Strange sound
10-10-2010, 03:19 AM
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Strange sound
Hi,
I have a problem on my new saito 125 ( 2 hours )
whenever i leave the engine on idle then after ~ 1 minute the engine sound is suddenly changed to someting that sound like very very loud air suction ( the sound is similar to the sound when you rotate the prop by hand around the TDC )
the engine continue to work ok but that sound remained till i shutdown the engine
there is cases when i start the engine and then the sound is ok, but then after landing when i taxi the airplane back to the parking the sound will usually start
any ideas ?
I have a problem on my new saito 125 ( 2 hours )
whenever i leave the engine on idle then after ~ 1 minute the engine sound is suddenly changed to someting that sound like very very loud air suction ( the sound is similar to the sound when you rotate the prop by hand around the TDC )
the engine continue to work ok but that sound remained till i shutdown the engine
there is cases when i start the engine and then the sound is ok, but then after landing when i taxi the airplane back to the parking the sound will usually start
any ideas ?
.
10-11-2010, 09:46 AM
#10
RE: Strange sound
ORIGINAL: selnekav
is there bearing for saito which is not exposed for currosion ?
is there bearing for saito which is not exposed for currosion ?
Check with Boca Bearings or RC Bearings for stainless steel or ceramic bearings. But, with proper maintenance and use of castor oil, bearing corrosion should not be an issue. Good luck.
Regards, Richard
10-11-2010, 09:58 AM
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RE: Strange sound
Remember that most stainless steel (440c) have a much lower dynamic load limit than SAE 52100 high carbon steel. So if the bearing failed because it was over loaded it might not be wise to move down to the weaker SS bearing. You should find the failure mode first. And Yes run 100% castor oil as your lubricant. And follow proper storage procedures.
10-11-2010, 10:34 AM
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RE: Strange sound
My understanding is that manufacturers tend to use the least costly parts like bearings. Thunder Tiger is known for tearing up factory bearings. Good new bearinsg from Boca or Paul are the answer. Not necessary to go to the super duper ceramics or stainless. IMHO it is necessary to have some Castor oil in the mix and your bearings will last longer.
Chip
Chip
10-11-2010, 11:28 AM
#13
RE: Strange sound
ORIGINAL: Konrad
Remember that most stainless steel (440c) have a much lower dynamic load limit than SAE 52100 high carbon steel. So if the bearing failed because it was over loaded it might not be wise to move down to the weaker SS bearing. You should find the failure mode first. And Yes run 100% castor oil as your lubricant. And follow proper storage procedures.
Remember that most stainless steel (440c) have a much lower dynamic load limit than SAE 52100 high carbon steel. So if the bearing failed because it was over loaded it might not be wise to move down to the weaker SS bearing. You should find the failure mode first. And Yes run 100% castor oil as your lubricant. And follow proper storage procedures.
Your previous discussion suggested corrosion as cause of failure, not load, so the reduced load capability of CRES should not be a factor here. SAITO do not recommend all castor in the fuel used in their engines because of exhaust valve stem fouling. Some castor, however, is generally deemed desireable.
Regards, Richard
10-11-2010, 02:32 PM
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RE: Strange sound
Gen Saito at one time did not want any castor oil. This was because he didn't want his technician spending time to clean the castings doing warranty work. Saito's big bore engines are prone to valve seal problems across the valve seat as a result of aluminum porosity. ( think I have a posted about this) This can be difficult to see if covered with carbon.
I have never seen a sticky valve on a Saito as a result of carbon from castor. Now I have seen valves and lifters stuck as a result of rancid castor. But this is a storage issue NOT an operational issue. Nor is it unique to Saito. I know of no operational issues with running castor (ok it might be hard to clean off) But the plethora of documented issue with synthetic makes their use questionable in any engine at any percentage.
No, I don't think I said the issue was corrosion. Just that corrosion can happen at any time. It is not dependent of run time but rather exposer to moisture. So any engine is susceptible to corrosion once you add fuel the carb. I think I said that one should find the failure mode before one sought a solution.
BTW Saito has had some of the best warranty policies that I have had to use and they actually honor them!
All the best,
Konrad
I have never seen a sticky valve on a Saito as a result of carbon from castor. Now I have seen valves and lifters stuck as a result of rancid castor. But this is a storage issue NOT an operational issue. Nor is it unique to Saito. I know of no operational issues with running castor (ok it might be hard to clean off) But the plethora of documented issue with synthetic makes their use questionable in any engine at any percentage.
No, I don't think I said the issue was corrosion. Just that corrosion can happen at any time. It is not dependent of run time but rather exposer to moisture. So any engine is susceptible to corrosion once you add fuel the carb. I think I said that one should find the failure mode before one sought a solution.
BTW Saito has had some of the best warranty policies that I have had to use and they actually honor them!
All the best,
Konrad
10-11-2010, 07:25 PM
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RE: Strange sound
ORIGINAL: Konrad
Remember that most stainless steel (440c) have a much lower dynamic load limit than SAE 52100 high carbon steel. So if the bearing failed because it was over loaded it might not be wise to move down to the weaker SS bearing. You should find the failure mode first. And Yes run 100% castor oil as your lubricant. And follow proper storage procedures.
Remember that most stainless steel (440c) have a much lower dynamic load limit than SAE 52100 high carbon steel. So if the bearing failed because it was over loaded it might not be wise to move down to the weaker SS bearing. You should find the failure mode first. And Yes run 100% castor oil as your lubricant. And follow proper storage procedures.
As a side note, the ceramic hybrid bearings(bearing steel races, ceramic balls) I tested in all three engines had the worst life but the engines did gain 100 to 200 rpm when they were fresh. The races started to get rough and were pulled, none grenaded. All bearing types were run-in richer than normal for two tanks, that's more than most guys would do.
10-11-2010, 07:31 PM
#18
RE: Strange sound
ORIGINAL: Konrad
Gen Saito at one time did not want any castor oil. This was because he didn't want his technician spending time to clean the castings doing warranty work. Saito's big bore engines are prone to valve seal problems across the valve seat as a result of aluminum porosity. ( think I have a posted about this) This can be difficult to see if covered with carbon.
I have never seen a sticky valve on a Saito as a result of carbon from castor. Now I have seen valves and lifters stuck as a result of rancid castor. But this is a storage issue NOT an operational issue. Nor is it unique to Saito. I know of no operational issues with running castor (ok it might be hard to clean off) But the plethora of documented issue with synthetic makes their use questionable in any engine at any percentage.
No, I don't think I said the issue was corrosion. Just that corrosion can happen at any time. It is not dependent of run time but rather exposer to moisture. So any engine is susceptible to corrosion once you add fuel the carb. I think I said that one should find the failure mode before one sought a solution.
BTW Saito has had some of the best warranty policies that I have had to use and they actually honor them!
All the best,
Konrad
Gen Saito at one time did not want any castor oil. This was because he didn't want his technician spending time to clean the castings doing warranty work. Saito's big bore engines are prone to valve seal problems across the valve seat as a result of aluminum porosity. ( think I have a posted about this) This can be difficult to see if covered with carbon.
I have never seen a sticky valve on a Saito as a result of carbon from castor. Now I have seen valves and lifters stuck as a result of rancid castor. But this is a storage issue NOT an operational issue. Nor is it unique to Saito. I know of no operational issues with running castor (ok it might be hard to clean off) But the plethora of documented issue with synthetic makes their use questionable in any engine at any percentage.
No, I don't think I said the issue was corrosion. Just that corrosion can happen at any time. It is not dependent of run time but rather exposer to moisture. So any engine is susceptible to corrosion once you add fuel the carb. I think I said that one should find the failure mode before one sought a solution.
BTW Saito has had some of the best warranty policies that I have had to use and they actually honor them!
All the best,
Konrad
You'll find overall member ratings for just about every model engine on the planet.
These "reviews" represent real world, hands on experience with these engines. I find the results/reviews opposite from your findings on just about every engine "make" that you discuss.
How can that be?
10-11-2010, 07:44 PM
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RE: Strange sound
ORIGINAL: w8ye
There was a 12 oz bottle of drug store castor oil on a shelf in my workshop for 40 years. I opened it last year and it didn't look any different than when new and was not rancid. So I used it.
There was a 12 oz bottle of drug store castor oil on a shelf in my workshop for 40 years. I opened it last year and it didn't look any different than when new and was not rancid. So I used it.
10-11-2010, 07:48 PM
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RE: Strange sound
ORIGINAL: freakingfast
Yes 440C stainless bearings are rated at about 85% dynamic load limit of their bearing steel counterpart, but what I've found in actual use so far has been surprising. I have found the stainless are out lasting factory, aftermarket performance non metallic cage and ceramic hybrid bearings....at least in my three different engines, a YS 45FR, OS 70 heli used with prop and a OS 46 VXDF used with carbon fiber prop. These engines do not have an easy life!
As a side note, the ceramic hybrid bearings(bearing steel races, ceramic balls) I tested in all three engines had the worst life but the engines did gain 100 to 200 rpm when they were fresh. The races started to get rough and were pulled, none grenaded. All bearing types were run-in richer than normal for two tanks, that's more than most guys would do.
ORIGINAL: Konrad
Remember that most stainless steel (440c) have a much lower dynamic load limit than SAE 52100 high carbon steel. So if the bearing failed because it was over loaded it might not be wise to move down to the weaker SS bearing. You should find the failure mode first. And Yes run 100% castor oil as your lubricant. And follow proper storage procedures.
Remember that most stainless steel (440c) have a much lower dynamic load limit than SAE 52100 high carbon steel. So if the bearing failed because it was over loaded it might not be wise to move down to the weaker SS bearing. You should find the failure mode first. And Yes run 100% castor oil as your lubricant. And follow proper storage procedures.
As a side note, the ceramic hybrid bearings(bearing steel races, ceramic balls) I tested in all three engines had the worst life but the engines did gain 100 to 200 rpm when they were fresh. The races started to get rough and were pulled, none grenaded. All bearing types were run-in richer than normal for two tanks, that's more than most guys would do.
All the best,
10-11-2010, 07:54 PM
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RE: Strange sound
ORIGINAL: Broken Wings
Now that you mention the ''plethora of documentation'' have you had a chance to review the RC Universe ''User Reviews'' section on the main page of this forum?
You'll find overall member ratings for just about every model engine on the planet.
These ''reviews'' represent real world, hands on experience with these engines. I find the results/reviews opposite from your findings on just about every engine ''make'' that you discuss.
How can that be?
ORIGINAL: Konrad
Gen Saito at one time did not want any castor oil. This was because he didn't want his technician spending time to clean the castings doing warranty work. Saito's big bore engines are prone to valve seal problems across the valve seat as a result of aluminum porosity. ( think I have a posted about this) This can be difficult to see if covered with carbon.
I have never seen a sticky valve on a Saito as a result of carbon from castor. Now I have seen valves and lifters stuck as a result of rancid castor. But this is a storage issue NOT an operational issue. Nor is it unique to Saito. I know of no operational issues with running castor (ok it might be hard to clean off) But the plethora of documented issue with synthetic makes their use questionable in any engine at any percentage.
No, I don't think I said the issue was corrosion. Just that corrosion can happen at any time. It is not dependent of run time but rather exposer to moisture. So any engine is susceptible to corrosion once you add fuel the carb. I think I said that one should find the failure mode before one sought a solution.
BTW Saito has had some of the best warranty policies that I have had to use and they actually honor them!
All the best,
Konrad
Gen Saito at one time did not want any castor oil. This was because he didn't want his technician spending time to clean the castings doing warranty work. Saito's big bore engines are prone to valve seal problems across the valve seat as a result of aluminum porosity. ( think I have a posted about this) This can be difficult to see if covered with carbon.
I have never seen a sticky valve on a Saito as a result of carbon from castor. Now I have seen valves and lifters stuck as a result of rancid castor. But this is a storage issue NOT an operational issue. Nor is it unique to Saito. I know of no operational issues with running castor (ok it might be hard to clean off) But the plethora of documented issue with synthetic makes their use questionable in any engine at any percentage.
No, I don't think I said the issue was corrosion. Just that corrosion can happen at any time. It is not dependent of run time but rather exposer to moisture. So any engine is susceptible to corrosion once you add fuel the carb. I think I said that one should find the failure mode before one sought a solution.
BTW Saito has had some of the best warranty policies that I have had to use and they actually honor them!
All the best,
Konrad
You'll find overall member ratings for just about every model engine on the planet.
These ''reviews'' represent real world, hands on experience with these engines. I find the results/reviews opposite from your findings on just about every engine ''make'' that you discuss.
How can that be?
I was commenting on castor verses synthetic. What does engine brand have to do with it? Now some engines have silicone components that one needs to be aware of.
What engines am I discussing and what is my stance on those engines. If I make a claim or statement I usually support it in the text of the post. So what is your issue with what I've post in this thread?
P.S.
No I haven't had the chance to look at this mystical form "User Reviews". Can you post a link?
10-11-2010, 08:19 PM
#23
RE: Strange sound
You just wrote;
quote" Saito's big bore engines are prone to valve seal problems across the valve seat as a result of aluminum porosity. ( think I have a posted about this)"
This can be difficult to see if covered with carbon.
I have never seen a sticky valve on a Saito as a result of carbon from castor." end quote...
I'm just trying to keep up.
At the top of the page of this forum you will see a menu. "Forums" "Buy and Sell" "User reviews",etc.
Can you lets us know at what displacement (size) Saito engines begin to show aluminum porosity?
Saito makes just about every size engine there is.
What does the size have to do with the aluminum porosity?
quote" Saito's big bore engines are prone to valve seal problems across the valve seat as a result of aluminum porosity. ( think I have a posted about this)"
This can be difficult to see if covered with carbon.
I have never seen a sticky valve on a Saito as a result of carbon from castor." end quote...
I'm just trying to keep up.
At the top of the page of this forum you will see a menu. "Forums" "Buy and Sell" "User reviews",etc.
Can you lets us know at what displacement (size) Saito engines begin to show aluminum porosity?
Saito makes just about every size engine there is.
What does the size have to do with the aluminum porosity?
10-11-2010, 10:30 PM
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RE: Strange sound
BW,
Really! In of itself nothing.
Saito is a fantastic four cycle engine for the sport pilot
The smaller bore Saitos use a large one piece brass valve guide/valve seat.
The larger bore Saitos use a smaller brass valve guide with the valve seat cut directly into the aluminum casting of the head. All Saitos show porosity in the aluminum head and cylinder casting. This is NOT a problem unless the valve seat cuts in one of these porosity holes. Only the big bores are subjected to this risk!
Again Saito has a very good warranty policy and actually honors it.
Now as displacement is dependent on other factors like stoke and number of cylinders the actual engine size is unknown. So just take a look and see if the exhaust seat is of aluminum or brass.
Here is a teaser from what I learned looking at the valve seat through a SEM. Note this was done years ago. I know nothing of the new gasoline series of engines.
As this is off topic it should now move to the Saito club thread.
Really! In of itself nothing.
Saito is a fantastic four cycle engine for the sport pilot
The smaller bore Saitos use a large one piece brass valve guide/valve seat.
The larger bore Saitos use a smaller brass valve guide with the valve seat cut directly into the aluminum casting of the head. All Saitos show porosity in the aluminum head and cylinder casting. This is NOT a problem unless the valve seat cuts in one of these porosity holes. Only the big bores are subjected to this risk!
Again Saito has a very good warranty policy and actually honors it.
Now as displacement is dependent on other factors like stoke and number of cylinders the actual engine size is unknown. So just take a look and see if the exhaust seat is of aluminum or brass.
Here is a teaser from what I learned looking at the valve seat through a SEM. Note this was done years ago. I know nothing of the new gasoline series of engines.
As this is off topic it should now move to the Saito club thread.
10-11-2010, 10:38 PM
#25
RE: Strange sound
ORIGINAL: Konrad
BW,
Really! In of itself nothing.
Saito is a fantastic four cycle engine for the sport pilot
The smaller bore Saitos use a large brass valve guide/valve seat.
The larger bore Saitos use a smaller brass valve guide with the valve seat cut directly into the aluminum casting of the head. All Saitos show porosity in the aluminum head and cylinder casting. This is NOT a problem unless the valve seat cuts in one of these porosity holes. Only the big bores are subjected to this risk!
Again Saito has a very good warranty policy and actually honors it.
Now as displacement is dependent on other factors like stoke and number of cylinders the actual engine size is unknown. So just take a look and see if the exhaust seat is of aluminum or brass.
Here is a teaser from what I learned looking at the valve seat through a SEM. Note this was done years ago. I know nothing of the new gasoline series of engines.
As this is off topic it should now move to the Saito club thread.
BW,
Really! In of itself nothing.
Saito is a fantastic four cycle engine for the sport pilot
The smaller bore Saitos use a large brass valve guide/valve seat.
The larger bore Saitos use a smaller brass valve guide with the valve seat cut directly into the aluminum casting of the head. All Saitos show porosity in the aluminum head and cylinder casting. This is NOT a problem unless the valve seat cuts in one of these porosity holes. Only the big bores are subjected to this risk!
Again Saito has a very good warranty policy and actually honors it.
Now as displacement is dependent on other factors like stoke and number of cylinders the actual engine size is unknown. So just take a look and see if the exhaust seat is of aluminum or brass.
Here is a teaser from what I learned looking at the valve seat through a SEM. Note this was done years ago. I know nothing of the new gasoline series of engines.
As this is off topic it should now move to the Saito club thread.
The old Saito's with the chrome plated brass sleeve also had the brass valve seats and in fact, the valve seat, valve pocket, and the valve guide were all one piece.
The newer Saito designs with the Chrome directly plated on the cylinders do not have the brass valve seats. The only brass is in the valve guide itself.
This goes for all sizes.
The porosity mentioned is in most Saito heads but apparently where the porosity is in a critical area, the heads are rejected?