RC-FIEND:

But the concensus in that thread is that break-in for a car is a thing of the past.

Bill.

Hear, hear, I'll drink to that. Bill, please whip them again if they get out of line. Now, how do I break in my new airplane? How many touch and go is needed before plane is flight-worthy?

Finally an update (but I'm not finished yet ). I ran another two tanks through it to take me up to 45 minutes which surely has to be enough! I made two mistakes on it with the last tank though. First I forgot (again!) to hook up the pressure line after I'd filled it and second I forgot to close the throttle after I'd primed it. But no drama, one flick and it was running in a 2 stroke for a few seconds while I reconnected the line

After the second tank I did the usual with the degree wheel and the pinch began at 40 degrees compared to the 45 I'd been getting before. I have the impression the pinch is less than what it started with but is still about the same as my Rossi which was run in the usual way (although it's done maybe 40 hours). The check for rod wear showed no detectable change. But seeing it was going to be the last rich run I stripped the engine down to see how things were inside it.

On the piston, the only evidence of any wear was the beginnings of the ring you usually see close to the crown. Most of this was on the transfer side of the piston with only a hint of it beginning on the exhaust side. The photo shows the transfer side. There was no detectable play in the wristpin bosses in the piston.

The liner was starting to show signs of smoothing out because the cross hatching was getting faint. One area between the front transfer and the boost port had taken on a very high polish like a mirror.

Now for the rod (and I know it's not one of the squeaky tight high performance engines). It's difficult to show in the photos because of reflections etc but the upper surface of the rod bush is taking on a nicely polished finish while the bottom half still has the original machining marks. This tells me there was definitely none of this "piston jamming in the pinch and the rod dragging it down" going on. In other words, no "compression-tension cycling" of the rod. One myth busted at least and it came as no surprise to me.

What I intend doing now is to treat it as a new engine and run it in according to the method given in "the thread" and then strip it down again. But before I run it I'll use whatever prop gets suggested rather than stay with the 9x6 I've been using up to now (which is the prop I would have used). So pick a prop...10x6...11x5...18x18...

I'm having fun here

What RPM is the engine rated at, Brian ? It should turn about 14,500 (guess)
with a 10-6 APC (which is also good for digging weeds). I would probably
hang a 9-8 MAS or Zinger on it, and wind the snot out of it.

I'm wondering if the pinch will go bye bye when you allow to piston to expand
at full running temp.

Dave.

Yes , for this car it is a thing of the past, but I'm willing to bet, with one out of the thousands of types of vehicles made in the world , someone continues to advocate using the passe method for breaking in an engine. And just think, the cars made way back when definitely lasted allot longer than they do now a days.
I still wish I had my 1985 ,(I think ) Buick Century. Bought it for $900 dollars and ran it until the wheels feel off. Never had any major engine problems. Those where the days. .

[Anyway, let's all lean back and cool it, just wait and see how Brian/Downunder comes out with his experiment.]

Bill

Which would seem to be the objective of any experiment.

I have been puzzled, if not astounded, to note that some of the corespondents seem to feel personally affronted by Downunder's experiment, even though he has yet to publish any conclusions! The consternation of some of those following this thread should be worthy of study by marketing experts. and social scientists.

I continue to watch with fascination the experiment and even more, the reaction(s) to same.

jess

Jess,


Most people have very little patience. Sometimes I do too.

In trying to trust what the manufacturers say, there are pitfalls.

Try reading the OS manuals for the FX/AX engines and compare them to the OS Q&A and Bax's words in the support forum.

The manuals say to run the engine at a four-cycle and occasionally at a two-cycle, then back to four-cycle, while both other sources say to run it at a rich two-cycle only...
So which are you supposed to trust???

The Super Tiger manual specifically says (about ABC models), to run the engine just beyond (lean of) the point it breaks into a clean two-cycle, as does the manual for the K&B Screamin' .48 ABC.

All the documents mentioned are on-line and you can see them where they should be.

With most of what the manufacturers say (those who speak with a single voice...) and what has been published in model magazine in the last 15 years, or more, there is a general consensus about the right way to break-in a tapered-bore engine.

Those manufacturers that tell you to do otherwise, just want to sell you an expensive piston+sleeve set ASAP. Much earlier than you would need it, if you do it the right way, as posted by someone about car engines, earlier in this thread.


Why should I wait for Brian (downunder) to go through with getting the results?

The worst case is that he will get an engine that is not up to its intended performance, as posted by another member and at best, he will be getting similar performance to an engine broken-in correctly, after having wasted a lot more fuel and much more time.

I doubt that even he thinks he will get any tangible advantage from this endeavor.

Dar,

Be careful what you say or you will be 'moderated'. I am contacting Marc about the fact that a post of mine here was simply deleted without explanation. It is almost beginning to look like the old RC Online 'Gestapo' is here.

Be patient for downunder to do his scientific experiment on TWO engines...We all have to wait and see what the results are so we know what we should do with ALL of our ABC/N engines when we break them in...yea...right

I'm sorry you've got such a short attention span Dar...watch out or you'll become known as Dar the Goldfish

You might find this interesting though.. http://home.kabelfoon.nl/~fiorimet/Index.htm side bar "Running in" and then the third para.

For the rest who are interested, I've started running in the engine according to the "Go here or you'll ruin it!" thread. I'm using an APC 10x6 and it chugs along quite nicely at 13,000 with a head temp of 300F and a very occasional 4 stroke "miss". There's a very pronounced rise in revs when I pinch the fuel line to shut the engine down so it should be rich enough. The rise is more than the 500 rev below peak as in post #7 of that thread so obviously it must be OK.

But could Dar explain to me, a rank beginner, how you find 500 below peak if it could damage the engine by peaking it in the first place?

I must admit the head temp of 300F worries me but what do I know? I'm just doing what I'm told to do

I have been following this with great interest, I have broken in AB? engines completely wrong, before I knew better, completely right, and some not at all. I run several ABC type engines as Diesels which according to some operate too cool for long ABC engine life. Dub Jett says the engines have a certain amount of ability to adjust to operating at differing temperatures, if this were not true you could not fly at part throttle to just cruise or land without damaging the engine. I believe Jett also recommends starting his engines 1/2 turn rich from your normal run setting to avoid shock heating the engine, then let the engine run a few seconds to stabilize then reset to your normal setting and fly. Bob Brassel can correct me if I'm wrong here. I think I read that when Dar was challenging Bob about their breakin and start up procedure.

Too bad the racing engine web site is written in FLASH. I don't do flash. That's what most ads are written in. If you don't have flash, you don't worry about crawler's and pop overs.

Now, not taking sides but only expressing my experience

On my first ABC(N) engine, I had never read much about the ABC(N) process. I was a ring man. Who reads that junk piece of paper that comes with a engine anyway?

Then, I started the engine on the bench and found that it didn't really like to run four stroke. That it could be very rich and still 2 stroke. So I broke it in running a rich two stroke. I would run short burst at rich W.O.T. and then at a lower intermediate speed (back and forth) the first four tanks while feeling of the head and watching the temperature that it was only warm and wasn't too hot. I only shut it down to re-fill the tank.

Then I couldn't resist any more, I found out what the engine was worth....

I still have that engine many flights and years later. It still runs like new, though it has burned crud all over the cylinder and muffler. I must have done no harm?

In fact, the first four or five ABC(N) engines, I had, were broken in this way for that seemed to be the way they liked to run.

And then some years later I read how to break in a ABC(N) engine or destroy it?(Do or Die) I was just glad that I had escaped with no apparent harm?

Someone mentioned George Aldrich. I remember he ruined a few early ABC engines with his Sunnen Hone before he got them figured out. He was a seat of the pants guy. He found out what worked (and didn't) for him the hard way. I don't remember him getting into any do or die break-in scuffs on the internet? He was a regular on the forums until shortly before his death.

Enjoy

Jim

[Why should I wait for Brian (downunder) to go through with getting the results? ]

No reason at all, Dar. In fact there is no reason to read any more of these posts at all, unless, like me you wish to follow the experiment out of curiosity.

I an sure this process will not change your procedure for break in, or mine.

What I find curious is the evident fear and loathing this thread has aroused in some.

jess

Hello!
Downunder...I thought everyone knew that todays ABC , AAC , ABN engine weren't that critical to run in!?
In the past (25 years ago)when K&B and some other ABC engines ruled supreme most ABC engines were queaky tight and should be run rather fast to get up to operation temp.
But todays engines are so damn good that this is not necessary any more. As long as you don't run them lean you can run them whatever way you like!
Guys ! Please ! Don't turn this into a rocket science thing again. Please!
30 years experience from Pylonracing, Scale, Aircombat, Aerobatics, CL-combat and General sportflying, has tought me that you will not destroy your engine just because you run it rich when running it in. I'm not saying that's the best metod to do it, it isn't ,but it will not hurt it either.
Regards!
Jan K
Sweden

Brian,


First, I did see your response before writing my previously last one.
In my response I was referring to the person who removed some of my posts and those of others.

This goldfish is going to out-litigate you...

In my discussion with Bob Brassell, he told me that due to their high timing numbers, Jett engines will not be run in a four-cycle state, but rather in an unsteady, misfiring state, when the needle is set to a very rich setting.

Profi engines that you entered here as evidence, are even more wildly timed then Jett engines.
So are they capable, despite their radical timing, of sustaining a real four-cycle mode???

I don't think so and it is probably their way of describing an unsteady misfiring state as well.

I have never run a Jett, or a Profi, so if you want to argue about this issue, take it for a few rounds with Bob Brassell (or maybe with Dub himself).


Also, peaking a brand new tapered-bore engine for a few seconds, to find peak RPM, will not cause it any damage whatsoever.
Heat soak cannot come this fast and, as said, they are nearly ready-to-run and run they do.

Some racing engines are tached by their manufacturer, to check if they are up-to-par (and to fish out the really powerful ones...).
Would they have done it if damage was a risk? I don't think so.

Besides, it is not only my thread that tells you to take this route, but also the instructions of the better engines manufacturers. Oh, and the late George Aldrich...

First, I congratulate Downunder for having fun. As I see it, the virtues of an ABC include a quick breakin, and ability to run hard without damage. But I have a couple of questions. If there is a problem with piston-liner friction when run rich, wouldn't there be a heat build up? If there is no heat build up, as shown by Downunder's numbers, is the friction happening?

Secondly, and more importantly, name me a current model of car which needs any special breakin running. I remember 50 years ago when you were supposed to run a new car at varying speeds, and not go too fast, but that's not the case any more, at least not with Ford products..

Jim

Yeah. thats about right. Although on the R/C sport engines, I rarely open the needle to start the engine - just start it at high-idle, let it warm up 20-seconds or so (about as long as it takes to put the starter and battery back in the box, and move to a safe spot behind the engine), then slowly advance to full power. Not really different than Id start any other engine.

(the racing engines are a slightly differnt story - not a good comparison toward the sport engines)

The aac/abc engines can and do adjust for varying rpm/temperature/fuel/ etc. Otherwise they would not throttle well. A well designed engine of this type will keep the relative fit and temperature of both the pistion and sleeve in proper balance.

The break in has more to do with achieving an optimum fit at max power setting. My proceedure for AAC/ABC involves running an engine with an undersized prop, up to the RPM I wish it to work at when I am done. Break-in involves running it at that RPM. The resulting mixture to keep at that rpm is always a bit on the rich side. After a few tanks (15 min or so) I switch to the flying prop, and finish setting the low end and then find the peak of the high end needle. Its ready to fly. Using the throttle during break-in is ok. Usually that very first run is the tough one - but Dub does those on the bench before anyone ever sees and engine from him.

Yes, you can run the engine REAL fat (4 cycleish), but it all that does is burn fuel... does nothing to improve the fit or operation of the engine at that point. With a brand new AAC/ABC engine, it simply will not run 'that' rich. Kinda self-determining factor there. The way the Jett engines (and most modern abc type engines) are constructed, the fit is pre-determined at the factory. The break-in period provides that final fitting.

The Ro-Jett CL engines are different. Different taper, materials, timing - plus they are designed to run at constant rpm. They tend to be fit tight when delivered, and require quite a bit of time on the test stand before flying - but then they run flawless forever.

Bottom line, is if you follow the mfg's break-in proceedure, it is unlikely you will have any trouble.

As an environmentaly conscious individual I would like to thank Downunder for starting this thread. Had it not been for reactions to his initial post I would have remained blissfully unaware that Sacred Cows were an endangered species.

Confusion still reigns however. Some of the cows seem diametrically opposed in opinion to others.

Should some of these cows become extinct? Which ones? Heaven forbid that readers of this thread be considered capable to make up their own mind, as that Downunder person had suggested.

What shall we do?! What shall we Do?!!!

Surely some Great Guru will step foward and tell us what to believe!

Thanks be to fate that there are not more people who decide to conduct their own experiments and share the results. If such occured the chaos flooding over this planet would be impossible to comprehend!

I shall now retire to the fetal position

jess

Jess, people were asked to let downunder post results. Is there a point to your post, other than an attempt at baiting people into more argument?

Jess:

Enjoyed reading that one.

Now for everybody:

There is one great inviolable rule for breaking an engine in.

You have to run it.

All else is subject to opinion, some of it informed, and some not.

People like Brian (Downunder) and others are posting/have posted real experimental results, the engine makers have said how they want it done, still people are speaking without posting real experimental results.

i DO NOT WANT TO CLOSE THIS THREAD because I want to see Brian's results. If, however, the sniping continues I WILL close it, and ask Brian to send me an email or PM when he's finished.

Bill.

Chuck:

I thought Jess' post was a good insertion of humor into a thread that had gotten too serious. Sorry you didn't see it.

Bill.

Gosh, Chuck. I have always enjoyed your posts and admired your insights. Only now did I come to understand your marvelous perceptiveness as a reader! Imagine reading things that, not only had I not written, but had not even thought!!!

Please expand on your post. I, as well, I am sure as many others, anxiously wait on more precognitions. What do you suppose I might say next??

Again, I respect your opinions and enjoy your posts.

jess

jess

Before this post is deleted, I would like to thank Jim Thomerson for acknowledging my information of how a car engine use to be broken in.... At one time it existed until the method was rewritten. The only reason I mentioned this method was to compare the way things are done by the book and what happens if they are not. Yes today most engines are tested( broken in) before the odometer is even connected. But I dont think RC engines are tested before leaving the manufactures shop.

If anyone can see the corrolation I am trying to make between RC engines and car engines then thank you , if not good luck.

P.S. I wonder if downunder would buy a car off ebay and use it to prove a point. Well me buying a RC engine is close to spending money for a new car . Like my mother use to say money doesn't grow on trees .

if you did this I think it would hurt downunder more than anybody else .

P.S. I if you did this I think it would hurt downunder more than anybody else .
[/quote]

How could any post in these fora be hurtfull to anyone? Do you feel Downunder expects in some way to profit from his experiment? Would you wish this thread to be shut down if you thought it would be in some way hurtfull to one of the corespondents?

I must admit my curiosity has been piqued.

Looking foward to your rerply

jess

Bill, I continue to be amazed and astounded. In Chuck's defense I feel his miss of my humor was a near miss. I believe I heard something whiz past my ear.

This is a source of personal concern to me, however. I have always wished for a military funeral with a piper playing "Amazing Grace".

I had felt that anyone who played the pipes would as a matter of necessity, if not survival, have a sense of humor. If this is not true, and coupled with the fact that I can no longer fit in my dress blues it would seem that I must live forever. A grim prospect in a humorless world.

A bemused jess

Jess....I can't fit into my dress blues either....but I can sing Amazing Grace.

Dave.