a powerful 30 cc engine
01-20-2010, 03:37 PM
#27
Senior Member
Thread Starter
RE: a powerful 30 cc engine
The thing thta looks like a filter ?
It is a filter
The exhaust pressure
very necessary -
the in flight adjuster - it works but was another "patch" .
carburation is wofully misunderstood at times
In this case - the engine witout pressure becomes incapable of drawing enough fuel at wide open settings
very common -even on gassers
The exhaust pressure builds ONLY at high power settings -this pressurizes the tank slightly - typically on this type muffer somewher under one pound
That pressurization makes full bore running using increased carb size
and typically increasing power
The std carbs are compromises that have venturi sizes determined by the pressure drop across the spray bar .
The additional fuel pressure is enough to de sensitize this condition ( progressive needle setups help)
On a related note: On a small block 283 Chev - years back the factory added dual four barrel carbs which caused a loss of fuel delivery -until the engines revved up- some of us used progressive triple carb setup and eliminatedthe pooor performance caused under low vacuum conditions- and blew off the stock setups-using smaller carbs
The correct delivery of fuel is dependant on vaccuum signal -this is why fuel injectioneventually won out in cars
The little computer driven injectors summed up the vacuum/ temperature etc, and doled out the correct squirt- perfet fuel/air mix always
On our carbs - we can correct for low vacuum - but you have to first understand and measure the changes in vacuum seen at the spray bar
My next slide please
It is a filter
The exhaust pressure
very necessary -
the in flight adjuster - it works but was another "patch" .
carburation is wofully misunderstood at times
In this case - the engine witout pressure becomes incapable of drawing enough fuel at wide open settings
very common -even on gassers
The exhaust pressure builds ONLY at high power settings -this pressurizes the tank slightly - typically on this type muffer somewher under one pound
That pressurization makes full bore running using increased carb size
and typically increasing power
The std carbs are compromises that have venturi sizes determined by the pressure drop across the spray bar .
The additional fuel pressure is enough to de sensitize this condition ( progressive needle setups help)
On a related note: On a small block 283 Chev - years back the factory added dual four barrel carbs which caused a loss of fuel delivery -until the engines revved up- some of us used progressive triple carb setup and eliminatedthe pooor performance caused under low vacuum conditions- and blew off the stock setups-using smaller carbs
The correct delivery of fuel is dependant on vaccuum signal -this is why fuel injectioneventually won out in cars
The little computer driven injectors summed up the vacuum/ temperature etc, and doled out the correct squirt- perfet fuel/air mix always
On our carbs - we can correct for low vacuum - but you have to first understand and measure the changes in vacuum seen at the spray bar
My next slide please
01-20-2010, 04:42 PM
#28
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RE: a powerful 30 cc engine
Next slide
G23 glow engines run very well using a Walbro WT499 gas carb...The fuel passages are large enough to pass the extra methanol required...
A stock G26 with spark ignition using a stock WT499 Walbro runs and adjusts EXACTLY like the gas version, but 600 rpm faster..Been doing it for years...
G23 glow engines run very well using a Walbro WT499 gas carb...The fuel passages are large enough to pass the extra methanol required...
A stock G26 with spark ignition using a stock WT499 Walbro runs and adjusts EXACTLY like the gas version, but 600 rpm faster..Been doing it for years...
01-20-2010, 04:46 PM
#29
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RE: a powerful 30 cc engine
Think maybe if the OS gasser needed exhaust pressure for the Walbro to work they might have included a muffler to get the pressure FROM ?
01-20-2010, 08:22 PM
#30
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Thread Starter
RE: a powerful 30 cc engine
ORIGINAL: Antique
Think maybe if the OS gasser needed exhaust pressure for the Walbro to work they might have included a muffler to get the pressure FROM ?
Think maybe if the OS gasser needed exhaust pressure for the Walbro to work they might have included a muffler to get the pressure FROM ?
also I have run Walbro on methonal - on competition engine
Frankly don't care for it
Walbros were jetted for gas /air use -
drilling passages etc, not my idea for good setup
PS the OSruns best for this application using a purpose built methonal carb.
And
pressure.
01-20-2010, 09:06 PM
#33
My Feedback: (5)
RE: a powerful 30 cc engine
If you want to run a walbro on a 2300 with glow fuel try the wt499. My 2300 runs great with this carb - easy to tune using 10% Omega fuel, with no changes needed in the wt499 carb to run this fuel. For that matter the 2300 may run ok with gas in this carb too- although I wonder if the bearings will hold up ok with gas.
I have run the wt499 on my 2300. i will post a pic or two.
By the way - I have been changing the diaphragm in the carb once a year because of the alcohol. Can someone here help me find a teflon diaphragn for this carb that would still run ok but not need changed out as often?
Ed
I have run the wt499 on my 2300. i will post a pic or two.
By the way - I have been changing the diaphragm in the carb once a year because of the alcohol. Can someone here help me find a teflon diaphragn for this carb that would still run ok but not need changed out as often?
Ed
01-21-2010, 10:14 AM
#35
RE: a powerful 30 cc engine
ORIGINAL: rmh
The thing thta looks like a filter ?
It is a filter
The exhaust pressure
very necessary -
the in flight adjuster - it works but was another ''patch'' .
carburation is wofully misunderstood at times
In this case - the engine witout pressure becomes incapable of drawing enough fuel at wide open settings
very common -even on gassers
The exhaust pressure builds ONLY at high power settings -this pressurizes the tank slightly - typically on this type muffer somewher under one pound
That pressurization makes full bore running using increased carb size
and typically increasing power
The std carbs are compromises that have venturi sizes determined by the pressure drop across the spray bar .
The additional fuel pressure is enough to de sensitize this condition ( progressive needle setups help)
On a related note: On a small block 283 Chev - years back the factory added dual four barrel carbs which caused a loss of fuel delivery -until the engines revved up- some of us used progressive triple carb setup and eliminatedthe pooor performance caused under low vacuum conditions- and blew off the stock setups-using smaller carbs
The correct delivery of fuel is dependant on vaccuum signal -this is why fuel injectioneventually won out in cars
The little computer driven injectors summed up the vacuum/ temperature etc, and doled out the correct squirt- perfet fuel/air mix always
On our carbs - we can correct for low vacuum - but you have to first understand and measure the changes in vacuum seen at the spray bar
My next slide please
The thing thta looks like a filter ?
It is a filter
The exhaust pressure
very necessary -
the in flight adjuster - it works but was another ''patch'' .
carburation is wofully misunderstood at times
In this case - the engine witout pressure becomes incapable of drawing enough fuel at wide open settings
very common -even on gassers
The exhaust pressure builds ONLY at high power settings -this pressurizes the tank slightly - typically on this type muffer somewher under one pound
That pressurization makes full bore running using increased carb size
and typically increasing power
The std carbs are compromises that have venturi sizes determined by the pressure drop across the spray bar .
The additional fuel pressure is enough to de sensitize this condition ( progressive needle setups help)
On a related note: On a small block 283 Chev - years back the factory added dual four barrel carbs which caused a loss of fuel delivery -until the engines revved up- some of us used progressive triple carb setup and eliminatedthe pooor performance caused under low vacuum conditions- and blew off the stock setups-using smaller carbs
The correct delivery of fuel is dependant on vaccuum signal -this is why fuel injectioneventually won out in cars
The little computer driven injectors summed up the vacuum/ temperature etc, and doled out the correct squirt- perfet fuel/air mix always
On our carbs - we can correct for low vacuum - but you have to first understand and measure the changes in vacuum seen at the spray bar
My next slide please
01-22-2010, 03:30 AM
#38
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RE: a powerful 30 cc engine
Son of gun - I can't believe Bjorn would use one of those
[/quote]
Normally I don't like pumps on glow engines for the same reasons Dick doesn't. I was never happy with pumps on standard two needle glow carbs. This one is a no needle, two servo carb that works well with the pump. OS had a carb like this at one time. Webra has one. This one uses the guts from the Webra grafted into a Super Tigre body. Webra wants $100+ for the whole carb. I got the guts for $20. The engine is inverted with a pipe running through the bottom of the plane. There is no way to get the tank low enough to work without a pump.
The Walbro pumper carb may be a good solution if the metering can be matched to the engine. Tough to do since gas and glow need such different flows.
All of this discussion is really about the point at which it makes sense to switch from glow to gas. That point is somewhere between 20cc and 40cc and can shift a lot depending on who is putting the system together. Average Joe needs a buy and fly solution. The gas powered route has lower fiddle factor which means a lot to some. I'm moving in that direction too.
02-07-2010, 01:32 PM
#41
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RE: a powerful 30 cc engine
I have just purchased a Stinger 1.20 plane used at a swap meet. It has a Super Tigre 3000 engine (glo) and under the 3000 is stamped a number 325. I dont know anything about this engine, but the carb is missing. I would like to replace the carb and have read that an ASP .91 carb works well. I was also told that I could convert this engine to gas by installing a Walbro carb. Could you possibly tell me how to mount the carb (walbro) and how to change the head for a sprk plug? Do you know anything about a gas/glo conversion? I would be just as happy to find a good carb for this engine for glo use, but the thought of using gasoline would be cheaper.
11-16-2010, 09:52 PM
#43
RE: a powerful 30 cc engine
ORIGINAL: rmh
The thing thta looks like a filter ?
It is a filter
The exhaust pressure
very necessary -
the in flight adjuster - it works but was another "patch" .
carburation is wofully misunderstood at times
In this case - the engine witout pressure becomes incapable of drawing enough fuel at wide open settings
very common -even on gassers
The exhaust pressure builds ONLY at high power settings -this pressurizes the tank slightly - typically on this type muffer somewher under one pound
That pressurization makes full bore running using increased carb size
and typically increasing power
The std carbs are compromises that have venturi sizes determined by the pressure drop across the spray bar .
The additional fuel pressure is enough to de sensitize this condition ( progressive needle setups help)
On a related note: On a small block 283 Chev - years back the factory added dual four barrel carbs which caused a loss of fuel delivery -until the engines revved up- some of us used progressive triple carb setup and eliminatedthe pooor performance caused under low vacuum conditions- and blew off the stock setups-using smaller carbs
The correct delivery of fuel is dependant on vaccuum signal -this is why fuel injectioneventually won out in cars
The little computer driven injectors summed up the vacuum/ temperature etc, and doled out the correct squirt- perfet fuel/air mix always
On our carbs - we can correct for low vacuum - but you have to first understand and measure the changes in vacuum seen at the spray bar
My next slide please
The thing thta looks like a filter ?
It is a filter
The exhaust pressure
very necessary -
the in flight adjuster - it works but was another "patch" .
carburation is wofully misunderstood at times
In this case - the engine witout pressure becomes incapable of drawing enough fuel at wide open settings
very common -even on gassers
The exhaust pressure builds ONLY at high power settings -this pressurizes the tank slightly - typically on this type muffer somewher under one pound
That pressurization makes full bore running using increased carb size
and typically increasing power
The std carbs are compromises that have venturi sizes determined by the pressure drop across the spray bar .
The additional fuel pressure is enough to de sensitize this condition ( progressive needle setups help)
On a related note: On a small block 283 Chev - years back the factory added dual four barrel carbs which caused a loss of fuel delivery -until the engines revved up- some of us used progressive triple carb setup and eliminatedthe pooor performance caused under low vacuum conditions- and blew off the stock setups-using smaller carbs
The correct delivery of fuel is dependant on vaccuum signal -this is why fuel injectioneventually won out in cars
The little computer driven injectors summed up the vacuum/ temperature etc, and doled out the correct squirt- perfet fuel/air mix always
On our carbs - we can correct for low vacuum - but you have to first understand and measure the changes in vacuum seen at the spray bar
My next slide please
11-28-2010, 08:10 PM
#44
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RE: a powerful 30 cc engine
ORIGINAL: rc34074
If you want to run a walbro on a 2300 with glow fuel try the wt499. My 2300 runs great with this carb - easy to tune using 10% Omega fuel, with no changes needed in the wt499 carb to run this fuel. For that matter the 2300 may run ok with gas in this carb too- although I wonder if the bearings will hold up ok with gas.
I have run the wt499 on my 2300. i will post a pic or two.
By the way - I have been changing the diaphragm in the carb once a year because of the alcohol. Can someone here help me find a teflon diaphragn for this carb that would still run ok but not need changed out as often?
Ed
If you want to run a walbro on a 2300 with glow fuel try the wt499. My 2300 runs great with this carb - easy to tune using 10% Omega fuel, with no changes needed in the wt499 carb to run this fuel. For that matter the 2300 may run ok with gas in this carb too- although I wonder if the bearings will hold up ok with gas.
I have run the wt499 on my 2300. i will post a pic or two.
By the way - I have been changing the diaphragm in the carb once a year because of the alcohol. Can someone here help me find a teflon diaphragn for this carb that would still run ok but not need changed out as often?
Ed
