After i used Polyeurethane on my Oak scratch built test stand... it almost looked professional for a second lol

Here is an engine that sounds nice with those flex pipes, a Saito FG-57TS

Start at 2:23

Aeronca C3　初フライト (7 min 40 sec)

...heckuva sweet plane

Originally Posted by Balsaworkbench

The alcohol boost was for overweight takeoffs.

Like drinking a Double whisky before having a fight,,

Originally Posted by mchandrayan

Is that single component PU or two part PU?

I only use 2 part Pu, car paint, you can get varnish and any colour mixed in,
mat satin or gloss and it won't harden, also where I shop they will mix any quantity.

Originally Posted by paulinfrance

Like drinking a Double whisky before having a fight,,

The drunk pilot must also be overweight

Absolutely loving running the Saito FA100 in my new GP Extra300s. I finally got to take the plane out yesterday and get some time on it. I didn't have a tach with me but I think I got the tune close. I love how great this engine runs! I bought it used from a fellow on here so I didn't have to break it in. These 4-strokes are wonderful. I also love how quiet they are. There were a couple times I thought I may have killed the engine, but no, it was just idling away! Transition is nice and smooth. I do feel that I'm not getting the most out of the engine yet, but I didn't want to push it without a tach. I also am only using 10%nitro Omega fuel. I have a 15X7 APC prop and the plane will hover, but does not have room left to pull out of it. I have a couple props to try and I may go up in nitro content once I finish this gallon of fuel. I also have the FA120 in my TP Corsair. I may switch out the engines as I think that would suit the flying characteristics of each plane better, but I want to get used to the flight characteristics of the Extra before I try to bump of the engine performance.

I haven't flown it yet, but I ran a few ounces through the new 150, fired right up with no surprises!

Originally Posted by forwardonly

Absolutely loving running the Saito FA100 in my new GP Extra300s.... I have a couple props to try and I may go up in nitro content once I finish this gallon of fue

They're great aren't they, that's the Saito experience for you. 10% nitro is pretty common with these engines, you might get a noticeable bump in power if you went to higher nitro and I've heard people say good things about using heli fuel with 30% nitro in them, but that's expensive fuel. I'd suggest consider a larger engine instead, I believe the FA-125a is a drop-in replacement for the FA100, same bolt pattern according to http://saito-engines.info/specifications.html and would be a good jump in power, same page says you'd go from 1.8 to 2.2hp peak for about another 10% extra weight, it's not a bad equation. There have been reports here of big improvements simply by using spark ignition (and obviously finding the optimal timing) and still keeping it on methanol, no nitro. Maybe up to 20% more power, and cheaper to refill to boot. I think you're right not to get too keen on HS tuning until you have a tachometer, they're just a cheap electronic thing now from hobby stores. I've spent my working life specifically listening for frequency changes in other equipment so I believe I could do it by ear, but I don't try. Better to use a gadget, get a real number and be sure of it. I haven't done it personally yet but if you lean them too much at full power they can backfire pretty savagely and eject a prop and spinner with a lot of herbs on it. Not something you want to stand in the wrong place for. Tuning is the key to these engines, by all means set your peak power but to really enjoy great economy, starting and response, spend more time on the LS needle. That's where the magic is, as the plane spends most of its time on it anyway.

Finally nearly ready to launch the model I intended all along for my FA-82B. I flew it recently in my trainer which has had an FA-56 in it, the 82 was much more power than it needed, too much really as drag limited the speed and it ended up just flying nearly the same on a lot less throttle. But the pickup and climb was great... for all of 4 minutes until the glow plug fell out, I hadn't tightened it properly. Well, if you learn the hard way you really learn it. It came down in the dirtiest dirt on the field, real black dusty stuff that went *everywhere*, no matter how I tried to blow and wipe it off there was always more right through the engine and model, and as the glow plug was out it got right in the cylinder (I'm glad it wasn't turning then). Thanks to a good tip from Cherokee Flyer I used methylated spirits to clean it with the cylinder and rocker covers removed, and the dirt just kind of jumped off, it's the cleanest it's been since new. And no grinding noises when I turn the shaft.

Originally Posted by BernardW

But the pickup and climb was great... for all of 4 minutes until the glow plug fell out, I hadn't tightened it properly. Well, if you learn the hard way you really learn it.

Holy snapping duck sh*t Bernard, that plug must have been very loose. How did you even manage to start the engine in the first place?

Did you find it?

* Danny M *

Originally Posted by danny mz

Holy snapping duck sh*t Bernard, that plug must have been very loose. How did you even manage to start the engine in the first place?

Did you find it?

* Danny M *

I'm still not sure, my best guess is that it was *almost* in place but not nipped up tight, so the threads sealed the plug hole but it was able to work loose with vibration. I assume my prop was slightly off centre or something leading to enough vibration to start it working its way out.... I mean, I wasn't aware of that and I've been more careful lately with centering, but how else could it have happened? There was no plug in it when it came down, that's about all I can tell you, and I never found the missing plug. The cylinder had quite a bit of dirt in it but definitely no scoring, telling me the hole for the plug was open but the engine not spinning when it hit the dirt... I'm kind of doing this by deduction, of couse I didn't see it pop out in flight.

U would need some good eyesight to see that pop out or finding it . I had one fall out when I was younger and dumber . Now Im older and still dumber . At least thats one thing I havent repeated ! I like hearing of dumb stuff . Its what makes the hobby more fun . Nothing worse than hearing excuses even when everyone knows its baloney , at least when u confess everyone can laugh with you instead of behind your back when u go home ..Cheers

Originally Posted by the pope

U would need some good eyesight to see that pop out or finding it . I had one fall out when I was younger and dumber . Now Im older and still dumber . At least thats one thing I havent repeated ! I like hearing of dumb stuff . Its what makes the hobby more fun . Nothing worse than hearing excuses even when everyone knows its baloney , at least when u confess everyone can laugh with you instead of behind your back when u go home ..Cheers

Totally, what's the point making excuses? Better to say, and especially to tell yourself, "I stuffed up." It's the truth, it's quicker and you learn from it. I've definitely had one come out that I had tightened, but I think that's because it didn't have the copper washer, and I knew it. Shouldn't have tried to fly it! But I did... "I stuffed up."

Going with the current sentiment, my recent goof up was with an ASP 160 twin (don't shoot me I know it's a Saito thread ).

I had replaced bearings on the 160 and assembled it back, put it on test bench and at the flying field fired it up. Started right away so was happy .
Proceeded to open the throttle a bit and the right cylinder made some strange noises . I shut down the engine.
Considered opinion of all the onlookers was, may be the tappets were way off. So I thought, let the engine cool down before I reset the tappets.
While the engine was still warm, I proceeded to nip all bolts to ensure that they were still tight after the metals expanded a bit.
And imagine my horror when I realized that all the head bolts on the right cylinder were just threaded a few threads . Pity that cylinder did not fly off the engine when I started the engine.
Needless to say, the bolts were snugged in tight, tappets readjusted and the engine once again sang a happy tune. Yes I had stuffed up

Originally Posted by gkamysz

For the sake of science one Saito cylinder was sacrificed. The combustion chamber including valve seats is not chromed. That is why it's not wise to lap Saito seats, aluminum is quite soft and it's easy to end up with very wide contact area which won't seal well. If they were chromed diamond lapping compound would be necessary to do anything, and the valves would see the most material removal. This is an FA-100.

I've used tooth paste or white polishing (fine) compound for automotive paint finises, neither of which have harsh abrasives , They just help clean varnish from the seats and don't remove any base material.

Originally Posted by mchandrayan

Going with the current sentiment, my recent goof up was with an ASP 160 twin (don't shoot me I know it's a Saito thread ).

I had replaced bearings on the 160 and assembled it back, put it on test bench and at the flying field fired it up. Started right away so was happy .
Proceeded to open the throttle a bit and the right cylinder made some strange noises . I shut down the engine.
Considered opinion of all the onlookers was, may be the tappets were way off. So I thought, let the engine cool down before I reset the tappets.
While the engine was still warm, I proceeded to nip all bolts to ensure that they were still tight after the metals expanded a bit.
And imagine my horror when I realized that all the head bolts on the right cylinder were just threaded a few threads . Pity that cylinder did not fly off the engine when I started the engine.
Needless to say, the bolts were snugged in tight, tappets readjusted and the engine once again sang a happy tune. Yes I had stuffed up

Not Saito related, not even RC engines related, but in my younger years I once started up a big 1000 kW dieselgenerator after a fuel pump and injector overhaul, heard a lot of hissing noises (hit the emergency stop while it was still busy revving up), and found that the nuts tightening down the fuel injectors were still outside the engine.... They were just hanging in there on the high pressure pipes....

Now that made me go over everything I have touched when working on an engine multiple times before starting, to this very day, regardless of big diesel or model engine....

Originally Posted by BernardW

Re. methanol and/or water injection. Several of them did it, I believe the 3350 and 2800 engines had it in some models and so did the later 4360, not sure about civilian aircarft using those engines but it wasn't unusual in the latter part of the war. It was only after I'd been interested in those big radials for years that someone explained to me they weren't model numbers but capacity in cubic inches... that's a lotta volume. I've read that some of the Korean War era Corsairs had it, but I don't know it for a fact. I really don't know whether the British engines had it or anything other than radials (and jets). Sorry to be vague but it's still a well understood system, sometimes it's water-methanol mixture, but this is a very different application to what Garry's talking about. Pure methanol as a fuel is great for performance and ease of combustion, when you hear at the dragstrip "Nitro Funny Cars" and Alcohol classes they're basically burning what we add oil to and call glow fuel. A mechanic I know says if it'll run, it'll run on that stuff (methanol). Water and/or methanol injection is an augmentation system as BWB says for takeoff or emergencies, I believe the action is that it cools and therefore shrinks the charge (of fuel/air) as it goes through the intake allowing you to cram more in - a kind of thermo-chemical supercharging, on top of or even without a mechanical supercharger. The same is done in many jet engines, the clouds of thick smoke you see in old Cold War pic's of B-52's on takeoff were with the injection turned on. It turns it into a dirtier-burning mix, not a clean efficient burn like at cruise. As with piston engines it's for short-term emergency or takeoff power. Plenty of info on water injection and methanol on wikipedia.

Originally Posted by Balsaworkbench

The alcohol boost was for overweight takeoffs.

The purpose of WM injection was to prevent detonation at higher boost levels. It cooled the intake charge and was classified as "war emergency power" for when you needed some extra HP to get out of a jam.. The Germans used nitrous oxide for "emergency power".

It is used on some drag race engines for the same purpose and is even employed on some N/A applications. It is still legal under "gas" rules as it is not a combustible fuel when mixed with water. Many use plain old windshield washer fluid by tapping into the bottom of the WW tank and using a high pressure pump to spray a fine mist into the intake stream.