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: "Le Roux Breytenbach breytenbachleroux@gmail.com" Received: from mail-ed1-f45.google.com ([209.85.208.45] verified) by logan.com (CommuniGate Pro SMTP 6.3.5) with ESMTPS id 74294 for flyrotary@lancaironline.net; Sun, 06 Jun 2021 00:43:18 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.208.45; envelope-from=breytenbachleroux@gmail.com Received: by mail-ed1-f45.google.com with SMTP id r7so1647806edv.12 for ; Sat, 05 Jun 2021 21:43:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=content-transfer-encoding:from:mime-version:subject:date:message-id :references:in-reply-to:to; bh=IwzRB5P4jbTm41NNOhYEA+wUilTJ99CaadqY5Yau+oQ=; b=p7cHp+22UrYuLpdxtFhLjEufWG7Z4VhjGTKMIOOvl3t4VYKs6rat4erGvc9DTeJLB6 pfVd+HUldByeRYGEajdpBegwq0dI7MqHL6CdH43IilM5jja9oA5s5XqqaeqrYAI2SbCU MU0JizDcoGVh5cnoJreg6nLvDRHG0ewG1s38p+IrFi31EGTidHUn29eUroLTg8bbK/p5 UeNgzu1i+Xywwy3zhfJKnaMzU3IO03MVm7LCNE61fGJzROnu6nZOttsKo91BPzHUA2at LqBeMptMjz0COPzmyJt3QsdX9U3NT3hqaWrTWFkgqcsCWvEXnbpaZ8k2fiSrhUobDup6 GdXQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:content-transfer-encoding:from:mime-version :subject:date:message-id:references:in-reply-to:to; bh=IwzRB5P4jbTm41NNOhYEA+wUilTJ99CaadqY5Yau+oQ=; b=FjfOXVLatXOh7xUAhsjNEKc6w+vb8ChgTLGh+QIkZhofdiewmMZm9ch4j4MvuPTIJr fe0oNnPam0sUAsxaVC9cnXtSaUjnXSkc2mnBif8WR0ChEaCwoBzV/ehUaeSJAmd9ohkd 7hJm4r037tnApb7SX0NRUGJLdsllGAjG7outBT4CyOoumR1oZW0jREVAClvnbjgC8TWI wFG3Av+yorWhOz+Mx66khszEfJsKsZ6QjFI/EW1ogVe1DZBL/MMquIOLaPjutlM9XqH5 WYkda43mCLJGAFmmwoTgyDGSHu7JjF7poj1uwBhMfnWBhDmp4aNRphNANvyKjIwrT7tL e61Q== X-Gm-Message-State: AOAM533w+H2GFcsudZTr9bk1aKiCy6bjj5xhpWvlJeGL6nLagD1Htwwp jZlFGkY1tSX0Hu1Z8yGB39Lm+VUTKCE= X-Google-Smtp-Source: ABdhPJyGtFWoKWtXmTzwKEHv8tIoEyuXO9iRfwEjxOLqzTB7pe4rxgkvWQ1dHoejIdZqSiU1Z44bBg== X-Received: by 2002:aa7:dd57:: with SMTP id o23mr13195833edw.98.1622954582357; Sat, 05 Jun 2021 21:43:02 -0700 (PDT) Return-Path: Received: from [192.168.88.97] ([41.164.183.106]) by smtp.gmail.com with ESMTPSA id w14sm5686717edj.6.2021.06.05.21.43.01 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 05 Jun 2021 21:43:01 -0700 (PDT) Content-Type: multipart/alternative; boundary=Apple-Mail-DF1FF081-261E-45D6-99F9-BDC0F97EA5BE Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) Subject: Re: [FlyRotary] Re: Tuning Date: Sun, 6 Jun 2021 06:42:59 +0200 Message-Id: <03246399-5841-4178-B50D-942F73A09B43@gmail.com> References: In-Reply-To: To: Rotary motors in aircraft X-Mailer: iPhone Mail (17H35) --Apple-Mail-DF1FF081-261E-45D6-99F9-BDC0F97EA5BE Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Matt: Yes i agree the 2 inch p- ports is a way =E2=80=9Coverkill=E2=80=9C fo= r aviation and more for racing where you can go up to 12 000 rpm. For aircraft use you run out of prop rpm before the 2 inch intake runners re= ach optimum VE - Volumetric Efficiency. This was my main reason why i decided to p-port a 13B turbo engine motor and= the availability in South - Africa. I build my engine on the basic principles that the late Steve Beckham did it= . https://youtu.be/EfreUJt-Fsk Was difficult for me to get info on the Beckham build and design, as that wa= s also =E2=80=9Cintellectual capital=E2=80=9D at that time. I got hold of a unused lycoming engine exhaust system. It is build out of a specific type stainless steel, not sure what type stai= nless ,but the inside diameter is 44 mm ( 1.73 inch) and it seems that this w= as the =E2=80=9Csweet diameter=E2=80=9D for the intake runners. The intakes runner must be between 21 to 28 inch and the specific length mus= t be adjust afterwards for optimum VE , say on 7500 engine rpm. At least i would not be kicked off the group =F0=9F=98=85=F0=9F=98=82=F0=9F=A4= =A3 for my opinion, but helped by guys with more experience than me. As Lynn H always say =E2=80=9C I could be wrong=E2=80=9D Le Roux Sent from my iPhone Le Roux Breytenbach=20 > On 05 Jun 2021, at 21:12, Matt Boiteau mattboiteau@gmail.com wrote: >=20 > =EF=BB=BF > Yeah I went up to 8000' feet the other day and did some simulated circuits= . Was hoping someone would give me a good starting point to see if I'm on th= e right track. >=20 > Yeah I don't know why Paul L got the machine shop to drill 2" p-ports. See= ms quite large. >=20 > - Matt Boiteau >=20 >=20 >> On Sat, Jun 5, 2021 at 11:46 AM Charlie England ceengland7@gmail.com wrote: >> Those that are already flying are much better equipped to answer the tuni= ng question, but IIRC, Tracy has talked about one of the 'problem areas' of t= uning that can't be tuned on the ground is the high rpm/low MAP region as y= ou'd see in a decent. Might be worth a dive into the archives to see what he= recommended.=20 >>=20 >> On port diameter: The 'conventional wisdom' is that you need to maintain s= ome (not well defined) level of air velocity in the manifold runners. So it l= ogically follows that the entire length should be the same diameter. Some tu= ning techniques use a tapered runner that is smallest at the valve (our inta= ke port) so that the air is accelerating as it reaches the combustion chambe= r, but seems to me that simply necking down the port at the side of the bloc= k would just create a really bad flow separation at that point.=20 >>=20 >> On 6/5/2021 9:51 AM, Matt Boiteau mattboiteau@gmail.com wrote: >>> High power isn't an issue with timing. >>>=20 >>> I'm trying to understand when you are on base/final and your prop is dri= ving the engine. >>>=20 >>> Do we treat it like coasting down hill in a car?=20 >>>=20 >>> Under 40kpa and 4500rpm, what timing does Tracy computer use? >>>=20 >>> On Fri., Jun. 4, 2021, 09:47 Matt Boiteau mattboiteau@gmail.com, wrote: >>>> Sorry I missed all the replies here. >>>>=20 >>>> Charlie - I'm measuring both in/out of oil and coolant. Usually when I l= ist the temp numbers, I try to say which one it is. Sorry about that. >>>>=20 >>>> The P-Port Renesis engine that I have, got 2" p-ports from Paul. Which s= ounds like they are too big? I wonder how I can bring them down to 1.75"? Is= the inlet to the engine more important, or the whole length of the runners t= o be 1.75"? >>>>=20 >>>> I still don't have a good answer for timing tables for the Rx8. Having a= bit trouble tuning for the low RPM's for downwind / final. I know for cars,= you can cut the fuel and raise the timing to coast downhill. Not sure for a= irplanes, since the prop is driving the engine, how we tune for that. Right n= ow I have 38degree timing for descending. I wonder if I should drop that dow= n to the low 30s and not try to lean it out like a car. >>>>=20 >>>> - Matt Boiteau >>>> -- >>>> Homepage: http://www.flyrotary.com/ >>>> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/L= ist.html >>=20 >>=20 >> Virus-free. www.avast.com --Apple-Mail-DF1FF081-261E-45D6-99F9-BDC0F97EA5BE Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable Matt: Yes i agree the 2 inch p- ports is a w= ay =E2=80=9Coverkill=E2=80=9C for aviation and more for racing where you can= go up to 12 000 rpm.
For aircraft use you run out of prop rpm before th= e 2 inch intake runners reach optimum VE -  Volumetric Efficiency.
This was my main reason why i decided to p-port a 13B turbo engine mot= or and the availability in South - Africa.
I build my engine on th= e basic principles that the late Steve Beckham did it.

<= div>https://youtu.be/EfreUJt-Fsk

I got hold of a unused lycoming engine exhaust system.
It is build out of a specific type stainless steel,  not sure w= hat type stainless ,but the inside diameter is 44 mm ( 1.73 inch) and it see= ms that this was the =E2=80=9Csweet diameter=E2=80=9D for the intake runners= .
The intakes runner must be between 21 to 28 inch and the specifi= c length must be adjust afterwards for optimum VE  , say on 7500 engine= rpm.

At least i would not be kicked off the group =F0= =9F=98=85=F0=9F=98=82=F0=9F=A4=A3 for my opinion, but helped by guys with mo= re experience than me.
As Lynn H always say =E2=80=9C I could be w= rong=E2=80=9D

Le Roux


=




Sent from my iPh= one
Le Roux Breytenbach 

On 05 Jun 2021, at 21:12, Matt Boiteau mattboiteau@gmail.com= <flyrotary@lancaironline.net> wrote:

=EF=BB=BF
Yeah I went u= p to 8000' feet the other day and did some simulated circuits. Was hoping so= meone would give me a good starting point to see if I'm on the right tr= ack.

Yeah I don't know why Paul L got the machine shop to drill 2" p-= ports. Seems quite large.

<= div dir=3D"ltr">- Matt Boiteau


On Sat, Jun 5= , 2021 at 11:46 AM Charlie England c= eengland7@gmail.com <f= lyrotary@lancaironline.net> wrote:
=20 =20 =20
Those that are already flying are much better equipped to answer the tuning question, but IIRC, Tracy has talked about one of the 'problem areas' of tuning that can't be tuned on the ground  is the high rpm/low MAP region as you'd see in a decent. Might be worth a dive into the archives to see what he recommended.

On port diameter: The 'conventional wisdom' is that you need to maintain some (not well defined) level of air velocity in the manifold runners. So it logically follows that the entire length should be the same diameter. Some tuning techniques use a tapered runner that is smallest at the valve (our intake port) so that the air is accelerating as it reaches the combustion chamber, but seems to me that simply necking down the port at the side of the block would just create a really bad flow separation at that point.

On 6/5/2021 9:51 AM, Matt Boiteau mattboiteau@gmail.com wrote:
=20
High power isn't an issue with timing.

I'm trying to understand when you are on base/final and your prop is driving the engine.

Do we treat it like coasting down hill in a car? 

Under 40kpa and 4500rpm, what timing does Tracy computer use?

On Fri., Jun. 4, 2021, 09:47 Matt Boiteau mattboiteau@gmail.com, <flyrotary@lancaironline.net> wrote:
  Sorry I missed all the replies here.

Charlie - I'm measuring both in/out of oil and coolant= . Usually when I list the temp numbers, I try to say which one it is. Sorry about that.

The P-Port Renesis engine that I have, got 2" p-ports from Paul. Which sounds like they are too big? I wonder how I can bring them down to 1.75"? Is the inlet to the engine more important, or the whole length of the runners to be 1.75"?

I still don't have a good answer for timing tables for the Rx8. Having a bit trouble tuning for the low RPM's for downwind / final. I know for cars, you can cut the fuel and raise the timing to coast downhill. Not sure for airplanes, since the prop is driving the engine, how we tune for that. Right now I have 38degree timing for descending. I wonder if I should drop that down to the low 30s and not try to lean it out like a car.

- Matt Boiteau
--
Homepage:  http://www.flyrotary.com/
Archive and UnSub:   http://mail.lancaironline.net:81/lists/flyrotary/List.html


3D"" V= irus-free. www.= avast.com
= --Apple-Mail-DF1FF081-261E-45D6-99F9-BDC0F97EA5BE--