vanom

I have just got my new DA100; this is my first gas engine other than Zenoah. I have no idea how to brake-in this engine. The owner manual specifies the oil type (no problem with that…) but says nothing on how to do it. Should the rpm be constant? Should I play with the needle? Should it be rich “four stroke like�? And more and more…
Please advice how to do it.

Thanks
Vanom

coony2787

My Feedback: (33)

Mix up some 32:1 oil and gas preferably lawnboy ashless. Then mount motor on plane, and go fly. That is the best way to break it in. The needle setting shouldnt even need to be turned. Make sure they are both set at one and half turn out. And your ready. Run about 2 to 5 gals of gas threw it at 32:1 in the air.

Chad

vanom

Thanks!
Any recommendation for RPM during the process?
Should it be constant?
What is the maximum RPM allowed?

coony2787

My Feedback: (33)

I would put a 27x10 prop on the engine , and just fly it avoiding long wide open throttle times. I just put my DA 150 on and adjusted for max RPM and backed off 400 on the high side and adjusted the low end for a good transition. And flew the pooh out of it. If your putting this engine on a test stand i would strongly recomend not doing that. JUst put it on your plane adjust the needles, and fly it. That engine will perform perfect from the first crank of it. The max RPM is 8500 and also check out there site alot of info there also
http://www.desertaircraft.com/engine...hp?Page=DA-100

Chad

famousdave

My Feedback: (61)

It never ceases to amaze me how anyone can recommend using the factory needle settings out of the box without any adjustment. We then wonder why engines run like crap, dead stick or why manufacturers don't replace burned up engines when they run too lean.

Not bashing anyone, I am only stating as a tuner - I never use the settings out of the box because very rarely are they even close to being close! Altitude, temperature, humidity and even transit effect the mixture requirements of these engines. If you don't have the experience, seek out those who do so you get the setup right ... if you choose to ignore this advise you could be making a costly mistake.

So .. to recap - 32:1 Ryobi, Lawnboy or Bel-Ray S2 oil for at least 3 gallons - adjust mixture at all throttle ranges with more emphasis on low and midrange during break in. Fly with the right prop avoiding WOT. NO HOVERING either!! The engine is going to run hot for a gallon or two anyway, so you want as little load and as much air as you can get. Hovering creates a big load and kills airflow!


I put my new engines in, start them and lean out the low needle to the point just where it hesitates on transition to abrupt WOT.. when it does that, I richen the low needle one screwdriver blade thickness at a time until the hesitation disappears. I then give a brief blast of WOT to verify top end is a little "muddy" meaning rich. Idle and midrange should be excellent (done with low needle) and high end is OK to be a little burbly or rich. After a few flights start leaning out the high needle a little at a time. When you adjust high low usually needs to move too to keep midrange intact.


Its a bit of a chore, but once done.. you rarely have to touch these engines!
Once broken in (about 3 gallons) switch to BelRay H1R full synthetic at 50:1 for best performance and power.

When you change oils you will probably have to adjust needle settings..

Despite what you read - don't ever use 100:1 oil mixes in these engines! BAD BAD BAD!!

DP

lsnover

My Feedback: (19)

Since 100:1 Amsoil is what DA recommends, why do you say not to use it? I run 100:1 Amsoil at 80:1 for a little safety and never have a problem. These motors really don't like a lot of gooey oil. My Brison will barely run right with 50:1 mixes. They recommned a 80:1 mix.

Regards,
Lee Snover

famousdave

My Feedback: (61)

We "engine guys" don't like the high mix oils. We have raced high performence 2-strokes most of our lives and in every situation we see more cylinder wear with 100:1 than with 50:1. 100:1 mixed at 80:1 is fine, as you say, better margin, but that mix could lead to excess deposits as it is formulated to use at 100:1 If I had the Amsoil though, that is what I would run it at .. 80:1

Of all the oils that I have used over the years, BelRay H1R at 50:1 provides the least wear, least deposits and best "slip". It has something to do with the fact that it does not burn in the combustion chamber like the other oils. As a result there are almost no deposits. We also have seen no scoring and lower overall temps. I did have to adjust my needle settings slightly with this oil (richer) since it does not burn you use a little more fuel. I was so impressed with this oil in my racing outboards and Yamaha YZ's that I tried it in my model engines. Same results!

I think DA is the only one who approves a 100:1 mix. Those who have tried it in the ZDZ have had real issues. DA knows what they are doing and I am sure they have tested it thoroughly, but I won't use it. H1R at 50:1 for over a year on my DA (100's of flights) and the inside still looks like new.. not even a black spot on the piston. The Amsoil guys I know have to tank their engines once a year to get rid of the crap.

I guess if you are going to err - err on the side of the manufacturer and don't just "jump in" to something you hear on RCU. Making a blind change could void your warranty!

That said, I have experience and data that shows very positive results from H1R 50:1 so I use that on everything. Besides, H1R you can get at any Moto shop... try finding Amsoil just anywhere !

DP

former spad

100:1 is for guys who want to get the absolute max power by increasing fuel in mixture instead of oil and are willing to lose some durability because they are likely to blow up or crash the engine first. The 80:1 is a good safety margin. They best oils will minimize carbon deposits, and that decreases cylinder / piston wear. Breaking in an engine too rich may cause excess deposits, too lean causes overheating, too high rpm can cause metal galling at points of close contact. It is all a matter of balance.

I break in my engines by initially running them on the ground just long enough to heat soak (not overheat) all the components, let it cool down completely. Go through this for 4 or 5 cycles. This stabilizes the tolerances as the parts expand and cool. Then I limit high rpm to short busts, ie take off, to avoid overheating. As the engine begins to loosen up, I slowly work up into the higher rpm ranges. Then I finally loose patience and start running it as hard as I want.

I must say that I have never owned a DA engine. I spent years racing 2 and 4 stroke motorcycles in the desert, and this worked for me. I am just sharing my experience, not recommending anything.

famousdave

My Feedback: (61)

No disagreement from me - you are right on with the heat soak. I have run my outboards in with OIL in the waterjackets to raise initial temps for 4-5 cycles to normalize the metallurgy, the oil is flushed and then its ready for the water. Works the same for our model engines (the heat soak that is, not the oil!)

On the counter point however we consistently see MORE power with more oil. We run 20:1 in our Chrysler V6s and they made more power than with a leaner oil mix. Ditto for the Maico singles.. those are different engines than our small singles..

DP

former spad

I have heard of more oil makes more power. But I think this applies only to some premix oils which have a small percentage of nitro in them which causes the power increase, but I can't remember specifics. I also posted an explanation on another thread that using petroleum oils for break in seats rings faster, but synthetic oils reduce friction so much that rings take much longer to seat. This should indicate synthetic oils reduce engine wear and extend engine life after break in. However, with chrome/polished bores, better tolerances and improved metals this is not as important an issue as it used to be.

The real problem is that most oil producers will not give the consumer the technical information needed to make meaningful comparisons. Most people have no idea how much complexity and variation there is in oil formulation is these days. That's why you can mix some at 20:1 and others at 100:1. It is all blurred in some fancy marketing scheme. Fortunately, most of it is good enough for the average guy.

Break it in on the easy side, don't overheat it or overrev it, keep combustion clean, use good oils, don't crash it, and most engines will outlast you.

famousdave

My Feedback: (61)

I think your last line sums it up perfectly! There is way to much emphasis on oils and not enough on care and feeding! With the right combination of the latter the former is practically irrelevant.


DP

Panzlflyer

My Feedback: (15)

I dont know where the " DA only recommends Amsoil at 100:1" comes from??
My DA instruction manual says Amsoil 100:1 or Belray H1r or ANY quality synthetic but people keep trotting out the Amsoil mantra...is it because they dont read or are sheep baa?

former spad

Break it in on the easy side, don't overheat it or overrev it, keep combustion clean, use good oils, don't crash it, and most engines will outlast you.

I called Dave, the owner of DA Engines and he basically agrees with the above statement. Saying few people see as many engines as he does, he recommends breaking in on petroleum oil to seat the rings and then switching to Amsoil Saber Professional 100:1. (10 years experience speaking) Not wanting to get involved in the public debate with the uninformed (my term, not his), he said running too lean, overproping, overheating is by far the biggest engine killer. He said his techs can look at the engine and tell what YOU did wrong. He acknowledges good oils of other brands will not harm the engine, use whatever you want. Fearing lawsuits, he won't say what the bad oils are, but they are out there: you won't be able to fool him. He agreed that breaking in on the rich side of lean to avoid overheating at high rpm is a good rule of thumb. Too lean is too hot, too rich causes carbon build up. Bench running may not alow enough cooling air. Heat soaking as mentioned above is OK, but not mandatory. Finally, break in time can vary, 50 - 2-3 gallons, 150 - 6-10 gallons. The owner should feel the engine loosen up over time, it runs smoother, better power and response. Flipping the prop on a cold engine to feel compression really doesn't mean much, because the rings need heat and pressure to seat properly. He rattled of a list of technical reasons why just because one oil works good in one application does not mean that it will work good in other applications. ie outboards are not airplane engines. (Sorry Desert Pig)

As a disclaimer, I will state that I have been using Amsoil in everything I own for years, technically I am an Independent Amsoil Dealer, although I don't sell enough of it to even make payments on a DA engine, and my mechanical background is diesel, automotive, and years of racing 2 and 4 stroke motorcycles. Amsoil is now making 4, that's right FOUR, 2 cycle premix oils. Saber Professional 100:1 is the one primarily recommended for air cooled carbureted engines, be sure to get the right one. I find many people who critisize Amsoil were not using according to recommendations or in correct applications. I will confess that in my 2 cycle dirt bike, I used 100:1 at 80:1. My fear factor. Yes, there are other good oils out there.

famousdave

My Feedback: (61)

I was never bashing Amsoil.. nor was I recommending it. Saber 100 is the only stuff to use, I don't think anyone debates that. My main point was that a good oil is a good oil and that too many of the "uninformed" as you put it dwell on the oil making or breaking an engine while they don't spend as much time as needed on the details that really make a difference like tuning, prop load and baffling!

As Dave and Brian say - oil is a choice, as long as you use a good one who cares!
I don't have the pictures to prove it, but I have seen extensive data that shows saber mixed at 100:1 eventually leaves scoring on our model engines. I think Dick Hansen, Ralph Cunningham and Elson (RCBugman) also will concur. 80:1 does not precipitate the scoring. My guess is it is not the oil iteself but more the use of 100:1 is so lean that overall fuel-air mix becomes critical. By using a higher oil content the engine can run a little leaner without the narrow margin of the 100:1...

Tell you truth I have never had an oil problem with any engine, I did get tired of cleaning deposits so that is probably the only reason I use H1R... H1R is REALLY expensive though.... ($5 a pint!)

DP

Panzlflyer

My Feedback: (15)

Make a mistake at 100:1 and what have you got ....easy to go lean on the gas to oil mixture in the can. Just my opinion.

former spad

I also am not trying to defend Amsoil, just trying to answer questions. I have had the same conversation too many times. Changing oil ratios does change fuel mixture. In fact, I used to vary the Amsoil ratio in my 2 cycle off road motorcycles to compensate for rides at different altitudes. Tuning an engine for 32:1 and then changing to 100:1 will cause engine to run rich, it should be re-tuned. The same applies in opposite directions, except the result is too lean. I will also admit that running 100:1 and then tuning too lean is disaster in the making. But that applies to all oils, and is the responsibility of the tuner. I once melted a piston on Amsoil, but it was my fault because I forgot to rejet for the low altitude. 70 mph on dirt road with a locked up rear wheel was more fun than 3D. Maybe 100:1 is less forgiving of lean mixtures. For conservation sake, how is it that every oil has some who swear by it, and others who swear at it?

I think Amsoil should be more specific on their directions, maybe stating 80:1 provides better durability. I did call the tech service department, and they said 50:1 ratios are OK, but not recommended for Saber Professional. Dave at DA says he has seen TOC engines that fly every day for years at 100:1. Something is not adding up. May be it is not the oil, but the loose nut holding the little screw driver.

Amsoil does have a warrenty that states, if their recommendations are followed, and the engine is harmed by their oil, and you can provide evidence, they will repair / replace the engine. There are naturally some procedures, they want an oil sample and want to see the parts. So if the parts were in fact damaged, contact them for details. My motorcycle cylinder lasted 3 times longer then my riding buddies who used brand x. But that is another story. Let me know what happens.

former spad

Oops, forgot to say motorcycles engines don't fit in airplanes.

RTK

My Feedback: (1)

Here are the recomendations on the back of a Amsiol Saber 100:1, hope the picture turns out. If it doesn't here it is "for severe duty applications such as racing or commercial equipment, richer ratios of 50:1 or 80:1 are recommended".

Crusty

Well, I come at this from an enduro racing background, I wouldnt even consider running a 100:1 oil ratio.
Not saying I'm an expert on 2-cycle engines but I have 20+ years of experience handling and maintaining them .......... the thought of running that little oil makes me shudder, im too old to change
Spad, Ive seen some converted motorycle engines in ultralights, but never model ...yet, im sure someone has done it...eh?

talking about engine usage.....I know its old but maybe some have not seen .....

jongurley

My Feedback: (29)

I read somewhere that RCshowcase said the they tested Lawnboy oil and it burned some rings on breakin,, I have recently bought a ZDZ60 and I have been running Amsoil Dominator 50:1 since new ,is there a problem from this,,,, the motor has only about 2-3 gallons through it,, would it hurt to run pertroulem in it to speed up break in for a gallon or two or just keep on running the synthetic,,

rmh

Break in----
fact or friction?
I don't believe in it .
How do you know when the engine is broken in?
My guess -
you don't
The process is a exponential thing --starting with most friction --then decreasingly loosing metal till an even seating occurs -then wearing out.
Anyone care to plot the curve?
Is the need for a breakin process, true for all engines?
How do you know when a Lycoming -just fresh from a major. is "broken in"?
As far as I can see--' break in" is simply a matter of controlling heat .
That is - what ever you do -and for how long you do it - just control heat -
Obviously, some engine manufacturers have developed a "SWAG"--for their engines , which says -oh --about 3.5 gallons of olive oil-or whatever- then it is broken in.
So now is it safe to over prop it , reduce oil content and lean it out?
Does that really make sense?

famousdave

My Feedback: (61)

More or less my thoughts too. I have run engines with break in oil and full synth and others with full synth from minute one... guess what.. they both ran the same, same temps, same power..

Dick - wasn't it you who suggested just running the full synth oil from day one? Can't remember...

That's all I have ever done with my bikes and boat motors... why not R/C engines?

Here is another interesting tidbit - on 4-stroke Harley motors when we do top ends (includes a hone and ring change and usually .010 piston oversize) instead of babying the bike for 500 miles like the "old school" set suggests, we now take the bike out and seat the rings in 10 miles by putting some very hard R's on it (basically drag racing it!). The first time I saw this done I thought they were nuts, but many of the hot rodders started doing this long ago and the data actually shows that the rings seat much faster and that the engine runs cooler sooner by shortening the period of time in which the rings break in. In the long term there were no differences in wear or durability of the rings as a result of doing this "procedure"....

Mechanics dig this too because instead of a baby ride around the block they get to light 'er up any time they do a top end now !

There is a lot to be said about fact or friction....
DP

Diablo-RCU

My Feedback: (1)

Information from the Society of Automotive Engineers does not recommend the full power on a new engine approach. The traditional method recommended by them and the folks that manufacture rings, pistons, and cylinders is to run the engine under light loads and low heat until the rings are seated. High loads and high heat tend to gall the rings and cylinder. This tears away chunks of metal and doesn't give the best wear surface for longevity and gas seal. Light loads and good lubrication during break-in promotes micro-machining of the rings and cylinder.

aviti

My Feedback: (54)

I appreciate all the experience that people share on these oils but you have to admit the conflicting information is confusing. There isn't one oil that no one has anything bad to say about. I spoke to DA and they swear Amsoil 100:1 is fine mixed at 100:1 but it worries me. BelRay HR1 sounds good and DA is OK with it but someone says it made their engine run hotter immediately. What about BelRay MC1? Someone said it doesn't burn as clean as other synthetics. I agree that avoiding lean runs is the most critical factor but their are some pretty strong opinions on here about these oils and it scares the less experienced guys for sure!

I still have a couple of gallons to go on my Lawnboy Ashless to decide what to switch to, but even the break in oil is up for debate (synthetic from day 1?). I used the Lawnboy because DA recommended it...but you guys got me second guessing that too! haha

famousdave

My Feedback: (61)

Aviti - H1R will make an engine run hotter if you switch to it without richening the mixture. H1R does not burn like other oils and so it will require a slightly larger fuel load. This is common sense any time you switch oils or mixes anyway so it should be no news. H1R does not run hotter than any other oil when tuning is correct.

Diablo - As far as the SAE - well they are light years behind the tuners. They do what is OK for the masses and what is least likely to get the manufacturer into a liability situation. If any of us racers used the SAE guidelines we'd all be in last place every time. Data suggests that on Harley's the ring seating works as I mentioned. Common sense says NOT to do that with your DA or you're going to be buying $400 worth of cylinders!


I baby the crap out of my RC engines... pound for pound they are 5X the cost of a good racing engine!

DP