Real world RPM

[wizard]

Biff, you are a sick man. Trying to get that sound, but still breaking in. Just was wondering about numbers.

[KrisW]

900 sounds a bit slow. . better turn it up to about 1250 or so. . . .

Better yet, reset the tach to TWO blade instead of 3-blade. . might give you a more accurate reading at idle. . . . .

[Jim Woodward]

Hi Guys,

3W 150 TOC, engine has 40 flights on it, HP2 Syn 50/1, 93 Octane, Mezjlick 28.5x12 3 blade, 5340 rpms, standard mufflers. This is a new engine converted to the 3W 6.0V ignition by A.I., as noted in other posts with the single-cylinder running problems. First flilght of the day was 5200 with obvious richness in flight. I leaned slightly for the next flight which produced the 5340 reading. I leaned again after that flight but did not tach, in flight power was improved though. I loved the way the 3B flew and is my new prop of choice. Still has plenty of horizontal speed, awesome vertical still achieved, but the throttle control and breaking allows for either both "constant-speed" type of flying or fast for wind. Loved it! Installed on my Dalton Aviation 42% 260. (engine was broken in with 6 gallons of Lawn-boy at 50/1, however, I was thinkng to run another 3 gallons of Lawn-boy through it on the advice of A.I., which would equate to more than 8 hrs of run time on the L.B.).

UPDATE: Same setup 10/15/06 turned 5600 rpms on the 28.5x12 3 blade.

Thanks,
Jim W.

[brianhole]

BME 50, fired up for the first time today, still trying to get it tuned (soon as my tx recharges).
22x8 3W/ Menz prop= 6480 with factory settings
leaned 3/8 turn= 7100
87 octane/ Stihl oil 50:1
still need to tweak the low end

[rdb127]

DA-50 R still on break in(AD 32-1) oil, 89 octane gas, sea level NX-22X8 7200

[Flyinrazrback]

3w 80cs with 3w can, 7th flight, mejzlik 26x10, 6540 (95 degrees, 40:1 pennzoil)

Edit: Now 2 gallons through motor, PT Models 26x10 6780. Awesome Prop.
2.5 gallons (last tank of break in fuel) Vess 27A 6220 on the ground, and 6680 in the air, great prop!

[KrisW]

DA-150, KS 1080 pipes and stock Flex headers, Biela 30-12 three blade.

Static RPM: 5400 Hot

Same engine with solid headers and 1090 pipes and the Biela 29-12 3-blade

Static RPM: 5850-5900 Hot.

I found that I prefer the KS1080 pipes over the 1090's because of the much smoother midrange throttle response, while not really losing very much on the top end power. Everyone wants the BIG numbers up top, but the plane definitely was easier to fly with the 1080's and smoother throttle curve.

I'll be happy to trade straight across for some 1080's if anyone has a set they want to get rid of

[rdb127]

First Place Engines FPE 3.2 on 32-1[edit: stock muffler} oil 89 octane gas,
Sea level- 80 degrees 5th flight, NX-22X8
6600 rpm.

Anyone with a FPE 3.2 who can tell me if the RPM seems right or not?
It pulls the plane like a bear on the first half of throttle (lots of low torque)
then less noticable increase on top. Top end is slightly rich, and seems like
there is no fade from lean.

[Flyinrazrback]

3W 80 info on p3 updated with a few more props

[Xipp]

You will find that a prop driven engine will need a lot of mid-range torque top end numbers really mean nothing other then more heat and viberation.
To date the best pipes we have found for really improved mid-range have been the Greve's long pipes with the headers set at 11".
Dont get me wrong the KS-1090's make power but it's way peakie and to fly IMAC with them is tuff.
Mind you some of the peakieness can be removed by adjusting the header but then you lose some of the pipes power potinal and when compaired to the Greve's the 1090's are heavy.

We have a AI Extra with a DA-150 and Greves pipes pulling 5950 hot on a Mejzlik 32x10 Mind you thats after porting the engine.

prior to porting the engine we were getting 5750 to 5800 with still good mid-range.

So remember it's more then just top RPM numbers,It's a lil factor called TORQUE...

[Flyinrazrback]

I agree ground numbers are a small part, an inflight tach will tell you what is really happening with the props. I didnt have any problems running full length pipes on my 3Ws, I guess the way they are built are more adapt to the full pipes compared to the DA.

[TprosRC]

	Quote: Originally Posted by wizard
	DA 50 Slimline Pitts mufler menz 22 X 8 Cheap gas lawnboy 32:1 ashless 1/2 gal thru Indiana 40% humidity 70 deg. 7100 Idle about 900 Question what should the idle be?

Ditto on the oil & prop, 1/4 gallon or so through it & getting 6800-6900. Idle is about 1800 though. 900 seems really low, if I get down to 1400 it shakes so bad it looks like it's gonna rip the aileron servos out.

[TManiaci]

3W50i, approx 50 flights
Amsoil 100:1, mixed @ 75:1
91 Octane from some arab country
Hot testing
NX 23x8, 6050 RPM
NX 22x10, 6250 RPM
NX 22x8, 6420 RPM

[harley6133]

FPE 3.2 with a Zinger Pro 22 x 10, 6580 rpm. Pulls hard from the bottom and mid-range, does seem to run out of speed at the top end, i am sure it is the prop limiting the top speed.

[Pale Rider]

DA 50
89 Octane
Stock Exhaust
NX 23-8
Bel Ray H1R 50:1
7020
1300 idle