craigteffe

My Feedback: (24)

I don't use a choke servo or the other throttle kill crap, just something else to buy or to go bad just program a switch to bring your throttle all the way back when you flip that switch. This eliminates the weight and another device you have to purchase. Use the KISS method(KEEP IT SIMPLE STUPID).

BOUND_4_HELL

Hi doublesixes,

In my case I had a lot of midrange miss-fires and burble, but the engine never quit. My Pitts is not 3D, but I do tumble it a lot. I do not think that running a little rich is going to harm the engine and if it keeps it from flaming out, you may want to leave things alone.

Here is a procedure that I have come across, for tuning the Walbro carbs, I'm not sure what four cycling is, so I have never tried it.

Geppino

__________________________________________________ __________________________________________________ _

(1) The low end needle on a Walbro carb is ALWAYS the one closest to the engine, the high end needle is the closest one to the intake/choke.

(2) There is no fuel adjustment for idle fuel, only air feed set by the idle stop or servo.

(3) Both low end AND high end needles feed the top end fuel supply.

Let's tune up a Walbro:

Set the low end & high end needles to about 1 to 1 1/2 turns each.

Choke the carb or prime it, until the carb is wet.

Fire up the engine and let it warm up.

Let's set the top end first since it's the easier of the two.

Go to full throttle, and adjust the top end needle for peak RPM.

Leave it wide open for about a minute to see if it changes any.

Should the engine go lean, open the low end needle slightly, if this doesn't work... you will have to adjust the needle valve inside the carb.

If the top end runs OK, then slowly pull the throttle down until the engine begins to "four cycle" hold the throttle there.

Adjust the low end needle until the "four cycling" stops.

Now lower the throttle more until it "four cycles" again, and adjust the low end again.

Keep doing this until you reach full idle.

Now, from full idle begin to throttle up until the engine starts to bog or hesitate.

Open up the HIGH END NEEDLE just enough to eliminate the bog or hesitation.

When this is done right, you will be able to set the throttle in any position and it won't four cycle, plus you will be able to transition from idle to full power without any hesitation at all.

BOUND_4_HELL

Hi Switch26

I started out flying electric park flyers 3 years ago and I have a lot of LiPo's just sitting in an ammo box, I now use LiPo's for every thing. One cell LiPo for ignition and 2-cell LiPo regulated down to 6 volts for the receiver.

If you are not comfortable de-soldering LiPo's, so you can use one cell, you can buy one cell LiPo's here.

http://www.maxamps.com/index.php

MaxAmps sells loose one cell LiPo's from 430 mah to 5000 mah.

I have a 4200 (two 2100 in parallel) on my DL 50 ignition (See photo) and a 4000 two cell regulated on my receiver, running the electronics on my Pitts and no worries of letting them sit for a week and then going flying. LiPo's keep their charge a lot better than NiCad's or NiMH. An now for the real bonus even though they are 4000 mah both are still lighter than the 1800 to 2500 mah 4 an 5 cell NiCad or NiMH that most people use.

I have been running my DL50 on a one cell LiP0 >> 4.2 V << (2 – 2100 in parallel) from the moment I first started the engine. I have over 60 flights and no problems. The engine has never flamed out on me. I have run the ignition battery down to 3.3 V with no discernable performance issues.

I did some research on ignition voltages after I fried my Fuji ignition module when my voltage regulator shorted that was regulating a 2 cell LiPo. I decided to try the one cell LiPo and eliminating the regulator after reading the following test done by CH ignitions. The DL50 use the same ignition modules as CH Ignitions.

Bound_4_Hell
Life should NOT be a trip to the grave with the idea of arriving safely in a well preserved body,
but rather to skid in sideways, a Rum and Coke in one hand, a joint in the other,
body thoroughly used up, totally worn out and screaming "WOO HOO what a ride".



__________________________________________________ __________________________________________________ ______

I just have done some battery drain tests.

All tests were done at 8000 RPM. .A new single cylinder, Version 2 CHXL Ignition.
7.2 Volts -725 MA
7.0 Volts -675 MA
6.0 Volts -650 MA
4.8 Volts -475 MA
3.7 Volts -375 MA
3.0 Volts 300 MA
2.5 Volts 250 -MA
2.0 Volts - 175-MA -Weak spark, Do not know if engine would run, probably not.

Under 2 volts Ignition dead. Ignition still working but Hall Effect dead. We have done test runs and the engines run fine down to 3.2 Volts. Why use any thing over 4.8 volts. Three Nickel Metal Hydride would probably be OK. 3.6 volts.

You can find the whole document here. It’s called “ STUFF WE HAVE LEARNED “ From CH Ignitions.

http://www.ch-ignitions.com/tech.html#pwr

switch26

My Feedback: (1)

very nice Geppino,i thought you were running a 7.4 pack (2s1p)lipo,cool then i guess ill get rid of the regulator for the ignition,im going to be running a 2600 pack ill have to desolder it and make it a (1s2p) this way it will be a 4.2 cell,i've never liked to use so many gadgets is just another thing that can cause problems,thanks for the info,i thought you had to run more then four volts on the ignition,i like the gas engine more as i learn more about it,well as of right now i already did all the cut outs on my cowl,need to smooth out the cuts and do very little adjustmens but it is all pretty much done,it was very tricky but i am happy with the results,now if i only knew how to upload the pictures for everyone to see i would but i'll have to figure that out,LOL i still need to make the tamplates and make the plates for the choke and the ignition so i can mount them but im going to take a little break on this,im a little stressed out (brainstom)LOL from all that work now if i can upload some pictures at least some of the other GP pitts owners can see how it was done and hopefully wont waste a perfectly good cowl like i almost did,i got lucky and it all worked out but i wish someone with the same setup i have would of posted pics of all the cut outs on the cowl wink wink Geppino,LOL

craigteffe

My Feedback: (24)

Switch,
It looks as though your plug wire is rubbing on the bottom of you cowl, you will want to tie that up or remove some more of your cowl or it will rub a hole thru your plug wire. I had the same issue once. The air and vibration from the engine will make this happen very quickly, you add to that the sand paper feel of fiberglass.

Just my .02.

Hibrass

My Feedback: (1)

Great info so far...

I'm expecting my DL50 this week! It will be my second gasser and it will go into my new Yak55 that should be here this week also! This should be an exciting week!

I did plan to use a small Elite 1500 6v pack for the ignition but there seems to be some inconsistancies on whether or not the ignition will handle an unregulated 6v Pack??? Are there 2 different ignitions with different standards??? Or should I just plan on using a 4.8V pack?

Thanks,

Ed

switch26

My Feedback: (1)

Thanks for the observation Craig,ill see what i can do but the plug wire is really not touching at all,it is a bit close to the cowl but not touching,it has about 1 to 2mms of clearance but i will pay close attention to that,the wire is just hanging since i haven't mounted the ignition just taped it into plase for all the cut outs to be done,i mounted the cowl just for the pictures and to see what els might need to be adjusted

Ed
take a look at this post,i was going to use a 7.4 volt lithium ion pack with a regulator to step down the voltage to 5 volts for the ignition but Geppino changed my mind,read his post here http://www.rcuniverse.com/forum/fb.asp?m=7831378 previews page,i wouldn't run 6 volts even regulated might damage the ignition since it is suposebly the highest voltage the ignition can handle,if you dont want to run lithiums then i would sugest a 4.8 pack but even the 4.8 pack can reach a higher than 6 volts fresh out of the charger

Hibrass

My Feedback: (1)

Switch,

Thanks for the info! I will just stay with the 4.8's that I have.. Simple and they work.. I will just have keep in mind that I'm using to different chemisties on the bird... :-)

Ed

switch26

My Feedback: (1)

dont mention it,now another question for the board,what prop should i get for my pitts?the prop in the picture was mounted only to take the picture and will not work on the DL 50,it is a 20x10 and i wont use it,it was given to me,i think i want to stay with wood props but im not sure what brand to get or what size,seems most everyone is using diferent ones but i would like to get the ideal one for the application,also do i need one for break in and another for flying?

BOUND_4_HELL

Hi Ed,

If you really want to use the 6v pack you can solder a couple of diodes in series with the positive lead. Each diode drops the voltage down 0.7 volts.

On the other hand the higher the voltage the higher the power consumption, and the faster your battery will drain.

The CH ignitions are the same a s the DL ignitions, and you still get a good hot spark with only 3.5 to 4 volts, just make sure that the gap is correct on your spark plug. 18 to 20 thousands max.

Below are the test done by CH ignitions………..

Bound_4_Hell
Life should NOT be a trip to the grave with the idea of arriving safely in a well preserved body,
but rather to skid in sideways, a Rum and Coke in one hand, and a beer in the other,
body thoroughly used up, totally worn out and screaming "WOO HOO what a ride".


__________________________________________________ ____________


CH ignition bench battery drain tests.

All tests were done at 8000 RPM. .A new single cylinder, Version 2 CHXL Ignition.
7.2 Volts -725 MA
7.0 Volts -675 MA
6.0 Volts -650 MA
4.8 Volts -475 MA
3.7 Volts -375 MA
3.0 Volts 300 MA
2.5 Volts 250 -MA
2.0 Volts - 175-MA -Weak spark, Do not know if engine would run, probably not.

Under 2 volts Ignition dead. Ignition still working but Hall Effect dead. We have done test runs and the engines run fine down to 3.2 Volts. Why use any thing over 4.8 volts. Three Nickel Metal Hydride would probably be OK. 3.6 volts.

You can find the whole document here. It’s called “ STUFF WE HAVE LEARNED “ From CH Ignitions.

http://www.ch-ignitions.com/tech.html#pwr

BOUND_4_HELL

Hi Switch26

Opinions on prop selection and manufacture vary a lot, and you will get 5 different answers from 5 different pilots.

You can break your engine in with a 22x8 and then fly with it or you can replace it with a 22X10 or a 23X8.

I like Xoar props, as they are very good value for the money. But Vess, Menz, Mejzlik, Bolly, NX, JXF, are all good as well, you will get higher RPM with Vess and Mejzlik, but I'm not sure how the thrust is. I can tell you that Xoar pulls like a bat out of hell. Even with the added drag of a bi-plane. I clocked my Pitts with a radar gun in straight and level flight at 95 MPH with a Xoar 22X8 .

I cannot tell you where to buy all the different props, but I can give you a web site for Xoar, they ship fast and have good prices, you can also pick up a couple of spare spark pugs for $7 bucks a piece as they are hard to find.
http://www.thunderboltrc.com/

Here is what I got with Xoar on the DL 50. The thrust readings may or may not be accurate, as I'm using a 50 lbs digital fish scale and did not verify its accuracy with dead weights. Also the digital fish scale bounces around within a ¾ lbs range ( it's not a steady number) I post the reading in the middle of the range.

The two readings can be compared to each other, as I measured both props the same way.

With Xoar 22x8 was turning 7200 and pulling 25 lbs of thrust @ 1200 ASL and 74 F
With Xoar 23x8 it's turning 6700 and pulling 26¼ lbs of thrust @ 1200 ASL and 74 F

My RC Guys Pitts with the DL50 and 22x8 Xoar combo is faster, but the 23x8 Xoar has better up lines.

With the 22x8 the DL50 engine accelerates a bit faster, but the 23X8 idles better.

Another thing I notice is that what I thought to be engine exhaust noise with the 22x8 turned out to be prop noise. The plane is noticeably quieter with the 23x8.

All in all I like the 23x8 better on the DL50 Pitts combo.

Bound_4_Hell
Life should NOT be a trip to the grave with the idea of arriving safely in a well preserved body,
but rather to skid in sideways, a joint in one hand, and another joint in the other,
body thoroughly used up, totally worn out and screaming "WOO HOO what a ride".

switch26

My Feedback: (1)

Thanks Geppino,i am going to get a Xoar 22x8,i guess it is all personal preference,kinda like the ford vs chevy kinda thing but i am looking for a good durable prop thats not going to bog the engine,i do want power and speed all together thats why i thought is better to ask since im new to gas,ill order a couple plugs just to have on hand,sorry,im full of questions but i guess it doesnt cost anything to ask,LOL,what oil to get for break in and for flying,and also,i dont really understand what the mixing ratio is,or how it works,when they say 30:1 ratio does that mean 30 parts gas to one part oil?im confused here,Thanks in advance Geppino,you've been alot of help Buddy

cavandish

'bog the engine' just wait till you fire it up for the first time !

OldRookie

My Feedback: (13)

Hibrass,

Here is part of the paragraph partaining to voltage from the DL50 manual.



IGNITION SYSTEM

The DL50 ignition system is designed for input voltage ranging from 4.8 to 6.0 volts, no more and no less. A battery pack of 1200mah or greater may be sufficient for a day of flying for most users. Check your battery voltage with a voltage meter before every flight and do not fly if the voltage is not between 5.2 and 6.0 volts; the voltage at the start of a flight may not remain for the duration of the flight. Disconnect the battery from the ignition system while charging the battery. The ignition module should be connected to the battery through a heavy duty switch, mounted where it can be reached easily when starting the engine.

NOTE: A 6 volt or larger battery pack must be regulated to between 5.2 and 6.0 volts or it will supply too high a voltage to the ignition module.


If you check here, from the Rcex site, it is telling you that you can use up to 7 volts. This is listed under input voltage in the specifications. It also lists the type of resistor to use to drop voltage.



http://www.rcaerobats.net/GAS_ENGINE...onInfo-v.2.pdf

Greg

elderair

My Feedback: (29)

Got my engine today and looks fine. Has a little inclusion in the casting of the cyl right in the transfer port so I hope it doesn't go all the way through the casting. Just awaiting the arrival of the 80" Katana to put it on. I am using a TBM 7.4V 2cell LiOn pack for the ignition on my DA with a 4.8V regulator. Just what I had laying around. I thiink a 1500 mah 4.8 NiMh pack would be fine and I have used them before on other gasser ignitions I have had. Just that the LiOn makes it easy for me to remember what batt. type I have in the airplane. Just plug three leads of my Powerflite LiOn charger into the three charge switches on the plane and let it go.

Hibrass

My Feedback: (1)

Greg,

It doesn't get anymore straight forward than that...

Thanks,

Ed

OldRookie

My Feedback: (13)

Hibrass,

I just fogged it up a bit.
I edited my original post with a shortcut to the Excel site.
Check it out.

Greg

Bob Pastorello

My Feedback: (198)

A diode voltage-dropping arrangement is much better than resistors. Resistors are power-consuming devices, and reduce voltage based on current flow through them, which also varies based on temperature. A diode is a better solution, as reverse-biased, it consistently "reduces" by .7v across it's P/N junction, up to the full amperage rating of the diode, and regardless (essentially) of the input source voltage. It also will be nearly unaffected by temperatures (within it's rating), and although it isn't regulating the output voltage (neither is a resistor), if the source voltage is relatively stable, then the output after the diode is equally stable and consistent with it's .7v drop.

All in what you want to wire in there.

After using regulators, I will stay with diodes.

switch26

My Feedback: (1)

LOL,i know that i just had to say it,LOL but i'll be fine with a good quality prop,it will still take me some time to maiden this popy,still need some items to finish and lets not forget the radio programing,im going abit slow on this project i know but is coming along just fine,i wouldn't want to rush into things and run into a bunch of problems,it'll get there,just give it time,ill be posting some pictures as soon as i finish it and if posible i'll do a short video of the maiden flight,if i only got my but off the computer things would go alot quicker

BOUND_4_HELL

Hi Switch26,

If your inclined to start world war three, then the oil question is a good bet. As far as oil goes, opinions vary more that props and pilots are very passionate about their oil. If you asked a 25 pilots you would get 25 different answers.

Here is mine opinion, does not mean that it’s correct, its just what I use.

There seems to be a consensus on the type of break in oil, but even here you will get some variations. Some will say to break it in with synthetic and stay with synthetic throughout the life of the engine. I personally do not buy into that argument.

I believe the consensus for break in is with Lawn Boy ashless mineral based oil. In my case I could not get a local supply of Lawn Boy oil, so I used a good quality mineral based low ash oil. I ran 5 gallons of fuel with the mineral oil at 30 to 1. ( 30 parts fuel to 1 part oil) I find it easer to convert gallons to ounces and then divide by 30 to get the correct amount of oil.

After break in …….. this is how I believe WWIII will start.

In my humble opinion the only mineral based oil good enough for our airplane engines after break in is Pennzoil 2 stroke oil, rated TC. Don’t confuse it with the general purpose Pennzoil, it has a different ratings. Having said that, I also strongly believe that synthetic oil is far superior to mineral based oils.

As far as synthetics oil goes you will get a lot of different answers as well. A lot of synthetic oils are not 100% synthetic, most use some mineral oil as a base stock. If you are going to use one of these, you might as well use Pennzoil.

AMSOIL 100:1 Sabre oil is good. A few of the guys use it at my field with good results. One word of caution with 100:1 AMSOIL Sabre, it needs to be mixed at 100 to 1 NOT 50 to 1 or 80 to 1. If it’s mixed lower that 90 to 1 you will get piston ring sticking and all kind of nasty things will happen including broken rings. It goes against the grain, but in AMSOIL Sabre’s case a little more oil will do more harm than good.

I was going to use Sabre, but because of the mixing problems I did some research and came up with RED LINE TWO STROKE RACING OIL, based out of California, as it’s the oil used by the racing pros in cart racing and 2 stroke bike racing. RED LINE TWO STROKE RACING OIL uses ESTER base stocks that provide the oil with extreme stability at high temperatures and superior film strength. ESTER based oils are used in Turbine engines ( they run really hot) and are fully 100% synthetic. And in my opinion are the most expensive and best base oil stocks money can buy, witch gives Red Line Oil the high-temperature stability that prevents deposits in the hottest upper ring and piston crown areas of our two stroke airplane engines and far superior lubrication for the rings and bearings.

Here is the bonus >> RED LINE 2 STROKE RACING OIL can be mixed from 16:1 to 100:1 without any problems, most people use it at 50 to 1. I personally mix it at 80 to 1. That’s how much I believe in this oil.

There is a few 100% synthetic oils out there, that are good enough to use in our 2 stroke engines, but you will need to do your homework to chose one.

That’s my .02 cents. Hope it helps with your selection.

Bound_4_Hell
Life should NOT be a trip to the grave with the idea of arriving safely in a well preserved body,
but rather to skid in sideways, a beer in one hand, and a Rum and Coke in the other,
body thoroughly used up, totally worn out and screaming "WOO HOO what a ride".

Bob Pastorello

My Feedback: (198)

whoo-hoo!!!!!!!
I'm starting the popcorn!

OldRookie

My Feedback: (13)

Bob,

Weren't you running a DL50 on one 2400 A123 nano phoshphate battery for ignition and the receiver?
I thought you didn't run any resistors/diodes in the battery pack wire on your original set up.
Are you reducing voltage on the A123's, to the ignition?
Are you still running one battery?

Greg

krproton

Well, now I gotta ask...

Why does it say "mix at higher ratios if desired" and why is there a 50:1 ratio included in the chart on the bottle? I'm not contradicting you, just wondering why this is?

Thanks if you know!

Tim

BOUND_4_HELL

Hi Bob,

Thanks for the laugh.

I’m betting you were keeping an eye on this thread, to see who was dumb enough to answer the oil question.

I’m a bit of a pyromaniac, and sometimes I like to stoke the fire till it gets nice and hot.

Geppino

switch26

My Feedback: (1)

Thanks for the explanation Geppino,i remember many years ago a friend used to fly a gaser heli on redline oil,he was very happy with the results but i wasen't sure if that would be ok to use and most of all i wanted to get some opinions but as you said world war III has now been started,im gonna try to find some lawn boy for break in and soon as i finish the break in im switching over to redline,ill have to figure out the mixing ratio but shouldnt be hard to do 50 to 1 should be just fine but ill have to experiment as long as i stay with in the recomended mixing ratio so i dont damage the engine.

hey Bob Pastorello
pass the popcorn Bro,