RV-6 Cruise Performance

I have searched the posts and can find some performance comparisons, but I wanted to throw out my observations and see what the RV experts have to say. Here is what I am experiencing in cruise. I know, lots of variables here missing here, but I am just trying to generalize for now.

Cruise alt - 3500, OAT 50, plus/minus

2400rpm, 24", my cruise speeds are in the 175mph-180mph indicated, LOP 8.4gph. 65% power

2550rpm, 25", 195mph, ROP, 13.5gph, 85% power

2300, 22", 160mph, LOP 7.2gph, 55% power (really fluffy as I dont spend much time here.)

The numbers are near spot on with Lycomings charts. My cruise speeds and fuel burn seem to be in line with other 6's. So, things seem to be "as advertised" for my 6. I am thinking that my ship is straight and clean.

I tend to run around my 50mile radius at 24/24 as the engine seems to run very smooth, speed and economy are excellent. So, I am liking living in the 24/24 world right now.

All comments welcome please. 35 hours down, 5 more to go then I can actually go somewhere!

Which engine and prop do you have? That data would help compare apples to apples.

Try running at 25"/2300 rpm

You should still have the same speed as 24"/2400 with less fuel burn (prop is turning slower, same % power). I run there all the time, actually more like 6500 - 7500 ft, wide open and 2300 rpm. I will see nearly 196-200 mph true at this setting burning around 8 gph or less.

sprucemoose said:

Which engine and prop do you have? That data would help compare apples to apples.

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That would be helpfull - IO360, CS Hartzell BA

Also, since you are early on in your test period- do you have all fairings installed? Many people leave them off for the first few flights, and they can amount to a considerable amount of speed.

BTW is your IO360 180 or 200HP?

sprucemoose said:

Also, since you are early on in your test period- do you have all fairings installed? Many people leave them off for the first few flights, and they can amount to a considerable amount of speed.

BTW is your IO360 180 or 200HP?

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180
Fairings on now. Before fairings at 25/25 full rich I would see 180.

Everything looks reasonable to me. Your number and Van's published number are pretty close.

A couple observations though:

24/24 LOP at 8.4 GPH LOP is closer to 69.5% power, according to my whiz-wheel.

22/23 at 7.2 GPH LOP is closer to 59.4%.

sprucemoose said:

Everything looks reasonable to me. Your number and Van's published number are pretty close.

A couple observations though:

24/24 LOP at 8.4 GPH LOP is closer to 69.5% power, according to my whiz-wheel.

22/23 at 7.2 GPH LOP is closer to 59.4%.

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Yup, your right. This process of my flight testing is over; it flies as fast as it should. I am very happy with it.

Getting to know my 6A

I finally got around to actually checking my cruise speed performance today. I am still getting to know my new to me 6A. I built a 7A and flew it for around 350 hrs with various Sube engines and finally gave that up. After building my own RV it seems strange to fly another one without knowing every rivet I keep opening things up and looking and looking, and I must say, all is looking good so far.

This 6A has a Factory Lycoming AEIO 360, (a little over 800 hrs on it) with the inverted oil parts removed. Hartzel constant speed, not blended airfoil. It seems to be a nice straight airplane with good paint and all the fairings etc in place.

At 8000' and got it all settled down at 24 square and ROP
GPS ground speeds
Due North heading 166 knots
West 180 knots
South 173 knots
for an average of 173 knots or 198.95 MPH.

I am not sure what the percent power is at that altitude etc, but I am pretty happy with these numbers. Sorry I did not note the GPH fuel burn.

Starting the thing is still an adventure for me every time. Need to learn a routine that consistently works.

Changes coming soon include Pmags and auto plugs. I have slicks and champion fine wire plugs now and want to get them out due to problems that seem pretty common with both the mags and plugs.

I really miss my flap position system and AOA that I had on the 7A, so I will soon steal them and put them on the 6A.

Flying the 6A does seem different to me than the 7A. Just little things that I can't really describe. Seems like I just had a better feel for the 7A when just about to touch down on a landing. Might be me still learning to fly with me left hand again as the 7A was set up with left throttle etc.

Randall in Carlsbad NM

Randy said:

I finally got around to actually checking my cruise speed performance today.
At 8000' and got it all settled down at 24 square and ROP
GPS ground speeds
Due North heading 166 knots
West 180 knots
South 173 knots
for an average of 173 knots or 198.95 MPH.

Click to expand...

Actually 169.8 knots, with a wind of 10.8 knots from 71.1 degrees, IF your ground tracks were 360, 270, and 180. Heading is useless.

The appropriate trig spreadsheet is available at the NTPS website, or at Kevin Horton's site.

RV6-o360 cs

Just got mine back from the paint shop in Swanton V.T. 10,500 +5c full throttle 2400rpm =175kts @8.5gph.

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