X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from smtp106.sbc.mail.mud.yahoo.com ([68.142.198.205] verified) by logan.com (CommuniGate Pro SMTP 5.0.9) with SMTP id 1127125 for flyrotary@lancaironline.net; Wed, 24 May 2006 23:58:27 -0400 Received-SPF: none receiver=logan.com; client-ip=68.142.198.205; envelope-from=dcarter11@sbcglobal.net Received: (qmail 75189 invoked from network); 25 May 2006 03:57:43 -0000 Received: from unknown (HELO davidsdell8200) (dcarter11@sbcglobal.net@67.41.226.150 with login) by smtp106.sbc.mail.mud.yahoo.com with SMTP; 25 May 2006 03:57:43 -0000 Message-ID: <19c701c67faf$b51d79d0$6401a8c0@davidsdell8200> From: "David Carter" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Another case of heat-soaked coils? Date: Wed, 24 May 2006 22:00:05 -0600 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_19C4_01C67F7D.69DE6560" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.2869 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2869 This is a multi-part message in MIME format. ------=_NextPart_000_19C4_01C67F7D.69DE6560 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I just sent a post asking Lynn to explain the .010 gap. I still had his = original e-mail in the in-basket and have just re-read it - I don't = understand the reference to "secondary ignition breakdown" and = "secondary breakdown" in the 2nd paragraph, "One quick check for = secondary ignition breakdown, is to quickly install two new plugs in the = leading holes, gapped at .010". If the problem is still there, it is = less likely the secondary output. If the problem is gone, it is likely = the secondary output." Please help an old timer used to "coil and distributor ignition systems" = who is a "first time owner" (and VERY HAPPY user) of a modern (1993 & = 1995 Ford Escort) ignition system: . . . Are these new "ignitor blocks" still using the = "primary"/"secondary" coil principle of the old round coils? If so, = what makes these 1990's and later "high energey" systems "higher = voltage"? Higher ratio of primary to secondary coil windings? (or vice = versa?) and/or the totally mysterious "ignition modules" that go along = with the coil packs? I.e., are the square coil/igniter coil blocks = doing the same thing, only better, than the old coils? . . . If so, then is Lynn's ref to "secondary ignition breakdown" a ref = to some kind of failure or degradtion of the secondary coil windings? = (such as internal shorting of sec coil windings to each other, so as to = reduce "effective" number of coils in secondary; or, arcing of secondary = to engine mount/block) so voltage to plugs is significantly down?) Also, why put the .010 plugs only in the leading holes, as opposed to = trailing, or both holes? David ----- Original Message -----=20 From: Lehanover@aol.com=20 To: Rotary motors in aircraft=20 Sent: Tuesday, May 23, 2006 8:35 AM Subject: [FlyRotary] Re: Another case of heat-soaked coils? In a message dated 5/23/2006 9:27:40 A.M. Eastern Daylight Time, = lors01@msn.com writes: John did tell me that the threshold of 'splutter' was around 38" Hg = MAP. Since the engine quickly went down hill even at lower throttle = settings and he thought it was only running on one rotor at the end of = testing, I suspect there are a lot of clues to what is wrong other than = the 'splutter' at 38". We just don't know what they are. The coils = being bad is a long shot since it would mean that two of them died at = once, not likely but possible. =20 Did the engine run well after cooling for some time? Not enough = information. One quick check for secondary ignition breakdown, is to quickly = install two new plugs in the leading holes, gapped at .010". If the = problem is still there, it is less likely the secondary output. If the = problem is gone, it is likely the secondary output. The lost spark coils of later RX-7s fire twice per revolution. They = fire both of the leading plugs twice for each revolution. So they work = with very short rise times. At 6,000 RPM that's 12,000 cycles per = minute. Try that with a Corvette coil. Even so, ignition problems at 6,000 to 6,500 RPM should not be = happening. We shift at 9,600 RPM, and with two MSDs even going a bit = lean at the top causes a minor misfire or skip. Re-gap the plugs to = .010" fixes that every time. =20 Also reducing throttle setting slightly restores good ignition = performance when this is the problem.=20 Stock Rotary engine coils are very good. The lost spark coils are = better. Using two lost spark coils, one for both leading and trailing on each = housing would be as close to bullet proof as is possible. The trailing = must be distributed otherwise. If Tracy's controller can light a stock (lost spark) coil, that is. Lynn E. Hanover ------=_NextPart_000_19C4_01C67F7D.69DE6560 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
I just sent a post asking Lynn to explain the .010 gap.  I = still had=20 his original e-mail in the in-basket and have just re-read it - I don't=20 understand the reference to "secondary ignition breakdown" and = "secondary=20 breakdown" in the 2nd paragraph, "One quick check for secondary = ignition=20 breakdown, is to quickly install two new plugs in the leading holes, = gapped at=20 .010". If the problem is still there, it is less likely the secondary = output. If=20 the problem is gone, it is likely the secondary output."
 
Please help an old timer used to "coil and distributor ignition = systems"=20 who is a "first time owner" (and VERY HAPPY user) of a modern (1993 = & 1995=20 Ford Escort) ignition system:
. . .  Are these new "ignitor blocks" still using the=20 "primary"/"secondary" coil principle of the old round coils?  If = so, what=20 makes these 1990's and later "high energey" systems "higher = voltage"? =20 Higher ratio of primary to secondary coil windings? (or vice versa?) = and/or the=20 totally mysterious "ignition modules" that go along with the coil = packs? =20 I.e., are the square coil/igniter coil blocks doing the same thing, only = better,=20 than the old coils?
. . . If so, then is Lynn's ref to "secondary ignition = breakdown" a=20 ref to some kind of failure or degradtion of the secondary coil = windings? (such=20 as internal shorting of sec coil windings to each other, so as to reduce = "effective" number of coils in secondary; or, arcing of secondary to = engine=20 mount/block) so voltage to plugs is significantly down?)
 
Also, why put the .010 plugs only in the leading holes, as opposed = to=20 trailing, or both holes?
 
David
----- Original Message -----
From:=20 Lehanover@aol.com
Sent: Tuesday, May 23, 2006 = 8:35 AM
Subject: [FlyRotary] Re: = Another case of=20 heat-soaked coils?

In a message dated 5/23/2006 9:27:40 A.M. Eastern Daylight Time, = lors01@msn.com writes:
John did tell me that the threshold of 'splutter' was around = 38" Hg=20 MAP.  Since the engine quickly went down hill even at lower = throttle=20 settings and he thought it was only running on one rotor at the end = of=20 testing,  I suspect there are a lot of clues to what is wrong = other=20 than the 'splutter' at 38".   We just don't know what they = are.  The coils being bad is a long shot since it would mean = that two=20 of them died at once, not likely but possible. 
 
Did the engine run well after cooling for some time?  Not = enough=20 information.
 
One quick check for secondary ignition breakdown, is to quickly = install=20 two new plugs in the leading holes, gapped at .010". If the problem is = still=20 there, it is less likely the secondary output. If the problem is gone, = it is=20 likely the secondary output.
 
The lost spark coils of later RX-7s fire twice per revolution. = They fire=20 both of the leading plugs twice for each revolution. So they work with = very=20 short rise times. At 6,000 RPM that's 12,000 cycles per minute. Try = that with=20 a Corvette coil.
 
Even so, ignition problems at 6,000 to 6,500 RPM should not be = happening.=20 We shift at 9,600 RPM, and with two MSDs even going a bit lean at the = top=20 causes a minor misfire or skip. Re-gap the plugs to .010" fixes that = every=20 time.  
 
Also reducing throttle setting slightly restores good ignition=20 performance when this is the problem.
 
Stock Rotary engine coils are very good. The lost spark coils are = better.
 
Using two lost spark coils, one for both leading and trailing on = each=20 housing would be as close to bullet proof as is possible. The trailing = must be=20 distributed otherwise.
 
If Tracy's controller can light a stock (lost spark) coil, that = is.
 
Lynn E. Hanover
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