X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 10 [X] Return-Path: Received: from bay0-omc3-s12.bay0.hotmail.com ([65.54.246.212] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1912087 for flyrotary@lancaironline.net; Fri, 09 Mar 2007 17:21:39 -0500 Received-SPF: pass receiver=logan.com; client-ip=65.54.246.212; envelope-from=lors01@msn.com Received: from hotmail.com ([65.54.250.79]) by bay0-omc3-s12.bay0.hotmail.com with Microsoft SMTPSVC(6.0.3790.2668); Fri, 9 Mar 2007 14:20:52 -0800 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Fri, 9 Mar 2007 14:20:52 -0800 Message-ID: Received: from 4.171.174.91 by BAY115-DAV7.phx.gbl with DAV; Fri, 09 Mar 2007 22:20:51 +0000 X-Originating-IP: [4.171.174.91] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: The truth??? / Injector flow rate mystery solved Date: Fri, 9 Mar 2007 17:20:46 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0039_01C7626F.46A21DF0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: MSN 9 X-MimeOLE: Produced By MSN MimeOLE V9.50.0034.2000 Seal-Send-Time: Fri, 9 Mar 2007 17:20:46 -0500 X-OriginalArrivalTime: 09 Mar 2007 22:20:52.0888 (UTC) FILETIME=[3305B980:01C76299] Return-Path: lors01@msn.com This is a multi-part message in MIME format. ------=_NextPart_000_0039_01C7626F.46A21DF0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageStill refining the exact numbers but here is the basic cause. The diode clamp on the injector drivers (in EC2) serves 3 purposes. It = limits the inductive flyback voltage to protect the driver transistor. = It recovers some of the energy used to open the injector thus reducing = the current consumption of the system. It eliminates arcing at the A/B = injector switching relay that can cause noise problems with the = processor chips. Unknown to me until recently, it also significantly increases the = closing time of the injector after the driver pulse ends. I thought the = delay would be negligible. The actual delay depends on several factors = but may be as much as 5 ms (!) Ed will know what a big deal this is. = The factors that go into this and how much it is magnified by the diode = clamp is still under investigation. The good news is that there is a very simple fix. (Note, Do NOT go out = and remove the diode clamps! That isn't the fix! Tracy ----- Original Message -----=20 From: Ed Anderson=20 To: Rotary motors in aircraft=20 Sent: Friday, March 09, 2007 7:13 AM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved I certainly don't know, Rusty. Like I said the only thing that Tracy = and I could conclude was that Mazda was under-rating their injectors - = I wondered whether it might have something to do with the way an engine = is taxed in Japan. In any case, Tracy is clearly ignoring our pleas for more information = - poor guy is undoubtedly working furiously getting orders completed = before Sun & Fun. But, he really shouldn't tease like that {:>) Yes, I understand what you mean about measured flow rates - I suspect = there is something subtle about this matter. Perhaps the current = profile used to open the injectors plays some role in this as Tracy = indicated he was working on a Fix. Perhaps a two stage or progressive = flow rate profile - opens and provides normal flow for typical = automobile usage but, when wide open (like ours are at cruise) perhaps = the flow rate is more. Who knows - Tracy Crook that's who. Ed ----- Original Message -----=20 From: Russell Duffy=20 To: Rotary motors in aircraft=20 Sent: Friday, March 09, 2007 12:19 AM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved Tracy and I have been discussing this injector flow rate anomaly for = years - =20 For some reason, I was certain that the Mazda injectors flowed more = than they were rated for, but after sifting through some old logs, = that's not true for all Mazda injectors. I sent 4 slightly used 550's = to RC Engineering, and they tested them at 547, 549, 551, and 551. If = that ain't 550, I don't know what is :-) =20 I guess I'm baffled now. Does Mazda operate them at 5 volts or = something, rather than 12V? That would slow down the response time. =20 Hey the HKS is a good little engine in my opinion - not as good as a = light weight rotary (which we don't have yet - Richard! get a move on = {:>)), but it'll get you flying again.=20 Thanks for the comments. It can't hurt much to try it, because I've = already got people who want to buy it if it doesn't work out. Still, = it's as much trouble to install as the rotary, so it really comes down = to a weight issue, and perhaps whether I'll ever get my redrive from = Autoflight... =20 Rusty ------=_NextPart_000_0039_01C7626F.46A21DF0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
Still refining the exact numbers but here is the basic cause.
 
The diode clamp on the injector drivers (in EC2) serves 3 = purposes. =20 It limits the inductive flyback voltage to protect the driver = transistor. =20 It recovers some of the energy used to open the injector thus reducing = the=20 current consumption of the system.  It eliminates arcing at the A/B = injector switching relay that can cause noise problems with the = processor=20 chips.
 
Unknown to me until recently, it also significantly increases the = closing=20 time of the injector after the driver pulse ends.  I thought the = delay=20 would be negligible.  The actual delay depends on several factors = but may=20 be as much as 5 ms (!)  Ed will know what a big deal this is.  = The=20 factors that go into this and how much it is magnified by the diode = clamp is=20 still under investigation.
 
The good news is that there is a very simple fix.  (Note, Do = NOT go=20 out and remove the diode clamps! That isn't the fix!
 
Tracy
----- Original Message -----
From: Ed Anderson
To: Rotary motors in = aircraft
Sent: Friday, March 09, 2007 = 7:13=20 AM
Subject: [FlyRotary] Re: The = truth??? /=20 Injector flow rate mystery solved

I certainly don't know, Rusty.  = Like I said=20 the only thing that Tracy and I could conclude was that Mazda was = under-rating=20 their  injectors - I wondered whether it might have something to = do with=20 the way an engine is taxed in Japan.
 
In any case, Tracy is clearly = ignoring our pleas=20 for more information - poor guy is undoubtedly working furiously = getting=20 orders completed before Sun & Fun.  But, he really shouldn't = tease=20 like that {:>)
 
Yes, I understand what you mean about = measured=20 flow rates - I suspect there is something subtle about this = matter. =20 Perhaps the current profile used to open the injectors plays some role = in this=20 as Tracy indicated he was working on a Fix.  Perhaps a two stage = or=20 progressive flow rate profile - opens and provides normal flow for = typical=20 automobile usage but, when wide open (like ours are at cruise) perhaps = the=20 flow rate is more.  Who knows - Tracy Crook that's = who.
 
Ed
----- Original Message -----
From:=20 Russell Duffy
To: Rotary motors in = aircraft=20
Sent: Friday, March 09, 2007 = 12:19=20 AM
Subject: [FlyRotary] Re: The = truth??? /=20 Injector flow rate mystery solved

Tracy and I have been = discussing this=20 injector flow rate anomaly for years -  
 
For some reason, I was certain that the = Mazda=20 injectors flowed more than they were rated for, but after sifting = through=20 some old logs, that's not true for all Mazda injectors.   = I sent 4=20 slightly used 550's to RC Engineering, and they tested them at = 547,=20 549, 551, and 551.  If that ain't 550, I don't know what is=20 :-)  
 
I guess I'm baffled now.  Does Mazda = operate=20 them at 5 volts or something, rather than 12V?  That would slow = down=20 the response time.   
 
 
Hey the HKS is a good little = engine in my=20 opinion - not as good as a light weight rotary (which we don't have = yet -=20 Richard! get a move on {:>)), but it'll get you  flying = again. 
 
Thanks for the comments.  It can't hurt = much to try=20 it, because I've already got people who want to buy it if it doesn't = work=20 out.  Still, it's as much trouble to install as the rotary, so = it=20 really comes down to a weight issue, and perhaps whether I'll ever = get my=20 redrive from = Autoflight...  
 
Rusty
 
=
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