New to performance

Tell us what you do to get the best performance from your engines.

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AIM
Posts: 801
Joined: Fri Aug 19, 2005 7:22 am
Location: Montpelier, Ohio

New to performance

Post by AIM »

Until joining into the combat world I never worried about engine performance. If the engine ran good I was happy. I never played with fuels, just buying whatever was on sale. I settled on the OS A3 glowplug due to durability. All I cared about were reliable runs. Sure I'll never trade reliability for performance but for the last year I've been watching many guys in the combat scene getting much better engine performance with equal to if not better reliability. I've been surfing through the forums and articles throughout the net on engine mods, fuel selection, plug selection, etc and quite frankly I'm a bit lost and don't know where to start. I just got a new gallon of fuel (Wildcat 15% w/ 18% synthetic oil) for my new Magnum 15. I plan to use a OS A3 plug with 2 gaskets, (just so I can use the same plug for all my engines) I want to begin some testing with all my engines to find the best performance possible using all the same fuel/ plugs/ etc. My question is. What do you veterans use? Do you use the same fuels for your .25s as you do your .15s? Can you get the optimum performance out of any engine using the same plug? I want to use the same fuel and plug for all my engines but I'm not sure this is possible while trying to achieve top performance.

My engine list
Magnum .28
Magnum .25
OS FX .25
OS FP .25

Magnum .15
trying to get my old FOX .15 back that I loaned out a year ago.

Just so you know I'm focusing on Limited B and getting started in SSC. I'm not concerned at this time on Open B. By this I mean I want everything to run good on a muffler. But saying that makes me ask if you guys run the same fuels etc when switching from a muffler to a MCP?
mad
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Joined: Mon Mar 11, 2002 12:28 pm
Location: USA

Post by mad »

Aaron,
Lou posted an excelent artical on fuel and oil content on the georgia combat sight. I find Powermaster to be the most consistant fuel.
Also I have seen many new comers not balance their props. This can rob you of as many as 1000 rpms. As well as causing excessive foaming which will hurt your runs as well.
sgilkey
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Joined: Mon Mar 19, 2001 8:26 am

Post by sgilkey »

I agree with Michael on balancing props. I do it too, though I hate doing it. i've used several fuels with good results, Sig Champion, Wildcat, Ritch's Brew, Omega. My personal pref are Byron's and PowerMaster. I mostly use Powermaster. I prefer a blend with some castor in it, and I like at least 19% oil. I blend Powermaster Sport and Heli to get this. I usually use 15%, unless I need to go down in nitro for SSC or LimB/2548. I use 25% for 1/2A and sometimes for SSC if rpm are down in the 17k range.

Any 15 that I know of (magnum GP, XL, TTGP, OS FP or LA) will run the A3 plug with only one gasket. OS A3 and 8 plugs are shorter than most r/c plugs anyway, but all these engines will take a regular long plug like K&B or Fox. Lots of guys use the TowerPower (?) plug which is a house-brand A3, I believe. The mcCoy MC9 is good if your engine tends to blow plugs. I prefer the OS8 and K&B 1L. The K&B seems to give a few more r's on some engines. With these plugs and powermaster fuel, if you have engine problems, they are not plug/fuel related!! Next most likely culprit (assuming you have checked your head and backplate bolts/gaskets) is fuel foaming- you don't have to SEE it to have problems with it. try to isolate your tank if you have erratic runs, surging, etc. Also look closely for fuel line nicks, esp. near the fittings. The RNV engines (esp the 25FX) are notorious for getting fuel line nicks when you tighten the muffler bolts. make sure there's no crap/dirt/little pieces of fuel tank plastic or fuel tubing shards in your needle valve/spray bar. make sure your clunk swings freely and does not hang up on the back of the tank. and one that can really fool you- if you have long fuel lines, esp if you have a broken off RNV that is flopping in the breeze, sometimes the tubing can get kinked by the airblast when flying, and make the engine go lean. sounds stupid but it's happened to me more than once!
jj
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Post by jj »

Likewise, balance your props.

Use only 1 gasket. As Scott said any of the OS or Tower plugs will work in any of the engines you noted with one gasket. You can run the same fuel and plug in all engines but don't expect the same performance. A safe bet is to stick with a good quality 15% nitro fuel. I use Omega, but many people like Powermaster better and it has doen a good job in my pylon planes. Many of us add an ounce or two of castor oil to the fuel to bump the percentage up by 1-2%. This is extra protection in case you have an unexpected lean run. Not required, but just adds a margin of safety. I think the A3 plug is actually a bit on the hot side. I prefer an A5 or R5. You can use the same fuel and plug with a MCP but you will be running faster and hotter. This is where an A3 might be too hot. The can pipes should get you at least 1,000 more rpms which is a lot.

Don't put too much effort int getting the Fox engine back. Fox used to make a great control line combat engine (.36) but their R/C engines tend not to do as well as the other engines you cited. You may want to try to sell some of the engines and standardize on one per size.
Captain America
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Post by Captain America »

I am so proud! After years of trying we finally have made Aaron see the light and the glimmer of the inner speed demon is starting to show through. I gave you my best advise on the old fp we finally got to 14500. That also works on the 15s. If you are ready to go for open rpm limits bring me an engine and we will go thru the exelerated course on port work.

Prop balancing, never really considered that a large gain though 3 of you cant be wrong. I will drag out the balancer and do some testing this week.

Aaron is only running limited and ssc right now. If i remember correctly(i may not) you need a cooler plug the more rpm you turn and the higher the nitro content you run correct? If that is the case, for limited rpm classes the A3 is probably an adequate choice. For open, a cooler plug such as the mcCoy could be a better choice to reduce temps and increase performance. Please correct me if im wrong, im still attempting to learn the 2 stroke mentalaty after a lifetime of 4 stroke thinking.
Hat Trick
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Post by Hat Trick »

For the limited classes a standard plug works fine and seems to last forever. The open classes with pipes need a colder and tougher plug. I've found the McCoy 9 to work great and last a long time. Regular plugs last 1 to 3 flights on the pipe!
sgilkey
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Joined: Mon Mar 19, 2001 8:26 am

Post by sgilkey »

i don't have much insight into the plug thing. we don't blow too many! the OS seem to last very well, even with pipes. however the K&B 1L seem to give a few hundred more rpm. I tried the Fox 8 which is cold, it gives good performance but does not like to idle, it is not good on engines like the Norvel that have poor carbs and rich low ends (the norvel carb seems to work fine on a muffler but on a pipe, the low end gets very rich). the mccoys are tough and great for engines that eat plugs but they don't idle well in my experience. Brian and I like to do the throttle-back thing which I think Doc just eats up as he swoops in low at full speed and takes a shot!

if you're blowing a lot of plugs it might be mixture. if your exhaust is dark, you're too lean. or you might be getting fuel foaming which makes for lean in the air.

If you got an FP to 14.5k on a LimB prop that's pretty good. Back when Brian and I were practicing with B ships with plain-bearing 25s on 10x4 (what I hoped would become the "SSC" class) we were getting high 13k, pushing 14ish.

i'm not sure prop balancing is necessary, lots of high scorers don't. it is a hassle and i hate it. but i think it helps avoid fuel foaming which i have had trouble with in the past so i just bite the bullet and balance.

prop balancing
RH
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Post by RH »

I was blowing a lot until I went to the OS R5. The only one I have blown so far was when a rear bearing let go and metal particles got to it.

r
AIM
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Location: Montpelier, Ohio

Post by AIM »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Captain America</i>
<br />I am so proud! After years of trying we finally have made Aaron see the light and the glimmer of the inner speed demon is starting to show through. I gave you my best advise on the old fp we finally got to 14500.
<hr height="1" noshade id="quote"></font id="quote"></blockquote id="quote">

Well I do have to admit that although I don't have a competitive bone in my body I am getting tired of just droning around at what seems like half the speed as everyone else.

I just got my very own tach in the mail the other day (I can quit borrowing Captains) so now I'll be able to do some more serious testing/checking of engine performance.

BTW that wasn't my FP that was my magnum 28. We had it on the test stand running at about 13800. Capn suggested reaming the stinger of the muffler out and walla 14400 to 14500 right on the money with an APC 10/3. I haven't tached the MA 10/4 yet.
Viat
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Joined: Thu Jul 08, 2004 11:11 pm
Location: USA

Post by Viat »

Hey guys, what do you think about the best way of breaking-in a Magnum XL15?
I just prepared one new XL15 and would like ypur opinion on it.
sgilkey
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Post by sgilkey »

in my experience the 15XL likes a good break in so give it some flight time before you fly it in competition. mine like just about any fuel but Powermaster seems to always work well no matter what the day. Engine likes most plugs I've fed it but the K&B seems to give a few more r's. Remove all the head shims but the one thinnest one. make SURE the jam nut on the carb rotor screw is snug (I put loctite on mine) if it loosens, the vibration will strip out the soft threads in the carb body quickly. put a piece of large fuel tubing over the low speed needle to keep it from creeping and changing settings, this I believe is a MUST. The HS needle is extremely sensitive, nothing you can do to fix it unless you use an OS remote needle. I just live with it, once set, it seems to hold a setting well. overall i really like these engines and think they are nice runners, reliable, and durable.
Viat
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Joined: Thu Jul 08, 2004 11:11 pm
Location: USA

Post by Viat »

Hi Scott, thanks for the info! So far I have done everything that Kirk wrote on the Midatlanticcombat site.
Can you guys tell me more details on breaking-in this engine?
sgilkey
Posts: 2351
Joined: Mon Mar 19, 2001 8:26 am

Post by sgilkey »

For break-in we just run the same fuel we normally use, run the engine just a bit rich from peak, and go flying for a bunch of flights. Probably the best running Mag 15XL we have, we've had since SSC started- that one, i put on a small sport plane (Lazy Bee) and let Brian fly the snot out of it for "break in". That engine has been going strong for years with essentially no maintenance and stil runs great.
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