flyrotary@lancaironline.net Mailing List Archive

Charlie, & all;

Yes it's an RD-1a left hand turning 2.19:1 (or I think it's 2.19)

2.15 you say? I've been calculating prop speed based on 2.19, so I guess I'd better refresh...

By my calculation 6110 RPM = 2790 Prop RPM. If 2.15:1 then = 2842 Prop RPM.

If I'm using the right numbers, I'm running a slightly higher power than a 180 Lyc @ 2700 RPM & altitude to overcome some of my scoop & muffler drag. I'm using a CATTO 2 blade for 180 HP O-360 Lycoming, just left hand turning. So comparisons should be easier.

I'm not trying to lean out to an optimal mixture for economy, I'm setting mixture to be rich enough to keep the exhaust temp below the alarm point which appears to be preset @ 1750.

I just passed 10 hours of Phase 1 testing, so I'm not very experienced yet.

I just checked VAN' swebsite for RV-8 performance specs, and I'm "at or slightly above" 75% power of a 180 HP Lycoming @ 8000'. About 8 MPH slow of top speed @8000'. Next time I'll dial in some more power, 29.2" MP isn't so much. 3200 RPM is the max for the prop, and I have a Prop Tach available to set on the dash, to be on the safe side.

-----Original Message-----
From: Charlie England <ceengland7@gmail.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Fri, Mar 21, 2014 4:34 pm
Subject: [FlyRotary] Re: Flight Progress

On 3/21/2014 5:45 PM, shipchief@aol.com wrote:

I can report some positive progress with the RV-8 13BT.

I took time out from flying to install the wheel pants, leg and intersection fairings. Although the left side didn't go on as well as I would have liked, I am flying it again, and it is faster.

Now I feel I am roughly equivalent to a stock RV-8. My radiator scoop, oil cooler air exit louvers and under slung muffler may increase aerodynamic drag, but that is a penalty I carry while comparing performance to a Lycoming equipped RV-8.

I took off today with roughly 37"Hg manifold pressure, left the throttle alone. We climbed to 8000 msl, where I leveled out and let the speed build until it stabilized. The vortex generator I installed in the oil cooler air plenum must be effective, as the oil temp only reached 197F

I took a picture of the EM-2, to evaluate after landing.

6110 RPM, 29.2 MP, TAS 206, EGT 1709

13.8 GPH,

161 H20 Temp, 186 Oil Temp. Oil Pressure 60.

The GPS read 197 ground speed, don't know what the winds aloft were.

Disclaimer: I have not calibrated the EM-2, I'm just getting familiar with programming the Fuel Map. I'm working out some of the lean spots, and after a measure of success, moving it over to the B controller.

I'm flying with full fuel, and some stuff in the cockpit, so I'm frequently about 1750Lbs take of weight, although I was about 1700 lbs TO weight on the second flight today, where I did see climb rates of 1500 to 2000 fpm at various speeds and altitudes from 1100 field elevation to 5000 MSL.

I have not gone to full power. I understand the application of a waste gate now. At low to moderated power, the turbo boost (I have it instrumented as well as manifold pressure) will stay about 30", but when I add manifold pressure above about 25", the turbo boost increases substantially more than the manifold pressure I select with the throttle. It would be nice to advance the throttle to wide open for take off, and close the waste gate gradually while climbing.

I have intercooler components, which I hold up to the engine and try to envision a mounting & ducting scheme. I'm also trying to do the same with a waste gate. I have a big clunky automotive unit from Turbonetics, but I like the concept used on a Turbo Aztec better...

Congrats on the good cooling & performance numbers. Can you refresh my memory? 2.15 drive? Those numbers look like 75% on a 180 hp Lyc (except the fuel burn: ~10gph at that altitude/speed with a Lyc). No wastegate or intercooler is probably why the fuel burn is a bit out of whack. Sounds like you've got a good thing going, though. Please keep the reports coming.

Charlie