SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
11-01-2010, 08:30 AM
#501
RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Thanks for the compliment on this thread I started quite a while ago as a simple set of questions. So manywise & experiencedpeople contributed as it grew so much longer than I ever thought it would.
ORIGINAL: Kostas1
Very nice thread!
Very nice thread!
11-01-2010, 07:25 PM
#502
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
I have been reading through this post and have read alot about finding just the right carb and fuel mixture. I am interested in how the 2 stroke ignitions are made to skip firing on the intake stroke or is there a different one for fourstrokes.
11-01-2010, 10:21 PM
#504
RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Here are some pictures from a previous Pullupnow! post in this thread of the CH type ignition sensor for the Saito 150. There is a magnet ring that is held to the rear of the prop driving hub by two 6-32 set screws. It has the Neodymium magnet stuck in a hole facing the rear.
The sensor mount is fashioned from a piece of aluminum angle that was purchased at the hardware store. The sensor is JB welded into a groove that is filed into the aluminum angle.
On a twin Saito, the sensor would have to be mounted on the forward cylinder cam box?
The sensor mount is fashioned from a piece of aluminum angle that was purchased at the hardware store. The sensor is JB welded into a groove that is filed into the aluminum angle.
On a twin Saito, the sensor would have to be mounted on the forward cylinder cam box?
11-01-2010, 10:41 PM
#505
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
ORIGINAL: w8ye
On a twin Saito, the sensor would have to be mounted on the forward cylinder cam box?
On a twin Saito, the sensor would have to be mounted on the forward cylinder cam box?
11-08-2010, 10:24 AM
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
ORIGINAL: Pull Up Now!
Regarding the FA270T conversion, since you mentioned using the stock carb, I assume you're sticking with glo fuel then? The stock carb won't work with gasoline well at all. What's the 20:1 then?
Some people like to just put EI on their glo fuel engines. I never really understood the attraction, unless it's low reliable idle. But a well running glo engine can idle fine anyway. I'm not really sure of the point of doing this type of conversion. Maybe you're not, and I just misunderstood your post.
Gasoline is cheaper, and cleaner. Yes, the power output lower despite it's higher heat content. So one would be wise to use a slightly bigger engine than would otherwise be necessary. Also, upsize the engine because you're now carrying the extra weight of a module and 2nd battery. All this means one should watch the wing loading and be careful of airplane choice. I once, unwisely, put a weedie EI conversion in a Super Star aerobatic plane. The plane was about 2lbs overweight. The wing loading approached 35 oz /ft2. I was doing a loop and the plane suffered an accelerated stall on the downside of the loop. The plane simple fell out of the sky. This was a dumb thing to do, so choose your plane carefully. Gas conversions are fun, but they must make sense. Nothing delivers the power of a lightweight 2 stroke. Despite all this, gas conversions are my first choice. Just don't do a conversion and make the mistake of pushing for RPMs as your measure of performance. Load the engine down with a bigger prop and use the torque they are best at delivering.
OK, this post got a bit preachy and opinionated. Itll probably set off a whole new set of arguments. But I don't feel like rewriting it, so here goes.
)
ORIGINAL: triumphman49
Hello, Have seen reference to the Walbro wt456-1 as a good 4-stroke 2-needle carb. Have a Honda GX31 & was wondering if this would be a good replacement for the stock carb? Also the phenolic mount is HUGE in thickness - any ideas where to get a thinner one. Additionally have a FA270T hoping to convert to EI using 20:1 gas\oil. If not satisfied with results of stock carb, would this same Walbro wt 456-1 be a viable option? Last question (for this post) would a rare earth magnet (like sold at Radio Shack) be the correct type of magnet to use with the Hall sensor pickup? Do appreciate all the great info these forums provide & extra thanx to w8ye for the many pm's Many Thanx T-man49
Hello, Have seen reference to the Walbro wt456-1 as a good 4-stroke 2-needle carb. Have a Honda GX31 & was wondering if this would be a good replacement for the stock carb? Also the phenolic mount is HUGE in thickness - any ideas where to get a thinner one. Additionally have a FA270T hoping to convert to EI using 20:1 gas\oil. If not satisfied with results of stock carb, would this same Walbro wt 456-1 be a viable option? Last question (for this post) would a rare earth magnet (like sold at Radio Shack) be the correct type of magnet to use with the Hall sensor pickup? Do appreciate all the great info these forums provide & extra thanx to w8ye for the many pm's Many Thanx T-man49
Some people like to just put EI on their glo fuel engines. I never really understood the attraction, unless it's low reliable idle. But a well running glo engine can idle fine anyway. I'm not really sure of the point of doing this type of conversion. Maybe you're not, and I just misunderstood your post.
Gasoline is cheaper, and cleaner. Yes, the power output lower despite it's higher heat content. So one would be wise to use a slightly bigger engine than would otherwise be necessary. Also, upsize the engine because you're now carrying the extra weight of a module and 2nd battery. All this means one should watch the wing loading and be careful of airplane choice. I once, unwisely, put a weedie EI conversion in a Super Star aerobatic plane. The plane was about 2lbs overweight. The wing loading approached 35 oz /ft2. I was doing a loop and the plane suffered an accelerated stall on the downside of the loop. The plane simple fell out of the sky. This was a dumb thing to do, so choose your plane carefully. Gas conversions are fun, but they must make sense. Nothing delivers the power of a lightweight 2 stroke. Despite all this, gas conversions are my first choice. Just don't do a conversion and make the mistake of pushing for RPMs as your measure of performance. Load the engine down with a bigger prop and use the torque they are best at delivering.
OK, this post got a bit preachy and opinionated. Itll probably set off a whole new set of arguments. But I don't feel like rewriting it, so here goes.
)
The reason for placing glow engine on ignition, and still run glow are:
1. Reliable idle-no cut outs
2. ease of handling (no kickbacks, and a witch to deal with)
This was the case with the YS1.70 made it a very nice handling..no kickbacks ect)
3. you can lean out the engine more. Mainly the bottom end...
This was the case with the ys 170...or so the guys that have that engine, reported...
11-08-2010, 11:04 AM
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
ORIGINAL: w8ye
I didn't search up above for the specifics but . . . .
In this thread and talking about the Walbro WT-456, it has a spring on the pressure signal side of the pump diaphragm to push the fuel out of the pump. The diaphragm works from a vacuum impulse only. The spring serves as the pressure impulse.
This spring is used on four stroke engine so the carb will work with a impulse signal from the intake manifold only.
All the Saito gas carbs on the FG-14, FG-20, FG-30, and FG-36 from the factory work this way.
The Walbro WT-456 was a OEM carb on a Ryobi Four Stroke weed whacker engine
Other Walbro carbs can be modified for the pump to work like the Walbro WT-456 by machining a spring seat in the pump cover and adding the spring
I didn't search up above for the specifics but . . . .
In this thread and talking about the Walbro WT-456, it has a spring on the pressure signal side of the pump diaphragm to push the fuel out of the pump. The diaphragm works from a vacuum impulse only. The spring serves as the pressure impulse.
This spring is used on four stroke engine so the carb will work with a impulse signal from the intake manifold only.
All the Saito gas carbs on the FG-14, FG-20, FG-30, and FG-36 from the factory work this way.
The Walbro WT-456 was a OEM carb on a Ryobi Four Stroke weed whacker engine
Other Walbro carbs can be modified for the pump to work like the Walbro WT-456 by machining a spring seat in the pump cover and adding the spring
I was looking at the additional tube added from the carb to the manifold....
I was thinking it needed to be pluged into the back of the crank case to make the pump work better, but apparently this isn't the case.
(I could hook it up this way but would have to have a drip can so the oil didn't make it's way into the carb.)
I am thinking of doing the same carb...
So don't use crank preasure.right??
I can do the setup just like the sweeds...(or are you austrian??)
Just messin w/ya Adrian.!!!
11-08-2010, 01:19 PM
#511
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Well... I was born in Brasov, Romania, 10 miles away from Dracula Castel. So be aware....doors, windows during the night ...BHHHHAAAAA 
.
Since 1998 I live in Frederick, MD. and work as Maintenance Supervisor at SB Thomas ( English Muffins)
Adrian
.Since 1998 I live in Frederick, MD. and work as Maintenance Supervisor at SB Thomas ( English Muffins)
Adrian
11-08-2010, 02:08 PM
#512
RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Kochj:
You missed the fact that I had admitted overlooking the easier starting using EI with glo fuel. Here it is, from the post dated 10-30-2010 at 4:07PM.
"You hit on the one advantage to glo-EI that I overlooked. They start easily. That is really true. The modeller will have to decide if that's worth the weight gain."
And yes, you can do your glo-to-gas conversion setup just like Adrian. "I can do the setup just like the sweeds...(or are you austrian??)
Just messin w/ya Adrian.!!!
"
Unless I'm mistaken, Adrian, a very energetic experimenter, got much of his guidance from this thread. And there have been many earlier pioneers too. My first EI glo fuel engine was in the 1970's, and it used an EI unit that had a mechanical advance coupled to the throttle arm. After that, I tried gasoline using the stock carb (very early Japanese 4 stroke). It was sensitive and it overheated. It probably needed ethanol, which wasn't available at the time!
That early effort also needed a more seasoned experimenter than I was at the time.
Just for the record, Adrian, I found a glo plug in my english muffin this morning. Would you mind not bringing your hobby to work please?
You missed the fact that I had admitted overlooking the easier starting using EI with glo fuel. Here it is, from the post dated 10-30-2010 at 4:07PM.
"You hit on the one advantage to glo-EI that I overlooked. They start easily. That is really true. The modeller will have to decide if that's worth the weight gain."
And yes, you can do your glo-to-gas conversion setup just like Adrian. "I can do the setup just like the sweeds...(or are you austrian??)
Just messin w/ya Adrian.!!!
"Unless I'm mistaken, Adrian, a very energetic experimenter, got much of his guidance from this thread. And there have been many earlier pioneers too. My first EI glo fuel engine was in the 1970's, and it used an EI unit that had a mechanical advance coupled to the throttle arm. After that, I tried gasoline using the stock carb (very early Japanese 4 stroke). It was sensitive and it overheated. It probably needed ethanol, which wasn't available at the time!
That early effort also needed a more seasoned experimenter than I was at the time.Just for the record, Adrian, I found a glo plug in my english muffin this morning. Would you mind not bringing your hobby to work please?
11-08-2010, 03:27 PM
#513
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Pull Up Now...
Sorry for that but...I do not think it was mine...I do not play with any glow, take a second look... maybe is a 1/4-32 Spark Plug
.
And it is correct people from this thread give a lot of guidance, fact stated on
http://www.rcuniverse.com/forum/fb.asp?m=10116529
Sorry that I mentionated only W8ye, that was the easy for me to remember, If we will go by names will be more easy to remember than RC forum ID.
Any way ...many thanks for all the guidance from all members from this thread and the one related.
Adrian
Sorry for that but...I do not think it was mine...I do not play with any glow, take a second look... maybe is a 1/4-32 Spark Plug
.And it is correct people from this thread give a lot of guidance, fact stated on
http://www.rcuniverse.com/forum/fb.asp?m=10116529
Sorry that I mentionated only W8ye, that was the easy for me to remember, If we will go by names will be more easy to remember than RC forum ID.
Any way ...many thanks for all the guidance from all members from this thread and the one related.
Adrian
11-08-2010, 04:55 PM
#514
RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Adrian, the lack of proper attribution wasn't from you. I was reminding Kochj of those who came before you started your development. Easy to ignore them, as there are now 21 pages to this thread, and it's a formidable task to read the whole thing!
As I'm now contemplating projects for the winter (it's Minnesota ya know), I'm considering putting the home made needle bearing rod back into the Saito 150 GK gas conversion and seeing how that runs.
Also, an old G23 conversion to EI for a Hangar 9 P47 Thunderbolt. I'm worried about the weight, but I've run the numbers on stall speed and wing loading and it shows the estimated extra weight would only increase the stall speed about 1-1.5 MPH and the wing loading would still be under the kiss of death 35 oz / ft2 level. I'm open to suggestions as to how to minimize the weight gain. Yes, there's the usual, smaller gas tank. lipo battery paks. Even using an ESC to save the batteries, there could be some gold there (weight savings to be had). How about nylon gear servos? ha ha ha. That's asking for it, right? I REALLY wonder why Walbros have to weigh as much as they do. Maybe a good project would be to come up with plans to hog out every bit of cast material not needed for actual operation? I think the overall size of Walbros is determined by how much force the venturi vacuum can exert upon that regulator diaphragm. After all, it's the biggest item on the carb. If one were to use thinner membrane material, and a lighter spring, the diaphragm could be made a smaller diameter. I'm assuming this size is what determines the size of the basic "cube" that those carbs are.
As I'm now contemplating projects for the winter (it's Minnesota ya know), I'm considering putting the home made needle bearing rod back into the Saito 150 GK gas conversion and seeing how that runs.
Also, an old G23 conversion to EI for a Hangar 9 P47 Thunderbolt. I'm worried about the weight, but I've run the numbers on stall speed and wing loading and it shows the estimated extra weight would only increase the stall speed about 1-1.5 MPH and the wing loading would still be under the kiss of death 35 oz / ft2 level. I'm open to suggestions as to how to minimize the weight gain. Yes, there's the usual, smaller gas tank. lipo battery paks. Even using an ESC to save the batteries, there could be some gold there (weight savings to be had). How about nylon gear servos? ha ha ha. That's asking for it, right? I REALLY wonder why Walbros have to weigh as much as they do. Maybe a good project would be to come up with plans to hog out every bit of cast material not needed for actual operation? I think the overall size of Walbros is determined by how much force the venturi vacuum can exert upon that regulator diaphragm. After all, it's the biggest item on the carb. If one were to use thinner membrane material, and a lighter spring, the diaphragm could be made a smaller diameter. I'm assuming this size is what determines the size of the basic "cube" that those carbs are.
11-08-2010, 06:12 PM
#515
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Iactually look in to that and ...it is not much materilal you can rmove. On one side where you have the mounting hole as a...tube you can cut that , the other side too and make those mounting years a little smaller. On the face of the choke you are able to drill couple holes. One of the big savings will be to remove the choke. Only time I was use it when I primed, other than that...NO. If you removed you may have to use a spinner. Li-Ion or lipo they are light and you will have to use a UBCE or BCE to get it down to 5 or 6 V. I use one of those and works pretty good.
On my setup the weight is 125 gr with all stuff. FG20 carb setup is 70 gr.
The wt 456-1 it self is 111gr. if you remove the choke and cut the mounting ears like WA120 you can get itdown to 90-95gr .so if that is the case for 20 gr more you have a rock solid running carb. Now if you replace the ignition ...Saito 165gr from where 14 gr is only the sensor. Rcexel is only...100gr.
so...165 ign +70carb =235gr saito setup
100ign +125carb =125 on my setup
If carb stipped 100 +95=195 gr so in any of this 2 situations is a win,win situation. You gain a min 10 to 40 gr. On my setup the overall lenght I am over with 2mm.
Any more suggestions?
Adrian Ciulei
On my setup the weight is 125 gr with all stuff. FG20 carb setup is 70 gr.
The wt 456-1 it self is 111gr. if you remove the choke and cut the mounting ears like WA120 you can get itdown to 90-95gr .so if that is the case for 20 gr more you have a rock solid running carb. Now if you replace the ignition ...Saito 165gr from where 14 gr is only the sensor. Rcexel is only...100gr.
so...165 ign +70carb =235gr saito setup
100ign +125carb =125 on my setup
If carb stipped 100 +95=195 gr so in any of this 2 situations is a win,win situation. You gain a min 10 to 40 gr. On my setup the overall lenght I am over with 2mm.
Any more suggestions?
Adrian Ciulei
11-08-2010, 09:17 PM
#516
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Hello, was wondering what would be a good prop size range to use with my FA270T conversion to gas. 20x8 to 20x10 is referenced in the instructions-of course using glow fuel. I have a 20x6 zinger, wondering if need to reduce diameter. Many Thanx
Mike Brennan
Mike Brennan
11-08-2010, 10:03 PM
#518
RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
ORIGINAL: triumphman49
Hello, was wondering what would be a good prop size range to use with my FA270T conversion to gas. 20x8 to 20x10 is referenced in the instructions-of course using glow fuel. I have a 20x6 zinger, wondering if need to reduce diameter. Many Thanx
Mike Brennan
Hello, was wondering what would be a good prop size range to use with my FA270T conversion to gas. 20x8 to 20x10 is referenced in the instructions-of course using glow fuel. I have a 20x6 zinger, wondering if need to reduce diameter. Many Thanx
Mike Brennan
I usually prefer their "Pattern" style props. In that style, they have a 18.1x11:
http://www.apcprop.com/ProductDetail...ctCode=LP18111
Even if APC doesn't have the exact prop size you had in mind, the difference in performance outweighs any slight mismatch. I haven't found any serious difference in required prop size based on conversion to gas.
11-15-2010, 11:01 PM
#519
RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Thought you guys would like to see a new walbro carb extension I made for one of the participants of this thread. This time, I made a real blueprint with dimensions and tolerances. Got tired of making them from either memory or by rescaling pieces of the motor and a walbro carb body. I've determined from my last effort that brass is the best material for this application. Aluminum just doesn't have the strength in those fine M16x1 threads to handle the torque needed to keep the carb from vibrating loose eventually, or even sooner. As I said before, a nylon engine mount is not the way to go here. It shakes the carb loose in a matter of minutes. Then, you'll suffer a catastrophic engine-leaning event. This can ruin the engine, or even the whole plane if it happens at the wrong time. Think takeoff. OK, here's the pics. The owner of the engine really takes care with things. The engine came packaged like the Hope Diamond. It should be on it's way back in a day or so.
By the way, have any of you out there had trouble with the "Beta: Multi-File Upload..." button. It doesn't seem to work anymore.....
It should be on it's way back in a day or so.By the way, have any of you out there had trouble with the "Beta: Multi-File Upload..." button. It doesn't seem to work anymore.....
01-07-2011, 04:35 PM
#521
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
well.....
the WT-456 carb is discontinued.... and I can't find any new online....
Found the Zama equiv. C1Q-p8
15$ a pop on sleezbay.,...
Report back sometime soon...
the WT-456 carb is discontinued.... and I can't find any new online....
Found the Zama equiv. C1Q-p8
15$ a pop on sleezbay.,...
Report back sometime soon...
01-08-2011, 05:58 AM
#523
RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
ORIGINAL: kochj
well.....
the WT-456 carb is discontinued.... and I can't find any new online....
well.....
the WT-456 carb is discontinued.... and I can't find any new online....
These guys say they have them: http://www.m-and-d.com/WL-WT-456.html
http://www.psep.biz/store/walbro_wt_carburetors.htm
FWIW.
Sincerely, Richard
01-08-2011, 12:09 PM
#524
RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
These guys say they have them: http://www.m-and-d.com/WL-WT-456.html
http://www.psep.biz/store/walbro_wt_carburetors.htm
FWIW.
Sincerely, Richard
http://www.psep.biz/store/walbro_wt_carburetors.htm
FWIW.
Sincerely, Richard
Oh, and their price is a lot better.
Hey, Zama guy....do you have the answers to my questions in the previous post? I'm sure everyone here is interested in the answers.
01-08-2011, 12:31 PM
#525
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RE: SMALL DISPLACEMENT FOUR STROKE GLOW TO GAS CONVERSION
Iremember that at one time I cross them on the net and seams to be compatibile,
Here is a link to site.
http://www.zamacarb.com/prodlist.html#C1Q
They are for 4 stroke, Iseen that has a fuel pump...but I did not seen a spring. (go to service/aftermarket). I think a spring can be added. I did not had one in my hands yet.
Adrian
Here is a link to site.
http://www.zamacarb.com/prodlist.html#C1Q
They are for 4 stroke, Iseen that has a fuel pump...but I did not seen a spring. (go to service/aftermarket). I think a spring can be added. I did not had one in my hands yet.
Adrian