Mailing List flyrotary@lancaironline.net Message #52895
From: Bill Bradburry <bbradburry@bellsouth.net>
Subject: RE: [FlyRotary] Re: Improved performance of my new (2009) intake manifold
Date: Thu, 11 Nov 2010 07:51:45 -0500
To: 'Rotary motors in aircraft' <flyrotary@lancaironline.net>

That is the second report I have seen of someone hitting the cold start switch while in flight.  The first time there was discussion about switch guards, etc., which I decided I didn’t need.  My cold start switch is not located anywhere on the panel where I should have my hands unless I am changing the mixture.  But now with two reports, I am beginning to wonder what I am missing.

Where are your cold start switches located and what were you doing when you accidentally hit them?

 

I just moved my staging point from 15 inches to 16 inches because 15 was right on top of 3800 rpm where the EC-2 changes map tables.

 

Bill B

 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of bktrub@aol.com
Sent: Wednesday, November 10, 2010 9:52 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Improved performance of my new (2009) intake manifold

 

Interesting manifold. Are you still using the VDO fuel pressure sender? I had heard that it might not be suitable for use with fuel, I am still using mine at present however.

 

I went up today for a few laps at 3000 over Paine Field. The engine ran well below the staging point, but started stumbling when above the staging point. It ran smoothly through the staging transition on the ground, but when in the air I could not tell by the mixture monitor if it was lean or rich. I tried leaning it out and richening it up, but results were inconclusive so I stayed below the staging point for the remainder of the flight. Temps were down around 130 degrees at 4800 RPM and 110 mph, MP was not noted.

 

I accidently hit the cold start switch while on downwind with two other planes ahead of me, the tower told me to go around on final, but the plane ahead turned off onto the taxiway just in time so I told the tower that I would really like to land, so they cleared me. The engine died as I turned off onto the taxiway and then I noticed the cold start switch. The first order of business was making and installing a switch guard for the cold start switch. I'm also going to pre-load the switch with a rubber band so it stays in the off position unless I'm pushing it on, and can just pull the rubber band off of it if I need to shut down a set of injectors and run the remaining injectors on cold start.(limp home mode for failed injector.)

 

The fuel self transfering issue was resolved by installing manual valve on the transfer line between the tanks.

 

Brian Trubee

 

 

-----Original Message-----
From: Dennis Havarlah <clouduster@austin.rr.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Wed, Nov 10, 2010 12:27 pm
Subject: [FlyRotary] Improved performance of my new (2009) intake manifold

As some of you know I started flying my RV-7A with a cut - off Renesis intake manifold.  In 2009 I installed an new intake designed to route pressure waves from the closing of rotor #1's intake into rotor #2 just before rotor #2's intake closed.  After using the new intake for over a year I am still very happy with it's performance.

 

I gained about 15 mph TAS at the same altitude and manifold pressure

My static engine rpm increased 300 to 350 rpm.

My takeoffs are faster and shorter with noticeable increase in acceleration

My climb rate increased

My oil and water cooling is more critical now because I make more HP.

 

But - I must confess I don't believe the manifold can be reproduced economically.  It's just too complicated.

I also believe it should have slightly shorter intake runners to increase the performance at higher RPM.  Decreasing the intake runner length probably would require complete new geometry of the system.

 

I have another concept for designing a Renesis intake that using a reflected wave from Rotor #1 returning to Rotor #1 .  

I believe it would be much easier to build and small enough to fit into the James rotorary cowl but because my intake works well I am not moving ahead with completing the design and building it.

 

Dennis Haverlah

 

 

 

 

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