Saito 125 engine bearing failure
01-28-2009, 03:22 PM
#101
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RE: Saito 125 engine bearing failure
ORIGINAL: Flyboy Dave
Welcome to RC-Bearings.com, your best source for low cost, high quality silicon nitride hybrid ceramic
and standard steel bearings.
http://www.rc-bearings.com/catalog/
OS 61 SF/FSR
[os61fx]
http://www.rc-bearings.com/catalog/p...2274e04d50b6f/
The R/Cbearings are the cheapest that money can buy.....plain steel everywhere....no chrome.
They are $5.97 for the set.
The Boca bearings are more money, but they have:
Econo RC Engine Bearing Kit. Our Economy line of RC Engine bearings are intended to be the most
affordable way to replace stock bearings. These bearings have chrome steel races, balls, retainers
and shields. The ENK-002 set is $11.88 for the chrome set....(same engine).
I can guarantee you guys one thing....I won't take the time to rebuild an engine....and put in a
cheap set of six dollar.... ready to rust plain steel bearings, when the better quality chrome bearings
are available on the market. You can bet on that.
Six bucks for a set of bearings ? I wouldn't put those in a roller skate.
Howz' that for veracity ??? [sm=red_smile.gif]
FBD.
Welcome to RC-Bearings.com, your best source for low cost, high quality silicon nitride hybrid ceramic
and standard steel bearings.
http://www.rc-bearings.com/catalog/
OS 61 SF/FSR
[os61fx]
http://www.rc-bearings.com/catalog/p...2274e04d50b6f/
The R/Cbearings are the cheapest that money can buy.....plain steel everywhere....no chrome.
They are $5.97 for the set.
The Boca bearings are more money, but they have:
Econo RC Engine Bearing Kit. Our Economy line of RC Engine bearings are intended to be the most
affordable way to replace stock bearings. These bearings have chrome steel races, balls, retainers
and shields. The ENK-002 set is $11.88 for the chrome set....(same engine).
I can guarantee you guys one thing....I won't take the time to rebuild an engine....and put in a
cheap set of six dollar.... ready to rust plain steel bearings, when the better quality chrome bearings
are available on the market. You can bet on that.
Six bucks for a set of bearings ? I wouldn't put those in a roller skate.
Howz' that for veracity ??? [sm=red_smile.gif]
FBD.
Maybe you should learn a little bit about bearings before you try passing yourself off as some kind of expert.
ALL of my steel bearings are made from either AISI chrome steel, or 440 stainless steel. ALL of my ceramic balls are silicon nitride.NO ONE, to my knowledge, makes bearings out of plain carbon steel.
Also, I can tell you that most other sellers and myself pay within 3-15 cents each for our steel bearings. We all get them from many of the same manufacturers. NOW, who is selling cheap junk??
01-28-2009, 03:55 PM
#102
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RE: Saito 125 engine bearing failure
ORIGINAL: mike early
To their credit, the Boca Bearings are performing wonderfully. After I turned the front bearing around the other way, there seems to be far less leakage from the front of the engine.
I still get the forward-backward (axial) play when the engine is hot, but performance doesn't seem affected whatsoever. The engine screams with delight.
To their credit, the Boca Bearings are performing wonderfully. After I turned the front bearing around the other way, there seems to be far less leakage from the front of the engine.
I still get the forward-backward (axial) play when the engine is hot, but performance doesn't seem affected whatsoever. The engine screams with delight.
1. The front bearing races are worn out or improperly formed, or,
2. The front bearing is loose in the crankcase.
The way the crank is designed is for the prop drive washer and/or split collar to lock the inner race of the front bearing against the shoulder of the crank. The crank can't move without the inner race moving.
01-28-2009, 03:56 PM
#103
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RE: Saito 125 engine bearing failure
Here is a rear bearing from a well abused Saito 91. It was run in excess of 13K RPM on High Nitro Fuel with no after run. Standard bearing which should have lasted a long time. I have a 91 that is over 6 years old and has been run extensively and the bearings are fine. Turns about 10K RPM on 10% nitro 100% Castor oil at 20%. I have never had a bearing do this and I have used dozens of engines.
There is no reason any standard bearing should fail if an engine is taken care of and not abused. I have found that the biggest cause of bearing failure is rust. ARO prevents that.
There is no reason any standard bearing should fail if an engine is taken care of and not abused. I have found that the biggest cause of bearing failure is rust. ARO prevents that.
01-28-2009, 04:03 PM
#104
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RE: Saito 125 engine bearing failure
ORIGINAL: ace4-40
Here is a rear bearing from a well abused Saito 91. It was run in excess of 13K RPM on High Nitro Fuel with no after run. Standard bearing which should have lasted a long time. I have a 91 that is over 6 years old and has been run extensively and the bearings are fine. Turns about 10K RPM on 10% nitro 100% Castor oil at 20%. I have never had a bearing do this and I have used dozens of engines.
There is no reason any standard bearing should fail if an engine is taken care of and not abused. I have found that the biggest cause of bearing failure is rust. ARO prevents that.
Here is a rear bearing from a well abused Saito 91. It was run in excess of 13K RPM on High Nitro Fuel with no after run. Standard bearing which should have lasted a long time. I have a 91 that is over 6 years old and has been run extensively and the bearings are fine. Turns about 10K RPM on 10% nitro 100% Castor oil at 20%. I have never had a bearing do this and I have used dozens of engines.
There is no reason any standard bearing should fail if an engine is taken care of and not abused. I have found that the biggest cause of bearing failure is rust. ARO prevents that.
01-28-2009, 04:20 PM
#105
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RE: Saito 125 engine bearing failure
I ran my old OS FS 90 on a 14x8 on a top flite P39 for years. Turned 8800 RPM and never had a bearing problem. Plane went lickety split.
01-28-2009, 04:31 PM
#106
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RE: Saito 125 engine bearing failure
ORIGINAL: ace4-40
I ran my old OS FS 90 on a 14x8 on a top flite P39 for years. Turned 8800 RPM and never had a bearing problem. Plane went lickety split.
I ran my old OS FS 90 on a 14x8 on a top flite P39 for years. Turned 8800 RPM and never had a bearing problem. Plane went lickety split.
03-12-2009, 05:59 AM
#107
Senior Member
RE: Saito 125 engine bearing failure
ORIGINAL: RC-Bearings
I know this is a day late and a dollar short, but axial play of a crankshaft is due to only two things (barring a loose prop nut):
1. The front bearing races are worn out or improperly formed, or,
2. The front bearing is loose in the crankcase.
The way the crank is designed is for the prop drive washer and/or split collar to lock the inner race of the front bearing against the shoulder of the crank. The crank can't move without the inner race moving.
ORIGINAL: mike early
To their credit, the Boca Bearings are performing wonderfully. After I turned the front bearing around the other way, there seems to be far less leakage from the front of the engine.
I still get the forward-backward (axial) play when the engine is hot, but performance doesn't seem affected whatsoever. The engine screams with delight.
To their credit, the Boca Bearings are performing wonderfully. After I turned the front bearing around the other way, there seems to be far less leakage from the front of the engine.
I still get the forward-backward (axial) play when the engine is hot, but performance doesn't seem affected whatsoever. The engine screams with delight.
1. The front bearing races are worn out or improperly formed, or,
2. The front bearing is loose in the crankcase.
The way the crank is designed is for the prop drive washer and/or split collar to lock the inner race of the front bearing against the shoulder of the crank. The crank can't move without the inner race moving.
You were right about the Front Bearing being Loose in the Crankcase! I bought another crankcase and problem solved.
03-12-2009, 06:51 AM
#108
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RE: Saito 125 engine bearing failure
I ran across a nice overview about sealed front bearings as this topic has come up here frequently.
http://www.mecoa.com/faq/crankshafts/blowby.htm
Bill
http://www.mecoa.com/faq/crankshafts/blowby.htm
Bill
03-12-2009, 07:28 AM
#109
Senior Member
RE: Saito 125 engine bearing failure
ORIGINAL: Ram Jet
I ran across a nice overview about sealed front bearings as this topic has come up here frequently.
http://www.mecoa.com/faq/crankshafts/blowby.htm
Bill
I ran across a nice overview about sealed front bearings as this topic has come up here frequently.
http://www.mecoa.com/faq/crankshafts/blowby.htm
Bill
That site has some useful info for those that don't have a break-in bench:
AIRBORNE BREAK-IN
1> BREAK-IN running should be done with the recommended propeller at a rich setting. The needle valve should be set at a point just into this range from a four cycle setting. Fly the plane at maximum throttle for 2 minutes, then throttle back for approximately 30 seconds. Repeat this sequence until approximately 45 minutes of accumulated running time has been obtained. Additionally, certain maneuvers, such as "CUBAN EIGHT'S", that allow the engine to load and unload are recommended. AVOID PROLONGED CLIMBING MANEUVERS AT MAXIMUM THROTTLE.
2> After the first 45 minutes change to normal size prop and fly an additional 45 minutes. Continue to run the engine at a slightly rich four cycle setting and fly your normal pattern.
3> After the above break-in period, run the engine at a normal peak needle valve setting. This should be a little on the rich side because engines run leaner in the air. 5% - 15% nitro may be used
03-12-2009, 08:35 AM
#110
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RE: Saito 125 engine bearing failure
ORIGINAL: mike early
That site has some useful info for those that don't have a break-in bench:
AIRBORNE BREAK-IN
1> BREAK-IN running should be done with the recommended propeller at a rich setting. The needle valve should be set at a point just into this range from a four cycle setting. Fly the plane at maximum throttle for 2 minutes, then throttle back for approximately 30 seconds. Repeat this sequence until approximately 45 minutes of accumulated running time has been obtained. Additionally, certain maneuvers, such as "CUBAN EIGHT'S", that allow the engine to load and unload are recommended. AVOID PROLONGED CLIMBING MANEUVERS AT MAXIMUM THROTTLE.
2> After the first 45 minutes change to normal size prop and fly an additional 45 minutes. Continue to run the engine at a slightly rich four cycle setting and fly your normal pattern.
3> After the above break-in period, run the engine at a normal peak needle valve setting. This should be a little on the rich side because engines run leaner in the air. 5% - 15% nitro may be used
ORIGINAL: Ram Jet
I ran across a nice overview about sealed front bearings as this topic has come up here frequently.
http://www.mecoa.com/faq/crankshafts/blowby.htm
Bill
I ran across a nice overview about sealed front bearings as this topic has come up here frequently.
http://www.mecoa.com/faq/crankshafts/blowby.htm
Bill
That site has some useful info for those that don't have a break-in bench:
AIRBORNE BREAK-IN
1> BREAK-IN running should be done with the recommended propeller at a rich setting. The needle valve should be set at a point just into this range from a four cycle setting. Fly the plane at maximum throttle for 2 minutes, then throttle back for approximately 30 seconds. Repeat this sequence until approximately 45 minutes of accumulated running time has been obtained. Additionally, certain maneuvers, such as "CUBAN EIGHT'S", that allow the engine to load and unload are recommended. AVOID PROLONGED CLIMBING MANEUVERS AT MAXIMUM THROTTLE.
2> After the first 45 minutes change to normal size prop and fly an additional 45 minutes. Continue to run the engine at a slightly rich four cycle setting and fly your normal pattern.
3> After the above break-in period, run the engine at a normal peak needle valve setting. This should be a little on the rich side because engines run leaner in the air. 5% - 15% nitro may be used
03-12-2009, 09:44 AM
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RE: Saito 125 engine bearing failure
ORIGINAL: RC-Bearings
If this is an ABx engine, I would modify that a bit to read run the engine at a rich TWO STROKE setting as running it so righ that it is four stroking means the engine is not getting hot enough to properly expand. Ringed engines don't need as much heat because the cylinders are not tapered. They need a lot of rich running to heep the ring and cylinder flooded with cooling while all the microscopic high spots are burnished smooth.
ORIGINAL: mike early
That site has some useful info for those that don't have a break-in bench:
AIRBORNE BREAK-IN
1> BREAK-IN running should be done with the recommended propeller at a rich setting. The needle valve should be set at a point just into this range from a four cycle setting. Fly the plane at maximum throttle for 2 minutes, then throttle back for approximately 30 seconds. Repeat this sequence until approximately 45 minutes of accumulated running time has been obtained. Additionally, certain maneuvers, such as "CUBAN EIGHT'S", that allow the engine to load and unload are recommended. AVOID PROLONGED CLIMBING MANEUVERS AT MAXIMUM THROTTLE.
2> After the first 45 minutes change to normal size prop and fly an additional 45 minutes. Continue to run the engine at a slightly rich four cycle setting and fly your normal pattern.
3> After the above break-in period, run the engine at a normal peak needle valve setting. This should be a little on the rich side because engines run leaner in the air. 5% - 15% nitro may be used
ORIGINAL: Ram Jet
I ran across a nice overview about sealed front bearings as this topic has come up here frequently.
http://www.mecoa.com/faq/crankshafts/blowby.htm
Bill
I ran across a nice overview about sealed front bearings as this topic has come up here frequently.
http://www.mecoa.com/faq/crankshafts/blowby.htm
Bill
That site has some useful info for those that don't have a break-in bench:
AIRBORNE BREAK-IN
1> BREAK-IN running should be done with the recommended propeller at a rich setting. The needle valve should be set at a point just into this range from a four cycle setting. Fly the plane at maximum throttle for 2 minutes, then throttle back for approximately 30 seconds. Repeat this sequence until approximately 45 minutes of accumulated running time has been obtained. Additionally, certain maneuvers, such as "CUBAN EIGHT'S", that allow the engine to load and unload are recommended. AVOID PROLONGED CLIMBING MANEUVERS AT MAXIMUM THROTTLE.
2> After the first 45 minutes change to normal size prop and fly an additional 45 minutes. Continue to run the engine at a slightly rich four cycle setting and fly your normal pattern.
3> After the above break-in period, run the engine at a normal peak needle valve setting. This should be a little on the rich side because engines run leaner in the air. 5% - 15% nitro may be used
I couldn't agree with you more. On a ringed engine I think short bursts of full throttle is effective in helping to seat the rings also.
Bill
