Ring Engine Compression
05-07-2012 | 12:02 PM
#26
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From: SalisburyWiltshire, UNITED KINGDOM
RE: Ring Engine Compression
Although heli engines don't have much of a life expectancy - once ranked with buggy and ducted fan engines - a very ditterent operating environment to propped aero engines.
05-07-2012 | 12:24 PM
#27
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From: SalisburyWiltshire, UNITED KINGDOM
RE: Ring Engine Compression
Oh dear - OS are definately not the flavour of the month - I have just read about the nickel plating peeling at the 'pinch' in sleeves of some ABN engines.
Thread is; <font size="+1">OS 46FX problem - see pics</font>
Thread is; <font size="+1">OS 46FX problem - see pics</font>
05-07-2012 | 07:29 PM
#29
RE: Ring Engine Compression
ORIGINAL: roojoose
Wow - I had no idea that OS had done a kamikazi raid on their justification for their high prices - guess I won't be buying another one any time soon!!!
The oldest engine I have still in use is an Enya 45 6001 that has two rings - it will probably out-last me!
I love my Super Tigres, but have never owned a Fox engine that I can remember...
Ringed is the way to go if you want an engine that will last - run it in right
ORIGINAL: Sport_Pilot
OS is not known for longevity.
For longevity try a Enya, Fox, or the older SuperTigre's (not sure about the Chinese versions).
OS is not known for longevity.
For longevity try a Enya, Fox, or the older SuperTigre's (not sure about the Chinese versions).
The oldest engine I have still in use is an Enya 45 6001 that has two rings - it will probably out-last me!
I love my Super Tigres, but have never owned a Fox engine that I can remember...
Ringed is the way to go if you want an engine that will last - run it in right
05-08-2012 | 02:49 AM
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From: HUNTSVILLE,
AL
05-08-2012 | 12:55 PM
#31
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From: SalisburyWiltshire, UNITED KINGDOM
RE: Ring Engine Compression
Nice going, Cap'n, I have retained 6 ABC engines including the first one I ever bought (25 years old now), I just prefer ringed engines.
Most on here would agree that it is the first few runs/tanks/gallons that make or break the longevity of an engine.
Most on here would agree that it is the first few runs/tanks/gallons that make or break the longevity of an engine.
05-08-2012 | 01:20 PM
#32
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From: SalisburyWiltshire, UNITED KINGDOM
RE: Ring Engine Compression
Next thing based on this logic will be a Cerium Oxide fuel additive to help polish the moving parts into their 'closest fit for max power'
Some poeple will believe anything.
05-08-2012 | 05:43 PM
#33
RE: Ring Engine Compression
Ok ringed model glow engines do not use motorcycle techniques for running in a engine.
The Fox engine methods would apply to most ringed engines though Fox engines have a hardened cylinder sleeve that can take a little longer to get the ring seated against it good.
On ABC engines I use this method or something close. Nelson engines hold more records in engine dominated events than any other engines. So they seem to know something.
http://www.pspec.com/breakin.asp
But unless you are racing use props more in line with what the engine manufacturer suggests.
The Fox engine methods would apply to most ringed engines though Fox engines have a hardened cylinder sleeve that can take a little longer to get the ring seated against it good.
To break in a Fox ringed engine one should run the engine in a four cycle mode. This is because in this condition the cylinder pressure is near the maximum. One needs to develop as much cylinder pressure as is practical to drive the ring into the cylinder. The driving of the ring into the cylinder is what allows the cross hatch in that hard Fox liner to shape the ring to conform to the cylinder bore. The power stroke (cylinder pressure) in the four cycle mode is noticeably higher than in the 2 cycle mode because it has a cleaner and larger inlet charge (more efficient scavenging between firings).
Now since the Fox is a sleeved timed engine the heating around the sleeve is not uniform. One needs to thermal cycle the engine to allow the cylinder to reach its final operating shape, rather slowly. A engine is broken in when the piston ring can seal against the cylinder when the cylinder is in its final shape under full power (heat load)! There is no heat treating going on in the metal's grain structure of the ring or in the cylinder just dimensional changes as a result of thermal growth!
Now a lapped meehanite iron piston and leaded steal cylinder do go through a stage where the grain structure is changed. But this is due to work hardening not heat treating.
Like I've said before; too fast too soon too hot too bad.
Now since the Fox is a sleeved timed engine the heating around the sleeve is not uniform. One needs to thermal cycle the engine to allow the cylinder to reach its final operating shape, rather slowly. A engine is broken in when the piston ring can seal against the cylinder when the cylinder is in its final shape under full power (heat load)! There is no heat treating going on in the metal's grain structure of the ring or in the cylinder just dimensional changes as a result of thermal growth!
Now a lapped meehanite iron piston and leaded steal cylinder do go through a stage where the grain structure is changed. But this is due to work hardening not heat treating.
Like I've said before; too fast too soon too hot too bad.
http://www.pspec.com/breakin.asp
But unless you are racing use props more in line with what the engine manufacturer suggests.
