Enjoy.... That's gonna be a "honker" on there LOL. I just stuffed a FG-90 on a Ziroli Texan/Harvard and had a good time doing it. Worked out well in the end weight wise, but had to a 2 inch longer cowl because I didn't want to recess the engine into the fuse. See you on the FG-90 thread?

Fg 90
 

Hey all, I managed to get some time to pull the engine off the plane, and do some inspection and teardown. Here are my observations, and I'm still in the dark as to what the ACTUAL cause of the failure was, but its my suspicion that there are a number of contributors.
Quick recap:
This engine was bought from a guy on these forums, and he had experienced a cylinder failure prior to me getting my hands on it, the cylinder that failed, was replaced under warranty, but this was before the new cylinder and piston design, so an original combo was used. I flew the engine many times in this format, using 20:1 redline, original timing setup and it never really flew well. It was on a 50cc Yak 3D plane and would barely tug it around....it was just disappointing. Tried a number of props 22x10 was the best of the lot, but tried 22x8, 21x12 but the thing never really excelled they way I was hoping. It went to the bench and was just being tested for all sorts....eventually got the timing sorted (I just rotated the hub on the crankshaft to get the timing to 28Deg). Eventually it got the MMM ring, and it just seemed to be running nicer, crisp throttle, good idle and seemed happier. We decided to run it on the SeaFury with the 4-bladed prop, as a test bed and after a while of good flying, it unexpectedly threw No3. I cant recall if we did the crankcase mod before or after that but the cylinder was replaced with the new design piston and cylinder. We have done maybe 30 flights in this config, until the other day, when it threw No2, also an original piston/cylinder combo.

So here we are now....upon removal there was NO leakage past the exhaust connectors (thanks Loctite flange sealer). There was NO leakage past the rocker gaskets (we put new ones on, but the crankcase mod is not allowing spooge out, so thats good). No 2 rocker cover bolts were all uniformly tight, nothing loose. There was PLENTY of lube on the valvetrain...nice and soaked in slippery stuff...The crankcase also had oil sloshing around in the bottom, but not nearly as much as I was expecting, I was fully expecting to have to POUR oil out since the crankcase mode, but it was maybe a few ml more than the last time I opened it up before the mod. Since we were running this on 30:1, there is less oil in both the air/fuel mix, as well as whats blowing by the rings...the excess might be getting atomised and passing through the combustion process...bottom line, I was happy to see that...Quite surprisingly there was NO gap on the inlet valve...it was not open, but the tappet gap was closed that there was no detectable gap. I thought it might have caused some burning/bypass on the inlet valve seats, but once we removed that, its apparent there was NO burning, and the seat and valve were clear and clean. The exhaust valve had a normal gap and was functioning well. There was some carbon buildup, but that has been there a long time but has not gotten any worse, in fact, when the last clylnider let go, there was a LOT of carbon on that one, as well as in the combustion chamber and on the piston crown. THis one had acceptable amonts of buildup in my opinion and most likely because we have run it on Stihl for the last 30 or so flights...we also put some engine cleaner treatment in a few tanks....could it be possible this has helped clean, or keep clean??
There is some weird marking on the piston and cylinder lining, but I dont know if this is from normal running or whether its happened after the cylinder went....the engine was still running, and we landed it still idling and running on 2, so with the cyl slighty crooked, it may have put the wier marks on it. They are not gouges at all, just seem like wear marks...
If you look at the pics, you can see that the cracks are EXACTLY where the new cylinders have been beefed up by Saito...and MOST of the other failures I have seen have been in a similar place (barring the incidents where engines have dismantled in flight and broken a lot more). My immediate reaction is that the cylinder material is not enough to cope with standard compression, and the timing has exposed that weakness. Even on my engine, with the amount of time it has been flying, its just been one 'bridge too far' on the metallurgy. I think that everyone with an older engine, is likely to have a failure at some point, and that failure will come sooner if you dont change the timing. I also suspect that running a 2-bladed prop is going to load the engine less, and will increase the time before a failure. If you manage to get a lot of flight time before that day comes, you are one of the lucky ones, and I know that some people may get a lifetime of use out of their engines, without any problems. If you are one of those people...go buy lottery tickets!

We are going to repair Frankensaito, but this time it will have ALL new version Pistons, Rings and Cylinders. We will put new valves in as well. Will continue to run it on the MMM timing at 28Deg, the crankcase mod from MMM and Stihl 30:1 mixed with pump gas...prepping to order parts, and will return once fitted up.

Pics here.

https://cimg9.ibsrv.net/gimg/www.rcu...4780ab8878.jpg

In situ cracks
https://cimg0.ibsrv.net/gimg/www.rcu...cb8cbad716.jpg

Other side
https://cimg4.ibsrv.net/gimg/www.rcu...cdd4dfae89.jpg

Crown wiped clean with cloth
https://cimg5.ibsrv.net/gimg/www.rcu...2878e628c0.jpg
https://cimg6.ibsrv.net/gimg/www.rcu...d03a021463.jpg

Crown before clean
https://cimg7.ibsrv.net/gimg/www.rcu...4ac871dd43.jpg

Crankcase oil level
https://cimg8.ibsrv.net/gimg/www.rcu...c6672e0f20.jpg

Combustion Chamber
https://cimg9.ibsrv.net/gimg/www.rcu...a5561c6eaf.jpg

Piston scoring

I’m curious what people suggest for break in fuel mix, in my situation:

I have an earlier FG60R3 without the modified cylinders, that’s still unrun but a few years old so presumably out of warranty. I’ve ordered the Morris Mini Motors intake kit and new prop driver/magnet ring, which I’ll be fitting before turning it over. Also Keleo exhaust.

So, given the intake mod and therefore ability to run on much lower oil mix (Morris uses about 30:1 from memory) I’m wondering what a safe run-in mix would be. Also whether the 4000 rpm sloppy run in is still ideal?

Happy to hear if anyone has had one from new with the MMM mods, and what their experience was.

Cheers,

Cam.

I don't have the 60R3 but have the 90R3 and bought the intake from MMM.
I told him that my engine was VERY low run time and should I continue to break in on 18-20:1?
He said go straight to 32:1. I'll do that but richen it up a bit initially.

Cheers,
Dave.

Camdy, I assume your engine has not run yet? If so, I would make sure to get some lube into it before running it, I mean manually lube it. Since you are taking the back plate off to change to the intake mod, just drop some oil into the moving parts, no need to go crazy, but just lightly to have some oil in there on first run. Put your initial mix at 30:1 and run it rich as per the manual, sloppy. It helps to have the original exhausts on it so you can see which cylinders are firing and which not. I inverted mine for half of the break in so that 2 and 3 also get some heat cycling. The thread is full of info on the break in process. After 2 tanks like that, I would set it up for flight (not on the cusp of going lean, just so you are getting good revs and a stable idle). Before doing anything, get the timing set up at 28 Degrees BTDC!
As in my posts, even with the intake and timing mods, mine still bust a cylinder, but that could be a number of factors at play:
The cylinder material in the place it breaks, is weak, thats why they have changed it
Compression is high, which is why they have changed the piston
The above two conditions combine to cause potential failure.

I have also abused the engine of mine, it runs in really high ambient temps, it had a 4-bladed prop on it and was run in its original state for a long time before the mods, so this could have caused problems which appeared later.

I suggest to make sure it is nicely cooled/baffled, run it on a 22x10 or 21x12 (depending on air frame) two-blade prop, and use Stihl HP oil and make sure it doesnt run too lean. This isnt a high performance engine, so treat it ias such. Trying to get the last rev out of it will likely cause some problems. After that, you hope you have one that lasts.

If you bought it new, before you run it, take it back to the place you bought it and TELL them that there are changes to new components, you have proof here, and tell them to send it back and get the new version. You will STILL need to change the timing, and the intake mod is always going to be a good option from a longevity perspective.

Good luck

If you bought it new, before you run it, take it back to the place you bought it and TELL them that there are changes to new components, you have proof here, and tell them to send it back and get the new version. You will STILL need to change the timing, and the intake mod is always going to be a good option from a longevity perspective.

Good luck[/QUOTE]
Do you know what version you have? Look through here to figure it out.
I doubt they will do anything at the hobby shop other than look at you with a blank stare... Horizon has an OUTSTANDING reputation for doing the right thing but I doubt that Horizon will honer any upgrades request. You could call Horizon directly and see if they are willing to do the upgrades.
Its easy to follow there breakin protocol. 20:1 oil . I use the red line oil available here in the US. For fuel I run methanol free gas and as low an octain as i can get.
Sparky

Wow - 32:1 on break in? Will definitely be lubing thoroughly and watching closely if I do that!

Whilst the older pistons/cylinders are a concern, a couple of my flying buddies have run this engine stock and not had issues, so with the modifications I feel I'll be ok. I fly slow and scale, so my engines have a pretty easy life.

Cam

30:1 is fine, as the oily fuel mix will be going through the crankcase, unlike normally where oil needs to make it past the rings first. With the mod, you have the best of both worlds.
Run it on 20:1 for a tank or two if you want but imho, that rich, with little oil burning off, leads to carbon.
i won’t open the can of worms that is the oil debate, but redline is great for high revving two-strokes, like go-karts. My personal feeling is that Stihl HP, or even HP ultra if you can get it, is preferable.
lots of people have been flying the engine without problems, ....you won’t find any of them on this thread. We are all the poor bums that lucked out...and Saito have made revisions, denied doing so...but we know...

Hi Andy,

First of all, thanks for sharing all the info and videos on the forums about the FG-60. You certainly had/have that engine idling and transitioning beautifully. Is this the engine that recently shat itself? I read through your posts and watched your videos. In fact, I've read through hours of forum discussions about breaking in this engine, ignition timing, cyl temps and lubrication or lack thereof.

I have a new FG-60 on my desk and an 80in Seagull FW190 to put it in. This is my first plane and motor of this size, so I'm more than a little bit keen to get this engine setup right. Had I not read the forums I would have followed the Saito instructions, so thanks again for your efforts.

Notwithstanding whether or not the spark (ECU) is triggered as the magnet approaches or departs the sensor, the MMM timing mod has the engine idling, transitioning and generally running sweet as. And by all available evidence, the MMM intake mod resolves the (Satio's) mixture distribution (and thereby the cyl temp variations) and bottom end/overhead lubrication issues.

Despite how it may appear, this is not an advert for MMM. I'm seeking clarification of the issues (and fixes) so I can spend a not-insignificant percentage of the engine purchase price with peace of mind, just to have it running as it should.

Do you agree that there's no point firing up this engine until the timing and intake mods are fitted?

I'm very interested in monitoring EGT via telemetry, however, CHT would suffice as a proxy. Does anyone here know of a good system that has EGT sensors suitable to attach to the FG-60 exhaust ports?

Andy did you make your own exhaust ring for the FG-60? It looks a slightly larger diameter than the kielio (excuse the incorrect spelling, I cannot be bothered looking it up). And it sounds/sounded wicked, we would appreciate a full-throttle low pass video :)

Regards,

Rob

Rob,
Welcome to the forum. Where do you live? This appears to be your first post on RCU....
The only justification for running your engine is to see what changes happen after modification. and to do that you need to have broken the engine in which would be a waste of time but it sounds so sweet. If you read through my posts I have the Ray full mod and then the MMM timing ring and frankly I haven't noticed any difference after the timing ring.
You need to determine what mods came on your engine before you can decide what other mods need to be done.
Look at my previous post and it will answer your questions.
I have had zero issues with my engine.
Sparky

Hi Sparky, I live in Ha Noi, Vietnam, sometimes. I'm Australian and until China (or the US, depends on who's conspiracy theory you believe (calm down, only joking, we all know it's the Chinese :) ) unleashed the virus, I shared my time between Aust. and Vn. Seems I'm going to hang here for a while until the virus is done. Yeah, I'm a newbie to RCU and planes larger than about.46 glow size. Been out of the hobby for too many years, so still feeling my way. These forums are invaluable and it's great to meet the guys here.

I gotta admit I'm floundering around trying to make sense of what to do about breaking in this FG-60 R3. And I'm coming to terms with spending over $700AUD on mods on a new current engine so it will perform and function as anyone would expect a new engine to do. My decision; I bought the thing without knowing what a disaster they are, so I'm going to git 'er done whatever that takes.

Unless I'm mistaken vids posted on this and the other forum (RCG) indicate that the timing mod causes a drastic improvement in starting, idling and transitioning.

The intake mod seems to have corrected the uneven cyl temps (mixture distribution) and provides better (than std.) lube to the bottom end and overhead gear. Not entirely undesirable features when running-in a new engine. Hence my question about doing the mods before starting it.

Is the Ray English intake mod the same as the MMM intake mod.?? I read somewhere that Ray's mod is now incorporated in std Saito production, I have no idea what that means for my engine.

You said "You need to determine what mods came on your engine..." True, any tips on how that can be achieved? I'm given to understand that Saito are not very forthcoming with info., nevertheless I'll contact them and see what they say. Does anyone else here know if the std. engine, as delivered from Saito, now has the intake mod done?

I'll check out your previous post as you suggest. I'm always up for new info.

There was some debate about whether the ECU throws a spark as the sensor first picks up the magnet (on approach) or if the spark occurs as the magnet leaves the sensor. Someone else posited the theory that it does both, claiming that under 400 rpm the spark occurs as the magnet leaves the sensor (retarding the timing to 30 degrees BTDC for starting), and at over 400 rpm the spark occurs 45 degrees BTDC as sensor first senses the magnet (on approach).

So the claim is that the std. Saito timing is 45 degrees BTDC and the mod adjusts (or corrects hahahahah) the timing to 30 degrees BTDCA. A bit of simple C=pie*D tells us that the difference, 15 degrees, is 5.76mm at the 44mm prop hub circumference. I haven't measured it yet, however, the difference between the approach and departure of the magnet could be close to 5mm.

I'm resigned to ordering both mods, it'd just be super annoying to find the intake mod (the expensive one) is already done when I go to fit it. Can anyone post a pic of the intake mod internals pls.?

Am I way off track here with all this? The reports of improved starting, running and lubrication and pics of cracked cylinders would indicate that for the standard FG-60 R3 there's room for improvement. It's great that you have had zero issues with your engine Sparky, however, I've seen enough on the forums to make me cautious.

I'm looking forward to hearing from experienced Saito owners, or anyone with insights, on all the above.

Cheers,

Rob

I dont have time to explain it all to you it will take a few hours to digest what has transpired with the engine. Have paper handy to read suggestions from various posts....
Look at post # 2187 and 1861 for a start.
Sparky

Yep, fair call, I'll keep reading and check those posts you mentioned, thanks.

Cheers,
Rob

First flight of the season with the P-47. Short video

That sounds and looks great, thanks for sharing the vid. What diameter is the exhaust ring tubing? Is it 16mm or 19mm? Certainly has a nice note.

Exhaust
 

I’m using the supplied exhaust tubes with a collector I made from plumbing supplies. Turned out nice. I did have the Keleo Exhaust ring on but with the talk of it causing cylinders to crack I took it off. I’m pretty happy with the sound of the exhaust.
https://cimg8.ibsrv.net/gimg/www.rcu...8620c514e.jpeg

Hi rob, as far as I know the only engine MMM has said comes with the “new” backplate mod from saito is the Fg90, I am getting a 60 after enjoying my 33 (with both mods) if I buy a brand new 60 it would still need the backplate and timing ring to run at its peak.

regards Tom.

Low needle is a pain
 

I decided to adjust the tappets and give my fg60 a quick tune before its maiden. It was running nearly perfect. Now i have been chasing my tail trying to tune this bottom end all day. Its sounds great on top end and idle and transition but seems to have a very very slight miss in the midrange.i have checked the rocker gaps again and cleaned the plugs but it just isn’t running as sweet in the midrange now. I might just fly it and see how it goes. Have you come across this ?
cheers Brad

It's difficult to trouble shoot from a distance away....some of that will smooth out with running did you do the bench break in?
Sparky

Gents sorry about changing the subject slightly have been trying to pose a question :confused:
It has to do with the Saito FG 90 R3 there a number of modifications now available for these engines, the "mod" i am considering is on the carb changing from the supplied carb to a walbro conversion
the reasons are as follows has a choke to prime engine and easy adjustent and pump
are there any drawbacks or improvements by the change that i am unaware of
all input from fellow radial enthusiasts greatly appreciated
Keep 10 Foot up !
Dave P

Hi Brad. Make sure you did the valve adjustments at the proper TDC (there's 2 per cycle). You can tell by looking at the valves; the proper TDC is when there's no overlap on valve movement.

One more thing: how fresh is your fuel mix? I had a similar experience when using old mix (>4 wks in storage). I don't know whether the oil settles or something volatile goes off the gasoline, but I tried a fresh mix and tune went back to normal.

Hector.

Running in
 

Well, after a false start due to test stand letting go, I finally began running in my engine. It has MMM timing and inlet mods, standard exhausts for now, and used KLOTZ at 25:1 (despite claims the intake mod allows even less oil....)

With recommended carb settings I managed to hand start it, and richened slightly to achieve 4000 rpm WOT. Will continue running in like this, then eventually reduce oil to Morris’ recommended ratio, and fit Keleo exhaust before it gets put into a Phoenix Waco.

Will have head temperature monitoring for next run too. So far so good.....

Thanks for the reply mate, i have a ford cleveland with solid lifters so am quite good at valve clearances 🤣. Fuel is fresh mixed in the same day. Its not too bad so i might just fly it ( when our fields are open from the dreaded virus)
might put some flight time on it and retune