X-CGP-ClamAV-Result: CLEAN X-VirusScanner: Niversoft's CGPClamav Helper v1.23.0 (ClamAV engine v0.103.0) X-Junk-Score: 0 [] X-KAS-Score: 0 [] From: "Stephen Izett stephen.izett@gmail.com" Received: from mail-pg1-f175.google.com ([209.85.215.175] verified) by logan.com (CommuniGate Pro SMTP 6.2.14) with ESMTPS id 1487086 for flyrotary@lancaironline.net; Fri, 07 May 2021 04:22:25 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.215.175; envelope-from=stephen.izett@gmail.com Received: by mail-pg1-f175.google.com with SMTP id m190so6686021pga.2 for ; Fri, 07 May 2021 01:22:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:mime-version:subject:date:references:to:in-reply-to:message-id; bh=k+fFFd7/gLnu8aG5eDTIal/D8wp+sgxWSFVLHsScnOc=; b=hBCDfownf/2RCPt1xUC6UtSlillwDUxY7aljPmkXaOz6qnhxRDFK44VS8q1uYvgzx8 ScYSPc9h/6pxNCIoFc7+Cz9NxBoCDqdVf1alS7zXydaTSpgmL+medlUCl6QQgi1b6vgd SqwlTIQRa8adXG4gBwaE0JT2yvb/sOmQl4awwxtjdIACh7Y2aEHgDiXJ523+Eui6RLVb sQgf+o/yxA4kCFEP9J3QR7OWpSTBRF1rynPs6pdDaYLidV9yWXOPcE88O4MXkbg0sGG+ Adlo+6kq4mNOoBA7aMlhOUO3FduDUiP20RHsQNxxUZ/nMn2HZeJ/+WS8hnQ1pKNEz3a7 ICkQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:mime-version:subject:date:references:to :in-reply-to:message-id; bh=k+fFFd7/gLnu8aG5eDTIal/D8wp+sgxWSFVLHsScnOc=; b=Lcyhm/8BIebZQAH49QpZ4kmf+vda6vrf+WobO6tY6/U1KJCDW2+E7IQGlKDLhR5ZSo ivsPUsekCP13IvUAuNUGgxIC4IYv7419xtgO7QVXq3YzYCw9E5r6UzC9W8MG262eK2k5 2G07C4MhZ+47pfuryzKywhei8G7QBBm/R+ZcvTvEJrODm3gV/2rEvJ5wp63k832JAkyQ KtuqB4lUl7KH3NNKnoS5JE5fsKeJF0sRvyHz4L5VjXZ6q8ZSV7OvWfWEwaT4B+iXczDN rBk4KGTVzhcEXq7Op5bKs3PDddwpKCzUv8x29M8pyCbnpI4zNfK0KOaT5gSMt+nkhdFG MKaw== X-Gm-Message-State: AOAM533DZw75yvu8C0KUMBh6vtz7jNpyuufvxfuCAYTGtzfed6Q/2oBn QpgliTQV9dgauoI7exH5nb2O/W2yiDk= X-Google-Smtp-Source: ABdhPJzHh2+nG5zE1EP8s1GPMdWLqWLCXyIfLkv4PimW3e0XcCEh/Eypwc62EptyEDFPpFdYMBkMfg== X-Received: by 2002:a63:5b20:: with SMTP id p32mr8476584pgb.173.1620375729108; Fri, 07 May 2021 01:22:09 -0700 (PDT) Return-Path: Received: from stephens-mbp.lan (220-235-121-235.dyn.iinet.net.au. [220.235.121.235]) by smtp.gmail.com with ESMTPSA id u1sm4229383pfb.97.2021.05.07.01.22.07 for (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Fri, 07 May 2021 01:22:08 -0700 (PDT) Content-Type: multipart/alternative; boundary="Apple-Mail=_A89F21B0-3FFB-414F-BEF2-EBCAE3B6C610" Mime-Version: 1.0 (Mac OS X Mail 14.0 \(3654.60.0.2.21\)) Subject: Re: [FlyRotary] Renesis secondary injectors Date: Fri, 7 May 2021 16:22:04 +0800 References: To: Rotary motors in aircraft In-Reply-To: Message-Id: X-Mailer: Apple Mail (2.3654.60.0.2.21) --Apple-Mail=_A89F21B0-3FFB-414F-BEF2-EBCAE3B6C610 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=us-ascii Hi Finn Looking at your CRO screen shot, can you confirm what I'm looking at? Is it set for DC, 1V/Div, 5mSec/Div ? If so where is 0v - Mid Screen? I would have thought any processor based engine monitoring system would = read and average many samples and so filter out any instantaneous = fluctuations in the pressure. Cheers Steve > On 7 May 2021, at 7:46 am, Finn Lassen finn.lassen@verizon.net = wrote: >=20 > OK, so I hooked up a scope to the fuel pressure sensor. > Sensor has 50mV/psi sensitivity. > Below 20"Hg (secondaries not opening) just very slight pulses. > But above 20"Hg -- about 4100 RPM -- I see 1.24V or 25psi peak-peak = pulses. > So that explains the wildly fluctuating fuel pressure readings. = Depending on when the pressure sensor voltage is sampled by the engine = monitor there can be 25 psi or more difference in engine monitor = readings and data logging. >=20 > If you look at the picture I attached on May 4th, you'll see the = pressure sensor is located at the end of the secondary fuel rail (solid = tube) . Apparently the rubber lines from the T-fitting to primary and = secondary rails are enough to somewhat dampen the primary injector fuel = pressure pulses. I probably should add an R-C filter between sensor and = monitor to get more reliable fuel pressure readings. >=20 > With today's 15 deg F lower OAT the engine transitions smoothly at the = staging point. I'm again seeing cracks in the JB-weld around primary = runners, so possible that they may be collapsing somewhat under high = ambient temps -- maybe not. Remember I'm using the stock exhaust = manifold. Even with the stock heat shield and an additional 0.016 alum = shield, the heat from the exhaust manifold is intense. That is a huge = chunk of metal that'll radiate heat with low or no airflow over it after = shutdown. A definite drawback from using the stock exhaust manifold. = Maybe I don't have a leak in my welds on the exhaust manifold and it was = just higher OATs? >=20 > Another suspect for odd behavior is the engine controller's = temperature sensor. I located it in the left radiator air scoop. = Probably a bad idea when running on the ground.=20 >=20 > Finn >=20 > On 5/4/2021 2:08 PM, Charlie England ceengland7@gmail.com = wrote: >> Does the pressure increase have a solid 'step' at the exact staging = point, or is it just rising in that area? How much increase on the = gauge? Where is the reference for fuel pressure measurement?=20 >>=20 >> The pressure *regulator* should be referenced to MAP (manifold = pressure), and will raise absolute fuel pressure as manifold pressure = rises. If the gauge is referenced to atmosphere (or absolute), it would = indicate a rise in pressure as the throttle is opened. >>=20 >> Charlie >>=20 >> On 5/4/2021 12:44 PM, William Schertz wschertz343@gmail.com = wrote: >>> Finn >>> No rx-8 injector experience, but if at the staging point, if the = EC-2-3 shuts off the primary injectors, and the secondaries haven't = opened, fuel out of the manifold decreases, so the pumps would raise the = pressure. Are you confident that the controller is reducing the = primaries and starting the secondaries at the same time? >>> Bill >>>=20 >>> On Tue, May 4, 2021 at 11:07 AM Bobby Hughes BHughes@qnsinc.net = > wrote: >>> Is the fuel pressure really increasing or is it the EM2/3 reading? = Steve B. has posted good advice for tuning around the staging point with = different size injectors.=20 >>>=20 >>> =20 >>> Bobby >>>=20 >>> =20 >>> From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net = ]=20 >>> Sent: Tuesday, May 04, 2021 11:46 AM >>> To: Rotary motors in aircraft >>> Subject: [FlyRotary] Renesis secondary injectors >>>=20 >>> =20 >>> I noticed that my indicated fuel consumption appeared to be about = 50% higher than actual. >>>=20 >>> So I decided to start calibrating engine monitor fuel flow. >>>=20 >>> The first step is to check/adjust fuel flow around the staging point = (20"Hg) where the secondary injectors open (secondary injectors are = larger than primary injectors on the 4-port Renesis). >>>=20 >>> I thought I had previously tuned the engine for a smooth transition = around the staging point, at least to the point when I didn't notice = anything when dvancing throttle through the staging point. >>>=20 >>> However, now doing stationary run ups around the staging point = (especially when engine is getting hot) I get the weird phenomenon of it = going very lean when secondary injectors (supposedly) open. Another odd = thing is that fuel pressure increases markedly. >>>=20 >>> On the HomebuiltAirplanes.com forum = a guy that raced RV-8s for a couple of seasons mentioned troubles with = the stock Renesis injectors. >>>=20 >>> Now I'm wondering if I have (intermittently) bad secondary injectors = -- not opening when they should. >>>=20 >>> However, I'm confused by the rise in fuel pressure. Is there a = injector failure mode where pressure in intake runners could push back = through the injector into the fuel line? >>>=20 >>> Note that these are factory-new, maybe 10 to 20 hours of total = engine run (or attempted run) time. >>>=20 >>> Another possibility is heated secondary fuel rail. But if there were = boiling fuel there the fuel pressure should still drop when secondary = injectors open... >>>=20 >>> I tried to look but didn't find a chart of 87 octane 10% ethanol = boiling point vs temperature. >>>=20 >>> Anybody here had any trouble with stock Renesis injectors? Symptoms? = Other ideas? >>>=20 >>> Finn >>>=20 >>> RX-8 4-port: >>> Primary: Denso 195500-4430 33.3 lb/hr @ 43.5 psi (350cc/min) = 13.8 ohm=20 >>> Secondary: Denso 195500-4460 51.4 lb/hr @ 43.5 psi (540cc/min) = 13.8 ohm >>>=20 >>> =20 >>> =20 >>> <~WRD000.jpg> =09 >>> This email has been checked for viruses by Avast antivirus software.=20= >>> www.avast.com >>>=20 >>>=20 >>>=20 >>>=20 >>> Disclaimer >>>=20 >>> The information contained in this communication from the sender is = confidential. It is intended solely for use by the recipient and others = authorized to receive it. If you are not the recipient, you are hereby = notified that any disclosure, copying, distribution or taking action in = relation of the contents of this information is strictly prohibited and = may be unlawful. >>>=20 >>> This email has been scanned for viruses and malware, and may have = been automatically archived by Mimecast Ltd, an innovator in Software as = a Service (SaaS) for business. Providing a safer and more useful place = for your human generated data. Specializing in; Security, archiving and = compliance. To find out more Click Here = . >>>=20 >>=20 >=20 > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: = http://mail.lancaironline.net:81/lists/flyrotary/List.html = --Apple-Mail=_A89F21B0-3FFB-414F-BEF2-EBCAE3B6C610 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=us-ascii Hi = Finn

Looking at your = CRO screen shot, can you confirm what I'm looking at?
Is it set for DC, 1V/Div, 5mSec/Div ?
If = so where is 0v - Mid Screen?

I would have thought any processor = based engine monitoring system would read and average many samples and = so filter out any instantaneous  fluctuations in the = pressure.

Cheers

Steve






On 7 May = 2021, at 7:46 am, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:

OK, so I hooked up a scope to the fuel pressure = sensor.
Sensor has 50mV/psi sensitivity.
Below= 20"Hg (secondaries not opening) just very slight pulses.
But above 20"Hg -- about 4100 RPM -- I see 1.24V or 25psi = peak-peak  pulses.
So that explains the wildly = fluctuating fuel pressure readings. Depending on when the pressure = sensor voltage is sampled by the engine monitor there can be 25 psi or = more difference in engine monitor readings and data logging.

If you look at the picture I attached on May = 4th, you'll see the pressure sensor is located at the end of the = secondary fuel rail (solid tube) . Apparently the rubber lines from the = T-fitting to primary and secondary rails are enough to somewhat dampen = the primary injector fuel pressure pulses. I probably should add an R-C = filter between sensor and monitor to get more reliable fuel pressure = readings.

With today's 15 deg F lower OAT = the engine transitions smoothly at the staging point. I'm again seeing = cracks in the JB-weld around primary runners, so possible that they may = be collapsing somewhat under high ambient temps -- maybe not. Remember = I'm using the stock exhaust manifold. Even with the stock heat shield = and an additional 0.016 alum shield, the heat from the exhaust manifold = is intense. That is a huge chunk of metal that'll radiate heat with low = or no airflow over it after shutdown. A definite drawback from using the = stock exhaust manifold. Maybe I don't have a leak in my welds on the = exhaust manifold and it was just higher OATs?

Another suspect for odd behavior is the engine controller's = temperature sensor. I located it in the left radiator air scoop. = Probably a bad idea when running on the ground. 

Finn

On 5/4/2021 2:08 PM, = Charlie England ceengland7@gmail.com wrote:
Does = the pressure increase have a solid 'step' at the exact staging point, or = is it just rising in that area? How much increase on the gauge? Where is = the reference for fuel pressure measurement? 

The pressure *regulator* should be referenced to MAP = (manifold pressure), and will raise absolute fuel pressure as manifold = pressure rises. If the gauge is referenced to atmosphere (or absolute), = it would indicate a rise in pressure as the throttle is opened.

Charlie

On = 5/4/2021 12:44 PM, William Schertz wschertz343@gmail.com wrote:
Finn
No rx-8 injector experience, but if at = the staging point, if the EC-2-3 shuts off the primary injectors, and = the secondaries haven't opened, fuel out of the manifold decreases, so = the pumps would raise the pressure. Are you confident that the = controller is reducing the primaries and starting the secondaries at the = same time?
Bill

On Tue, May = 4, 2021 at 11:07 AM Bobby Hughes BHughes@qnsinc.net <flyrotary@lancaironline.net> wrote:

Is the fuel = pressure really increasing or is it the EM2/3 reading?  Steve B. = has posted good advice for tuning around the staging point with = different size injectors. 

 

Bobby

 
From: Rotary motors in aircraft = [mailto:flyrotary@lancaironline.net] 
Sent: Tuesday, May 04, 2021 11:46 = AM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Renesis = secondary injectors

 

I noticed that my = indicated fuel consumption appeared to be about 50% higher than = actual.

So I decided to start calibrating engine = monitor fuel flow.

The first step is to check/adjust = fuel flow around the staging point (20"Hg) where the secondary injectors = open (secondary injectors are larger than primary injectors on the = 4-port Renesis).

I thought I had previously tuned the = engine for a smooth transition around the staging point, at least to the = point when I didn't notice anything when dvancing throttle through the = staging point.

However, now doing stationary run ups = around the staging point (especially when engine is getting hot) I get = the weird phenomenon of it going very lean when secondary injectors = (supposedly) open. Another odd thing is that fuel pressure increases = markedly.

On the HomebuiltAirplanes.com forum a guy that raced = RV-8s for a couple of seasons mentioned troubles with the stock Renesis = injectors.

Now I'm wondering if I have (intermittently) = bad secondary injectors -- not opening when they should.

However, I'm confused by the rise in fuel pressure. Is there = a injector failure mode where pressure in intake runners could push back = through the injector into the fuel line?

Note that = these are factory-new, maybe 10 to 20 hours of total engine run (or = attempted run) time.

Another possibility is heated = secondary fuel rail. But if there were boiling fuel there the fuel = pressure should still drop when secondary injectors open...

I tried to look but didn't find a chart of 87 octane 10% = ethanol boiling point vs temperature.

Anybody here had = any trouble with stock Renesis injectors? Symptoms? Other ideas?

Finn

RX-8 4-port:
Primary: = Denso 195500-4430    33.3 lb/hr @ 43.5 psi = (350cc/min)    13.8 ohm 
Secondary: = Denso 195500-4460    51.4 lb/hr @ 43.5 psi = (540cc/min)    13.8 ohm

 
 

<~WRD000.jpg><= /span>

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Disclaimer

The information = contained in this communication from the sender is confidential. It is = intended solely for use by the recipient and others authorized to = receive it. If you are not the recipient, you are hereby notified that = any disclosure, copying, distribution or taking action in relation of = the contents of this information is strictly prohibited and may be = unlawful.

This email has been scanned for = viruses and malware, and may have been automatically archived by Mimecast = Ltd, an innovator in Software as a Service (SaaS) for business. = Providing a safer and more = useful place for = your human generated data. Specializing in; Security, archiving and = compliance. To find out more Click = Here.



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