Mailing List flyrotary@lancaironline.net Message #66846
From: Matt Boiteau mattboiteau@gmail.com <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Tuning
Date: Sat, 5 Jun 2021 10:51:39 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
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
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster