RE: Lanier Ripper info  
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RE: Lanier Ripper info - 5/22/2007 3:18:33 PM   
JohnMcGowan


 

Posts: 797
Joined: 12/14/2001
From: Birmingham, AL, USA
Status: offline 		good morning Kirk,
the cg range is from 2 1/4 to 2 3/4 so I just split the difference for a starting point.
Thanks, I will pick me up a 3 oz tank and give it a go.
Thanks again for all your help, I appreciate it very much.
On another note, the new magnum 15 XL has had 3 two oz tanks run thru it last weekend so I know it could stand a little more run time. I had a mas 8x4 prop on it and it was turning 14,500 rpms on 15% synthetic cool power. Im hoping that when the engine gets a little time on it , the rpms will come up more than that. I ran 1 tank of 30% heli fuel at the end and the rpms came up to 15,100. Is this anything to be concerned about (lower rpms than what I expected)?
John

< Message edited by JohnMcGowan -- 5/22/2007 3:23:42 PM >

(in reply to Montague)
       Post #: 26

RE: Lanier Ripper info - 5/22/2007 3:46:52 PM   
Montague



Posts: 4630
Joined: 4/19/2002
From: Laurel, MD,
Status: offline 		The 8x4 prop is just too big for that engine. Overloading it isn't helping break the engine in, and may reduce the power you eventually get out of it. 14.5k on the overly large prop and 15% fuel is fine though.

The Magnums like a smaller prop. Break in with a 7x4 MAS, and fly with the 8x3. Throw that 8x4 away. And take a headgasket out if you haven't already, the Mags come with 2 installed. With the 8x3 and 15% fuel, depending on the weather, and after the engine breaks in more (they take a bit of time to reach full power), you should see around 17k, sometimes 17.5k or more, sometimes in the high 16s. Don't sweat it, if you are over 16.5, you'll be fine, the Mag XL unloads quite a bit in the air (well, if the airframe is clean enough anyway). The OS LA turns more RPM on the ground, but doesn't unload nearly as much in the air.


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Kirk Montague Adams
RCCA 560

(in reply to JohnMcGowan)
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RE: Lanier Ripper info - 5/22/2007 3:55:04 PM   
JohnMcGowan


 

Posts: 797
Joined: 12/14/2001
From: Birmingham, AL, USA
Status: offline 		thats what I needed to hear Kirk, I had no idea that 8x4 was too big. Im use to bigger glow 2 strokes and saitos 4 strokes, so these smaller engines will teach me something, lol. I will do as you say and remove one head shim. Do you see that the 30%heli fuel will be a problem?
I will go and buy me a 7x4 and re-tach after I remove one head shim and see what we get.
Our club combat meet will require the use of the 8x3 combat prop, as you stated.
You da MAN Kirk!!

(in reply to Montague)
       Post #: 28

RE: Lanier Ripper info - 5/22/2007 3:57:15 PM   
Montague



Posts: 4630
Joined: 4/19/2002
From: Laurel, MD,
Status: offline 		I've never run 30% fuel in my .15s, so I can't say. I've actually never run anything other than 15% in my MagXLs. I did run some 5% in my XLS because that engine is too darn powerful.


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Kirk Montague Adams
RCCA 560

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RE: Lanier Ripper info - 5/22/2007 4:00:54 PM   
JohnMcGowan


 

Posts: 797
Joined: 12/14/2001
From: Birmingham, AL, USA
Status: offline 		A guy at our club has a ripper with a ThunderTiger 15 on a car pipe that he uses 30% in it and it absolutely SCREAMS!!

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       Post #: 30

RE: Lanier Ripper info - 5/22/2007 4:37:27 PM   
glowplugboy


 

Posts: 580
Joined: 12/26/2001
From: Pasadena, TX 77505/77508, TX, USA
Status: offline 		Outstanding! 2 oz. won't be enough, and if you can find the 3 oz. Hayes tank, this is the one for competition. I use a 4 oz. tank for sport combat. The CG instructions on the Ripper are not real specific, but the CG is pretty important on this model. Put your forefingers about at the spar and see how the model balances. It should be nose heavy. Keep moving your fingers forward to about 1/2" forward of the spar. That's the true CG point, at least for my Rippers. If you can have a nice level airframe somewhere between these two reference points, you will be fine, just don't fly it tail heavy!
Regards,
Mike

(in reply to Montague)
       Post #: 31

RE: Lanier Ripper info - 5/22/2007 5:05:28 PM   
JohnMcGowan


 

Posts: 797
Joined: 12/14/2001
From: Birmingham, AL, USA
Status: offline 		Hi Mike!!
yes, my balancer was placed at 2 and a half inches which is right at the spar, and it was just a tad nose heavy, Ill say it was hanging nose down maybe 5 degrees or so, so this from what your describing should be just about right. We'll see this weekend
You doing ok?
John

(in reply to glowplugboy)
       Post #: 32

RE: Lanier Ripper info - 5/22/2007 5:50:46 PM   
glowplugboy


 

Posts: 580
Joined: 12/26/2001
From: Pasadena, TX 77505/77508, TX, USA
Status: offline 		Hi John,
That will be a great starting point as the Rippers are CG sensitive. I am up and walking again, getting my "gate" back and less pain in the ankle which is good news. I had to layout of combat this past weekend because I got the flu! Ouch!
Mike

(in reply to JohnMcGowan)
       Post #: 33

RE: Lanier Ripper info - 5/24/2007 3:00:09 AM   
JohnMcGowan


 

Posts: 797
Joined: 12/14/2001
From: Birmingham, AL, USA
Status: offline 		update: Today I picked up a 7x4 mas prop and a 3 oz fuel tank but left the 2 oz tank on this evening just to try the prop before dark got me. Last nite I did what Kirk told me and pulled 1 head shim on the magnum 15. On 15% synthetic cool power and after I tweaked the low end just a tad to get rid of the slight rich low end hesitation I got an amazing 18,500 with still a couple clicks on the rich side to go. I didnt want to max it out just to see what it would do because I am only on my 4th 2 oz tank of fuel. Id say I got a winner so far , what about it Kirk and Mike? Im curious to see waht 30% heli fuel will do now! Alll I can say is I'm very impressed with this engine now!!! That little 7x4 made it scream. You were absolutely right Kirk, it needed that prop to help the break in and to turn up. Im excited!!
Thanks both of you for your advice!! All I gots to do now is fly it on the maiden this weekend. Will keep yall posted.
John

(in reply to glowplugboy)
       Post #: 34

RE: Lanier Ripper info - 5/24/2007 3:51:34 AM   
glowplugboy


 

Posts: 580
Joined: 12/26/2001
From: Pasadena, TX 77505/77508, TX, USA
Status: offline 		Outstanding! I believe that Kirk meant the small prop as a break in prop, right? It might be a little small for flying. With it broken in on the small prop, you should be able to get the minimum 17,500 quite easily on a combat prop. I happen to sell 8 X 3's by the dozen if you need some....

Regards,
Mike

(in reply to JohnMcGowan)
       Post #: 35

RE: Lanier Ripper info - 5/24/2007 5:06:07 AM   
Montague



Posts: 4630
Joined: 4/19/2002
From: Laurel, MD,
Status: offline 		Actually, when we flew OpenA out here, we used the 7x4 most of the time. The Mags love that smaller prop in the air on a small, clean airframe. The 8x3 pulls the larger SSC planes a little better in the vertical, but slower in level flight. Of course, the A class planes were a bit smaller in the wing, and closer to 2lbs rather than 2.5


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Kirk Montague Adams
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       Post #: 36

RE: Lanier Ripper info - 5/24/2007 5:43:39 AM   
glowplugboy


 

Posts: 580
Joined: 12/26/2001
From: Pasadena, TX 77505/77508, TX, USA
Status: offline 		Kirk, that is interesting. I have never seen Open A flown. SSC and Open B still remain the favorites here in Texas. I bet a .15 does like that small prop. BTW, the new Magnum .15 is a vast improvement over the old one, huh? Easily the equal of the LA .15, and is not too far off the performance of the CVA .15. And on only 15% nitro, too.

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RE: Lanier Ripper info - 5/24/2007 1:58:23 PM   
Montague



Posts: 4630
Joined: 4/19/2002
From: Laurel, MD,
Status: offline 		Well, the funny thing is that OpenA, the way we were flying it out here is that it was a lot like SSC now. However, there were differences. The mid-airs did almost do damage, the planes were lighter, and only a hair faster than SSC, so they climbed better, but the furball spread out more than SSC does, so there were less mid-airs and we spent less time repairing and needed fewer planes to survive a contest. SSC is like bumpercars sometimes, with constant mid-airs, and contests decided among the top pilots mostly by how well you do at avoiding heat-ending early mid-airs. We didn't have that problem in A class here.

(We flew with a sportsman's understanding not to use the super expensive exotic .15s developed for various FAI events. We are able to be competitive and sporting at the same time out here, but that's apparently not possible in some parts of the country)


As for the new Magnum XLS, it is more powerful than the old Magnum and way more powerful than the LA if it was allowed to run as it was designed to. Since SSC has an RPM limit, you have to work to get the engine down under the limit and keep it running well at the lower RPM. Part of this comes from the larger carb and exhaust openings. Those larger openings allow more fuel and air in and out, but they also reduce fuel drawing ability. I run a standard clunk tank, so the engine's fuel draw ability is a small issue for me, I need to make sure I launch slightly on the rich side to avoid getting lean towards the end of the tank. It's not a big deal, and I'm thinking I might reduce the exhaust opening to improve the backpressure a little. The new XLS has a better carb than the old mags, but it still leaks around the needle valve o-ring after a little while. The first few runs will be fine, but I ran mine, then let the engine sit a couple of weeks and when I ran it again, it was leaking like crazy.


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Kirk Montague Adams
RCCA 560

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       Post #: 38

RE: Lanier Ripper info - 5/24/2007 3:29:18 PM   
JohnMcGowan


 

Posts: 797
Joined: 12/14/2001
From: Birmingham, AL, USA
Status: offline 		so Kirk, you think I should do my maiden this weekend with the 7x4 thats still on it or should I go ahead and start using the 8x3 combat prop? The actual combat meet isnt for a month or so yet, but I want to fly it and get the bugs worked out.
I couldnt get over that .15 turning 18,500 with the 7x4 !! Thats honking man!!!
Thanks!
John

(in reply to Montague)
       Post #: 39