Author Topic: It's all coming back to me now. 1/2a nightmares. (Read 3292 times)

Paul Taylor · « **on:** August 06, 2012, 05:19:42 PM »

I've spent the past two hot afternoons trying to get these %#*! norvel .061's running. I got a pop yesterday and two 10 second runs today!

Now I remember why I stopped fiddling with 1/2a engines. What a head banger!

Or a PITA!!!

I quit.

Heman Lee · « **Reply #1 on:** August 06, 2012, 05:57:02 PM »

There are 2 models of Norvel .061, AME and BigMig Sport. From the exterior it is very hard to tell them apart. Look for the model no. on the case eith A6 (AME) or BS6 (BigMig). If you hare the AME, it needs a pressurized fuel system like a bladder to run consistent.

The second reason that it could be hard to start is your battery. If you have the revlite cylinder with the Hotter Plug you need more battery that your single cell plug type ignitor. Like Cox engine, you either need to make up a battery using 3 D cells in parallel or use an RC Power Panel. I use the later just because I have a 1/2a starter - which is the way to go.

The third reason good be the fit. The piston/cylinder are extremely tight, to need to lap them by hand first; just remove the head to a a drop of Machine oil and turn it over about 200 times. If the engine is still to tight, add an extra head gaskets.

I have about a dozen Norvel engine and they all run extremely well. Even the old worn out ones turn 20K.

Wynn Robins · « **Reply #2 on:** August 06, 2012, 06:08:19 PM »

go electric

Balsa Butcher · « **Reply #3 on:** August 06, 2012, 06:21:08 PM »

Go Electric?...and miss out on all that fun...Never! Actually Heman is quite accomplished in both electric and IC. Me, I'd rather fight than switch but have to admit that 1/2 A IC engines present many challanges.

Trostle · « **Reply #4 on:** August 06, 2012, 06:30:47 PM »

Like Heman Lee suggested, you might want to check whether your engine is a Big Mig or the AMA version. One way to tell for sure is to remove the head so you can clearly look at the intake ports. The Big Mig (sport version) will have 5 relatively small intake ports besides the single exhaust port. The AMA (performance version) will have 3 fairly large intake ports besides the single exhaust port. I think the timing is a bit different also, but it is the number of ports to determine one model from the other.

Because these things have a really tight upper piston seal, they can be difficult to start at first. An electric starter is almost absolutely required until these thing get some break in time, like up to a full hour on the bench.

One thing I have done at the beginning of the breakin is to remove the head/glow plug when the engine is on the stand and hook up the fuel line. Then spin the thing with the eleectric starter in several 5 second bursts. You will be amazed at how much fuel the thing pumps into the cylinder, so there is plenty of lubrication in this process. I have done this with each of my engines four or five times, they start easier, and I do not think there has been any harm done. For the engines going into my 1/2A multi-engine scale models, this process seems to work just fine.

Keith

kenneth cook · « **Reply #5 on:** August 06, 2012, 06:51:19 PM »

Paul, I assume this is the engine for the combat wing? Are you currently trying to run it on a bladder or just test running on a stand? The prop of choice would be a APC 4.6 x 3. This certainly isn't going to be easy to flip unless your acclimated to doing so. In the event you have a Norvel starter spring this will help a whole lot. Is this engine new? these can be very problematic initially. If new, having a heat gun right next to you is in order. Norvel's have a very tight pinch and you can really flood them so be very cautious on priming. One to two drops in the cylinder. Lose the muffler if it has one as well. I know you said your not crazy about the noise they make. Ken

Paul Taylor · « **Reply #6 on:** August 06, 2012, 07:13:35 PM »

Hey guys
These are RC engines. I have ran them in the past so they are well broken in. I was using a starter panel and electric starter. 15% nitro.
No pressure. Just on a test stand.
And yea Ken. I was going to put this on the Hacker.

Bob Whitely · « **Reply #7 on:** August 06, 2012, 08:34:27 PM »

I think the biggest problem you are having is not using enough nitro. You'll have
to trust me on this as I have some experience with these tiny motors. Use at least 30%
or more nitro, I am usually around 40-45% nitro with mine. They really respond
to this more than you think. .RJ

Larry Renger · « **Reply #8 on:** August 06, 2012, 08:46:18 PM »

Mr. 1/2 A here! I ONLY try to start small engines with an electric starter. I hate to suffer.

Wynn Robins · « **Reply #9 on:** August 06, 2012, 09:55:37 PM »

Quote from: Balsa Butcher on August 06, 2012, 06:21:08 PM

Go Electric?...and miss out on all that fun...Never! Actually Heman is quite accomplished in both electric and IC. Me, I'd rather fight than switch but have to admit that 1/2 A IC engines present many challanges.

I've spent endless hours flicking 1/2a motors......I still like them - just easier and less frustrating if you actually want to FLY if you go electric.

kenneth cook · « **Reply #10 on:** August 07, 2012, 06:03:13 AM »

Paul, looking back on the picture I noticed you have a Galbreath Nelson plug. This is a big plus and certainly all my Norvel's have run better using that setup. My question is, have you used your power panel with this plug before? These require a good starting battery. I recently switched to a pit box using a Tower panel panel and have experienced problems lighting off certain plugs. I'm thinking if your using the starter in addition, you may also be suffering a voltage drop as well. I would take the plug out and check even if you have a meter telling you all is good. Ken

Brett Buck · « **Reply #11 on:** August 07, 2012, 03:31:59 PM »

Quote from: Larry Renger on August 06, 2012, 08:46:18 PM

Mr. 1/2 A here! I ONLY try to start small engines with an electric starter. I hate to suffer.

  You think it's bad trying to fly them, try judging. I was at a WAM contest in Vacaville in August about 15 years ago, and got tagged for 1/2A (NOV/BEG/ADV/EXP). I stood out there with it well over 100 degrees for an hour and a half, and no one made it past 1/2 lap, most never starting at all. Here's a hint, please do not show up at a contest with a TeeDee .049 on suction and try to run it on Fox Superfuel or K&B 100. For that matter, don't show up at a contest with a new airplane and a new Tee Dee 049 that you have never run before. I know, because about half the contestants that day fell in one category or the other.

Get yourself a nice Medallion, a can of Cox Racing Fuel, and test-fly the airplane at least a couple of times first, anything else is abusive.

   I think that was also the day that we never made it to the FIRST ROUND of Expert. Or, rather, one of the days that happened.

I almost always volunteer to judge at every contest I go to, but I flat refuse 1/2A anymore.

   Brett

kenneth cook · « **Reply #12 on:** August 07, 2012, 03:54:06 PM »

One thing for certain, modern engines like Norvel's, VA's AP's etc. all start easier. Were flying 1/2 A combat weekly and I get these engines lit off in weather from 35 deg -100 deg in quite a short period of time. Some are better than others. Generally, the engines are running in under 1 min when the timer says go. I don't use an electric starter and probably never will. The key is just finding the sequence to get them started. A hot battery is a must especially for a Nelson plug. My last experience with a Norvel r/c carb was trying to run the .074. What a pain in the a$$. The instructions didn't want the throttle opened fully and we had it wired open for control line. That being said, I certainly feel the r/c carb is going to be problematic for control line use. I know many have used it, in this case the engine is going to be run on pressure. The entire r/c carb can be removed as we don't need a venturi here. I took the bolt out that holds the venturi in place. I opened the hole to .108". I used a stock fine threaded needle valve spray bar from a red Cox plastic backplate. The spray bar is knurled so it was pressed into the case and this will keep the entire assembly from turning. These needles have the 128 TPI which is important for pressure. When the bladder is filled and attached, point the bathtub opening in the case towards the ground. Adjust needle so the drips of fuel are about 3/4" apart. Just for the record, the stock venturi can be reinstalled using the stock through bolt. Ken

Paul Taylor · « **Reply #13 on:** August 07, 2012, 04:11:03 PM »

Ok Ken
You gave me some food for thought.
I will let it cool off a bit and might try this set up on my .061

kenneth cook · « **Reply #14 on:** August 07, 2012, 04:46:41 PM »

Paul, this is just one example for using a 1/2A on pressure. Another would be to use a remote needle like the OS 1A which can be found on many OS carbs. Basically all you need is a tube for fuel delivery into the case after the remote needle. If for instance , you don't want to drill the case like I did you can go to another option. That would be to try and use a WD-40 straw into the case. I got pretty good at heating the straw with a heat gun and it automatically bends into a 90 deg elbow. You can secure the straw into the venturi through bolt hole with a bit of epoxy even. Use small fuel tubing onto the opposite end of the straw and the other end directly to the remote needle. Don't give up. It really is a lot of fun and quite exciting. Ken

Arlan McKee · « **Reply #15 on:** August 07, 2012, 05:04:03 PM »

Paul,

I've got plenty of nitro if you want to juice up your fuel.

Paul Taylor · « **Reply #16 on:** August 07, 2012, 05:42:35 PM »

Ken
Are you saying I can use a remote NVA of of a LA 40?

What size hole in the WD 40 tubing spray bar?

Arlan
Thanks for the offer. Might take you up on it.

kenneth cook · « **Reply #17 on:** August 07, 2012, 07:40:14 PM »

The LA.40 needle valve will not work unfortunately. This is a real shame too. That needle, if the thread was finer would be IDEAL for combat as it comes equipped with a o-ring. If they did there homework on that needle it would work for stunt as well. I'm sure you had to try it. Right when the engine is starting to sound good breaking back and forth, it falls on its face due to the needle leaning out so much it starves the engine for fuel. Many Norvel engines are different. I'm assuming since I see your engine being a Revlite version (round fins olive drab like in color) is a later version therefore the venturi is through bolted in the case. I'm curious to the hole size that the through bolt is. I was suggesting just to insert a WD-40 straw into that hole and epoxy around it. All the straw is doing is providing means for the fuel to get to the crank. You could then attach small tubing from the straw to a remote needle. The needle I was mentioning is what we typically use on the larger combat planes http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXCR44&P=M These needles typically screw into the r/c carbs. You would need to make a bracket for it. Most flyers use a control horn and drill one of the holes large enough for the nipple to pass through and the hex nut on the spraybar holds it on. Ken

Paul Taylor · « **Reply #18 on:** August 07, 2012, 08:18:19 PM »

Ken,
That looks like a OS needle that I have in drawer of spare parts.
I am going to have to dig it out tomorrow.

YAWN...

john e. holliday · « **Reply #19 on:** August 08, 2012, 07:12:24 AM »

I have heard the same stories about the COX reed engines. Yes sometimes they can get cantankerous, but with correct/good fuel, right prop and good battery, I have had little problems unless they have set for a while. Then it is only taking time to prime and flip. Yes I have had to take them apart and do things.

Jim Thomerson · « **Reply #20 on:** August 08, 2012, 12:26:07 PM »

Flipping a Cox engine is an exercise in futility. TD 049, 09 or 15, give a head prime. How much will vary with individual engines. Have the needle set. Now turn the prop backwards to vertical. Attach a good hot battery which will light the plug up like a flashlight, and hit the prop forward with your gloved finger. With a little practice, this will work every time. If you are not running crankcase pressure, you may have to choke it a couple of times first. Takes me back to the mouse racing days.

kenneth cook · « **Reply #21 on:** August 08, 2012, 01:31:51 PM »

The engine in question here is a Norvel. As I stated above, with the proper set up and sequence, this should light off in less than a minute. Paul, I provided a picture of the bladder and I surely wish we had some time at Brodak's to give a close up demonstration. This looks way more complicated than it is. In fact it really is quite easy. The picture shows how I make my bladders. Use a 1/8" long pop rivet and remove the center portion of the rivet. This gives you a perfect bladder fitting and they're cheap and readily available. The bladder tubing I show here works very well on 1/2A's due to the thin wall and low pressure they give. Cut a piece about 3 1/2" long, tie a knot in the other end and insert it onto the rivet. I next use a piece of regular fuel tubing over the fitting and bladder material to lock it onto the rivet. This is the hardest part of making these bladders is getting that little donut on. This is important for needling and engine run. The size is on the package and it's latex. Nothing really crazy here as well.

The assembled bladder is directly below and I use a small line clip on the tubing for a pinch off device which is needed after you fill the bladder with fuel. The tubing I use from the bladder to the engine is a product known as Theraband. This is a medical tubing which is made of Latex as well. Problem is, it will burn if exposed to exhaust. Routing your tubing away from the exhaust is a must. Any soft thin walled tubing would also suffice from your bladder to your engine. I like this tubing due to the fact the wall collapses easily unlike small fuel tubing.

Training the bladder is the next step. I hold it in my hand and make sure the bladder is filling at the back towards the knot. I do this with fuel in it and once filled, I leave it like this for a few minutes so that it will always fill the same way in the future. Once the bladder is full and the pinch off device is locked in position, prime the engine and flip. Once the engine fires off, release the line clip and all should stay running. Be prepared to pinch the fuel line if needed until you can adjust the needle. If the engine quits you need to readily pinch off the fuel as the engine is going to flood out. Then the problems start as you need to clear the flood and start all over again. Let us know how you make out Paul. Ken

Heman Lee · « **Reply #22 on:** August 08, 2012, 06:00:13 PM »

Quote from: Balsa Butcher on August 06, 2012, 06:21:08 PM

Go Electric?...and miss out on all that fun...Never! Actually Heman is quite accomplished in both electric and IC. Me, I'd rather fight than switch but have to admit that 1/2 A IC engines present many challanges.

I am still working on a 1/2a electric setup for my Half-Lite stunter. I met this father & son duo with a nice electric setup for the Li'l Hacker. Check it out:

Heman

kenneth cook · « **Reply #23 on:** August 08, 2012, 06:28:42 PM »

That electric setup would last until the first hit into the ground. I certainly wouldn't recommend trying to put electric on a combat plane if indeed that's your true intention. I know pilots that just like to fly these planes just for fun. Durability is number one. It would appear to me that even a mild midair would bend that prop shaft. I'm quite certain it would be neat on a stunt plane, certainly not for combat. I'd certainly like to know what that set up costs opposed to a Tee Dee or a Norvel. Ken

Brett Buck · « **Reply #24 on:** August 08, 2012, 06:45:24 PM »

Quote from: john e. holliday on August 08, 2012, 07:12:24 AM

I have heard the same stories about the COX reed engines. Yes sometimes they can get cantankerous, but with correct/good fuel, right prop and good battery, I have had little problems unless they have set for a while. Then it is only taking time to prime and flip.

When I was doing a lot of 1/2A flying (a very long time ago) I had no real problem with any of the reed-valves or the Medallion, other than the obvious starting backwards issue with the reedies. I didn't have a big problem getting reliable starts on the Tee Dee either, but not much luck keeping them running reliably in stunt on suction.

Bret

dave siegler · « **Reply #25 on:** August 09, 2012, 06:40:18 PM »

ask anyone one that flies combat. The secret is everyone overprimes 1/2a.

One small drop in the exaust blow it in and hit it. Start with the muffler off. no fues in the tank or bladder. Should be able to get a 5 sec run. If you can't you are overpriming.