RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

This happened to me too

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

There is not supposed to be any difference in the crankcase breathers of the FG-20 and the FA-125A. They have the same part number.

There has been a problem with the Saito breather fittings as some have a burr across the hole caused by bad tooling on the bar lathe that makes them.

You can take a scribe and insert into the hole and open it up by removing the flashing that was pushed over the hole

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

W8ye,

Yes you are right, After you said this...I went and took it out and look at it. I could see the othe end that the hole is smaller, I took a file and got some off and opened the hole. Here is a pic on how it was before. Small hole is FG 20. Now both are the same cca 2mm, before was 1.25mm and I thought that Saito did it for a reason. I was thinking to try the engine after is set and tuned with the bigger hole to see if make any diffrence. In my mind it was to keep in some oil for lubeing the inside since is a gas and fuel does not run as much as Glow.well now I open it ...will see what happends. You have one of those, yours was big hole from start?


Adrian

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

I have two FG-20's. The first one had the small hole and the second one did not.

I bought a Saito 56 back 10 or 11 yrs ago and it had a restricted hole in it also. At the time I already owned a Saito 50 and it was not restricted. So I opened up the one on the 56. I eventually bought two more 56's and they were not restricted.

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Hey Adrian, I don't recognize those off-white plastic (?) parts holding the carb. Are they home made? The one below the carb almost looks molded, with those stiffening ribs.

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Pull UP,
From original setup I went and stiffen up a little bit. From 1/16 aluminum bottom part I went to 1/8 , Find out that was not quite strong. Imade the aluminum part and made a mold off of it. On the plastic version I put the ribs to make sure is strong.. The top part I madeis 1/4" and I do not use the nipple for pulse soldered in to the tubbing. I made that interal.
I JB weld the tube in and if you look Imade 3 little holes on the part . Idea is that JB, once the tube is in to get also trough this holes and give more strenght.
And Yes all is home made, The plastic is gasoline rezistent. I made the carb to stay much more straight with the motor. On old setup find out that the neddle adjustments angle will get you close to the prop when mounted on the plane. So for Safety ....Ichange that.

Adrian

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

I finaly got a better diagram of the ZAMA C1Q carb. I look a littlein the manual and will be couple Zama carbs with accelerator pump. If any one need any info on a specific carb ...let me know and I will post it.

Thanks
Adrian

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

What's the plastic you used to mold the parts from?

It almost looks like the plastic from a rapid prototype printer?

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Stereo Lithography? If so, I doubt that plastic will have the necessary thermal properties to hold up once the engine gets hot. Or did I miss where you said you'd already run the engine with these plastic parts? What was the molding process you mentioned? Injection? Home made poured? Material properties?

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

You'd be surprised then. We've used it to prototype cooling ducts for UAV engines. Nothing melted even at the mounting points on the cylinder head. It would definitely work for this.

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

<div style="margin: 0in 0in 10pt"><span style="line-height: 115%; font-size: 10pt">Hi guys, I tied a Zama carb on my FG 20 .here is another video. It is not that great but you can see it on action.
I made another bracket for the bottom from AL6063. I test the plastic" Home Made" and that works to. But I think I will trust the AL for 3 gr more. Total weight with Zama carb, muffler, C&amp;H <span style="color: black; text-decoration: none; text-underline: none">ignition</span> is 875Gr, close to 31OZ. I can say that runs great, started better than Walbro, easy to adjust, DOES not need a spring for fuel pump. I took the <span style="color: black; text-decoration: none; text-underline: none">cover</span> off and I machined a place for the spring(from Walbro 456-1) but not need it. The membrane there is different than Walbro, it is much more stiffer.</span></div>
Thanks
Adrian

[youtube]http://www.youtube.com/watch?v=4ViBbZXdsqY[/youtube]

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Nice information, Adrian. Have you run that 125 yet? I noticed the FG20 has an external pulse tube to the intake, but the 125 is an internal slot-to-the-venturi. What is that ignition unit you're using? Kind of looks like a modified BBQ starter circuit. Is there a uprocessor there somewhere with an advance curve built in? Also, why is the backplate to the 4-blade prop so big? Nice work, overall.

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

just an FYI been running /converting these engines for about 20 yrs, bushing works fine on 9 per cent oil, Will call my walbro guy to see about your springgary nice machining job!!

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Thanks guys,

Pull Up, what is your real name,I will like to adress by that...if you do not mind.
The one on the video, is the old style top part. I did not had any more intake tubes and they are ....pricy at HH, so I used that one on this Zama carb.
The FA125 runs great, I test it. The FG20 and FA 125, both with Walbro 456-1 performs the same. With a APC 16 W5 WOT around 7950-8100 RPMS. Idid not had my stuff ready to make a good video.Like I said, I did it with my Iphone....was quick on hand. The FG 20 and FA125 I run them with the ....internal pulse design(second version of top plate). and runs great. I am looking now to make my own intake tubes.. S. Steel tube at 90 degree silver soldered.Do you think will work?
With this Zama Carb, Itest the FG 20with diffrent props:
APC 16 w 5 WOT 7950-8100Rpms
Master screw 3 balde 14 x 7 -8500Rpms
Evolution 15 x 6 8700-8900 rpms
Evolution 16 x 6 same as APC above.
And you all seen the Zinger4 prop.
The back plate is True Spin for P51D mustang 4 1/4 dia. I did not put the cone as I was changing props.
Now...the BBQ is a C&amp;H Ignition that I am starting to build with all components from Bill. So It is a C&amp;H ignition without the Box. I am working on a box for that and Yes it has the autoadvance timing board.
The new sensor bracket I made is to be universal,FG 20, FA125, FA 180, After molding, it takes a lot of time to...finish it, some time is a waiste of material...but it is a part of the game.I am in process of making another mounting for a FA 180 that I converted and tested as you seen on youtube next will be a FA 91S, OS 91, and the bigest ....cooking is a 1:7 scale V12 of the Merlin engine, supercharged and fuel injected. At that scale....lot of chalanges but it will get done in time....2-3 years as money are ...short and...on the march 12 I get "Hung" ( married) http://www.rcuniverse.com/forum/js/f...eeth_smile.gif.
I will be back on March 20 to my little world.

Thanks Guys
Adrian Ciulei

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Hey Adrian,

My real name is Rick.

Careful using stainless steel on the intake. Mismatched metals can lead to loosening due to different coefficients of thermal expansion-aluminum is the greater of the two. Not saying it won't work, just be aware. But yes, it can be brazed and otherwise it should work. Brass would work too. I'm visualizing something like a brass close elbow. Also, copper 1/8 or 1/4 sweat fitting might be a possibility too. I've gone that copper route to make brazed custom exhausts before. I did that for a Fokker DVII with a particularly difficult engine installation.

Got it, on the spinner backplate. From the video, it looked like it had something to do with the 4-blade retention setup. But it's just the spinner backplate.

YOU'RE GETTING MARRIED AGAIN SO SOON?? Last one bugged out only last April 23rd if my memory serves. :D Well, congratulations. Man needs woman. Better if she "understands" or can "withstand" this hobby. Did you sit her down and give her the RC Hobby talking-to? :)

I still remember the day that hobby realization finally dawned on Ingrid, my wife. ha ha. She though I was just going to sit there in the living room like a potted plant, watching "Survivor". ha ha.

Bringing nostalgia into the picture, my latest project is a blast from the past. In 1983, I bought plans and a locally made (in California) short kit for a Brisighella 26% Steen Skybolt. It's been on my shelf all these years. The plans look more like parchment by now. Anyway, it's going together nicely. This needs a minimum 50cc power plant. It builds heavy, because remember this was drawn up before there was laser cutting of wood and it was literally the dawn of giant scale RC. No one knew how these planes would hold up, so they were all built like Sturmoviks. For example, the rudder, vertical stab, and the elevator are all 3/8" thick! Final weight projected at 22lbs.

I was in contact with the designer, Dario Brisighella, because I had a few questions. He's retired now. Also tried to get in touch with the guy who fab'd the landing gear and cabanes. His name is Lee Richter. Dario says he's retired in Florida and no longer makes the parts. Well, I suppose if I can machine an engine, i can weld some music wires together no problem.

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Hi Rick,

You are correct about ...last year...but that is past and I need to move on, luckly found a nice good girl that is supportive of my hobby and she liks seeing that I am creating and doing stuff.
When I am getting lazy ...she is remainding me that I still have stuf to do. All I can say now Thanks Godthat I found her ( Camelia), Lets see next year how things will be.

When I get back I will take another video with much more details.

Adrian

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

well after mating a RCexel ignition module to my OS120FS I decided to go all the way and fit a WT465-1 Carb. What a difference it made to the reilabilty and idle. I just made a brass plate and reused the orignal OS manifold but swapped the elbow around so the out further from the cylinder.

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

That looks great, Take a video and post it.
One thing that wonders me is the carb is only supported by the intake, it is any way you can add a bottom support? 1/16/ (1.5mm).

Adrian

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Looks like some real nice conversion work being done here Guys....keep up the good work ! Best Regards Capt,n

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Very nice job brazing, etc. So far, I've only converted Saitos to gas ignition. Curious how the OS's will hold up. Especially the bottom main journal (plain?) and the valves. A friend of mine's conversion (Saito 150) kept developing a leaking exhaust valve. No amount of lapping would completely cure it. I see a need for the availability of a Saito valve keyseat cutter. Lapping is troublesome because the annular grooves that are created during the lapping cause valve sticking, or lack of sealing. I believe the sticking is because the micro grooves created by the lapping particles get interlocked. And the leaking, in turn, is caused by those same grooves failing to mesh. I got around it by first grinding the valves, then lapping very briefly with toothpaste, and then finally regrinding the valves again (same angle). This minimized the grooving. But it still was not perfect. A keyseat cutter is really the only way.

On your OS, perhaps you could next time angle the brass carb plate and in turn the carb too, before brazing. This will present the throttle linkage arm squarely to the firewall thus simplifying the servo-to-throttle installation.

But a really good effort! What is the material you used for the carb-to-intake insulator?

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

I still have to make a bracket to support the underside of the carb. the insulator is just a piece of actel sheet, 3mm thick.

Curious how the OS's will hold up. Especially the bottom main journal (plain?)
what do you mean by plain main journal? the bottom end of the OS120FS has a bronze bush, I think the later alphas series do not.

I've run the engine on glow and clocked up enough run time now to switch over to gas. Im running redline synthetic oil at 16:1. I know it may seem like alot but redline is very clean burning and in the grand sceme of things 16:1 is still alot lower than 16-18% glow mix.

I was thinking about installing a small nipple (such as a exhaust nipple) in the backplate to allow a small shoot of pure oil to be injected from time to time, to aid in bottom end lubication. there's two bosses in the back plate so drilling and tapping this area will be easy. Any thoughts?

I should mention my inspiration came from the work that "pull up now" has done and the videos "i7x58" has posted of his sweet running satios. not to mention w8ye and others in this thread and there trial and error examples. And not to mention the fact this is my last glow engine that I own, no more hydroscopic, rustly, slimely glow fuel;)

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

good point about the throttle linkage, did'nt think of that. videos will come with time also

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

Engines running on gasoline do not rust inside like the ones running on glow fuel

RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
 

I know, thats the major plus side for me. never had a single problem with corrosion since running gas engines