vertical grimmace

My Feedback: (1)

Yes OF, it is the Jerry Bates design. Not sure how I stumbled on the design, but it kind of fits the bill for what I want to do right now. I wanted a somewhat gentle flier for scale competition. And yes, the design begs for a 4-stroke. But, I do not want glow fuel for anything this big. The cost and mess of the fuel mainly.

Yeah, I certainly do not want to drag this thread int an oil brand discussion. I was just interested in the percentage. 15-1 is very rich. Why so much oil? Does a lot of this get thrown out of the exhaust casing a mess? Too bad the engine cannot handle a 30-1 mix. Mainly because this is what I run in all of my other gas engines, and it would be nice to not have to have 2 gas cans with different mixes.

FNQFLYER

Ok , yes Old Fart I am still alive, just sorting out family problems. Now the most common cause of failure of the early FG saitos was in correct fuel / oil mix, usually carbonned up exhaust stems. Follow the factory /horizon hobby specs and you will have no problems especially during the break in phase. Check out the Saito gas section here in RCU and you'll get a lot of good guts. (ideas and info). Re wooden props, especially those expensive ones (yes I have some for scale projects and initial running in), for almost the same money there are very good carbon fibre props that survive vertical arrivals a lot better. Re the Moth Minor, as an apprentice and in a "stupid stage" = doing work for nothing, I helped restore numerous Tiger and Gypsy Moths but one of the best was a Moth Minor, all good original DeHavilland product and from experience well built models flew with the same characteristics as the full sized ones. On Methanol and spark ignition, McCoy 60's on spark and petrol are ok but have an unreal transformation when fed "steroids" mixed with methanol. On Klotz 200 I have got a fair amount at a "good" price" so along with Cool Power it is my lubricant of choice.

acdii

Very little mess, I also setup a scavenge system with a brass tube connected to some silicone line to the breather on the crankcase, the end sticks out behind exhaust outlet and sucks the oil out and away. I only have a little black slop to clean up after an hour of fling off the landing gear. My DLE20 with 32;1 makes more mess.

Reason for the higher oil content, the FG is the same engine as the FA, which use high oil content to start with. 4 strokes need more oil too to get up into the rockers and crankcase. 2 strokes dont need as much oil content since the oil/fuel is delivered through the crankcase.

SrTelemaster150

I have a Stihl FS-90 4-sroke weed whacker that uses the exact same 50:1 mix as my 2-stroke Stihl chainsaw.

spaceworm

Without going into detail, the Stihl 4 Mix uses an entirely different induction and lube system. It also uses ball or needle bearings such as used in their 2 stroke gas engines. Apples and oranges. But, you know this already.

Sincerely, Richard

Rudolph Hart

Vert can you post some photos?

I admit running wooden props can be a short term proposition trev specially in overpowered tail draggers and i'm challenging you to a dual pard...i'm bettin i've shaved more mas classic 15x8 white tip off on the takeoff run than you have,the prop looked black with the white ends missing and it still took off well but man did that 115 pull some revs.

ps sr you flyin that chainsaw or what...does it sound like a fourstroke??

FlyerInOKC

My Feedback: (6)

Rather then frag the SOB why not put an exploding canister of some purple/reddish dye the stuff that won't wash off it has to wear off. Just think of the poor sod having to explain it to everyone he meets including the nice constable that arrests him because the dye matches his warrant for trespassing and petty theft!

SrTelemaster150

The OP I quoted cited that 4-stroke somehow need mire lube than 2-strokes. It is the lack of needle bearing that you cited that required more oilfor the Saito FGs than normal "gas" engines that have such bearings. It has nothing to do with whether or not it is 2 or 4-stroke.

spaceworm

Yes, what I said. I knew you knew what you know.

Sincerely. Richard

acdii

What I was saying is that the 4 stroke GAS Saito engines are the exact same engines as the GLOW engines. To lube them, its done through the intake and exhaust valve guides using the crankcase pressure/vacuum, and blowby past the rings. The 20:1 mixture in gas is similar (but not exact) to the 18-20% oil content in glow fuel. The DLE, DA, XYZ, and other 2 stroke GAS engines get their lube through the crankcase every time the piston draw fuel/oil/air in, so the oil content doesn't need to be as high.

Needless to say, if you ran 32:1 or lower oil content, your FG will seize up rather quickly. As it is with 16:1 mix, there is very little residue coming out of the breather. First time I ran the FG-11, I was concerned there wasn't enough oil with 20:1 since there was nothing coming out of the breather, so I added more oil, upping it to 16:1, then I saw black residue coming out and then I felt better that the bottom end was getting lube. After I ran a tank through, which took an hour following the manual, 4000 RPM WOT stepping it up after so many minutes, I took the covers off to check valve clearance and saw it got enough oil at 16:1 so kept it there. After an hour flying, or one tankful, there is so little residue on the plane that I seldom bother to wipe it off, only the left gear strut gets a wipe down, as thats directly inline with the muffler, and gets a very thin coat on its leading edge, and its all from the breather tube.

FNQFLYER

Actually in a 20:1 fuel to oil mix the volume of oil by percentage is 5%. By following the recommended break in procedures people I know here in OZ have not had any problems with the FG 20 unlike it appears elsewhere. BTB the one I have been monitoring (FG20) is now running (after suitable running in and the "modified carby" being fitted) is now running a 30:1 mix quite happliy. On your Moth Minor, a similar sized Gypsy Moth in our club operates quite happliy with a Saito 180 as long as the engine stays in the airframe.

FNQFLYER

Old Fart, what are these white tipped black props you are talking about? I have something like that in my "extra" prop box and I use them as either paint stirrers (or epoxy mixers) or I "lend" them to people needing a prop to operate with. BTB I do have some large Xoar props in my collection and some Zingers left over from running Rossi racing engines in.

Rudolph Hart

Trev you toffee nosed(flash so and so in aussie speak)prop man you..those mas classics look good on a nice aeroplane,the midget with 115 used to sonic boom on the prop tips,see if i can dig up a photo of the old girl.As for zingers on small block saito's phut! anybody else want to say how much oil we should run in gas saito's? i run one and would like to hear peoples opinions.

acdii

Oh the FG will run quite well on 30:1, but for how long?

Right from the manual



They also recommend installing the engine inverted.
Most likely to make sure oil gets to the rockers since the oil volume is so low compared to glow. Run it with lower oil content, and it wont last very long, the cam, pushrods, lifters, rockers will all wear out quickly. I have already taken the rocker covers off on mine and there is very little oil in them, and it is inverted. Just enough oil to keep it lubed, but it is also dirty oil, so always a good idea to give it a flushing with clean oil every few flights. Better to be safe than sorry.

Hobbsy

My Feedback: (102)

The blow by oil is sparkling clean as shown here, people call it all kinds of derogatory names but it's quite clean.

acdii

Looks like glow lube. I didn't know they made Golden Knight Gas engines.

FNQFLYER

old fart as a rule I only used wooden props for the first part of an initial run in so as not to load the engine and get oil etc into all the right places. I have a heap of those black plastic props (MS?) left over from my days in Malaysia. We have a Midget Mustang running an OS 120 but an appropriate APC. Overrated a/c (full size).

Hobbsy

My Feedback: (102)

That is the very first 1.50 sold by Horizon, it is black with chrome rocker covers. No wimpy gas engine will ride on one of my planes. That particular engine was sent to my local Hobby Shop, which is only 400 miles from here, to be a display engine. My daughter talked the HS owner into selling it for a Christmas present for me. They cost $449.00 back then. A little lower than that now, I think. The oil is red because I use Wildcat exclusively, the camera enhanced its redness.

braddock VC

I'm really pissed off today, for the second time one of my saito 82s has seized solid, same problem conrod seized onto crankpin. I use 20% oil and 10% nitro. Doesn't happen to my OIS 4 strokes.

vertical grimmace

My Feedback: (1)

I have not started building the Moth minor yet. I am just gathering info and parts right now. Working with Lenny at Shindin for the gear struts. IF I go with a Saito, I will get the 30 FG.

Hobbsy

My Feedback: (102)

I never had it happen to any Saito in 23 years of using them. How do you do that?

spaceworm

What prop/rpms? Overheat? Oil out of breather? Whose fuel? More info would help us help you. That is, if you are looking for help.

Sincerely, Richard
AMA 861960
Club Saito #635; Saito 56, 100, 120abc, 130T, 180
YS F 120

Rudolph Hart

Dave you make synthetic smell like castor and i'd dive right in the back of that crankcase and have a swim in the pool.Don't be tempted to buy a 150 like dave's acdc,it will murder your wallet on props.Wimpy gas engines?? you swing a big prop on a saito gas fourstroke for the first time it fires dave,your harley could'nt drag you backwards fast enough

Hobbsy

My Feedback: (102)

The truth is Pete, my old 1.50 only kicked props off twice, it broke them both times, my fault though. I broke this prop because I had the timing at 40 btdc, it didn't like that. I made myself a better degree wheel. That is an early 1997ish C&H Ignition system. Dan fixed me up.

braddock VC

As I mentioned in post # 30269, my 82a seized up solid, and I mean solid. It happened to me one time before on one of my other 82a and I bought a new conrod. As the engine is now 11 years old and well used I decided to have a look to see if I could get it serviceable again, I have a bnib 82a (I bought 3 together in 2004 when I sold my old vintage diesels and made enough to buy the 3) So if I fail I have a new engine to install.
Way I see it there's two difficult tasks in this job, 1. getting the prop drive hub off and 2. assembling the engine so the valve timing is correct.
I used a total of three special tools, (i) a hot air gun for shrinking covering film usually; (ii) a battery terminal puller; (iii) an 8 mm 4 inch bolt, nut and two washers.
Today I stripped the engine down, leaving the prop nut on I hooked up the battery terminal puller and really turned it up tight, Then I started the hot air gun on high setting and aimed it at the prop drive hub. After two minutes or so there's an almighty bang and the prop drive hub is off but retained on the shaft by the prop nut.
Then I took the carb and backplate off and squinted in the crankcase, bearings look rusty but unbroken, then off comes the head/liner I marked up the pushrods inlet and exhaust and set them in an old wine bottle cork and popped them in a tupperware container with all the allen screws. The piston is free on the gudgeon (wrist ) pin so off comes the piston and I take care to remove the pads that prevent the pin scoring the liner and popped them and the piston plus cylinder liner into the tupperware.
The conrod is really tight on the crankpin but two minutes with the hot air gun frees it up enough so \i can lever it off with a piece of 1/2" square beech engine bearer stock so there's no marks on anything.
The conrod bigend bore is 7mm clearance so I pushed the shank of a drill thru and twisted it until it freed up. I could now get the conrod on the crank pin but it was still tight.
I decided to lap it in so rather than use carborundum grinding paste I used some hob cleaning paste and a couple of minutes with this and the rod is free as a bird on the crankpin and can fall under its own weight. Quick clean up then out with the hot air gun and heat up the crankcase (after removing the cam cover together with the camshaft) a quick wack with a piece of timber and the crankshaft is out. Two minutes more with the heat gun and both bearings are free.
Final thing to do today was fill the inlet and exhaust ports with gasoline to check if the valves are tight, they are so no work there.
New bearings are ordered up and part 2 will be posted when they are installed.
BTW for some reason my cameraphone is playing up, I can't seem to transfer the pix, if they come through I'll post them in part two.