jclark4x4

My Feedback: (23)

I would appreciate any and as much info on Gas Airplane engines anyone wants to give me...Once I have the engine picked out for the plane, what do I need and how do I do it...I have always flew 2 stroke glow engines, now that I am flying more 25% with Mokie 1.8 and O.S. 1.60FX, my money goes to the fuel costs. Do you have to have and ignition system? Basicly, I want to set the planes up with Gas engines with the most efficient and cheepest ways possible. I would appreciate any and all advice you can give me. Thanks, Joel

Dr1Driver

I've used Zenoah engines on standard ignition. They are not the lightest, nor the most powerful, but the are very reliable, user friendly, and cheap.

Gas engines need a longer break in time than glow. Run at least a gallon through it before flying. Use a good 2 cycle oil at the manufacturer's recommendations for break in. I then switch to Amsoil at their recommended 100:1 or 75:1 ratio. Amsoil lubes well and burns cleanly. Use the same prop to break in as you will use to fly. Be careful tweaking the HS needle. Gas engines will get very lean without you knowing it.

Any good electric starter will spin a 25cc gas engine. I've used a Bennett's recoil starter on a 38cc and it worked great, too. You CAN hand prop them, but I don't recommend sticking your fingers into the prop arc, even for flipping it over. The electric starter or recoil starter will spin the engine fasst enough to give you reliable starts. Gas engines like to start "wet", somtimes with fuel actually dripping out of the carb throat. They start at idle, just like glow engines do.

A fancy 6 bolt prop hub is not necessary unless you're running a VERY big engine and prop. I've like to used a "cup" engine mount and a flat firewall mounting plate. Both work well. I've never used vibration isolation mounts, and in the smaller sizes, don't think they're necessary. Be sure to balance the prop well. ALWAYS use a kill switch. This grounds the primary of the coil and prevents accidental starting. Remember, a gas engine is ALWAYS ready to go. You can also use a servo-driven kill switch, but I've never found it necessary. Killing the engine by closing the throttle is chancy. Gas engines idle erally slowly.

You can use the stock muffler provided with some engines, or go with whatever you need to fit your installation. Gas engines do not need fuel tank pressure like glow engines do. Gas engines are also not picky pertaining to tank placement. The Walbro type carbs used are "pumpers" and will pull fuel from quite a distance. And speaking of carbs, DO NOT take the carb apart unless you REALLY now what you're doing. Compared to our simple glow carbs, these little gems are rocket science. Lots of small parts and some pieces that must be properly orientated.

That should give you a good start. Keep asking questions. Gas is a lot of fun. Bigger planes, more user friendly, no flameouts, reliable idle, good torque, and CHEAP to operate.

Dr.1

OLD_SLOW and in the WAY

an easy way around any start support equiptment is get the Zenoah Heli engine woth a prop hub adaptor or just get the start pawl and add a pull start to the G26 and you now have a plane that is safe to start by your self. straddle fuse lean over wing and give her a yank in two pulls your runnin. i have set up a couple G26's this way for guys and they will never go back to flipping props. the starter only weigh a few ounces and will not get in the way of the zenoah back mount plate

Josey Wales

My Feedback: (61)

Thats the exact opposite from what Ive been told..When I spoke directly with DA they said not to bench run the engine but rather just set the needles on the ground and fly it to break in. Maybe Zenoahs are different ?

Dr1Driver

Maybe. I know both my G-38 and G-23 had to break in before they'd stop throwing little specks of black oil out the exhaust. After running a while, the exhaust came out clean. Both engines increased power greatly after a period of break in, on the bench and in the air.

Dr.1

jclark4x4

My Feedback: (23)

not sure If I understand everything...So I have the option of converting to a pull start... If I wasn't to do that, how else could I set the Zenoaha G26 up? Can I just buy the engine and set it up with a kill switch? do I need something to light the spark plug like the 2-strokes need? Thanks for all the advice but keep it comin guys. Joel

Josey Wales

My Feedback: (61)

You can either get a spring starter, have it converted to elecric ignition or use a electric starter..

You should always have some kind of kill switch I have a choke servo and I have my TX set up to kill the throttle by flipping a switch..

Look up rcign here on rcu he knows everything about Zenoahs

OLD_SLOW and in the WAY

the spring starter( BEnnett sels them) is probably the best start unit you can get... maintains the stock magneto ign and set up right you are only a few flips from flying. mine is 8 years old or better with more than 400 flights and all it takes is a once a year greasing and a few drops of 3n1 oil every now and then

dragoonpvw

My Feedback: (7)

Joe, you don't need anything except the engine and gas, a kill switch is recommended and if you go the zenoah way it has a self contained and self powered ignition. That is called a coil ignition. Other gas engines have a seperate electronic ignition which needs a battery (3w, zdz, da etc.). I use all types but I would use zenoah if they were right for my planes, as they are very easy to use, unfortunately they rarely fit my needs as I need them to fit in cowls or need high power to weight. You need gasoline type tanks and fuel lines and a good gas can and pump. Gas damages glow type hardware. You can start most engines by hand, you need to use a protective glove , I get mine from home depot, it is a welders glove and has padding on the back of the hand where it is needed, you can also use an electric starter but a gear reduction or the big megatron is needed for above 38cc or so.
What size and type of plane are you flying as that wil determine which route is best for you.
Good Luck
Paul

karolh

Hi jclarke4x4

Welcome to the world of gas engines, where you fly all day for pennies, no more needles to fiddle with, no more dead sticks and above all no big mess to clean up after an enjoyable day's flying.

Very good information and advice being given you by the guys on this forum who were most helpful in assisting me during my transition period.

To date all my gas engines have been the smaller sized Zenoahs. Though not the lightest or most powerful, they are possibly the most economical and their reliability and ease of operation certaintly helped make my transition from glow to gas as painless as possible.

The addition of a recoil spring greatly aids hand starting but adds weight and requires periodic maintenance. The stock mufflers supplied with the engine make for a very quiet exhaust noise but do cause quite a loss of rpm, so unless your flying field has a strict noise level rule, a good quality aftermarket muffler is best for optimum engine performance.

More importantly however might be the size and type of model you wish to gas power, as gas powered models are set up different for glow models primarily due to the weight of the engine up front.

Planes that are best suited for small economical gas engines range from about 11-18 lbs in weight depending on the design and type of model.

Once you go gas I'm quite sure you won't want to return to the expensive and messy world of glow power.

flier

My Feedback: (7)

Get a Wild Hare 28% Extra and a DA-50R.
Best money you'll ever spend on a plane.
Call or E-mail Tom and ask all you want.
He'll treat you fair and honest.
Best setup for the "new to gas" group.

http://wildharerc.com/

Do a search on this comp. and plane.
You can't find a better flying setup for the price either.

sillyness

My Feedback: (25)

If you put a zenoah on the planes you have you will be sorely dissapointed... they won't fly anything like they have been with the 1.80 or the 1.60... they are just TOO HEAVY!!!

Look for light... it will cost initially though.

Also... PLEASE don't run your motor on the ground for any extended period... it's horrible for them.

Dr1Driver

If you put a zenoah on the planes you have you will be sorely dissapointed...

I STRONGLY disagree. The ARE heavier than a comparable glow engine, and DO have less power, but the benefits by far outweigh the drawbacks. BTW, they WILL swing a larger prop.

Also... PLEASE don't run your motor on the ground for any extended period... it's horrible for them.

Ah...I believe Zenoah recommends an extended break in. I've run both of mine in on a test stand mounted about 18" above the ground, and they show no ill effects from it.

Dr.1

SitNFly

My Feedback: (54)

Get the book "Gas Engines Giant Planes" from Don's Hobbies. Excellent introduction to gas planes and will help you avoid a lot of common mistakes.

GRANT ED

I reciently bought a Zenoah G-62 (also my first gasser) for a wildhare edge. In the manual it states and this is word for word.
'No specific break in is required. The engine is gradually getting breakin as it is used and the output is also increased gradually". I really like the Japanese to english conversion

Whistling Death

Sorry dude but Zenoahs run for years after being broken in on the ground. It is ludicrous to think you can't run them on the ground. That is the beautiful thing about Zenoahs, they can be tortured as where other engine of the same size can't handle the pressure.

Rcpilot

My Feedback: (78)

Zenoah engines are reliable as hell. They are also the cheapest commercially produced engines out there. They may not be the fanciest, or the lightest, but they were around long before DA, ZDZ, or Brison ever came onto the scene. And they will be here for a long time to come.

Most of the BS you read from people about Zenoah engines being weak on power, or too heavy, are from people who've never even had one. They are just repeating the same old crap they've been reading and listening to for years. Never actually owned a Zenoah engine though.

I guess it depends on how much money you've got to spend. If you can afford it, then get one of the new lightweight engines with electronic ignition and go fly. If money is tight, then buy a Zenoah and fly it stock for awhile. Save your pennies, and eventually, you can buy another muffler for it. That will improve performance. Then, if your so inclined, buy an electronic ignition for it later on down the road. That will make it easier to start, and it will help to lighten the motor a bit. You'll still have less money invested in the Zenoah than one of the expensive engines. And it will run just as good.

You'll need to get a gas can, and a pump for gas. You'll have to pick a 2-stroke oil for your engine. I personally run Husqvarna chainsaw oil in my engines, but really, oil is oil. So long as you put the oil in the gas, and mix it up according to the label on the oil bottle--you could literally buy the cheapest 2-stroke oil off the bottom shelf at the Wal-Mart store. You don't need synthetic oils, or fancy oils that cost $10 per quart. My Husqvarna oil costs me $15 per gallon, and I use it in my chainsaw, weed eater, and my airplane engines. Haven't cooked one yet.

You'll need to learn how to adjust the carb on a gas engine. The neeldes are much more sensitive than a glow engine. 1/4 turn rich is going to be REALLY, REALLY stinking rich. Most guys make adjustments about the thickness of the screwdriver blade, and then see how the engine sounds. Adjust in small increments. My gas engines do not react instantly to needle adjustments like a glow engine. Make an adjustment, and wait 2 or 3 seconds before you do anything else.

You adjust the high speed needle first. Lean it to max RPM, and then back it off about 200RPM. Now lean the low speed needle untill it reaches max RPM. Once you go to far, it will slow down or die. Just back the needle up about 1/8th turn and restart the engine. I set my low speed at max RPM, and then back it up about the thickness of a screwdriver blade. Then, go back and check the high speed needle again. I've found that if I have to do a lot of adjusting (leaning) on my low speed needle--it will effect the high speed, and I'll have to go back and richen it a bit. Make sure that you go back and double check it to make sure your not lean, or right at max RPM. You still want to run a gas engine a little rich, but not like a glow engine. Glow engines lean out as the tank gets empty, because of the lower pressure when the tank is running out of fuel. Gas engines have a pump in the carb, and it doesn't care how much fuel is in the tank. It pumps the fuel untill the tank is dry. So, just run it about 200RPM short of peak, and go fly it. If the engine surges at high speed, it's lean. Richen it untill the surging goes away, and the richen it untill it just barely slows down.

You won't be using muffler pressure on a gas engine. Remember that carb that pumps fuel? But, you'll need to vent that fuel tank so that it doesn't collapse from the carb sucking all the fuel out of it. Just run a brass vent line in the tank, as normal. And run that fuel line back up and around the back of the tank. Then run it forward, and punch it out the bottom of the plane. By running the vent line around the back of the tank, you will prevent fuel from dripping out if the plane is tipped up on it's nose on the bench. Gas can't run uphill.

You'll want to keep your servos, RX, battery, and your ON/OFF switch 12" away from the engine. These ignition systems can sometimes put out interference. It's commonly refered to RF interference. So long as your RX, and all the servos and switches are 12" or more away from the magneto or ignition unit and ignition battery, you should be fine.

You'll want to do a good range check on the plane before you fly it. Range check it with the engine off. Then start the engine and do the range check again. Run the engine at various throttle settings while your doing the range check. You should not loose much range with the engine on. It it glitches or jumps around--you got an RF problem, and you need to find it and fix it before flying the plane. It won't go away in the air. It will get worse, and you'll probably crash the plane.

Don't use any metal clevis' to connect your throttle to the engine. Gas engines vibrate a lot, and a metal clevis on the carb is going to cause problems. I use a 2-56 or 4-40 ball link and socket. As long as you've got a plastic connection at the carb, so that it can't vibrate metal too metal, you should be fine. It's okay to use a metal pushrod, just don't use a metal clevis on the metal carb arm.

Gas engines are heavier, so you'll be putting the RX and some servos farther back to achieve balance. Your wing loading could be higher, depending on the plane you choose for your first gas engine. Be prepared to fly in a little hotter for your landings.

If your hand flipping--get a good heavy duty leather glove. Hand flipping a gas engine without a glove is kinda risky--especially for a beginner. You can dump the glove once you get familiar with your engine and it's starting procedures. But, I'd strongly recommend a good leather glove or a big chicken stick for your first season. First time you get whacked on your bare knuckles from an 18" or 24" prop--you'll know what I mean.

Everything is bigger and heavier with a gas plane. Your 2-56 pushrods are not good for anything but a throttle cable anymore. You'll need 4-40 pushrods on the control surfaces now. Start buying heavy duty hardware. These planes are big and dangerous. You don't want to kill someone or put an airplane through the windshield of a car going down the highway because you skimped on the hardware and lost control of the plane.

Good luck.

jbflier

I simply purchased a 19 volt Sears (or similar) cordless drill and a Sullivan Megatron cup/insert from Sullivan direct ($62.95 UPS Collect) and voila. Works on a G-62+ with no effort.......

LSP972

My Feedback: (13)

Joel, I recently got a "gas" set-up, after years of flying glow.

From your post, I assume you're flying aerobatic models in the 70"-80" wingspan range.

Of course, the variables are infinite, but if you are looking for super performance (3D, "unlimited vertical", etc.) in this class of airplane, then you'll want a modern lightweight purpose-designed gas engine with electronic ignition. And pal, such ain't cheap. I have a BME 50. I got a pretty good deal on a NIB engine/ignition module, and still ended up dropping close to $800, JUST ON THE ENGINE AND ACCOUTREMENTS, before I was done. I do have an electronic kill system, which just makes sense. Some will pooh-pooh that, but I've seen what happens when a gas engine loses throttle control at a mid setting and must be flown until it runs out of gas. The main question is; will your receiver battery last a bit longer than the fuel supply???

The older gas engines, such as the Zenoah, aren't seen too often on these types of planes; because of their greater weight, I suppose. I know the big iron scale guys at my club run a lot of these older converted chain saw, etc., engines, with little problem in their warbirds. So if all you're after is decent performance in a "sport" type airplane, then one of these would be, by far, the least expensive way to go.

Perhaps the older engines need a bench break-in. But while I was researching my purchase, I spoke with every major manufacturer/distributor of all the "new", light weight electronic ignition engines; and EVERY one of them said DO NOT run the engine on the ground or a bench for extended periods.

Mine spewed out a lot of black flecks. Other than making the firewall rather unsightly, no harm done.

One last caveat... while they are definitely not as finicky as glow engines, don't think for a minute that a gas engine won't fail you when you least need it to.

Murphy lives...

karolh

These are some very informative responses especially from Rcpilet, and in one go you are getting as much or more info than I got over an extended period when I first ventured into the world of gas engines. There is no great mystery here, only some basic differences from glow engines, most of which have been already been discussed here.

Some other things to note is that all fuel lines, fuel pumps and tank stoppers MUST be for gas fuel. Gas carbs are much more sensitive to dirt than their glow counterparts so filter all fuel going to tanks and engines. Many folks use felt type filters as found on trimmers etc. as tank clunks with excellent results.

Having been around several Zenoah engines and owning a G23 and G45, I can attest to their reliability which is legendary and user friendly behavour. Having used my G23 in stock form for some time, I eventually had it converted to electronic ignition by RCIGN which reduced it's overall weight by 16 ozs and which in no way compromised any of it's good traits. Apart from it's reduced weight it now hand starts much easier and idles much smoother.

Try not to be misguided by the ignorant and misinformed about these engines. There are several other very good engines available, but depending on the application, the Zenoah though not the lightest around, is at times the preferred engine.

Karol

jongurley

My Feedback: (29)

www.desertaircraft.com
www.cactusaviation.com
www.rcshowcase.com
www.chiefaircraft.com "greatest selection of all sorts"
www.horizonhobby.com

sillyness

My Feedback: (25)

Zenoahs are great, durable, reliable engines... just not for 3D ships. A DR-1 and a 80"-84" Extra are two completely different animals. To be unlimited you need more power and less weight than a Zenoah can provide. I've flown planes with Zenoahs and let me tell you... a G-38 has no place on a 25%-28% aerobatic airframe... the aircraft handling with the lighter engine is night and day better with the purpose built engine. I switched from a G-38 to a DA-50 and EVERYTHING improved dramatically... taking pounds off the wing loading made the plane much more forgiving, stable, and 3D capable... at the same time I had much more power and felt safe doing things I wouldn't have dreamt with the Zenoah. Plus, for high G manuevers, the lighter engine puts far less stress on the airframe (if a engine is 2 lbs less, that's 30lbs of load off the wing at 15Gs). Landings are also slower so there is less stress on the landing gear... important at the planes get bigger with longer legs.

As an example... a DA-50R gives you the power of a Zenoah G-62 with the weight of a G-26... that is a completely fair and accurate description. In addition... the DA-50R is very easy to start... no spring starters, electric starters, or any other equipment required. My field box went to a small flat tool box... no power power panel, starters, etc...

As for running your engine on the ground... Zenoah is likely the only exception. Every other engine builder says DO NOT DO IT!!!! I can measure the heat build-up with the temp gun... why would you want this? It will get a better break-in in the air. As for getting black specks on your plane... buy a rag.

Rcpilot

My Feedback: (78)

Gas engines is so much more than just choosing the motor. There are a lot of things that we take for granted, like plumbing the tank. It's different than a glow engine, and you need a different stopper and different lines. Adjusting the carb is a learned technique with these engines. Choking and starting is something else that has to be learned--if you like your fingers.

It's up to jclarke to decide how money he has to spend, and if he wants long term reliability, or lightweight right now. I think we owe it to him to try as best we can to educate him on the use and operation of gas engines. Not just let this thread turn into another engine war about why every engine sucks but the DA. That speech is soooooo old, and it's just not true.

The fact is, all of the gas engines available today will put out very good power. They all work. Some are cheaper than others. Some have electronic ignition, and some don't. Some come with a muffler, and some don't. Any of these gas engines would be totally fine for a beginner.

I can see this thread turning into another engine war, so I'm ducking out. You guys can fight--or you can do him and others a huge favor by telling him the risks, general rules, and techniques involved with safe gas engine operation.

Have fun.

rmh

There are application specific gassers -just as there are application specific glow or diesel--
In reading your letter - I see that the 1.6 engines are your present choice. and there are lots of excellent models for this size.
For a high performance gasoline engine in this size and weight- with equal or more power --there are presently two engines on the market : the MVVS or Evolution 26. and they are the same setup - front intake and side exhaust. basically both have origins in the glow engine.
No electric starters are needed -or desireable.
On a factory pipe these engines outpower the same sized glow engines -NOT piped
So why do it?
1- they are dead reliable on idle or attituded in the air - this is due to the pumper carbs used
2-tho the ignition and a decent battery weigh 7 ounces more than their glow relatives, the fuel requirement is that much less.
Starting is easier than the glow-If you get good info to start.
fuel use is again, much less and cost of fuel per ounce is less - typically $16.00 vs $3.50 per gallon.
Those who are adamant these engines will not equal a glow engine are not comparing in the same manner as I just described.
For large engines -- lots of choices - depending on your type of flying. some are better than others and some inexpensive ones are just fine.
If very simple engines -no reeds or valve timing -fit your flying - the prices are less . The rotary valve or reed valve engines are used in the more expensive engines . Thes do offer real performance advantages - if they did not- there would be no need for them.
However . some very basic piston ported engines off er excellent performance/value.
But, some are really crude - choose carefully.

sillyness

My Feedback: (25)

I wasn't trying to start a brand war... I was just offering an example from personal experience... G-38 was bad, DA-50 was good. Other's in the "good" category could have been 3W, ZDZ, MVVS, etc... anything light and strong with a good ignition... but then I would not have been speaking from personal experience, would I?

As for "beginner engines"... my biggest regrets in RC deal with wasting my money on beginner engines... if you are going to spend the money, get something you can grow with and you will be happy with for a long time. Don't get something that will be anorexic and heavy feeling in the air.

Here's my best advise on converting to gas:

Step 1: Choose an engine that is reliable, strong, light, and has good customer service... whatever brand you want... do searches for ZDZ, DA, 3w, MVVS, FPE, anything you want... remember that a light engine will pay huge dividends. At the risk of getting flamed, I do not recommend Quadra, Zenoah, or the like for a 3D ship... you will be sorely dissapointed come 3D time.

Step 2: Get the engine in the mail, open the box, and READ THE MANUAL!!! It will tell you everything else you want to know. If you have a question, call the company or do a search on here. It will talk about the $3 worth of Tygon fuel tubing you need, the $0.25 stopper you need, the ignition battery voltage and size, how to wire the ignition switch, how to keep your radio gear away from the motor, etc... I should talk about cooling too... if not go to the cactus aviation website... there's a great tutorial on baffling there.

There... that should be non-brand specific enough for any audience, minus the warbird and race enthusiests... for these areas, Zenoahs truly are a great match.

Forgot to mention... search RCU for used engines for sale... have the maker check it out... you can get some great deals on great engines.