Saito FG-60R3
#576
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Join Date: Jun 2002
Location: Ladera Ranch, CA
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Just adding on to the band wagon here...
I've just had the 5th cylinder failure (3rd on this motor) while in flight at a Scale Master event... Mid-throttle position, at least 4 minutes into the routine, 21lbs TF GS FW190, level flight...
I have two of these FG60's (originally bought from HH for a TF GS Zero and my TF GS FW190...
it's been either cylinder 2 or 3.. .no loose bolts... I check every bolt before every days flying... I run 17:1 Amzoil with 87 gas...
Folks at my flightline are convinced it's a hydro-lock issue but that's not verified... HH support told me that they don't sell enough of these motors that would force them to rectify in other way than to fix it under warranty.
As a result I feel terribly frustrated and disappointed that I invested so much into motors that will likely fail in the wrong part of the sky and potentially wreck one of my birds. I have several friends I fly with that have 84's that don't have this issue.. .
In the last two years the only issue I've heard about on 84's is that they heat to a lean setting and blow a rod or seize.
I've just had the 5th cylinder failure (3rd on this motor) while in flight at a Scale Master event... Mid-throttle position, at least 4 minutes into the routine, 21lbs TF GS FW190, level flight...
I have two of these FG60's (originally bought from HH for a TF GS Zero and my TF GS FW190...
it's been either cylinder 2 or 3.. .no loose bolts... I check every bolt before every days flying... I run 17:1 Amzoil with 87 gas...
Folks at my flightline are convinced it's a hydro-lock issue but that's not verified... HH support told me that they don't sell enough of these motors that would force them to rectify in other way than to fix it under warranty.
As a result I feel terribly frustrated and disappointed that I invested so much into motors that will likely fail in the wrong part of the sky and potentially wreck one of my birds. I have several friends I fly with that have 84's that don't have this issue.. .
In the last two years the only issue I've heard about on 84's is that they heat to a lean setting and blow a rod or seize.
#577
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Had a friend who worked for a big model shop who had a issue with a particular servo . They would say thats the 1st they heard of a issue and would replace the servo and chuck the defect one in a box , full of other buggered ones . Just cause they say it dont make it true . Cheers
#580
My Feedback: (14)
I think the concern is that during a cold start, if a cylinder has excess fuel/oil, when the piston comes up on compression it might over stress the cylinder casting and create a tiny stress fracture. Later when the engine is running this stress fracture could eventually fail. Full size radials are subject to the same thing.
http://www.avweb.com/news/pilotlounge/182680-1.html
"If you detect a hydraulic lock on a radial engine the only certain way to cure it is to remove the lower cylinder spark plugs and let the oil drain out. Pulling the prop through forward WILL result in a bent connecting rod and/or expensive damage to the engine if it does not cause a catastrophic failure. Pulling the propeller through backwards only reduces the chance of a bent connecting rod; it does not eliminate the risk"
https://en.wikipedia.org/wiki/Hydrolock
Hydrolock is common on radial and inverted engines (cylinders pointing downwards) when the engine sits for a long period. Engine oil seeps down under gravity into the cylinder through various means (through the rings, valve guides, etc.) and can fill a cylinder with enough oil to hydrolock it. The seepage effect can be observed by the blue-white smoke commonly seen when a radial engine starts up. In order to prevent engine damage, it is universal practice for the ground crew or pilot to check for hydrolock during pre-flight inspection of the aircraft, typically by hand-cranking the propeller for several turns to make sure the crankshaft cycles normally through all cylinders.
http://www.avweb.com/news/pilotlounge/182680-1.html
"If you detect a hydraulic lock on a radial engine the only certain way to cure it is to remove the lower cylinder spark plugs and let the oil drain out. Pulling the prop through forward WILL result in a bent connecting rod and/or expensive damage to the engine if it does not cause a catastrophic failure. Pulling the propeller through backwards only reduces the chance of a bent connecting rod; it does not eliminate the risk"
https://en.wikipedia.org/wiki/Hydrolock
Hydrolock is common on radial and inverted engines (cylinders pointing downwards) when the engine sits for a long period. Engine oil seeps down under gravity into the cylinder through various means (through the rings, valve guides, etc.) and can fill a cylinder with enough oil to hydrolock it. The seepage effect can be observed by the blue-white smoke commonly seen when a radial engine starts up. In order to prevent engine damage, it is universal practice for the ground crew or pilot to check for hydrolock during pre-flight inspection of the aircraft, typically by hand-cranking the propeller for several turns to make sure the crankshaft cycles normally through all cylinders.
#581
My Feedback: (46)
I think the concern is that during a cold start, if a cylinder has excess fuel/oil, when the piston comes up on compression it might over stress the cylinder casting and create a tiny stress fracture. Later when the engine is running this stress fracture could eventually fail. Full size radials are subject to the same thing.
http://www.avweb.com/news/pilotlounge/182680-1.html
"If you detect a hydraulic lock on a radial engine the only certain way to cure it is to remove the lower cylinder spark plugs and let the oil drain out. Pulling the prop through forward WILL result in a bent connecting rod and/or expensive damage to the engine if it does not cause a catastrophic failure. Pulling the propeller through backwards only reduces the chance of a bent connecting rod; it does not eliminate the risk"
https://en.wikipedia.org/wiki/Hydrolock
Hydrolock is common on radial and inverted engines (cylinders pointing downwards) when the engine sits for a long period. Engine oil seeps down under gravity into the cylinder through various means (through the rings, valve guides, etc.) and can fill a cylinder with enough oil to hydrolock it. The seepage effect can be observed by the blue-white smoke commonly seen when a radial engine starts up. In order to prevent engine damage, it is universal practice for the ground crew or pilot to check for hydrolock during pre-flight inspection of the aircraft, typically by hand-cranking the propeller for several turns to make sure the crankshaft cycles normally through all cylinders.
http://www.avweb.com/news/pilotlounge/182680-1.html
"If you detect a hydraulic lock on a radial engine the only certain way to cure it is to remove the lower cylinder spark plugs and let the oil drain out. Pulling the prop through forward WILL result in a bent connecting rod and/or expensive damage to the engine if it does not cause a catastrophic failure. Pulling the propeller through backwards only reduces the chance of a bent connecting rod; it does not eliminate the risk"
https://en.wikipedia.org/wiki/Hydrolock
Hydrolock is common on radial and inverted engines (cylinders pointing downwards) when the engine sits for a long period. Engine oil seeps down under gravity into the cylinder through various means (through the rings, valve guides, etc.) and can fill a cylinder with enough oil to hydrolock it. The seepage effect can be observed by the blue-white smoke commonly seen when a radial engine starts up. In order to prevent engine damage, it is universal practice for the ground crew or pilot to check for hydrolock during pre-flight inspection of the aircraft, typically by hand-cranking the propeller for several turns to make sure the crankshaft cycles normally through all cylinders.
Last edited by aquaskiman; 04-09-2016 at 08:56 AM.
#582
My Feedback: (2)
For hydra lock to be an issue for this engine one would need to turn it over using an electric starter when experiencing a flooded cylinder. Now if you pull the engine though before hand, making sure your engine is working properly you won't/ can't have hydra lock.
So clearly it is fuel related because there are no reports of #1 cylinder failing.
Repeated pre-detonation over time stressing the marginal cylinder strength? Just looking at possible issues here. Not trying to say that's the real cause.
I will use higher octane fuel just to be sure. Can't hurt.
So clearly it is fuel related because there are no reports of #1 cylinder failing.
Repeated pre-detonation over time stressing the marginal cylinder strength? Just looking at possible issues here. Not trying to say that's the real cause.
I will use higher octane fuel just to be sure. Can't hurt.
#583
Join Date: Jan 2007
Location: Dubai, UNITED ARAB EMIRATES
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This is rather disturbing given that we have all invested in what we believe to be a 'premier' product. I must say, this has made me wonder whether I will ever be able to fly this engine with complete confidence. Anyway, I suppose that at some point my disappointment will be minimized when it does carp itself....I would have seen it coming.
I am glad that there are enough people here to provide input on their thoughts and experiences, maybe we will be able to find a way to minimize the chance of failure, even if we cannot avoid it all together.
I thought I would chime in with some of my findings, maybe all the pieces of the puzzle will lead us to an answer that will save our investment.
I agree that the hydrolock potential is there, especially if it is in the lower cylinders all the time, but as people have said, the chances of the cylinder filling with oil, is not really a consideration. Fuel, yes, but not likely to be oil. We all know that the induction system of these engines has been a factory/design problem, and whether it is possible to redesign or create a fix, is available with many people with the skills, such as Ray English. I have not really followed up on his recommendations (if any) from him regarding this engine. I know the 84 has received a lot of upgrades to minimize failure. THis engine was supposed to have received the upgraded inlet and bushing scenario, but since I bought mine from rcjapan, I don't know whether I got these or not. Are all the failures happening on the new and the old version, or is it just one of the two?
Ok, so here are some things i have noticed on the engine, since I got it. I followed the break in procedure where I was running the engine as per the manual, with 15:1 redline oil mix. During the break in procedure, I was tilting the stand in order to get the lower cylinders rotated up, and it was clear that they only fired in the 'rich' state, when they were in the upper position. You can see clearly through the smoke coming from the pipes, and the cyl temps. After a litre of gas through it, I mounted it inverted on the stand, and did another litre that way. In order to heat cycle it, I was removing plugs alternately (probably not good for the ignition, but I would rather replace that than cylinders and internals). After the 2 litres of fuel, I mounted it in the plane, and leaned it up to good idle, transition and HS. It runs beautifully. Added the Keleo exhaust for 'that' noise. Love it.
I checked the cylinder bolts after the first two flights, and got a SLIGHT 'click' from them, just cinched them down. I did it again yesterday, and again, just a click. I am afraid to over tighten now, so will leave them for a few flights.
So, now on to engine temps......I installed a Spektrum TM1000 and put the probe on cyl 1, one fin down, directly under the exhaust port. I know it might not be the ideal place as it will be affected by EGT, but since I started there, and I have multiple flight data, it is my control and I will leave it there for now.
The engine is mounted in an El Cheapo Yak-55M as I wanted a stable platform to test it. Running in an engine on a heavy warbird is not ideal.
As you know, the Yak-55M cowl is like a big bucket, and I installed some louvres to help remove air coming into it. Before I went down this route, I flew it without the cowl for max cooling effect. I recorded temps as follows, all in Deg C.
Idling on tarmac - 110 to117
Mid Stick on tarmac - 115 to 138 (continuous for around 30 secs)
Full bore on tarmac - 125 to 147 (continuous for around 30 secs)
Its interesting to note that as soon as you back off the throttle, it takes around 8 secs before the temps drop down sharply to the idle range.
For flight, with a 22x8 Xoar wooden prop, the following
Mid to 3/4 throttle cruising: 120 - 130
Full bore continuous around the circuit 125 to 143
Full bore vertical - 145 to 155.
Its under propped for sure, there is not enough pitch speed on this prop, so will do a 22x10 on the next flight. There are a few things to consider here.
This plane will not prop hang without over-heating....any lack of airflow over the cylinders will see sharp temp rises.
The temps fluctuate a LOT and temp changes are RAPID. For example, after the vertical, up to a hang, I put her in a steep dive, and by the time I had pulled out of the dive, the temps were back at 130 Deg C. The changes are steep and quick!!
I then mounted the cowl and although there was no baffle, there were three small louvres installed behind each cyl, and I 'assumed' enough air going out, I have come to the conclusion, that assumption was wrong.
So temps were:
Idling on tarmac - 117 to 135
Mid Stick on tarmac - 125 to 140 (continuous for around 30 secs)
Full bore on tarmac - 138 to 155 (continuous for around 30 secs)
Again, temp drops were very quick
In flight we got:
Mid to 3/4 throttle cruising: 135 to 145
Full bore continuous around the circuit 145 to 150
Full bore vertical - 155 to 160 (it crossed the 160 mark briefly, and I immediately put her in a dive to cool down.)
From this I can see that regardless of where I have the temp sensor, this engine seems to have VERY rapid heat cycles from cooler to hot. I also took the time to get her to fly around for a circuit every now and again, completely inverted, to make sure those lower cyl's are seeing some action. I don't want to do too much inverted as the Keleo ring will probably fill up with oil.
I was thinking of finishing the 3 liters of fuel that I have, and then changing the ratio to 18:1 from 15. The plugs are burning a little oily, and although I am running it on what I think is a little rich, I would rather reduce the oil content and keep it rich a little, than lean the hell out of it.
I am not sure if any of this is any use but given that parts are breaking, there may be some connection between that and the big temp fluctuations that I am finding. Metal behaves very differently at different temps and these parts are seeing big variations in temps. Well, mine does anyway.
Regards to all,
Andy
I am glad that there are enough people here to provide input on their thoughts and experiences, maybe we will be able to find a way to minimize the chance of failure, even if we cannot avoid it all together.
I thought I would chime in with some of my findings, maybe all the pieces of the puzzle will lead us to an answer that will save our investment.
I agree that the hydrolock potential is there, especially if it is in the lower cylinders all the time, but as people have said, the chances of the cylinder filling with oil, is not really a consideration. Fuel, yes, but not likely to be oil. We all know that the induction system of these engines has been a factory/design problem, and whether it is possible to redesign or create a fix, is available with many people with the skills, such as Ray English. I have not really followed up on his recommendations (if any) from him regarding this engine. I know the 84 has received a lot of upgrades to minimize failure. THis engine was supposed to have received the upgraded inlet and bushing scenario, but since I bought mine from rcjapan, I don't know whether I got these or not. Are all the failures happening on the new and the old version, or is it just one of the two?
Ok, so here are some things i have noticed on the engine, since I got it. I followed the break in procedure where I was running the engine as per the manual, with 15:1 redline oil mix. During the break in procedure, I was tilting the stand in order to get the lower cylinders rotated up, and it was clear that they only fired in the 'rich' state, when they were in the upper position. You can see clearly through the smoke coming from the pipes, and the cyl temps. After a litre of gas through it, I mounted it inverted on the stand, and did another litre that way. In order to heat cycle it, I was removing plugs alternately (probably not good for the ignition, but I would rather replace that than cylinders and internals). After the 2 litres of fuel, I mounted it in the plane, and leaned it up to good idle, transition and HS. It runs beautifully. Added the Keleo exhaust for 'that' noise. Love it.
I checked the cylinder bolts after the first two flights, and got a SLIGHT 'click' from them, just cinched them down. I did it again yesterday, and again, just a click. I am afraid to over tighten now, so will leave them for a few flights.
So, now on to engine temps......I installed a Spektrum TM1000 and put the probe on cyl 1, one fin down, directly under the exhaust port. I know it might not be the ideal place as it will be affected by EGT, but since I started there, and I have multiple flight data, it is my control and I will leave it there for now.
The engine is mounted in an El Cheapo Yak-55M as I wanted a stable platform to test it. Running in an engine on a heavy warbird is not ideal.
As you know, the Yak-55M cowl is like a big bucket, and I installed some louvres to help remove air coming into it. Before I went down this route, I flew it without the cowl for max cooling effect. I recorded temps as follows, all in Deg C.
Idling on tarmac - 110 to117
Mid Stick on tarmac - 115 to 138 (continuous for around 30 secs)
Full bore on tarmac - 125 to 147 (continuous for around 30 secs)
Its interesting to note that as soon as you back off the throttle, it takes around 8 secs before the temps drop down sharply to the idle range.
For flight, with a 22x8 Xoar wooden prop, the following
Mid to 3/4 throttle cruising: 120 - 130
Full bore continuous around the circuit 125 to 143
Full bore vertical - 145 to 155.
Its under propped for sure, there is not enough pitch speed on this prop, so will do a 22x10 on the next flight. There are a few things to consider here.
This plane will not prop hang without over-heating....any lack of airflow over the cylinders will see sharp temp rises.
The temps fluctuate a LOT and temp changes are RAPID. For example, after the vertical, up to a hang, I put her in a steep dive, and by the time I had pulled out of the dive, the temps were back at 130 Deg C. The changes are steep and quick!!
I then mounted the cowl and although there was no baffle, there were three small louvres installed behind each cyl, and I 'assumed' enough air going out, I have come to the conclusion, that assumption was wrong.
So temps were:
Idling on tarmac - 117 to 135
Mid Stick on tarmac - 125 to 140 (continuous for around 30 secs)
Full bore on tarmac - 138 to 155 (continuous for around 30 secs)
Again, temp drops were very quick
In flight we got:
Mid to 3/4 throttle cruising: 135 to 145
Full bore continuous around the circuit 145 to 150
Full bore vertical - 155 to 160 (it crossed the 160 mark briefly, and I immediately put her in a dive to cool down.)
From this I can see that regardless of where I have the temp sensor, this engine seems to have VERY rapid heat cycles from cooler to hot. I also took the time to get her to fly around for a circuit every now and again, completely inverted, to make sure those lower cyl's are seeing some action. I don't want to do too much inverted as the Keleo ring will probably fill up with oil.
I was thinking of finishing the 3 liters of fuel that I have, and then changing the ratio to 18:1 from 15. The plugs are burning a little oily, and although I am running it on what I think is a little rich, I would rather reduce the oil content and keep it rich a little, than lean the hell out of it.
I am not sure if any of this is any use but given that parts are breaking, there may be some connection between that and the big temp fluctuations that I am finding. Metal behaves very differently at different temps and these parts are seeing big variations in temps. Well, mine does anyway.
Regards to all,
Andy
#584
Join Date: Jan 2013
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Retarding the ignition or higher octane fuel might certainly improve the situation. There will be some power loss in retarding but quite frankly, I already had it difficult to reduce the max rpm with h needle. Everytime I reduced top end a little, it would start with misfiring. So, retarding might solve that also.
#585
I'm still waiting for the replacement cylinder from HobbyPlastic, here's the picture of the cracked #2 cylinder which I didn't share earlier.
#587
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#588
For hydra lock to be an issue for this engine one would need to turn it over using an electric starter when experiencing a flooded cylinder. Now if you pull the engine though before hand, making sure your engine is working properly you won't/ can't have hydra lock.
So clearly it is fuel related because there are no reports of #1 cylinder failing.
Repeated pre-detonation over time stressing the marginal cylinder strength? Just looking at possible issues here. Not trying to say that's the real cause.
I will use higher octane fuel just to be sure. Can't hurt.
So clearly it is fuel related because there are no reports of #1 cylinder failing.
Repeated pre-detonation over time stressing the marginal cylinder strength? Just looking at possible issues here. Not trying to say that's the real cause.
I will use higher octane fuel just to be sure. Can't hurt.
I wonder if the FG60 owners that have experienced cylinder head failure have had hydra lock and didn't recognize it as hydra lock during hand starting when the prop would not pass through the compression stroke two or more times? Then not correctly clearing the hydra lock?
#590
Join Date: Jan 2007
Location: Dubai, UNITED ARAB EMIRATES
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I never use a starter on any of my engines. Granted I only have this engine, a DLE 30 and a DLE 55RA. If they don't start by hand flipping, there is something wrong, and a starter is unlikely to solve the problem.
Flooding 2 Strokes is not as prevalent I find, but too much choke will do it. Doing it on an inverted 4 stroke is much more achievable
Flooding 2 Strokes is not as prevalent I find, but too much choke will do it. Doing it on an inverted 4 stroke is much more achievable
#592
My Feedback: (2)
Of course you can have hydra lock when attempting starting. To much fuel in the cylinder. You can clear it by removing the plug or turning the engine backwards. In most cases either will work.
BUT we are not talking about starting.. we are talking about running engines. Lots different situation.
As for rapid temperature changes that's good and bad news..
The good news.. it means the cylinder is transferring heat to the fins and off the engine.
The bad news.. It also means there is relatively thin material to aid in this efficient heat transfer.
Some where there is a balance.
BUT we are not talking about starting.. we are talking about running engines. Lots different situation.
As for rapid temperature changes that's good and bad news..
The good news.. it means the cylinder is transferring heat to the fins and off the engine.
The bad news.. It also means there is relatively thin material to aid in this efficient heat transfer.
Some where there is a balance.
#593
I wonder if the FG60 owners that have experienced cylinder head failure have had hydra lock and didn't recognize it as hydra lock during hand starting when the prop would not pass through the compression stroke two or more times? Then not correctly clearing the hydra lock?
#594
Join Date: Feb 2013
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Well...interesting to me that it appeared to happen at mid-throttle range (if I read the post properly?). I wonder if the lower cylinders are actually firing at that lower rpm, my no.3 cylinder appears to drop out at idle and chimes in with higher rpm. If the cylinder is not firing could fuel build up? Wouldn't it drain when the valves open? Perhaps not, certainly not on the compression stroke.
I guess I'm just wondering if it's an overfuelling problem on the lower cylinders at lower rpm's? At lower rpm's it can be difficult to tell if a cylinder has dropped out, other than a drop in temp on that cylinder.
I guess I'm just wondering if it's an overfuelling problem on the lower cylinders at lower rpm's? At lower rpm's it can be difficult to tell if a cylinder has dropped out, other than a drop in temp on that cylinder.
#595
If you have a hydra lock during the starting procedure and force the prop through the compression stroke without clearing the hydra lock, the cylinder head is usually stressed beyond what it is engineered to handle. Over stressing a cylinder head usually results in hair line cracking. This hair line cracking will not be noticed or immediately affect the engines performance after it starts. The crack will slowly spread over time as the engine is operated due to normal combustion pressures. The crack will continue spreading throughout the cylinder head to the point where cylinder head has become so weakened due to the spreading of the crack that the cylinder head will fracture and fail, which is usually in flight. This is actually what happens in full size radial engines when a hydra lock condition is ignored and not properly cleared.
I have seen this happen many times in the 37 years I have been working in the aerospace industry. These RC radial engines are really no different than their big brother full size radials when it comes to hydra locking and cylinder head fracturing.
I have seen this happen many times in the 37 years I have been working in the aerospace industry. These RC radial engines are really no different than their big brother full size radials when it comes to hydra locking and cylinder head fracturing.
#596
My Feedback: (2)
To our knowledge no one has reported ever having a hydra lock on this engine that they forced through.
I'm not saying that hasn't happened but why don't we hear of these issues with other radial engines? We just don't which leads me to believe that is a repeated but inaccurate cause in this case.
I'm not saying that hasn't happened but why don't we hear of these issues with other radial engines? We just don't which leads me to believe that is a repeated but inaccurate cause in this case.
#597
Could the great heat fluctuations cause the tappets to go out of adjustment? Maybe we're going to have to stay after them often?
Dan
Had mine quite a while now and still havn't run her
Dan
Had mine quite a while now and still havn't run her
#600
Thread Starter
My Feedback: (9)
... THis engine was supposed to have received the upgraded inlet and bushing scenario, but since I bought mine from rcjapan, I don't know whether I got these or not. Are all the failures happening on the new and the old version, or is it just one of the two?
...
Regards to all,
Andy
...
Regards to all,
Andy
He offers a mod which corrects (reduces) this and modifies the carb to match. Again, I'm not asserting that this is the issue contributing to the failures and I'm certainly no thermal/hydro/mech engineer, and I'm not promoting anyone throw more $$$ after already buying a premium engine. Having said that, both my FG-33R3 & FG-60R3 w/RE mods seem to run fine. Morgan Cool Power mixed 15:1, 1 oz /Seafoam/gal, non-ethanol. RCExcl plugs.
Lastly, I may be wrong, but I don't think there have been any running changes on any of the FG radials, so they should all be the same irrespective of when or what channel purchased from.
Your mileage may vary....
Cheers
Last edited by marksp; 04-11-2016 at 08:25 AM.