X-Virus-Scanned: clean according to Sophos on Logan.com X-SpamCatcher-Score: 2 [X] Return-Path: Received: from ms-smtp-04.southeast.rr.com ([24.25.9.103] verified) by logan.com (CommuniGate Pro SMTP 5.1.7) with ESMTP id 1913896 for flyrotary@lancaironline.net; Sat, 10 Mar 2007 18:15:54 -0500 Received-SPF: pass receiver=logan.com; client-ip=24.25.9.103; envelope-from=eanderson@carolina.rr.com Received: from edward2 (cpe-024-074-103-061.carolina.res.rr.com [24.74.103.61]) by ms-smtp-04.southeast.rr.com (8.13.6/8.13.6) with SMTP id l2ANEwTe022182 for ; Sat, 10 Mar 2007 18:14:59 -0500 (EST) Message-ID: <000701c76369$ef050cf0$2402a8c0@edward2> From: "Ed Anderson" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: The truth??? / Injector flow rate mystery solved Date: Sat, 10 Mar 2007 18:15:03 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0004_01C76340.05D6D2D0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3028 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 X-Virus-Scanned: Symantec AntiVirus Scan Engine This is a multi-part message in MIME format. ------=_NextPart_000_0004_01C76340.05D6D2D0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable MessageThat's what it boils down to, George. After the open pulse = terminates and the injector should close in less than a millisecond, a = diode causes the injectors' magnetic field to hold open the pintel up = to several milliseconds longer than it should. Therefore the mixture = actually ends up richer than the EC2 intended. =20 Now, what is not clear to me, is if you tune using an Air/Fuel Ratio = indicator and then program that value into the EC2 via the program mode = does that compensate for the longer open period by making the pulse = shorter until you get the A/F mixture you want. I suspect that it does = at least to some extent. =20 About the only place you would ever really notice it is at idle - = because at higher rpms - the extra fuel just burns on through - but at = idle more fuel can make a big difference as there is so little air to = begin with in the manifold. It sounds like the "hold" period is not constant therefore, one = correction factor won't work for all the different injector pulsating = duration. But, Tracy will develop a fix for sure. Ed ----- Original Message -----=20 From: George Lendich=20 To: Rotary motors in aircraft=20 Sent: Saturday, March 10, 2007 3:48 PM Subject: [FlyRotary] Re: The truth??? / Injector flow rate mystery = solved Is Tracy saying that the injector stays open longer - putting in more = fuel and making the inlet charge richer? George ( down under) Still 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_0004_01C76340.05D6D2D0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Message
That's what it boils down to, = George.  After=20 the open pulse terminates and the injector should close in less than a=20 millisecond, a diode causes the injectors'  magnetic field to hold = open the=20 pintel up to several milliseconds longer than it should.  Therefore = the=20 mixture actually ends up richer than the EC2 intended.  =
 
Now, what is not clear to me, is if you = tune using=20 an Air/Fuel Ratio indicator and then program that value into the EC2 via = the=20 program mode does that compensate for the longer open period by making = the pulse=20 shorter until you get the A/F mixture you want.  I suspect that it = does at=20 least to some extent. 
 
About the only place you would ever = really notice=20 it is at idle - because at higher rpms - the extra fuel just burns on = through -=20 but at idle more fuel can make a big difference as there is so little = air to=20 begin with in the manifold.
 
It sounds like the "hold" period is not = constant=20 therefore, one correction factor won't work for all the different = injector=20 pulsating duration.
 
But, Tracy will develop a fix for=20 sure.
 
Ed
----- Original Message -----
From:=20 George=20 Lendich
Sent: Saturday, March 10, 2007 = 3:48=20 PM
Subject: [FlyRotary] Re: The = truth??? /=20 Injector flow rate mystery solved

Is Tracy saying that the injector stays open = longer -=20 putting in more fuel and making the inlet charge richer?
George ( down under)
Still refining the exact numbers but here is the basic = cause.
 
The diode clamp on the injector drivers (in EC2) serves 3=20 purposes.  It limits the inductive flyback voltage to protect = the=20 driver transistor.  It recovers some of the energy used to open = the=20 injector thus reducing the current consumption of the system.  = It=20 eliminates arcing at the A/B injector switching relay that can cause = noise=20 problems with the processor chips.
 
Unknown to me until recently, it also significantly increases = the=20 closing time of the injector after the driver pulse ends.  I = thought=20 the delay would be negligible.  The actual delay depends on = several=20 factors but may be as much as 5 ms (!)  Ed will know what a big = deal=20 this is.  The factors that go into this and how much it is = magnified by=20 the diode clamp is still under investigation.
 
The good news is that there is a very simple fix.  (Note, = Do NOT=20 go out and remove the diode clamps! That isn't the fix!
 
Tracy
----- Original Message ----- =
From: Ed Anderson
To: Rotary motors in = aircraft=20
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=20 said the only thing that Tracy and I could conclude was that Mazda = was=20 under-rating their  injectors - I wondered whether it might = have=20 something to do with the way an engine is taxed in = Japan.
 
In any case, Tracy is clearly = ignoring our=20 pleas for more information - poor guy is undoubtedly working = furiously=20 getting orders completed before Sun & Fun.  But, he = really=20 shouldn't tease like that {:>)
 
Yes, I understand what you mean = about=20 measured flow rates - I suspect there is something subtle about = this=20 matter.  Perhaps the current profile used to open the = injectors plays=20 some role in this as Tracy indicated he was working on a = Fix. =20 Perhaps a two stage or progressive flow rate profile - opens and = provides=20 normal flow for typical automobile usage but, when wide open (like = ours=20 are at cruise) perhaps the flow rate is more.  Who knows - = Tracy=20 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=20 truth??? / 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=20 through some old logs, that's not true for all Mazda=20 injectors.   I sent 4 slightly used 550's to=20 RC Engineering, and they tested them at 547, 549, 551, and=20 551.  If that ain't 550, I don't know what is=20 :-)  
 
I guess I'm baffled now.  Does = Mazda=20 operate them at 5 volts or something, rather than 12V?  = That would=20 slow down the response=20 time.   
 
 
Hey the HKS is a good = little engine=20 in my opinion - not as good as a light weight rotary (which we = don't=20 have yet - Richard! get a move on {:>)), but it'll get = you =20 flying again. 
 
Thanks for the comments.  It can't = hurt much to=20 try it, because I've already got people who want to buy it if it = doesn't=20 work out.  Still, it's as much trouble to install as the = rotary, so=20 it really comes down to a weight issue, and perhaps whether I'll = ever=20 get my redrive from=20 Autoflight...  
 
Rusty
 
=
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