RE: DL-50 engine
 

The carb is about 3/4" away from the firewall and I did drill a 3/4" hole in the firewall for extra room for the carb to breathe. The more I am looking at where the static port is and imagining how the air would flow through the cowling and where it all exits at the bottom I am thinking it is creating one heck of a vacuum effect on the port. When I started off the day I had it set where no matter how fast I gave it full throttle she transitioned instantly on the ground anyway and I was able to have a steady idle at about 1800 rpm.

RE: DL-50 engine
 

Well, for sure, George.... it's easy to do the static pressure thing, don't change anything else, and see what happens. If it doesn't fix it, then I'd tend to think you need work on that main inlet needle lever....one thing I always try to remember, is just to change ONE thing at a time....Keep us posted!

RE: DL-50 engine
 

Ya I need to root through my stuff here and see if I can find something suitable to solder onto it. What have you used?

RE: DL-50 engine
 

The best I do now aren't soldered. I use that alum tubing that is included in all the arf tanks that you can't really use. I remove the plate, drill the hole, carefully roughen the outside around the drilled hole. Cut about 3/8" long piece of the alum tubing, roughen it...gently tap (friction fit) into the hole just flush with the inside edge. Small bead of thin CA, little accelerator, clean, lasts forever.

You can do the soldering thing, too. 1/8" brass tube, silver solder. Use the edge of a dremel cutoff wheel to dress the inside so there's nothing protruding.

RE: DL-50 engine
 

I got er all soldered up. You'll probably laugh but I removed the tank from the cannister tunnel and removed the plug and borrowed a piece of brass tubing from that. Little extra work but then I don't have to run to the hardware store

RE: DL-50 engine
 

My engine has about fifteen gallons through it now. After having some trouble this morning I ended up "chasing the needles" all over the place until I realized the spark plug was loose. Tightened the plug, set both needles at 1-1/2 turns out, now she runs super. Could use a little more tuning, but I'm definitely in the ballpark. Don't know what the stock settings are.

RE: DL-50 engine
 

Factory settings are 1.5 low and 1.75 high according to the manual. I had to lean out a ways from there.

RE: DL-50 engine
 

I think my settings were probably pretty close at least on the ground anyway. I of course being the dummy because of putting one of those carb plates on and thinking I was invincible LOL. She would run great on the ground and transition great but as I would go to take off the faster I went the more it burbled and the same once it was in the air. It would reach top end after some burbling and the top seemed like it was alright. I was chasing an ignition problem also on trying to get the last start in. We had it running was getting ready to shut it off to make an adjustment and she died. Made the adjustment and went to fire it back up and for the life of me it wouldn't fire. So I checked the spark and there wasn't any. So I wheeled the plane to the front of the van to hook the charger up and the cellpro wouldn't pick it up so I packed it up and came home.

Once I got home and got everything unloaded I took the plane into the basement to work on it. I took my voltmeter and checked voltage and I should have a better memory but the voltage was 3.50 - 3.89 give or take a few. I am using an A123 1100mah on the ignition. Anyway I thought that can't be right and I didn't think I left the switch on and even if I did without the radio being on the only thing that draws current on that circuit is the little led on the switch and that would take hours and hours to draw down. I tried putting the cellpro on the charge jack and nothing. So I took my ice charger and put it on the power lead and set it for a 2s 1100mah lipo and figured I would let it charge a little bit to bring the voltage back up. I also move the ignition pack around wiggling it and what not. I only put maybe 100 mah in it with the ice charger. I put the cellpro on it and it is showing that it is 97% charged and charges it in like a minute. I'm thinking this can't be right, at least not for the voltage I was showing with the voltmeter. I pulled the shrink off of the pack and checked the soldering job. The bottom flat tab didn't look the greatest so I re-soldered it. It has been fine and I even discharged it and recharged and it is fine so I dunno if I fixed it or not. Just sucks because it was too many variables.

RE: DL-50 engine
 

hey tim,Thanks for the good advice bud,i havent yet figure out the CG im too slow i guess,i started the engine for the first time just about half an hour ago from this post,only to make sure the engine works ok on a lipo battery as Geppino sugested,that was so cool,i dont need to use a regulator there so thats great,im only a few tanks away from flying this beauty,i ran the engine no more than 15 or 20 seconds,LOL i know,i should of kept on going but it is too early in the morning here and i dont want to disturb the neighbors,i ran it in the garage,im just waiting for the sun to come out so i can go at it,anyway heres the pictures you asked me to post,yes i had them saved in my computer

RE: DL-50 engine
 

ok guys time to start another world war,:D why do we have to break in the engine?a well known pilot at the field flys a DA 150,he went strait to amsoil right from the very first run he says that it doesnt make sence to put wear on a brand new engine and he has been flying for several years now with no problems,anyway just something to discus i guess

bring on the popcorn :)

RE: DL-50 engine
 

You're kidding, right?
If you aren't, then we've failed somewhere between the first post and this one to cover what the instructions for the DL 50 state.

I'll be interested to see what responses surface on this one........:eek:

RE: DL-50 engine
 

If you haven't tied the sensor connector to it's mating connector from the module, you probably should consider it. The pics look like that connection is just laying on top of the engine box. It will bounce a LOT if that's true, and will likely unplug itself, which will create a deadstick on a Pitts.

BTDT, didn't like it, wasn't fun, cost some bucks.

If you have ANY kind of irregular running in flight near full throttle, you will likely need to cut a hole in the firewall. That looks uncomfortably close to me.

RE: DL-50 engine
 

It also looks like you have lots of "IN" openings in the cowling, but *NO* "OUT" openings. That engine will overheat as shown in the pics. That big half-circle flat spot in the cowling needs to be gone. And then, you may need to baffle the "scale" openings blocking them from letting any air in. I'd look at that pretty hard.

RE: DL-50 engine
 

For all of you having issues with your engine and other equipment. Get your setup right before flying! :D There are some very simple rules for rear intake gas engines:

[ul][*] Even if it seems there's enough space between the carb and the firewall, the firewall must have a hole in it to keep the air pressure around the carb even;[*] Some report issues with engine burbles, some don't. It doesn't hurt to mod the carb vent by soldering a piece of brass tubing to it and by leading some medium sized Tygon fuel line into the fuselage. I use a film roll container for a consistent air pressure and to isolate the gasoline fumes from getting into the fuselage;[*] Be sure to use regular 1/8" Tygon fuel line for your setup and keep the lines short. Use fuel barbs and cable ties on all connections. Besides fuel barbs, also glue the fuel lines inside the tank with some CA. Use a long piece of brass tubing bent to lay on the bottom of the tank for filling/draining and a Tygon fuel line with a piece of brass tubing in the middle and a clunk at the end for pickup;[*] The DL50's CDI is rated 4.8 to 6v so don't use a 2-cell A123 w/o regulator! In time it'll fry your ignition and can cause other undesired effects like a poor running engine. Simply solder a 1N5003 diode in series with the positive wire coming from the ignition switch. The 1N5003 is rated 3A and is good for a .7v voltage drop on idle to .9v full throttle which equals 5.9 to 5.7v. Your engine will run almost 2 hours on a single 1100mah 2-cell A123;[*] Use 87 octane gas w/o (m)ethanol for a regular, 89 for a tuned pipe setup.[*] Break your engine in with at least 3 gallons mixed with mineral oil 1:32 or if mineral oil isn't available in your area you could also use a decent synthetic oil mixed 25% richer than the manufacturer's recommendation and add 1/2oz of pure Castor per gallon. Use a 22x8 prop and 23x8 after the 3 gallons for a regular setup and 23x10 or even 24x8 for a tuned pipe setup. For 3D you want your rpms not to exceed 7200rpm;[*] For the first run set the needles to the manufacturer settings, fire the engine up, let it run for 5 minutes, cool off, fire up again and already start leaning the engine out a bit by carefully increasing throttle until it surges. Then open the LS needle 1/8 and let the engine run @2500rpm for 2 hours;[*] After the 2 hours, adjust HS for max rpm and back off about 200rpm. Slowly close the LS until the engine starts surging again then open it 1/8. Repeat these steps at least twice;[*] Run the engine for an other 2 hours 3500-4500 rpm or go fly circles;
[/ul]

Success guaranteed! Your engine will run smooth w/o burbles. A well adjusted engine needs to be choked frequently if it hasn't been running for over 30 minutes. If it always fires up on a days flying, the LS might be too rich.

Attached setup allows you to balance charge your ignition battery w/o taking the canopy off. I used the regular Ultraswitch II for ignition and Ultraswitch II HD for Rx.

RCU gives me an error message uploading pics. Here they are:

http://tweakshop.net/DL50-install/1.jpg
http://tweakshop.net/DL50-install/2.jpg
http://tweakshop.net/DL50-install/3.jpg
http://tweakshop.net/DL50-install/4.jpg
http://tweakshop.net/DL50-install/5.jpg
http://tweakshop.net/DL50-install/6.jpg
http://tweakshop.net/DL50-install/7.jpg
http://tweakshop.net/DL50-install/8.jpg
http://tweakshop.net/DL50-install/9.jpg
http://tweakshop.net/DL50-install/10.jpg

And an other tip: If you want to use a servo for the choke, use a nylon gear one because they'll withstand vibration better. I'm using the Hitec HS-81. Also remove the small metal retainer ball from the carb.

RE: DL-50 engine
 

thanks for the observation Bob,those pictures are from before i cut out the half circle,so thats done already,i did cut a 1"inch hole right behind the carb and the ignition connector has a clip to secure it from comming apart,the wire is not yet secured so yea i am going to strap it down so is not bouncing around,i pretty much know what im doing but do apreciate all the help i can get and thanks for telling me,im just too lazy to take anymore pictures but i will do that soon,i dont understand why that guy says he doesnt break in the engine when even a new car's engine has to be broken in,doesnt make sense but thats what i heard from a good friend at the field,i might want to speak to the pilot that he is talking about,i wouldnt fly the plane with out breaking in the engine though,i usualy follow the manufaturers instructions,that way it wouldnt void the waraty

RE: DL-50 engine
 

Those are good tips, evidently based on your experience. Also illustrates that there are many ways to accomplish the same result. Good info!
Certainly won't do any harm!

RE: DL-50 engine
 

What do you make of this?

Front bearing obviously. Engine was running perfectly yesterday, but quit in flight today. Dead-sticked no problem, then looked in the cowl and this is what I saw. Happened quickly because the engine had been super clean before.

Now, I just crashed the model this engine was in last Saturday and it is mounted on a replacement model I built this week. The carbon prop was broken, so I was concerned the crank could be bent (which would contribute to a failed bearing), but the engine ran smooth as silk (as far as I could detect) in the new model.

Do bearings just "go bad" all of a sudden? Or, do you think the crank could be bent (even if the engine seemed to be running fine and smooth)?

Is this something I can replace on my own, or are these things pressed into the case? I've replaced bearings in glow engines all the time (heat in the oven until it drops out).

Is there some "super" bearing I should purchase from somewhere else (like Boca Bearing)?

I'll contact DL USA, but in the mean time, just wonder what anybody has to say.

Thanks!

Tim

RE: DL-50 engine
 

Tim,

I'm sure getting a bearing will be no problem... Finding a machinist that can confirm that your Crank is straight is another story... LOL Seriuosly though you really need to have the crank checked for true before bothering with a bearing or the same thing will happen in short order..

Good Luck!

RE: DL-50 engine
 

Tim - my guess, although un-educated - is that the impact actually tweaked the CASE housing. You have alum wearing someplace... that wouldn't be what the crankshaft/center race would do.
I agree with Highbrass... the stud probably took the shot, the bearing tweaked the front crankcase half because it was at full operating temp, probably a little soft. A CF prop is a HARD ass piece of stick to leverage on a 11-12" moment arm against that stud.

I hope that I'm wrong, but I would not replace just the bearing.

RE: DL-50 engine
 

Probably best thing then is just to send it in. Is DL USA pretty good and can they confirm if the crank and/or case is tweaked?

Here's another scenerio; I shimmed both standoffs on the left side of the engine with 1/32" plwood disks to add in more right thrust. Do you think this could "tweak" the case?

Tim

RE: DL-50 engine
 

I have always been told to make thrust shims only at the firewall end of standoffs. Is that where you shimmed? If not, it is possible, I suppose, that the hit would have tweaked the rear case, too. I hate to speculate on this stuff... I don't have first-hand experience of this type of damage on a multi-part crankcase.

I've been on this thread since it started, and I honestly can't remember anyone reporting a crash/prop breakage impact and what they experienced. You may be the first to share the learning on this one.

Please keep us posted.....

RE: DL-50 engine
 

Yes, the shims were at the firewall-end of the standoffs. And like I said, just 1/32" thick. I did not have these shims on the model that crashed - just on my new model that the DL is mounted on now.

Hey, we can speculate all we want - I guess that's what I'm asking for. I'll end up sending it in to DL and, (if they are good) they can once-and-for-all tell me what is the problem.

Thanks Bob!!! :D

RE: DL-50 engine
 

Yes, the shims were at the firewall-end of the standoffs. And like I said, just 1/32" thick. I did not have these shims on the model that crashed - just on my new model that the DL is mounted on now.

Hey, we can speculate all we want - I guess that's what I'm asking for. I'll end up sending it in to DL and, (if they are good) they can once-and-for-all tell me what is the problem.

Yes, that black deposit is oil mixed with aluminum (black/gray = aluminum, right?).

Then, it makes sense that the engine still seems to run so smooth (if the crank was not bent) but the case is tweaked.

Hmm, I could chance it and just buy new bearings and case rather than sending in to DL.

Bob, are those bearings easy to get out?

Thanks Bob!!! :D

RE: DL-50 engine
 

Yes... once you have all the crankcase parts disassembled... but... you probably do not have the right hub puller to get that off...and...even if crankcase and bearing were replaced, if the crankshaft has been tweaked - even just a little - you'll be back where you are.

I had a BME impact the earth once. Front end was wooden prop, and it was about at 1/3rd throttle when it hit....tweaked the crankshaft nicely. And needed bearing, too.

RE: DL-50 engine
 

Well that's it then. I'll have to send it in.

My wife is going to love this one. Just got a brand new DL for my Edge, now have to send in my other one. Well, at least we know what happened - the crash tweaked something. Makes sense. Otherwise, the engine has been running superbly.

Sigh.

Already emailed DL USA (Bob). Maybe he'll reply this weekend yet.

I'll keep you all posted on the findings.