Saito FG-60R3
#2751

My point regarding the ignition was as follows;
I know that on ALL Saitos, you will have to slide the hall-sensor a bit back and forth so that you hit approx 28 degrees.
I allways do that, on all engines. I even have a tool for measuring the angle.
The problem on the Saito FG 60 specifically is that ONE cylinder is different form all the others. So you fu#¤"% either way.
And my concern is then;
Can this be the explanation that the same one cylinder, pointing straight upwards, was blown off the crank-case?
First the original cylinder, then buying a brand new cylinder, and that one blowing off too, also ruining the crank-case.
I don't know how many flights I had on the Sist Fw 190-D9 before it happened. Maybe 20-30. Don't know, didn't count.
Then the same happened to my friends TopRc zero with his FG-60.
He had lots of flights on his too, and adjusted it a bit richer just before the final flight.
He now has a FG-90 in his Zero, and gave me the remnants of his FG-60.
I know that on ALL Saitos, you will have to slide the hall-sensor a bit back and forth so that you hit approx 28 degrees.
I allways do that, on all engines. I even have a tool for measuring the angle.
The problem on the Saito FG 60 specifically is that ONE cylinder is different form all the others. So you fu#¤"% either way.
And my concern is then;
Can this be the explanation that the same one cylinder, pointing straight upwards, was blown off the crank-case?
First the original cylinder, then buying a brand new cylinder, and that one blowing off too, also ruining the crank-case.
I don't know how many flights I had on the Sist Fw 190-D9 before it happened. Maybe 20-30. Don't know, didn't count.
Then the same happened to my friends TopRc zero with his FG-60.
He had lots of flights on his too, and adjusted it a bit richer just before the final flight.
He now has a FG-90 in his Zero, and gave me the remnants of his FG-60.
Last edited by kwik; 12-08-2022 at 04:32 AM.
#2752

I hope it´s ok to elaborate even if I actually don´t know all the fact´s involved in your unfortunate disaster.
Normally the ignition is set for cylinder1/ the top one, (at least on my 170R3 with MMM set up), The Saito ignition timing problem is that
number 2 and 3 does not follow the same crank/ con rod geometry as number 1. (Not sure how this is done for the 5+ cylinder engines)
This is (to my understanding) taken care of with the MMM and CH magnet ring, where the magnets are adjusted for the "geometry error".
The next issue is that in a petrol/gas engine there is much higher temperatures giving a high thermal material stress,
Saito re-enforced the cylinder base on later models.
Looking at your picture briefely I would suspect that it all started with cracks on one of the fasterners/screws at the cylinder,,
It should be possible to identify the beginning and the "chain of events" studying the surfaces.
However,, temperature variations is a killer for any air cooled engine. In your case(es) I guess that a combination of Ignition setting & mixture is the main cause.
Sure there is also a "load factor" involved as well,, light load (prop) will not stress the material as much as a high load.
Please don`t take my theory for absolute,, I am only guessing based on what I have seen on other engines.
EDIT: With the original (early) intake manifold I suspect that No 1 will always run hotter than 2&3, when you lean the engine.
Normally the ignition is set for cylinder1/ the top one, (at least on my 170R3 with MMM set up), The Saito ignition timing problem is that
number 2 and 3 does not follow the same crank/ con rod geometry as number 1. (Not sure how this is done for the 5+ cylinder engines)
This is (to my understanding) taken care of with the MMM and CH magnet ring, where the magnets are adjusted for the "geometry error".
The next issue is that in a petrol/gas engine there is much higher temperatures giving a high thermal material stress,
Saito re-enforced the cylinder base on later models.
Looking at your picture briefely I would suspect that it all started with cracks on one of the fasterners/screws at the cylinder,,
It should be possible to identify the beginning and the "chain of events" studying the surfaces.
However,, temperature variations is a killer for any air cooled engine. In your case(es) I guess that a combination of Ignition setting & mixture is the main cause.
Sure there is also a "load factor" involved as well,, light load (prop) will not stress the material as much as a high load.
Please don`t take my theory for absolute,, I am only guessing based on what I have seen on other engines.
EDIT: With the original (early) intake manifold I suspect that No 1 will always run hotter than 2&3, when you lean the engine.
Last edited by RoKit; 12-08-2022 at 08:39 AM.
#2753

The most obvious is the huge temperature diff´s due to uneven fuel distribution in for 120, 170, 200 and 33 engines.
The 60 have been modified over the years and to my knowledge it is a much better engine but very far from perfect in regards
to ignition timing and fuel distribution.
It have been suggested to Saito several times the past 10 years to at least offer a aftermarket "service kit-fix", but they
refuse to acknowlige there is a problem. So sad and not logical to handle their customers like that.
#2754

My Feedback: (6)

I hope it´s ok to elaborate even if I actually don´t know all the fact´s involved in your unfortunate disaster.
Normally the ignition is set for cylinder1/ the top one, (at least on my 170R3 with MMM set up), The Saito ignition timing problem is that
number 2 and 3 does not follow the same crank/ con rod geometry as number 1. (Not sure how this is done for the 5+ cylinder engines)
This is (to my understanding) taken care of with the MMM and CH magnet ring, where the magnets are adjusted for the "geometry error".
The next issue is that in a petrol/gas engine there is much higher temperatures giving a high thermal material stress,
Saito re-enforced the cylinder base on later models.
Looking at your picture briefely I would suspect that it all started with cracks on one of the fasterners/screws at the cylinder,,
It should be possible to identify the beginning and the "chain of events" studying the surfaces.
However,, temperature variations is a killer for any air cooled engine. In your case(es) I guess that a combination of Ignition setting & mixture is the main cause.
Sure there is also a "load factor" involved as well,, light load (prop) will not stress the material as much as a high load.
Please don`t take my theory for absolute,, I am only guessing based on what I have seen on other engines.
EDIT: With the original (early) intake manifold I suspect that No 1 will always run hotter than 2&3, when you lean the engine.
Normally the ignition is set for cylinder1/ the top one, (at least on my 170R3 with MMM set up), The Saito ignition timing problem is that
number 2 and 3 does not follow the same crank/ con rod geometry as number 1. (Not sure how this is done for the 5+ cylinder engines)
This is (to my understanding) taken care of with the MMM and CH magnet ring, where the magnets are adjusted for the "geometry error".
The next issue is that in a petrol/gas engine there is much higher temperatures giving a high thermal material stress,
Saito re-enforced the cylinder base on later models.
Looking at your picture briefely I would suspect that it all started with cracks on one of the fasterners/screws at the cylinder,,
It should be possible to identify the beginning and the "chain of events" studying the surfaces.
However,, temperature variations is a killer for any air cooled engine. In your case(es) I guess that a combination of Ignition setting & mixture is the main cause.
Sure there is also a "load factor" involved as well,, light load (prop) will not stress the material as much as a high load.
Please don`t take my theory for absolute,, I am only guessing based on what I have seen on other engines.
EDIT: With the original (early) intake manifold I suspect that No 1 will always run hotter than 2&3, when you lean the engine.
1) I had forgotten about the slave/master rod problem that all radials (with this setup) share. And Saito couldn't adjust the timing for this well known problem? Crazy.
2) You are of course correct with regard to temp variations. This is why I tell everyone running these (or most any air cooled engine) to install effective BAFFLING. Look, you spent over a thousand bucks for this little jewel, don't you want to take as good care of it as possible?
3) I have the latest version of this engine and I can attest that when set up as HPERGM spells out in post #46 of this thread, this engine will run VERY close to even cylinder head temps. Yes, in some operational regimes #1 cylinder will have slightly higher excursions - but nothing major and NOTHING like what happens if you set the engine up according to Saito's instructions for this engine. Remember: the LOW needle is the MAIN needle on this engine (at least the version I have it is). Once opened enough to feed the "low" needle the high needle has no function whatsoever.

Last edited by mitchilito; 12-09-2022 at 03:20 AM.
#2755

2) You are of course correct with regard to temp variations. This is why I tell everyone running these (or most any air cooled engine) to install effective BAFFLING. Look, you spent over a thousand bucks for this little jewel, don't you want to take as good care of it as possible?


https://www.modelbouwforum.nl/attach...-1-jpg.428046/
https://www.modelbouwforum.nl/attach...-1-jpg.428222/
Yet it weighs only 27 grammes and works a charm.
#2757

Thanks!
That was literally a 6 hour session of cutting individual scraps of Balsa to size as I went along, together with some quick setting Aliphatic. But the end result was that in flight, the cowled engine now cools better than when it was uncowled and fully exposed to the propwash.
Finished it looks even better, but not very demonstrative of how it was built.
https://www.modelbouwforum.nl/attach...-1-jpg.428289/
Can you tell I'm proud if it despite it being a dirt cheap ARF with a dirt cheap Chinese clone engine?
That was literally a 6 hour session of cutting individual scraps of Balsa to size as I went along, together with some quick setting Aliphatic. But the end result was that in flight, the cowled engine now cools better than when it was uncowled and fully exposed to the propwash.
Finished it looks even better, but not very demonstrative of how it was built.
https://www.modelbouwforum.nl/attach...-1-jpg.428289/




#2762

My Feedback: (6)

In this vid I had not got the two needles sorted out yet. This is what the engine runs like when set as you would a traditional two needle carburetor ie. lean the high needle out then tweak the low needle for low end response. This is what the Saito manual recommends (so wrong). It was tolerable but when set correctly like it is now it runs like a watch.
#2763

Dang! It is not that you did not have any confidence in that engine, doing a roll straight after take-off...
Unfortunately the station I am on does not have sound, so I have to wait until after work for that.
Edit: I like the sound... Sounds "racy"...
Unfortunately the station I am on does not have sound, so I have to wait until after work for that.
Edit: I like the sound... Sounds "racy"...
Last edited by 1967brutus; 12-12-2022 at 10:22 AM.
#2764

My Feedback: (6)

I never had any doubts that this engine would keep running. It was at that time still very reliable even though it would drop cylinders and sputter a little in aerobatics - but only in reduced power settings. More of an annoyance. But I was not happy at all. Then I started in on this thread and now it runs like a watch. Just a fantastic engine IMO.
#2765

I just HAD to post what happened today. I only stumbled on this thread a week or two ago and something amazing came of it.
I’ve been flying a phoenix Waco with a Saito FG 60 for a couple months now and was never happy with the way it was running. I followed the manual, broke it in carefully etc. but as many of you know, with this engine you throw all that right out the window.
The break through was HPERGM’s post #46 where he explains how the high speed needle is just there to feed the “low” needle - which actually is what we need to use to set the MAIN fuel mixture. It’s nuts but boy was he right.
I hooked up a three channel thermocouple today and set the engine up exactly like he said and for the first time, after several months of flying (never happy with the behavior) finally have an engine that runs like a watch and has DEAD EVEN cylinder temps.
It’s crazy: In effect, there is actually only ONE mixture needle on this engine: the “low” needle. And no actual low needle exists because if one needed to adjust idle/transition mixture there would be no real way to do it because the low needle is the MAIN needle!
But here’s the thing: once you open the main needle enough to feed the low needle and then get the low set for max rpm (minus a few revs for safety) you have a PERFECT running engine. No low end mixture needle needed. And it’s a good thing because this engine doesn’t have one!
Mainly I just wanted to say:
THANK YOU SO MUCH HPERGM!!!
I’ve been flying a phoenix Waco with a Saito FG 60 for a couple months now and was never happy with the way it was running. I followed the manual, broke it in carefully etc. but as many of you know, with this engine you throw all that right out the window.
The break through was HPERGM’s post #46 where he explains how the high speed needle is just there to feed the “low” needle - which actually is what we need to use to set the MAIN fuel mixture. It’s nuts but boy was he right.
I hooked up a three channel thermocouple today and set the engine up exactly like he said and for the first time, after several months of flying (never happy with the behavior) finally have an engine that runs like a watch and has DEAD EVEN cylinder temps.
It’s crazy: In effect, there is actually only ONE mixture needle on this engine: the “low” needle. And no actual low needle exists because if one needed to adjust idle/transition mixture there would be no real way to do it because the low needle is the MAIN needle!
But here’s the thing: once you open the main needle enough to feed the low needle and then get the low set for max rpm (minus a few revs for safety) you have a PERFECT running engine. No low end mixture needle needed. And it’s a good thing because this engine doesn’t have one!
Mainly I just wanted to say:
THANK YOU SO MUCH HPERGM!!!
Happy flying and safe landings,
Hector.
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mitchilito (12-26-2022)
#2775

No, the engines are bone stock. I estimate about 10hrs on each (I do not keep a time log). But, I do re-oil the valve train and check/retighten the cylinders every 6 tanks (i.e. 1hr or approx every 2 flying days). A little bit of a chore...