L2 Prop Surprise

[crispy critter]

Re: L2 Prop Surprise

The easiest way to determine the exact lenght of the prop (i.e. 70,71,or ??) is with a tape measure....tip to tip.

[Ed O'Brien]

Re: L2 Prop Surprise

I just got this message from the Prop Shop:
ed
the new propeller is installed on your aircraft and the static rpm is now
2225 which i think you will be very happy with
dave

NEW METAL PROP!!! SO tomorrow, hopefully I'll get to fly it!!! It has the McCauley 71-50 on it. I'll let you know how it goes. It should be a fast as a cruise missile... I just hope it flies a little higher than said missile.
With regards; ED OBRIEN

[Forrest Barber]

Re: L2 Prop Surprise

Static of course is a good start, then go to full throttle level flight ( on the STEP if you wish) THEN record the pressure altitude and temperature and correct everything back to sea level & 59 degrees F for comparision. OR just give me pressure altitude, temperature & FT RPM....level flight.

[Ed O'Brien]

Re: L2 Prop Surprise

Forrest;
I just got back from a 3 hour flight test. Flight test started at 69 degrees and ended at 76 degrees. I flew at sun-up and barometer was 30.22. Field elevation 4709ft. I was probably about 1190-1200 lbs. I got the following results:
1. Lift off: tough to judge but about 10 percent more runway used to get my 60mph rotation speed. That said I was off in about the same distance as a 172 that was in the pattern at the same time. I never saw more than 2275rpm until I got to the cruise tests. I did the climb and take off tests first so temp should be close to 70 degrees plus 2-3 degrees.
2. Climb: 490-515 ft. per minute from 5000-8000 at 55-58 mph indicated. 330-375 fpm 8000-1000ft at 53-55mph. Rpm 2250-2275. Oil temp 225. Cruise climb 5000-8000 ft was around 3-350fpm at 65 mph indicated. Oil temp- 210
rpm 2250-2275.
3. Cruise: I boxed the compass and made 4- 5 mile runs at both 7000 and 9000 ft. 7000 ft average cruise at 2450rpm was 105.8 mph. At 9000 ft 2450 rpm was 98.15 mph
Not much wind this morning. I also did about 5 stop and goes and 3 touch and goes. The new prop slows the airplane slower... meaning (I think because of the efficiency of the prop at 550-575 rpm idle) I'm still getting some thrust. I land fine but then the plane slows down slower (or remains going faster, longer) and therefore requires a bit more braking to exit at my usual
spot.
This is on the new 71-50 McCauley Prop/Don's Dream Machine C-85 revving 94-96 hp. One other thing I noticed was the engine seemed to be lugging a bit on take-off and climb. But it may be the difference between the smoother/softer wood prop and the different vibrations harmonic of the metal prop. Or it could be the extra weight of the prop not letting the engine spin it up as fast. I can't tell at the moment. I also had a bunch of black char on the right landing gear... just like you get when the carb heat is on. Meaning, this thing is running rich on the Stromberg carberator. Would a leaned Marvel carb give me another 100-150 rpm at these altitudes? I think, maybe. Anyway -- I'm interested in the analysis. Let me know what you think. With regards; ED OBRIEN

[M Towsley]

Re: L2 Prop Surprise

Ed,

The carb sounds rich, but the only time I noticed the black soot was when I accidentally didn't lock the primer down earlier this year when it was cold out. The engine definitely did not run right due to the extra fuel. You may want to confirm the correct jetting in the carb. Good luck.

[Ed O'Brien]

Re: L2 Prop Surprise

Thanks Marty;
I get this soot all the time. I'm at nearly 5000 ft. My Stromberg runs at full rich 24/7. I'm likely putting in a Marvel carb. I've got to wait a few weeks to get the money but that's the plan. All the best; ED OBRIEN.

[VictorBravo]

Re: L2 Prop Surprise

Thanks Marty;
I get this soot all the time. I'm at nearly 5000 ft. My Stromberg runs at full rich 24/7. I'm likely putting in a Marvel carb. I've got to wait a few weeks to get the money but that's the plan. All the best; ED OBRIEN.

Jeez Ed, try hooking up the mixture before you toss out the carb!

The carb has to be built properly for the mixture to function, but it shwould do at least OK at 5-8000 feet with the "regular" Stromberg mixture.

We landed in Devner today at about noon (In an Airbus) and the atmosphere was really rockin and rollin below 15,000 MSL. Now I'm in Chicago, going to OSH tomorrow morning. See y'all there I hope!

[Ed O'Brien]

Re: L2 Prop Surprise

VictorBravo;
Landing in Denver from the West requires the plane fly through the "mountain wave." It is a nutural phenomenon. It keeps the number of visiting Californians to a manageble level and we vote for the mountain wave every 4 years. Sorry you were subjected to it. Next time you come to Denver... I'll be glad to include your name in the mountain wave exemption... usually only available to state residents -- and it'll save you some anxiety. For you Sir are always welcome here!

On the Stromberg Carb note... I thought these things were rigged only full open with no tuning available. I'd love to save the gas and fine tune to this altitude... and not buy a
Marvel... if there's a way to do that let me know.
With regards;
ED OBRIEN

[Ragwing nut]

Re: L2 Prop Surprise

They have a mixture option on them where they are not installed, wire full rich, or have a cable attached to them. Mixture cable doesn't do much below 5000 ft. At the altitude you are flying around at you need to have mixture. 2225 static is on the low side for me. That is 350 off redline and I doubt you picked up that much in flight. Could you reach redline in level flight? At that altitude I still say you need a 71-46 or 48. Your climb numbers will be worse on those 100* days.

Mike

[tawadc95]

Re: L2 Prop Surprise

Wish we had a mountain wave or coast wave phenomenon in Calif to keep the rest of the nations and worlds rejects out of Ca.
Native Californians are very conservative by and large and quite outnumbered by every other states disgruntled moving here,they have certainly screwed this beautiful place up and given REAL Californians a bad rap that we do not deserve.
Maybe Ed you can make your mountain wave keep your states people in.
Here's to dreaming of the good old days in Calif!!!!

[Ed O'Brien]

Re: L2 Prop Surprise

Tawadc95;
California is great, particularly around Yuba City. Do you know Flournoy? Named after a member of my family. I've got relatives all around olive country... Woodland, SAC, and a few little towns here and there. I was visiting there last April and had a spendid time.

The mountain wave gets to all of us and shakes off members of my family who are concerned about flying in small planes. Once one of them is with me and gets whomped by a bit of it... the number of family members asking for a scenic airplane rides goes down percipitously. Mountain Wave shorthand for "land this thing and buy me a bus ticket."
All the best ED OBRIEN

[flyguy]

Re: L2 Prop Surprise

Sixties/70's were nice here, light traffic, no gangs (at least where I lived) lots of sportscars, lots of small airports. Controller on Sunday morning in response to requesting altitude to fly across SF bay: "Pick one, you're the only one out there."
Considerate people you could talk to in English, cheap gas, cheap airplanes, hadn't destroyed the dollar yet, people knew their neighbors, if you accidently left your door unlocked, nothing happened, taking a trip by commercial air was still fun-- ah, yes.

I have to check my prop/engine to see if it actually redlines in level flight--never noticed. There, I said something on subject.
DC

[tawadc95]

Re: L2 Prop Surprise

Sorry Ed,
I am off my soap box.
Like Flyguy said this was a very special place just a mere 20 years ago,especially the valley.Nothing but real fine farm folk.Alas the city people have found us and move next to the farm then have the audacity to complain about the dust and noise and think the ag pilots are a menace and seek to change our way of life into their utopian image.
Sounds like I crawled back onto that box.

[Ed O'Brien]

Re: L2 Prop Surprise

Flyguy-Los Banos,CA./Tawadc95-Yuba City Ca.; You guys are on the same damn thread... and it's Interstate-5. Complain all you like... but you can do it in the company of each other and rather easily too. Plan to meet at one of those wonderful little $50 burger fly-in joints in that part of the world. Commiserate until it's time to beat the dark back home. Good luck and all the best; ED O'Brien

[M Towsley]

Re: L2 Prop Surprise

Ed,

I checked my friends L-2M with the 85, he is running a McCauley 71-48, which is stamped on the hub. Of course, I cannot be positive those are the 'real' numbers.

Sorry, forgot about you altitude issue. Of course it will be just a tad bit rich where you live. The mixture parts for your Stromberg, if they already aren't on there, can be found. Run a mixture cable, if you don't already have one, and try it out. Might be the cheaper alternative. I threw one back on 'just in case' though here in the flat land of Illlinoi anything over 2,500 feet gives me a nose bleed. Adding the mixture control also makes the control console look complete. Good luck!