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ABC...wrong break in? - 4/8/2005 2:17:23 PM   
downunder



Posts: 3198
Joined: 10/10/2002
From: Adelaide, AUSTRALIA
Status: offline 		I just picked up a Bluebird N.S. 51 from eBaaaaaaa at a very good price but imagine my surprise when it arrived and turned out to be absolutely brand new! I took off the backplate and found two pieces of swarf about the size of dust but flushed it out anyway. There was however a LOT of swarf between the carb and housing. But the moment I realised it was new I decided to use it to find out once and for all what happens to an ABC if it's run in rich (see above about "very good price"...read "cheap" . We all know the horror stories...it'll be junked...the rod will fall to pieces...etc etc. I've never totally believed in that but I've only ever run in one ABC and that was too valuable to go experimenting with.

So onto the test stand with it. Now one thing I go along with is using a smaller than normal prop so I found a 9x6 wood. Fill the 8 ounce tank with fuel (zero nitro, 24% oil with 1/3rd being castor), give it a bit of prime and in one flick it was running. Nice. But so rich it couldn't keep running so close the needle a little. Another flick and it's running again. It sat there in a solid 4 stroke turning 11.7K with a head temp of 175F. I let it run for about 2 minutes then pulled the fuel line off...let it cool then restart (one flick again). I did 3 runs like this on the first tank and called it quits for the day (I think my neighbour was getting irritated ).

The pinch still felt exactly the same as before I ran it, meaning that you could feel the piston start to tighten up when the prop got to the same position as before so I removed the muffler to check the piston. There wasn't a mark on it (even using a magnifying glass), nothing to indicate that the top portion below the crown had been subjected to any torture whatsoever.

Today I ran two more tanks through it (at 3 runs per tank as before) but this time I went even richer. The first tank it ran at 10.3 K with a head temp of 160F then the second tank at 8.7K and a temp of 145F. Total time so far is a bit over 18 minutes. Once again I took off the muffler and used the magnifying glass on the piston. It still looks brand new. No signs of scuffing near the crown, the pinch still starts in the same position.

As for the rod wearing out, there's no signs of that either. The way I check is to slowly turn the prop until the piston is tight enough to lock in place then see how much movement there is at the prop tip. Any movement is the combined clearances of both ends of the rod plus any piston boss clearance. It's unchanged from new.

It's early days yet and I intend putting several more tank fulls through it before I even consider letting it 2 stroke but so far I'd have to say that not only has it not destroyed itself but I'd go so far as to say it doesn't even appear to be running in. Mythbusters anyone???



       Post #: 1

RE: ABC...wrong break in? - 4/8/2005 3:18:44 PM   
w8ye



Posts: 17492
Joined: 12/11/2001
From: Taylortown, OH, USA
Status: offline 		Keep us informed with this break'n story.

Only thing is... What is a Bluebird N. S. ?

Good job.

enjoy,

Jim

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RE: ABC...wrong break in? - 4/8/2005 4:26:19 PM   
Flyboy Dave



Posts: 13467
Joined: 3/20/2002
From: San Bernardino County, CA, USA
Status: offline 		Hail to "Brian the Mythbuster"....

I knew that "Tapered Bore break-in" was hogwash from the get go.

1. The engine expands out of the pinch in 3 seconds after starting.
2. It is not possible for an engine to "seize" back into the pinch at 80
times per second while running.
3. Most engines that have been run and are hot will not cool down enough
to return to the pinch for several minutes.
4. Control line flyer's start-up and run ABC type (ringless) engines in a
full rich four cycle for the life of the engine without mishap.
5. When a ringless engine is running, the oil between the piston and cylinder
makes the seal. There is no metal to metal contact.
6. The new ABC type (ringless) four cycle engines obviously run in a four
stroke manner for their lifetime without any problem.

quote:

I removed the muffler to check the piston. There wasn't a mark on it
(even using a magnifying glass), nothing to indicate that the top portion below
the crown had been subjected to any torture whatsoever.


I run my engines on 1/3 castor as well, there's a reason for that....heh heh.

Good job, downunder....keep flogging that engine for awhile.

FBD.




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RE: ABC...wrong break in? - 4/8/2005 5:37:58 PM   
DarZeelon



Posts: 7105
Joined: 4/9/2003
From: Rosh-Ha'Ayin, ISRAEL
Status: online 		Brian,


Excerpt from my break-in thread:

------------------------------------------
quote:

ORIGINAL: DarZeelon

Many sport type engines are virtually ready-to-use, just start and fly.
But I prefer treating my engines, as well as any engine I am entrusted with its break-in, as if it is an expensive, racing engine.


------------------------------------------

This means most engines will survive unscathed, even the richest break-in.

So do you have the time and money to experiment?


Even OS themselves tell you not to do the break-in so rich as to four-cycle, in this engine type.

So FBD is welcome to tell Bill Baxter that his Q&A and his words in his own column are also 'hogwash'....


The one thing we all agree on is that Castor oil is essential for these engines (at least in North America).


Metal fatigue that causes failure, does not need metal-to-metal contact.
It occurs in sliding bearings in engines, as the oil film transfers pressure, causing them to fail eventually.

The piston could screech even without touching the sleeve's chromium, apparently.



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RE: ABC...wrong break in? - 4/8/2005 5:51:50 PM   
ZAGNUT



Posts: 2436
Joined: 2/26/2003
From: tel-aviv, ISRAEL
Status: offline 		but what happens when you lean it out and heat it up?? is it going to have the same power as another engine that went through a proper break-in??

and i agree with Dar, a lot of sport engines are very loose when new and probably wouldn't suffer at all with this practice but i doubt you could get away with it on one of the really tight engines. the fact that everything went smoothly with no sudden seizures says it was loose enough not to matter...

i have had plenty of abc/abn engines change their running clearances/characteristics when playing with different fuels/props/pipes. the only one that never changes no matter what abuse it gets is the little enya.11cx with aac cylinder/piston


dave

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RE: ABC...wrong break in? - 4/8/2005 5:55:22 PM   
piper_chuck



Posts: 7896
Joined: 6/13/2004
From: Pittsboro, NC, USA
Status: offline 		It seems odd that one person's brief experiment would lead to statements like " I knew that "Tapered Bore break-in" was hogwash from the get go." Is it perhaps a bit early to declare victory? The wrong conclusion on this sort of issue could lead to hundreds of ruined engines.

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RE: ABC...wrong break in? - 4/8/2005 6:20:39 PM   
Flyboy Dave



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From: San Bernardino County, CA, USA
Status: offline
quote:

ORIGINAL: piper_chuck

The wrong conclusion on this sort of issue could lead to hundreds of ruined engines.


Show me one chuck. Until someone does....the "procedure" is nothing more than
another Internet "old Wives Tale"....nothing more.

Dave.


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RE: ABC...wrong break in? - 4/8/2005 6:46:54 PM   
jaka


 

Posts: 4536
Joined: 12/11/2001
From: Upplands Vasby, SWEDEN
Status: offline 		Hi!
Did you honestly belive that running an ABC engine a little rich would destoy it...???
Nothing could be further from the truth!
You can run any two or fourtsroke as rich as you like without destroying anything.
The only thing destroying our engines is heat (running too lean, wrong compression, wrong glowplug, too much nitro) and dirt.
Nothing else!
Our engines can tolerate much... we don't have to be soo finicky about how rich we run them as long as we don't run them too lean!

Regards!
Jan Karlsson
Sweden

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RE: ABC...wrong break in? - 4/8/2005 7:30:58 PM   
Flyer95


 

Posts: 978
Joined: 9/21/2004
From: STOCKHOLM Akersberga, SWEDEN
Status: offline 		Hi guys,
IMO the most logical break in process for an ABC/ABN engine is as Dar Zeelon has described in his "tappered bore break in" column . Not every ABC/ABN engine will get destroyed immidiately by fourstroking but the high output tight engines will probably do if fourstroking and running cold for a long time. My friend just bought a new OS46FX and he turned it over the TDC just by rotating the propwasher . So I dont think his engine needs a break in (to loose to begin with). Good luck.

< Message edited by Flyer95 -- 4/8/2005 7:37:27 PM >

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RE: ABC...wrong break in? - 4/8/2005 8:01:03 PM   
DarZeelon



Posts: 7105
Joined: 4/9/2003
From: Rosh-Ha'Ayin, ISRAEL
Status: online 		I have seen a Webra .50GT (ABN) get destroyed (peeled the nickel) after the third tank four-stroking. The only Webra I have seen do this... They are generally pretty loose.

It happened at the hands of someone I was trying to convince to lean it out a little... He was reluctant to.
It was luckily replaced under warranty.

The replacement was broken-in was under my supervision and it was uneventful.
This engine is still running strong, with nearly 50 hour logged.

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RE: ABC...wrong break in? - 4/8/2005 8:01:59 PM   
MerlinL14



Posts: 501
Joined: 1/3/2004
From: Liverpool, UNITED KINGDOM
Status: offline 		I'm in the DarZeelon camp on this one. His documented procedure works, I use it and have never had a problem with Irvine, ASP, SC, TT or Magnum engines by following it. When downunder's procedure has been 'proved', and this could take years testing on all/most of the ABC brand name engines, I may change my judgment. Untill then.......................

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RE: ABC...wrong break in? - 4/8/2005 8:44:02 PM   
w8ye



Posts: 17492
Joined: 12/11/2001
From: Taylortown, OH, USA
Status: offline 		All I ever see at the flying field is the "Give Her Hell" attitude.

The guy brings a brand new engine out to the field.

He starts it up.

Leans it out to the last breath of rpm.

Puts it up in the air.

Then complains about the "no good" engine because it quit on him at the top of the first loop.

Cannot tell them a thing.

Enjoy,

Jim



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RE: ABC...wrong break in? - 4/8/2005 9:13:51 PM   
piper_chuck



Posts: 7896
Joined: 6/13/2004
From: Pittsboro, NC, USA
Status: offline
quote:

ORIGINAL: Flyboy Dave
Show me one chuck. Until someone does....the "procedure" is nothing more than
another Internet "old Wives Tale"....nothing more.

Show me conclusive proof that ignoring the recommendations of engine manufacturers and people with a huge amount of experience does not damage engines. Such proof would be controlled testing of a significant number of engines over a long period. One person's limited testing (9 total runs) on a cheap engine proves nothing other than he has time and money to throw away. Until such conclusive testing is done, I personally think it's wise to follow the voices of experience, and of the people who made the engines.

Besides, what's the point of trying to prove the manufacturer wrong in this case? Other than sticking to tradition (engines must be broken in sloppy rich) what's the goal? Experience, and experimentation by engine manufacturers and others, has shown that it's not necessary, and harmful to the engine. I can't see the value in trying to prove them wrong, or jumping on the bandwagon of someone who's advocating ignoring them.

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RE: ABC...wrong break in? - 4/8/2005 9:28:14 PM   
piper_chuck



Posts: 7896
Joined: 6/13/2004
From: Pittsboro, NC, USA
Status: offline
quote:

ORIGINAL: jaka

Hi!
Did you honestly belive that running an ABC engine a little rich would destoy it...???
Nothing could be further from the truth!

He's not talking about a little rich, he's talking about running it sloppy rich. There is a difference.
quote:


You can run any two or fourtsroke as rich as you like without destroying anything.
The only thing destroying our engines is heat (running too lean, wrong compression, wrong glowplug, too much nitro) and dirt.
Nothing else!
Our engines can tolerate much... we don't have to be soo finicky about how rich we run them as long as we don't run them too lean!

Jan, why don't you put your engines where your mouth is? Take a sample of let's say 2,000 ABC engines of various sizes and manufacturers. Mount these engines on test stands. Put each of them through a similar number of runs that the average sport engine would go through, perhaps 5,000 each. Oh, and while you're at it, why don't you use some of the 10% oil fuel you so strongly advocate? Run 1/2 of them sloppy rich as the OP proposed, and with your fuel. Follow the engine manufacturer's recommendations for the other half. When you're finished, report the results here. If the sloppy rich procedure you've so enthusiastically endorsed works better than that recommended by the manufacturers people might listen. Until then, I'm sticking with the opinions of those who know what they are doing.

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RE: ABC...wrong break in? - 4/8/2005 11:16:37 PM   
Flyboy Dave



Posts: 13467
Joined: 3/20/2002
From: San Bernardino County, CA, USA
Status: offline 		piper_chuck....you're missing the point. I/we are not advocating running the
engines sloppy rich....I/we never did. I/we are saying that doing so might
waste some fuel and prolong the break-in by not allowing the engine to
reach maximum operating temperature....however, it will not harm the
engine running it very, or sloppy rich.

No one will argue that running the engine at a rich two cycle is not proper.
We are saying that....in fact I/we agree wholeheartedly.... that is a good
procedure. Not one manufacturer has said that running an engine sloppy rich
will hurt it....ever. Not that it matters, but the reference to the OS FAQ's
was in reference to ABN engines.

If that were the case, there would be no such thing as running a ringless control
line engine....they would have all been destroyed "by the reckless operators"....

...."that didn't know what they were doing".

And of course the new ringless four-strokes would be doomed to failure as well.

BTW....I chunked an OS nickel liner. It wasn't because the engine had run too rich.
It wasn't because the engine had been run too lean. It wasn't because the engine