3-1)*180 + 25 =3D 360+25 =3D 385 deg. The sixth face n=3D 6 fires at (6-1)*180 + 25 =3D 925 deg and if we go = back to that first face, we have n =3D1 so (1-1)*180+ 25 =3D (0)*180 + = 25 =3D 25 Deg BTDC or back where we started. This is just for the = leading plug, but you can do it for the trailing plug. So if the 1st face TDC point is used as a reference and was on the = number one rotor, then the 2nd face to fire will be on the number two = rotor. So number one rotor will fire n =3D 1,3,5 and rotor number two = will fire 2, 4, 6. (even and odds alternating of course)=20 Number one rotor will have firing events at 25, 385 and 745 degs, = number two rotor will have firing events at 205, 565 and 925 degrees of = e shaft rotation. That is if I have not screwed things up somewhere along the line Ed. ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Wednesday, September 19, 2007 6:30 PM Subject: [FlyRotary] Re: TDC Can someone answer this questions, if the timing is set at 25 = degrees BTDC and the leading fires at 25 degrees BTDC and the Trailing = fires 15 degrees later (10 degrees BTDC) - when does the third spark = event fire, is that another 15 degrees with the leading firing again? The pulley end keyway points to 9.00 at TDC ( plug sides) on the = housing closest to the pulleys ( Front/ our rear) - is this what is = referred to as No1 housing? George (down under)=20 In a message dated 04/26/2005 12:00 Central Daylight Time, = Lehanover writes: << In a message dated 04/25/2005 07:00 Central Daylight Time, = jwvoto@itlnet.net writes: I can look into the spark plug hole and see the apex seal go by, = so are you calling apex seal crossing leading plug TDC?=20 There are a number of gags to locate TDC close enough to get the = engine to run. (1) Remove one spark plug from number one housing. Screw a length of = hose into the plug hole. Put your tongue on the end of the hose. Gently = turn over the engine. When you get a null, where there is no pressure = and no suction on your tongue, that's TDC. Good to within a few degrees. = (2) Or, Bend up a piece of welding filler rod so as to make a pointer that = can touch a flywheel (flexplate) tooth. Bolt or clamp the wire to the = rear iron. Take both plugs out of number two rotor housing.=20 Turn the engine until you see an apex seal in the center of the = trailing plug hole. Bend the filler rod so that it points to the center of a flywheel = tooth. Put a white paint drop on that tooth.=20 Turn the engine in the running direction, until that same apex = seal appears in the center of the leading plug hole. Put a paint drop on the tooth the rod is now pointing at.=20 Count the teeth between the paint dots. Divide by 2.=20 The point half way between the two paint dots is TDC in the number = one housing. Good to within a few degrees. Also, you can count the total number of teeth and divide that = number into 360 to get the number of degrees per tooth. Paint the = correct tooth yellow and make the rod a permanent piece, for setting = accurate timing in an easy to see location.=20 (3) Or, (Similar to above) Take both plugs out of number one.=20 Turn engine in running direction until an apex seal appears in the = trailing plug hole. Gently turn the engine backwards until an apex seal appears in the = leading plug hole.=20 Half way between those two events is TDC. With practice, accurate = enough to do by just feel and rocking back and forth by hand and to find = TDC within a few degrees, or close enough to drop in the distributor and = have the engine fire instantly and run fine.=20 (4) If you used grease or Vaseline on the side seals, you can have a = plug prepared with the center knocked out of it and a plug in place with = a piece of brake line soldered through the center. Screw this special = plug into the bottom plug hole. Push a length of plastic tubing over the = piece of brake tubing. Pour auto trans fluid through the top plug hole. = Reinstall the top plug. Hold the hose in the vertical. Turn the engine = until the fluid level nulls.=20 That's TDC number one with a degree.=20 (5) The flywheel end counter weight is centered between the plugs on = number two rotor housing. That's TDC number one within about 10 degrees. = But you can get good at it, and get more accurate. (6) If you have the front pulley bolt and washer off, looking from the = front=20 pulley end, the keyway in the 9:00 O'clock position is TDC number one within a = few=20 degrees. My TDC rig is for setting up port timings and requires a = disassembled=20 engine, so that won't help you. Good for inside of one degree.=20 (6)=20 Quick and dirty. Take out either plug from number one housing. Wet a finger. Hold it gently over the empty plug hole. Turn the = engine in=20 the running direction. When the air quits pushing past your = finger, that's TDC=20 within 10 degrees or less.=20 Lynn E. Hanover =20 On 9/19/07, bmears9413@aol.com wrote:=20 Changing the subject a bit, I want to make sure i have my motor = on TDC to set my timing marks on the flywheel. This is my plan, tell me = what you think. I'm building a fitting to screw in the spark plug hole, = and running a vacuum line to a small suringe (like a insulin suringe). I = can eyeball the rotor location close to TDC, the install this = contraption and rotate the motor so the suringe moves out to the end and = starts back in. then back the motor up again till the suringe tops out. = I figure that outa be and accurate TDC. Whadda ya think???=20 Bob Mears Supermarine Spitfire -----Original Message----- From: Ed Anderson To: Rotary motors in aircraft Sent: Wed, 19 Sep 2007 1:16 pm=20 Subject: [FlyRotary] Re: Strange Ignition?=20 I do not believe that is a significant factor, either, Al. = After all, we're suppose to do our ignition checks on the ground before = take off {:>). My understanding is that best power on the 13B has = ignition timing between 25-28 deg BTDC, so not surprising that the 20B = would fall in that range also. Sounds reasonable to me.=20 Ed ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Wednesday, September 19, 2007 3:08 PM Subject: [FlyRotary] Re: Strange Ignition?=20 =20 I wondered if perhaps one issue was that I was doing the = ignition check static, on the ground; where the combination of RPM and = MAP would be different than in the air. But on checking with Tracy 's = spreadsheet on the timing settings, over a fairly broad range above = about 4900 the timing is (should be) in the range of 26 to 28 degrees = BTDC. Al ------------------------------------------------------------------------ Email and AIM finally together. You've gotta check out free AOL = Mail! =20 -------------------------------------------------------------------------= - No virus found in this incoming message. Checked by AVG Free Edition.=20 Version: 7.5.487 / Virus Database: 269.13.22/1015 - Release Date: = 18/09/2007 11:53 AM -------------------------------------------------------------------------= ----- No virus found in this incoming message. Checked by AVG Free Edition.=20 Version: 7.5.487 / Virus Database: 269.13.25/1018 - Release Date: = 19/09/2007 3:59 PM ------=_NextPart_000_0021_01C7FC24.BCE38CC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
 Thanks Ed!
Some of the questions I ask are for = setting-up my=20 single rotor demonstrator and others are just ignorance.
 
So now on the single rotor the=20 No 1. housing ( front/our back/ pulley end) - is = superimposed on=20 number two, however the keyway slot is now 180 degrees ( opposite = side)=20 from the 2 rotor placement (because of balancing requirements). So I = guess I=20 will have to set my timing marks 180 degrees on the opposite side of the = pulleys=20 - as per Lynn's descriptions/ instructions.
 
However as I'm driving the rear rotor ( = now the=20 front as well), I was wondering why we take the timing from the front = rotor,=20 when the timing is 180 degrees, it could be from either = end.
 
Question:- Does the timing pick-up have = two timings=20 marks, one on either side of the wheel? I don't seem to recall seeing = that=20 !
 
Confused - me too!
 
George ( down under)
This message failed its original transmission = attempt,=20 so here goes again
 
Ed
 
----- Original Message -----=20
From: Ed=20 Anderson
Sent: Wednesday, September 19, 2007 7:40 PM
Subject: Re: [FlyRotary] Re: TDC

George, if you are talking about the ignition = sequence=20 for a two rotor, there is a combustion event every 180 degrees of = the e=20 shaft rotation.  So one complete cycle of a rotor face =3D 180 = deg of e=20 shaft rotation.  6 faces * 180 =3D 1080 deg e shaft rotation = for all=20 six faces to fire.
 
The six faces are therefore 180 deg apart = (eshaft=20 reference).  IF face #1 of rotor #1 fires at 25 deg BTDC then the = next=20 face on rotor #2 will fire 180 degrees later, then 180 degrees later = the face=20 #2 on the #1 rotor will fire. Then 180 degrees later the #2 face on = rotor #2=20 will fire etc.
 
So to answer your question, ALL Faces fire the = leading=20 spark plug 25Deg BTDC for their respective=20 cycle. But if you want to know where the nth face fires = relative=20 to the first face firing,  the answer is  the nth rotor face = fires=20 at  (n-1)*180 deg + 25Deg later = - where=20 n is the face number in question.  Remember the=20 firing faces will alternate from rotor to = rotor. 
 
 
 So the second face, n=3D 2 fires at = (2-1)*180 + 25 =3D=20 205 deg (using the first face firing at 25 BTDC).  The third = face, n=3D 3=20 fires at (3-1)*180 + 25 =3D 360+25 =3D 385 deg.
 
The sixth face n=3D 6 fires at (6-1)*180 + 25 = =3D 925 deg=20 and if we go back to that first face, we have n =3D1 so (1-1)*180+ 25 = =3D (0)*180=20 + 25 =3D 25 Deg BTDC or back where we started.  This is just for = the=20 leading plug, but you can do it for the trailing plug.
 
So if the 1st face TDC point is  used as = a=20 reference and was on the number one rotor, then the 2nd face to=20 fire will be on the number two rotor.  So number one rotor = will fire=20 n =3D 1,3,5 and rotor number two will fire 2, 4, 6. (even and odds = alternating=20 of course)
 
Number one rotor will have firing events at = 25, 385 and=20 745 degs, number two rotor will have firing events at 205, 565 and 925 = degrees=20 of e shaft rotation.
 
That is if I have not screwed things up = somewhere along=20 the line
 
Ed.
 
 
 
----- Original Message ----- =
From:=20 George Lendich
To: Rotary motors in = aircraft=20
Sent: Wednesday, September = 19, 2007=20 6:30 PM
Subject: [FlyRotary] Re: = TDC

Can someone answer this = questions, if the=20 timing is set at 25 degrees BTDC and the leading fires at 25 = degrees BTDC=20 and the Trailing fires 15 degrees later (10 degrees BTDC) - when = does the=20 third spark event fire, is that another 15 degrees with the = leading=20 firing again?
 
The pulley end keyway points = to 9.00 at=20 TDC ( plug sides) on the housing closest to the pulleys = ( Front/=20 our rear) - is this what is referred to as No1 = housing?
George (down = under) 
 
<snip>

In a message dated 04/26/2005 12:00 Central Daylight Time, = Lehanover=20 writes:

<< In a message dated 04/25/2005 07:00 Central Daylight = Time, jwvoto@itlnet.net = writes:

I can look into the spark plug hole and see the apex seal go = by, so are=20 you calling apex seal crossing leading plug TDC?

There are a number of gags to locate TDC close enough to get = the engine=20 to run.

(1)

Remove one spark plug from number one housing. Screw a length = of hose=20 into the plug hole. Put your tongue on the end of the hose. Gently = turn=20 over the engine. When you get a null, where there is no pressure = and no=20 suction on your tongue, that's TDC. Good to within a few degrees. =

(2)

Or,

Bend up a piece of welding filler rod so as to make a pointer = that can=20 touch a flywheel (flexplate) tooth. Bolt or clamp the wire to the = rear=20 iron.

Take both plugs out of number two rotor housing.

Turn the engine until you see an apex seal in the center of the = trailing plug hole.

Bend the filler rod so that it points to the center of a = flywheel=20 tooth. Put a white paint drop on that tooth.

Turn the engine in the running direction, until that same apex = seal=20 appears in the center of the leading plug hole.

Put a paint drop on the tooth the rod is now pointing at.

Count the teeth between the paint dots. Divide by 2.

The point half way between the two paint dots is TDC in the = number one=20 housing.

Good to within a few degrees.

Also, you can count the total number of teeth and divide that = number=20 into 360 to get the number of degrees per tooth. Paint the correct = tooth=20 yellow and make the rod a permanent piece, for setting accurate = timing in=20 an easy to see location.

(3)

Or,

(Similar to above)

Take both plugs out of number one.

Turn engine in running direction until an apex seal appears in = the=20 trailing plug hole.

Gently turn the engine backwards until an apex seal appears in = the=20 leading plug hole.

Half way between those two events is TDC. With practice, = accurate=20 enough to do by just feel and rocking back and forth by hand and = to find=20 TDC within a few degrees, or close enough to drop in the = distributor and=20 have the engine fire instantly and run fine.

(4)

If you used grease or Vaseline on the side seals, you can have = a plug=20 prepared with the center knocked out of it and a plug in place = with a=20 piece of brake line soldered through the center. Screw this = special plug=20 into the bottom plug hole. Push a length of plastic tubing over = the piece=20 of brake tubing. Pour auto trans fluid through the top plug hole.=20 Reinstall the top plug. Hold the hose in the vertical. Turn the = engine=20 until the fluid level nulls.

That's TDC number one with a degree.

(5)

The flywheel end counter weight is centered between the plugs = on number=20 two rotor housing. That's TDC number one within about 10 degrees. = But you=20 can get good at it, and get more accurate.

(6)

If you have the front pulley bolt and washer off, looking from = the=20 front

pulley end,

the keyway in the 9:00 O'clock position is TDC number one = within a few=20

degrees.

My TDC rig is for setting up port timings and requires a = disassembled=20

engine, so that won't help you. Good for inside of one degree. =

(6)

Quick and dirty.

Take out either plug from number one housing.

Wet a finger. Hold it gently over the empty plug hole. Turn the = engine=20 in

the running direction. When the air quits pushing past your = finger,=20 that's TDC

within 10 degrees or less.

Lynn E. Hanover

<snip>



 
On 9/19/07, bmears9413@aol.com = <bmears9413@aol.com> = wrote:=20
Changing=20 the subject a bit, I want to make sure i have my motor on TDC to = set my=20 timing marks on the flywheel. This is my plan, tell me what you = think.=20 I'm building a fitting to screw in the spark plug hole, and = running a=20 vacuum line to a small suringe (like a insulin suringe). I can = eyeball=20 the rotor location close to TDC, the install this contraption = and rotate=20 the motor so the suringe moves out to the end and starts back = in. then=20 back the motor up again till the suringe tops out. I figure that = outa be=20 and accurate TDC. Whadda ya think???

Bob = Mears
Supermarine=20 Spitfire


-----Original Message-----
From: Ed = Anderson=20 <eanderson@carolina.rr.com >
To: Rotary = motors in=20 aircraft <flyrotary@lancaironline.net>
Sent: = Wed, 19 Sep=20 2007 1:16 pm
Subject: [FlyRotary] Re: Strange Ignition? =

I do not believe that is a significant = factor,=20 either, Al.  After all, we're suppose to do our ignition = checks on=20 the ground before take off {:>).  My understanding is = that best=20 power on the 13B has ignition timing between 25-28 deg BTDC, so = not=20 surprising that the 20B would fall in that range also.  = Sounds=20 reasonable to me.
 
Ed
 
 
----- Original Message ----- =
From: Al = Gietzen
To: Rotary motors=20 in aircraft
Sent: Wednesday, = September 19,=20 2007 3:08 PM
Subject: [FlyRotary] = Re: Strange=20 Ignition?

 
I = wondered=20 if perhaps one issue was that I was doing the ignition check = static,=20 on the ground; where the combination of RPM and MAP would be = different=20 than in the air.  But on checking with = Tracy = 's=20 spreadsheet on the timing settings, over a fairly broad range = above=20 about 4900 the timing is (should be) in the range of 26 to 28 = degrees=20 BTDC.
 
Al
Email and AIM finally together. You've gotta check out free AOL = Mail!
 

No virus found in this incoming message.
Checked by AVG = Free=20 Edition.
Version: 7.5.487 / Virus Database: 269.13.22/1015 - = Release=20 Date: 18/09/2007 11:53 AM

No virus found in this incoming message.
Checked by AVG Free = Edition.
Version: 7.5.487 / Virus Database: 269.13.25/1018 - = Release Date:=20 19/09/2007 3:59 PM
------=_NextPart_000_0021_01C7FC24.BCE38CC0--