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Author Topic: Evo setup by old guy  (Read 1147 times)

Offline Leo Mehl

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Evo setup by old guy
« on: February 02, 2009, 04:11:36 PM »
I put my evo in a green box Nobler. tyhe first time out I could not get it to settle down and I was getting 10 min runs with the medium venturi and the super Tigre needle valve assembly placed in the venturi. I still had a hard time with it so I took it home and drilled out the large venturi and put Super Tigre needle valve in it and took it out today to fly. The engine ran perfect with this setup. I am running a little too much caster in my fuel so it was running cold and would berp on the transition between inside and outside manuevers. The best thing is the flight times were right on with big venturi and I think I can make the burp go away with a more synthetic fuel. It also increased the power a whole bunch. If anyone is interested in what I did just ask and I will post pictures. This is a great engine. You have to mount the tank three eights of an inch above the motor mounts to get the right hieght with this setup. What I did was run a piece of wire in the pickup tube of the tank and lined it up with the pickup tube of the needle valve assembly. It was right on. that was my set up and I was real pleased with it.  #^ #^ #^ #^ HB~>
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Willis Swindell

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Re: Evo setup by old guy
« Reply #1 on: February 02, 2009, 05:21:45 PM »
Leo
What did you drill the venturi out to. I am running a Tigre needle in the large venturi which is around .276  and thinking about enlarging it a little.
Willis  ???
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Offline Leo Mehl

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Re: Evo setup by old guy
« Reply #2 on: February 02, 2009, 05:48:04 PM »
Quote from: Willis Swindell on February 02, 2009, 05:21:45 PM
Leo
What did you drill the venturi out to. I am running a Tigre needle in the large venturi which is around .276  and thinking about enlarging it a little.
Willis  ???
I left it stock whatever that is. I am also swinging a 11/5 zinger wide prop on it. I dont think it would hert to drill it other than it will use more fuel. Right now I am getting about 6 Min on a four and a half oz. tank. but am using too much caster oil. It will probanly do better on more synthetic but have not tried that yet. If the weather is good will go flying tommarrow afternoon and will let you know. How much fuel it uses for the pattern will matter if you fly competition but don't matter just sport flying. I would drill it out so you get at least 6 an1/2 min. I would also keep the Middle size venturi just in case you want to redo this. The needle valve assembly drilled thru the venturi shuts off some of the opening and if you do thisd with the stock medium venturi it cuts the power way back. Have good day, Leo HB~> H^^
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Offline FLOYD CARTER

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Re: Evo setup by old guy
« Reply #3 on: February 03, 2009, 12:48:26 PM »
Another Evo puzzlement!  The spraybar is almost 1" higher than the beam mount!  All "normal" stunt motors are 1/2" in height.  So I had to shim the tank upwards to center the tank to the spraybar.  Haven't flown it yet, so I may have it correct.

Raising the tank height aposes problems fitting the thing in the fuselage!  What do you do?

Floyd in OR
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Offline Leo Mehl

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Re: Evo setup by old guy
« Reply #4 on: February 03, 2009, 05:22:29 PM »
Quote from: FLOYD CARTER on February 03, 2009, 12:48:26 PM
Another Evo puzzlement!  The spraybar is almost 1" higher than the beam mount!  All "normal" stunt motors are 1/2" in height.  So I had to shim the tank upwards to center the tank to the spraybar.  Haven't flown it yet, so I may have it correct.

Raising the tank height aposes problems fitting the thing in the fuselage!  What do you do?

Floyd in OR
If you put the spraybar through the hole that is already drilled in the venturi the spray bar will be 3/8" higher than the pickup tube. However I have run into a problem of the engine going rich inverted with the pickup tub being parrelel to the spray bar. I am puting my plane on the bench and raising the tank 1/32" to get an even run. When I do the vertical 8 it burps an goes rich on the outside part of the eight and today we figured I needed to raise the tank. I think I better take picture and show what I have done so Far seeing I have to do this anyway. Hang in there guys Pictures coming and I really do like this engine. Today I ran it on 10% 22%  powermaster so I got a little longer run. I am sure this will be OK at VSC.
« Last Edit: February 03, 2009, 08:28:45 PM by Leo Mehl »
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Offline L0U CRANE

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Re: Evo setup by old guy
« Reply #5 on: February 04, 2009, 02:10:01 AM »
Hey, guys!

You CAN "ground check" tank height - which happens to be the BASIC factor in running the same up or down.

I've been trying to sell this idea for many years, and, tho it works, it hasn't caught on.

BEFORE first flight- start the engine a bit rich. Stand the model on its outboard wingtip ( I usually add on your shoe, so as not to scuff the finish). Relax a mo' to get an idea of the setting.  Keep the fuse centerline horizontal.
Then.....

Rotate the model in "roll" to the attitude where 'the pilot' in the cockpit would "see" 45° bank, with his head up. Listen to the RPM\setting in that position. ..Even tach it...

Rotate the model so 'the pilot' in the cockpit would "see" 45° bank, with his head down. Check the sound (or RPM wth a tach). If the RPM drops richer, the tank was too high for that position. And vice versa...

Shut it off -nose down, inboard tip up, and perhaps a finger to block the vent-air entry.  Takes pnly a few seconds...

Adjust the tank height so that the tank is lower to the side where the engine ran richer, or vice versa.

Crank 'er up again, and do the same check.  IF there's still an RPM difference, shut it down and repeat the procedure. After two or three suich checks, you should have the tank height where there is little or no difference between the "rolled" positions. You are now safe for a first flight - if you re-checked that engine mount and any tank mounting bolts remain solidly drawn home.

FINAL tuning only happens when the model will fly consistently, if not perfectry, on  a dependable basis
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Offline FLOYD CARTER

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Re: Evo setup by old guy
« Reply #6 on: February 04, 2009, 12:47:58 PM »
Well, I haven't even tried to run the Evo in the plane yet.  For info, the engine is upright, and I'm using the stock remote NVA, and I'm measuring from the beam mount up to the center of the spraybar.  I put the center of the tank level with spraybar.
I sure hope it's right because the hatch is glued on and no seams show!

Floyd
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Online Dennis Adamisin

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Re: Evo setup by old guy
« Reply #7 on: February 05, 2009, 10:19:01 AM »
Looks to me like you "old guys" know what you're doing!  8)

BTW, while you have supplanted the remote needle, the drop in venturi gives you one other option: if you rotate the venturi slightly you can make it angle back from the prop.  Even a couple degrees will buy you quite a bit of "finger room" betwen the needle and the prop disc.  Because Leo's is mounted inverted but flying CW and Floyd's is upright & CCW you are both ending up with the needle on the opposite side from the mufler - and THAT is a good thing too!

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As I've grown older, I've learned that pleasing everyone is impossible, but pissing everyone off is a piece of cake!

Offline FLOYD CARTER

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Re: Evo setup by old guy
« Reply #8 on: February 05, 2009, 11:12:46 AM »
Yeah!  I think those remote needle valves are the greatest thing since sliced bread!  I can't imagine why anyone would replace one with a S.T. or such in the venturi. 

(also love my OS 46LA with remote NVA)

Floyd in OR
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Offline Leo Mehl

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Re: Evo setup by old guy
« Reply #9 on: February 08, 2009, 10:22:59 PM »
Quote from: FLOYD CARTER on February 05, 2009, 11:12:46 AM
Yeah!  I think those remote needle valves are the greatest thing since sliced bread!  I can't imagine why anyone would replace one with a S.T. or such in the venturi. 

(also love my OS 46LA with remote NVA)

Floyd in OR
Floyd, I get a better needle setting with the tiger needle valve. It gives me more range and It is a good practice to not stick your fingers in the prop so this keeps this old guy alert. LL~ HB~>
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