ahicks

My Feedback: (2)

With all due respect, your opinion is just that, an opinion. One of many? Please don't feel snubbed or take it personally when somebody has a different one? For what it's worth, the way I read the responses before and after yours, several here agree with what you said 100%? Nobody said anything about it being wrong?

Hope I can still fly, or even think about it, when I'm your age!

Brian Smith

My Feedback: (117)

+1................ Thanks guys. It is sorta like the best oil question. Every one has their opinion and most based on long time use. Keep doing what you feel works for you, and makes you happy. Brian

Muttdog

I am on my first gasser but I do have a lot of experience with high performance 2 stroke engines in the personal watercraft racing and Motocross scenes. I used the same break in procedure on my DLE 30 as I would on a full blown Race engine. Slightly richer oil mix (32:1) for the first tank, mixture screws pretty close to correct perhaps a bit on the rich side (These aren't glow ABCmotors so they do not need to be four cycling rich). Run it on the ground for a few minutes to be sure everything is fine and throttle transistions are good. Once I put her in the air I make sure to not hold a stready throttle for any long periods of time. The rings seem to seat better when the engine varies in temps so I make sure to go up and down on the throttle. After 2 tanks I switched to 40:1 oil and leaned it out to full RPM. After that it's dialed in and ready for battle.

vertical grimmace

My Feedback: (1)

There is a difference between "test" running and "breaking in".

freeonthree

My Feedback: (1)

What is Ming ? I remember it as an optional protective coating they put on automotive paint jobs in the 70's or 80's.

Luchnia

My Feedback: (21)

Agreed test running and breaking in are different.

I have had the pleasure of touring an engine plant many years ago. It was not a 2-stroke engine plant but still an engine plant and it was nice to see how each new engine, as part of the process, was pre "run in" as they called it in those days. This assured a number of things, one being that any engine that was shipped out to the customer was sound and ready to go.

Believe it or not, you would see marks on the engine test room walls where parts had hit the wall when some of the pre-run engines failed. I for one am glad that process is done as it will usually ensure a good engine is shipped. I certainly hope that RC engine manufacturers do the same with their engines. If not the burden is on the customer.

av8tor1977

My Feedback: (6)

Here's an idea.... If you want to run your engine for a good while on the test stand but are worried about overheating, grab your leaf blower and give it a blow job!

AV8TOR

freeonthree

My Feedback: (1)

In my opinion, as long as the prop is blowing air thru the cooling fins, an air cooled engine should not overheat, unless the fuel or oil mixture is too lean, or the engine is abnormally tight due to missaligned bearings, poor piston fit, or lack of ring end gap. A vacume leak will cause overheating also, but that falls under the previously mentioned laen condition deal. Dennis

jp1961

Brian,

On page 13 of the owners manual for a Zenoah G-20 it states "Different from a glow engine, this engine does not require any special brake in"

Jeff

bjr_93tz

The two-stroke motor in my race bike has very specific break-in proceedures depending on what parts of the motor you've just replaced, so I'd say there's merit in not flogging a new gas motor at full power with a lean needle setting right from the get go either on the bench or in the plane.

If the gas motor is undersized for the plane and will be installed in a tight cowl (ie need full power all the time and marginal cooling) I'd spend some time on the bench with it to make sure it's running well and has about 1/2hr (6-7 minute runs) on it to bed things in. If it's oversize for the job and got heaps of cooling (cruise 1/4-1/3 throttle) then break it in in the air with a good full power upline every now and then to clean it out and help the rings bed in.

When all else fails follow the guidelines given by the manufacturer.

One motor I have runs a slighty oversize prop that it can't swing properly right after a rebuild (won't clean transition from idle to fullpower), but it's happy on it after about 10-15 flights with a slightly smaller prop.

Luchnia

My Feedback: (21)

That makes sense that Zenoah does not require any special break in period. You can bet Zenoah, like DA has some quality control measures in place or we would have engines that would not even turn over when we unbox them. Components have to be tested by some standard as things go wrong.

I have seen how one company test crankshafts on an industrial engine and somehow reverses polarity on a high voltage electrical charge to work with hardening and then they are dipped in an acidic vat and tested. I must say, it was one of the most fascinating things I had seen on engines parts being tested at the manufacturer. They had a "mountain" of cranks that didn't pass the test and had to go back through to be melted down and used for some other component.

All it would take are problems like a bad case mold, incorrect lathe run out, a tooling problem, etc., to ruin an entire batch of engines. I think some manufacturers probably just "cast the lot" and send them out and we take our chances, but I don't think that is the case for all of them.

There are measures of standard in place for most. That is why when we get our engines they don't require any special treatment other than running the mixes the manufacturer implies and take 'em to the friendly skies.

BobH

My Feedback: (2)

On the industrial side of things most engines never get "broken in". I'm speaking of chain saws, pumps, blowers etc. These get filled, started and used. Does it shorten the longevity of the engine? Doubtfull.
Of course Two stroke engines are simpler and lap in a little quicker. Four strokes have valves to seat in addition to the rings.
Yes there will be a gain in performance after a short period of running a new engine. How much depends on a lot of things like the materials used, tolerances etc.
Either method is fine for the most part. Heat is the enemy of any engine so just keep that in mind. Running an engine wide open for prolonged periods of time does nothing to break in the engine. Run up the engine enough to heat it up to operating temps and then back it down. Repeat the process several times. The parts need to expand and contract within the engine in order to properly break in.

After a session of that your engine will pretty much be broken in.. either on a stand or in a plane

Propworn

My Feedback: (3)

I work in an engine plant (automotive) all are very similar in their methods as it’s the most economical.

More expensive are forged cranks where a slug of steel is beat into rough shape gives it grain and a stronger crank for high performance motors and truck engines mostly. Very few are being done this way as powder and cast cranks are getting stronger and are less expensive to produce.

Cast cranks have the slag and casting flash as well as sprues often beat off with sledges and pneumatic chipping hammers.

All surfaces including journals and counter weight cheeks are rough machined within a few thou TIR then key ways, flats etc. are machined on.

Surfaces that need to be hard are heated by induction coils and quenched in a salt bath to harden the surfaces

Crank journals and mains are then ground as needed.

At the end of each of these operations checks are made it is very rare for bad cranks to make it into service in this day and age. Out of the thousands of cranks produced each week I doubt there would be very many that had to be scrapped.

With our small engines stuff like the engine parts are most likely to be farmed out and the quality would depend on how diligent the engine assembler would be. When parts are made in house quality is much easier to control when your engine is a sum of parts from many individual suppliers it’s much harder to control the quality. That being said its amazing how well 200 dollar weed whackers run. At the end of each year most are hung by the shed door with little thought to winter storage yet most fire up and run fine 6 months later with the addition of little more than some fresh gas. The gas engine mechanically is very tolerant of the abuses we tend to heap on it in our careless moments. A little tender loving care and there is no reason they wont last for a very long time.

Dennis

Ernie Misner

How many, like me, have fired up their racing motorcycle engine while on the trailer and let it run while towing it down the freeway?

Rudolph Hart

Yes i have,ernie you are being too #n#l

With regards to running in gas fourstrokes some manufacturers specify bench running.

Rudolph Hart

I thought "ming" was related to "ying and yang"