Subject: [FlyRotary] Re: Improved performance of my new (2009) intake manifold
Hi Brian,
Yep! any time the drone of the engine changes - it immediately gets your attention (or should) {:>). I too have turned on the cold start when meaning to change controllers - but fortunately have always immediately recognized the problem.
There are several possibilities about your staging problem.
1. You may not have the cross over adjustment (mode 6) tuned properly and when it stages its either too rich or too lean when running on all four. However, adjustment of you manual mixture control should indicate which direction (lean or rich) helps the situation.
2. Always possible that a secondary injectors is not functioning properly - you should be able to check this possibility easily (if you have the injector disable switches that Tracy shows in his installation). While on the ground - switch off the primary injectors (you may get a momentary hiccup if you secondaries are not adjusted properly, but a quick tweak of the mixture control should keep it running), If it idles/runs fine on the secondaries then they are likely to be OK.
3. You Fuel Map bin values right after the staging point could have inappropriate values - Tracy's default is 128 or I guess it shows up as zero on the EM2 and your adjustments are +- to that zero reference (128).
You mention the results of enrichen/leaning was inconclusive - what exactly do you mean? Do you mean you could not tell if the engine was running rich or lean? The Air/fuel Ratio indicator of the EM2 is not giving you consistent readings?
Its pretty important as you know to be able to discern what effect any adjustments are having and mixture is one of the more important ones.
You'll get it sorted out - some installations simply take a bit more sorting out than others
Ed
Sent: Wednesday, November 10, 2010 9:51 PM
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