X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from defout.telus.net ([199.185.220.240] verified) by logan.com (CommuniGate Pro SMTP 5.2.0) with ESMTP id 2786186 for flyrotary@lancaironline.net; Mon, 10 Mar 2008 22:14:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=199.185.220.240; envelope-from=tomk@telus.net Received: from priv-edtnaa05.telusplanet.net ([207.216.205.78]) by priv-edtnes27.telusplanet.net (InterMail vM.7.08.02.02 201-2186-121-104-20070414) with ESMTP id <20080311021416.KRPC2450.priv-edtnes27.telusplanet.net@priv-edtnaa05.telusplanet.net> for ; Mon, 10 Mar 2008 20:14:16 -0600 Received: from familygr7vkfo2 (d207-216-205-78.bchsia.telus.net [207.216.205.78]) by priv-edtnaa05.telusplanet.net (BorderWare MXtreme Infinity Mail Firewall) with SMTP id 4CR6E4T66F for ; Mon, 10 Mar 2008 20:14:14 -0600 (MDT) Message-ID: <001301c8831d$9a2e6080$6401a8c0@familygr7vkfo2> From: "Tom-Lynn Koftinoff" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Unusual Noise in Engine Date: Mon, 10 Mar 2008 19:14:14 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0010_01C882E2.EDA236F0" 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 This is a multi-part message in MIME format. ------=_NextPart_000_0010_01C882E2.EDA236F0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Yes, I am using the stock (Heavy) flywheel. I am also using the stock = Mazda coils (with a 20 watt .33 ohm resistor added to the leading coil, = as per Tracy's guide) that came with the '88 engine, and Tracy's EC2. =20 I'll try to determine if the sound is coincidental with one of the plugs = firing. I appreciate the help. Thanks, Tom ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Monday, March 10, 2008 6:32 AM Subject: [FlyRotary] Re: Unusual Noise in Engine Does it have the stock (Heavy) flywheel on it? It would be difficult = to detonate the engine without a load and at least partial throttle. = More typically it takes wide open throttle to do it. But low RPM is not = protection against it. My driver has done it right off idle. With just = a flex plate the engine can shake the transmission in acceleration and = deceleration hard enough to sound like it has rocks inside it. With the = stock flywheel this is not possible. Typical race car idle is at 2,000 = to 2,200 RPM with no flywheel mass to avoid trans damage. That timing is fine. anywhere between 20 and 27 degrees is fine. It = can be fixed at those numbers and still start and run just fine. The = lowest octane fuel is fine.=20 Check the timing on the trailing (upper most) plugs to be sure that = they do not fire ahead of the leading (lower) plugs. If there is a = timing split at all the trailing must be behind the leading. For your = operation the stock plugs are a very cold heat range and with no load to = heat the plugs, fouling will be a problem.=20 You can run a conventional looking street plug medium or retracted tip = with no problems at all. For a high load like a prop, then you need to = go back the Mazda plugs.=20 The sound you describe sounds like a cross fire or a light detonation. = So put a timing light on all 4 wires and see if the sound is = coincidental with one of them firing. The split timing helps torque just = a bit down low. With the RPM that will be used in aircraft leading and = trailing at the same time is simple and effective.=20 Dress the wires well away from each other. Is it a direct fire = ignition? Lynn E. Hanover In a message dated 3/10/2008 3:17:31 A.M. Eastern Daylight Time, = tomk@telus.net writes: My question is regarding the noise that I hear. Has anyone = experienced such a noise? I have noticed the engine missing = sporadically at low RPM's with a load on it, and the fuel/air mixture = gauge showing five to six LEDS. Can a miss, detonation, bad timing, = fouled plug(s) etc cause such a noise? My timing is very close to 23 = degrees BTDC. When I turn the engine over manually (i.e., with socket = and ratchet) the engine feels like it has good compression, and doesn't = make any strange noises, such as, anything broken or loose inside. I = may tear the engine apart to inspect the inside, later this year. =20 Thanks, Tom -------------------------------------------------------------------------= ----- It's Tax Time! Get tips, forms and advice on AOL Money & Finance. ------=_NextPart_000_0010_01C882E2.EDA236F0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Yes, I am using the stock (Heavy)=20 flywheel.   I am also using the stock Mazda coils (with a 20 = watt .33=20 ohm resistor added to the leading coil, as per Tracy's guide) that = came=20 with the '88 engine, and Tracy's EC2. 
I'll try to determine if the sound is=20 coincidental with one of the plugs firing.
 
I appreciate the help.
 
Thanks,
 
Tom
----- Original Message -----
From:=20 Lehanover@aol.com
Sent: Monday, March 10, 2008 = 6:32=20 AM
Subject: [FlyRotary] Re: = Unusual Noise in=20 Engine

Does it have the stock (Heavy) flywheel on it? It would be = difficult to=20 detonate the engine without a load and at least partial throttle. More = typically  it takes wide open throttle to do it. But low RPM is = not=20 protection against it. My driver has done it right off idle. =  With just a=20 flex plate the engine can shake the transmission in acceleration and=20 deceleration hard enough to sound like it has rocks inside it. With = the stock=20 flywheel this is not possible. Typical race car idle is at 2,000 to = 2,200 RPM=20 with no flywheel mass to avoid trans damage.
 
That timing is fine. anywhere between 20 and 27 degrees is fine. = It can=20 be fixed at those numbers and still start and run just fine. The = lowest octane=20 fuel is fine.
 
Check the timing on the trailing (upper most) plugs to be sure = that they=20 do not fire ahead of the leading (lower) plugs. If there is a timing = split at=20 all the trailing must  be behind the leading. For your operation = the=20 stock plugs are a very cold heat range and with no load to heat the = plugs,=20 fouling will be a problem.
You can run a conventional looking street plug medium or = retracted tip=20 with no problems at all. For a high load like a prop, then you need to = go back=20 the Mazda plugs. 
 
The sound you describe sounds like a cross fire or a light = detonation. So=20 put a timing light on all 4 wires and see if the sound is coincidental = with=20 one of them firing. The split timing helps torque just a bit down low. = With=20 the RPM that will be used in aircraft leading and trailing at the same = time is=20 simple and effective.
 
Dress the wires well away from each other. Is it a direct = fire=20 ignition?
 
Lynn E. Hanover
 
 
 
In a message dated 3/10/2008 3:17:31 A.M. Eastern Daylight Time,=20 tomk@telus.net writes:
My = question is=20 regarding the noise that I hear.  Has anyone experienced such a = noise?  I have noticed the engine missing = sporadically at low=20 RPM's with a load on it, and the fuel/air mixture gauge showing = five to=20 six LEDS.   Can a miss, detonation, bad = timing, fouled=20 plug(s) etc cause such a noise?  My timing is very close = to 23=20 degrees BTDC.   When I turn the engine = over=20 manually (i.e., with socket and ratchet) the engine feels like it = has good=20 compression, and doesn't make any strange noises, such as, anything = broken=20 or loose inside.    I may tear the engine apart = to=20 inspect the inside, later this year.  
 
Thanks,
 
 
Tom



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