How can you tell if an engine is broken in?
06-30-2007, 07:11 PM
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How can you tell if an engine is broken in?
Hi all,
Is there one tell tell sighn or is it combination?"If you don't know history of an engine" What happens if you don't break in a ringed engine? and my last question, why some engine requiar adverse break in like airplane gas/glow in comperson other engines like motorcycle or weedwacker?
Thank you in advance.
Is there one tell tell sighn or is it combination?"If you don't know history of an engine" What happens if you don't break in a ringed engine? and my last question, why some engine requiar adverse break in like airplane gas/glow in comperson other engines like motorcycle or weedwacker?
Thank you in advance.
06-30-2007, 07:58 PM
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RE: How can you tell if an engine is broken in?
This is a hot topic, everyone has their own ideas about the correct way to do it. The type of piston/cylinder arangement and fit will determine the best break-in procedure. Most sport engines made these days are loose enough to use right out of the box to use without any special treatment. Ringed engines will begin to run better after the first few tanks, ABC engines run good from the beginning. The bennefits of a careful break-in are quickly lost when the plane is flown from a dusty runway.
06-30-2007, 09:48 PM
#4
RE: How can you tell if an engine is broken in?
Regardless of the break in method when complete the engine will hold RPM when leaned and throttle wide open it should hold if it drops not broken in fully also the revs pick up
from the first couple of runs it will run faster and as stated hold its peak martin
from the first couple of runs it will run faster and as stated hold its peak martin
07-01-2007, 08:32 AM
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RE: How can you tell if an engine is broken in?
On my full scale gasser, the only way to tell is the cylinder head temp starts to stabilize at about 300F, which occurs after about 10 hours of use. Even after the initial breakin it ran at full power, cranking the prop at the correct RPM's, but ran about 330F on the CHT for a while. That's the only difference I could see..
On r/c motors, though, you can't really measure the cylinder head temp in the air (though I think there are monitors out there that allow you to read it after the flight)....
My OS and Saito motors always were able to hold full throttle RPM's and ran great after the initial breakin so always assumed they were broken-in at that point. I do remember my OS 1.40 (now R.I.P.) started developing a little more power after about 5 or 6 flights (it later succumbed to bad bearings and then retirement of the plane).
Yeah I won't even start trying to suggest what breakin procedure to use or anything, that'll start a flame war probably
. I will say 2 things though:
- ringed motors usually do go ahead and breakin ok eventually without any special running beyond a bit rich for the first couple tanks
- motors usually die of crash damage long before you can tell if the breakin affected the lifetime or not
LS
On r/c motors, though, you can't really measure the cylinder head temp in the air (though I think there are monitors out there that allow you to read it after the flight)....
My OS and Saito motors always were able to hold full throttle RPM's and ran great after the initial breakin so always assumed they were broken-in at that point. I do remember my OS 1.40 (now R.I.P.) started developing a little more power after about 5 or 6 flights (it later succumbed to bad bearings and then retirement of the plane).
Yeah I won't even start trying to suggest what breakin procedure to use or anything, that'll start a flame war probably
. I will say 2 things though:- ringed motors usually do go ahead and breakin ok eventually without any special running beyond a bit rich for the first couple tanks
- motors usually die of crash damage long before you can tell if the breakin affected the lifetime or not
LS
07-01-2007, 11:36 AM
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RE: How can you tell if an engine is broken in?
ORIGINAL: lucien
- ringed motors usually do go ahead and breakin ok eventually without any special running beyond a bit rich for the first couple tanks
LS
- ringed motors usually do go ahead and breakin ok eventually without any special running beyond a bit rich for the first couple tanks
LS
The ringed engines that I have experience with like my ST's and Magnum 4s' need more than just running a little rich for the first couple of tanks. First tanks are VERY rich and then gradually you lean them out over an extended period. This is what the manufacturer recommends. If I recall the magnum manual recomends at least 45 minutes of run time before flying (thats 5 minutes running, then a 10 minute cool down).
Personally I always take my time in break in on a ringed engine. Its a small investment to protect your engine. Maybe its a little overkill but better safe than sorry.
As far as ABC engines I generally run 3 to 4 tanks through them.
When in doubt follow the manufacturers instruction. I have broken in probably 10 or so engines all following the manufacturers instructions and ALL of my engines run great.
07-01-2007, 12:16 PM
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RE: How can you tell if an engine is broken in?
Hello,
Thanks for all replies . Now for example, if you take a motor out of a box and ignore all the break-in recommendations, what happens?
beside a slight less compression, what else would go wrong?
Thanks for all replies . Now for example, if you take a motor out of a box and ignore all the break-in recommendations, what happens?
beside a slight less compression, what else would go wrong?
07-01-2007, 12:36 PM
#9
RE: How can you tell if an engine is broken in?
ORIGINAL: shawn45
Hello,
Thanks for all replies . Now for example, if you take a motor out of a box and ignore
all the break-in recommendations, what happens?
Hello,
Thanks for all replies . Now for example, if you take a motor out of a box and ignore
all the break-in recommendations, what happens?
FBD.
07-01-2007, 02:33 PM
#11
RE: How can you tell if an engine is broken in?
Jaka you may be able to pull it off with a ABN but an ABC lean and hot could be an issue if the engine is not real tight maybe-- you can. one of my irvine 53s was super tight and needed about 5 runs, cool downs before it was right for high speed and full lean out you might get away with it with more castor martin
the break in instructions packed with the engine are there for a reason
the break in instructions packed with the engine are there for a reason
07-01-2007, 02:56 PM
#12
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RE: How can you tell if an engine is broken in?
Shawn (or is it Sean (Connery) the proper British way to spell your name),
[link=http://www.rcuniverse.com/forum/Tapered%2DBore_Engine_Break%2Din_%2D_Upgraded/m_1850473/tm.htm]This[/link] is the way to do it with a tapered-bore, ring-less engine.
A ringed engine will need a much cooler, more careful, elaborate procedure...
[link=http://www.rcuniverse.com/forum/Tapered%2DBore_Engine_Break%2Din_%2D_Upgraded/m_1850473/tm.htm]This[/link] is the way to do it with a tapered-bore, ring-less engine.
A ringed engine will need a much cooler, more careful, elaborate procedure...
07-01-2007, 07:13 PM
#13
RE: How can you tell if an engine is broken in?
ORIGINAL: shawn45
Hello,
Thanks for all replies . Now for example, if you take a motor out of a box and ignore all the break-in recommendations, what happens?
beside a slight less compression, what else would go wrong?
Hello,
Thanks for all replies . Now for example, if you take a motor out of a box and ignore all the break-in recommendations, what happens?
beside a slight less compression, what else would go wrong?
Notrhing, dial it in and fly it, I do that with all mine and been running fine for years--inverted to boot!
07-01-2007, 11:03 PM
#15
RE: How can you tell if an engine is broken in?
- ringed motors usually do go ahead and breakin ok eventually without any special running beyond a bit rich for the first couple tanks
07-01-2007, 11:17 PM
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RE: How can you tell if an engine is broken in?
ORIGINAL: Sport_Pilot
I have never run across even an ABC engine that broke in in two tanks of fuel, let alone a ringed engine. But I don't consider it broken in just because it will fly withoug deadsticking. It is broken in when it develops peak power. Probably a couple of gallons of fuel or more for some ringed engines, much less for ABC.
- ringed motors usually do go ahead and breakin ok eventually without any special running beyond a bit rich for the first couple tanks
My OS 1.40 was like that. The intial ground breakin was a couple of tanks and after that you go fly. But it took probably 8 flights or so for it to develop full power.
My gassers run hot, about 330F on the cylinder head temp, for about the first 10 hours. After that, they've settled down to about 300F at which point you can conclude they're broken in...
LS
07-01-2007, 11:37 PM
#17
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RE: How can you tell if an engine is broken in?
Hugh, Lucien,
MVVS .12-.91 glow engines reach their full potential after 5-10 hours, yet they will accept sustained, lean full throttle (without any elevated temperatures) after just 200-500 cc of fuel has been consumed.
Would you see it as a two-tank break-in, or a 5-10 hour break-in?
MVVS .12-.91 glow engines reach their full potential after 5-10 hours, yet they will accept sustained, lean full throttle (without any elevated temperatures) after just 200-500 cc of fuel has been consumed.
Would you see it as a two-tank break-in, or a 5-10 hour break-in?
