bjor

Hi Guys.
This is NOT a bash over brands - just an observation.

I am a user of both a DA100 and DL100 engines - both in 2.6 Mtr planes. I'm not an extreme 3D pilot, but do like to have a "bash" every while and also dabble in a bit of IMAC. Both engines - for my purposes, have been extreamily reliable and problem free.

Recently though I have noticed 2 seperate incidences whereby the DL's have thrown a piston during, in what I would call, extreme 3D flying i.e - a LOT of throttle management, high revs and extreme transitions between idle and WOT.
Both occasions resulted in a complete "engine seize" and on both occasions the planes landed with relativly little damage.

I'm won't pretend or assume that DA have not had any failures, but would I be fair in now assuming that while both are extremily adequate for their purpose's, the DA's are more reliable (or less prone to failure) when it comes to extreme "abuse" during 3D flying.

Whistling Death

For the price of either engine you should expect the type of performance you get from them.
But still this thread will get ugly fast.

closetguy

My Feedback: (13)

you get what you pay for,DA pays more attention on building tolerance then DL.machine cases means better fitting of parts, better bearings,a true round cylinder bore,etc
on the other hand you can rebuild the DL and still not have the money in it that a DA would cost you.i have both engines and they both serve me well,you just have to expect a sooner rebuild on one.

Tired Old Man

My Feedback: (1)

One needs to get "up to date" if you will. DL is the early version and had some problems. With the exception of perhaps only one brand all the brands had problems. DA has had their share andover timecorrected them to become the engines they provide today. That's one of the signs of a good manufacturer. Had you been around in the early days of DA and 3w you would have experienced engines that tossed the front housings, locked up bearings, had engines extremely difficult to tune, had engines die when you lifted the tail of the plane, and other items.

By comparison DL, between the time they were first released and today, has been on the market for about 3 years. It should be noted that the DL brand is no longer commercially available and has not been for somewhere in the area of a year or so. The reason? Because the engines were upgraded, just as DA did, to a newer version named DLE. Even the DLE has, since the later release, been upgraded again.

If viewed from a perspective that compares the comparitive ages of the manufacturers one would be able to determine that DL/DLE is on a similar path other better engine manufacturers have followed. Constant improvement. This is a path not folowed by most of the Chinese manufacturers, which is one of make it cheap and move on to another brand name when they start falling apart.

I'll suggest you consider upgrading to the later DLE designs and see the difference for yourself. One thing I said three years ago was that the quality of the engine was going to be determined over time, and how the manufacturer dealt with problems would establish if they were good or not. DL/DLE is following a path of constant improvement which is a good thing. The only downside is the Chinese do not support their dealers in warranty repair labor costs, where DA handles that by charging a lot more upfront in the engine cost to offset the later "free" service. So DLE screws the dealers out of labor while DA gets the customer to handle those expenses.

pe reivers

good points,
I also ask myself, is the setup identical concerning cooling, carb tune, maintenance etc. The DL engines needed a bit more oil. Was that catered for? What oil used? I have many more questions, but will stop for now. All I know is that seized piston do so for a reason.

MetallicaJunkie

when the engine seized , did it throw the prop?

Tired Old Man

My Feedback: (1)

Pe,

You make good points. Too much is missing to make an objective comparison. When apples are not viewed side by side with other apples, including how they were grown and in what climates, you can't accurately depict the reason for the end result.

I go through this all the time with engines of even the exact size and class, set up identically, tuned to exacting standards, using fuel with exactly the same composition, with oils of exactly the same type/brand and ratio. The arguements happen all the time because this engine did this while that engine did that. Often overlooked are differences in climate/atmospheric conditions, and operational methods, severely impacting the outlook for each of otherwise identical engines.

Whistling Death

Hmmm, I never considered the oil ratio question when I read the OP. I know some people will 100:1 that is what DA recommends for their engines.

pe reivers

That is what DA used to recommend.

ggraham500

My Feedback: (4)

What is DA recommending now for their engines oil mixture ratio? 32:1? 50:1?

Tired Old Man

My Feedback: (1)

Go to the DA site and read EVERYTHING they have to say about oil selection and ratios. Don't do as so many others have and stop halfway through the first sentence.

I don't agree with about half of what they provide but the other half is good stuff.

pe reivers

They added some oils to the list for the DA50. The differences in ratio however do not make sense to me. In a small engine like 50cc, 1:100 clearly is too little oil, and oil replenishment inside the engine is about non-existing. There is more internal friction, and all users that switched to higher oil ratios reported a gain in rpm.
I quote from the manual:
"

For Break-in

As for brand, we recommend a petroleum-based oil such as Lawn Boy Ashless or Pennzoil Air Cooled 2 stroke oil at 32:1 ratio. Run at least 2 to 4 gallons of petroleum

oil/gas mix for break-in. This allows the rings to seat quickly without blow by. Use a

prop that allows peak RPM over 6.500 during the break-in process. Set the High

needle slightly rich during break-in.

After the break-in process, we recommend a high quality synthetic oil.

of oil, there are many good ones on the market. Some oils, and their mix ratios, that

Desert Aircraft recommends are: Amsoil 100:1 Pre-Mix (100 to 1), Amsoil Saber

Professional (100 to 1), Amsoil 2000 (50 to 1), Red-line (40 to 1), Bel-Ray H1-R (50 to

1). Mobil MX2T (32 to 1) These oils can be found at most motorcycle shops.

"

daltonaviation

The info posted above is from a older manual and I am working on getting the website manuals updated to the current ones. The following is copied from our updated manual. I can also be called or emailed with any questions at 520 722-0607 or [email protected].

We recommend a high quality synthetic oil. As for brand of oil, there are many good ones on the market. Some oils, and their mix ratios, that Desert Aircraft recommends are: Red-line Two Stroke Racing Oil (40 to 1), Motul 800 (50 to 1), and Stihl HP Ultra (50 to 1). These oils can be found at most motorcycle or chainsaw shops. An option for initial break-in, is to use a petroleum-based oil such as Lawn Boy Ashless 2 stroke oil mixed at 32 to 1. This can speed ring seating and limit the opportunity for blow by that can cause permanent damage. 2 gallons fuel/oil mix is sufficient. (Mix 2 gallons of premium gas with 8 oz of oil.) The rings can seat in correctly without using petroleum-based oil, but it will take longer.
4

Tired Old Man

My Feedback: (1)

Good to learn you folks are also now suggesting the Stihl HP Ultra.

MetallicaJunkie

i noticed they took out penzz for break-in , in favor of lawn girl[:'(] i broke in my dle20 on 30:1 stihl hp ultra... kinda scary at first using a synthetic from the start

JoeAirPort

My Feedback: (41)

Yeah that was all good except they include Lawn boy but not Pennz. Maybe because Pennz keeps changing their name on the bottles and makes their manual out of date in short order.

I recently decided to just break in my DA-120 on Stihl Ultra 32:1. Why? That petro goo is some nasty sludge, I don't care what brand it is. No more petro oils for me, not even for break in.

I have both brands of engines and one thing I can say is that I probably trust DA's bearings more than DL/DLE. I had a DL-50 blow a con rod bearing. My DA-50 never did that. Rings? No idea, I'm not a ring expert but you could have easily been running slightly too lean on one cylinder causing a stuck ring (on the DL-100). Probably a good idea to run more oil on the DL/DLE. They are great running engines from my experience. Never one dead stick in 3 years of running a DL-50 and 2 years on a DLE-55. And that was extreme 3D flying just like the guy posting this thread.

PS: Even though you probably used same oil brand and ratio on both brands of engines could you at least mention what the oil brand and ratio were?

Tired Old Man

My Feedback: (1)

If you work with enough different engines, and work with them enough, you learn that generally bearings themselves are not the problem, although some bearings are worse than others. What you do learn is that manufacturers screw up all the time with machine work, messing with bearing and crank alignment. That's the reason most bearings fail, along with being sized incorrectly. In this respect there isn't too many engine makers that don't make those mistakes periodically. For this reason alone I won't put one manufacturer over another. Even the majors commit those errors.

There is nothing wrong with breaking in with a synthetic, especially with engines possessing better machine tolerances. It's done everyday, using a great many engines in both small and large size classes. Pennzoil and Stihl mineral oils are better than Lanwboy if someone desired to continue using a mineral for break in. There really is no reason to break an engine in as fast as possible, although just about every yard and chain saw engine is done that way. Then again, not one of the yard and saw tools use a special break in oil, and considering they generally use the same bearings, pistons, cylinders, and rings, they manage to last a very long time.

People often overlook marketing when they buy something, especially in our hobby. They get sold a lot of stupid stuff, like break in props, suitable only for glow engine applications, that only increase the sellers bottom line while doing nothing in particular for the buyer. Our engines are not really any different from the chain saw engines their designs came from. The cases look and are sized differently but they are otherwise the same. There is no need to treat them like some critically sensitive piece of scientific equipment.

MetallicaJunkie

that's good to know ....thank you for turning me onto Stihl....its nice to use one oil for the life of the engine

Antique

My Feedback: (4)

pe reivers

When the cylinder is perfectly round, like in ground bores, it takes very little running in time even on synthetic oil, and there is no danger of blowby to cause seized pistons in new cylinders.
However, all engines I see nowadays have honed bores which in two strokes with their porting are bound to be horribly out of round. When run in with mineral oil, the ring wears much too fast, and lots of carbon build up in the ring lands, unless the load is kept low for the duration of the running in process. The cylinder does not get rounder all that fast, and the ring still has a hard time following the humps and bumps.
Just for the heck of it, I did that after an engine rebuild. Never again! I rather use lots of synthetic oil during the running in, so a good seal is provided to prevent blowby. If the engine feels low on compression, just use more oil until the compression goes up.
If the carb mixture is set well, no plug fouling will occur at high oil ratio mixes, because the plug burns itself clean.

gkamysz

My Feedback: (19)

I guess it all depends on the equipment.

http://www.sunnen.com/graphics/asset...6bcac2b33a.pdf

Greg

Tired Old Man

My Feedback: (1)

I wish that were truly so. Who knows, with that vendor it might actually be.

Going to the absolute best manufacturers, platers, and honers of cylinders money can buy does not bring the level of accuracy you would expect. I KNOW this to be true. I've gotten to where I read stuff like that and discount about 50% of it going in the door as pure advertising hype. You send work out and what you get back isn't what was promised, from anyone.

frieshoo

My Feedback: (20)

Add me to the Stihl HP Ultra crowd. I'm on my last gallon of Penzoil 32:1, it was a great ride... but 50:1 Ultra has been in my 111 all winter, and I swear it's getting stronger...

BTW, my local Stihl dealer is selling HP Ultra 2.5 gallon mix for $5.99 if you have bought a chainsaw, weedeater, or blower from him. I bought a nice 280 chainsaw off of him last year.

Tired Old Man

My Feedback: (1)

Just figure that Chinese cylinders are very out of round and take a very, very long time to break in. About the time the process is complete it's time for a new ring since the old one was wore out finish honing the cylinder into some level of concetricity.

So for those that want to run Lawnboy for about 30 gallons of air time-go for it. We'll be hearing from you with tales of woe about having stuck rings and gobs of black goo

Eganwp

My Feedback: (1)

Very very good info posted here by TOM and PE. I 100% agree with everything they've said on break-in oil and ring seating. For me, it all comes down to quality and trueness in the decision making process. I'll personally never break-in the first few tanks of a DL/DLE with synthetic as the tolerances for a true high performance engine just aren't there. If this was a Rolls Royce engine, yep, 100% synthetic forever. Because the tolerances, roundness and quality just aren't there with the cheap hobby grade engines we run, it's critical to get a good ring/wall seat with a bit of runtime and wear-in (aelibit it doesn't need to be really fast like PE says), but does need to be done. I've rebuilt engines where it's obvious the ring has never properly seated being run on synthetic from day 1, but yes there are other factors. Using a very rich synthetic mixture to seal the ring works well too, as PE said. I've personally never had an issue with ring carboning on good dino oil (ie Stihl), which is why I prefer to use it for a couple gallons before switching to Stihl synthetic @ 40:1 on the 55/100. Just makes the fun come along a little faster! I'd never ever run lawnboy ashless, but lets not get into an oil debate, lol.

And TOM is very correct in saying that many people over-analize these little toy engines, trying to treat them as a high precision instrument. Just use them for what they are.