Fabian
Well-Known Member
This system seems to be a much better setup for out motorised bicycle engines: ultra small and compact:
http://youtu.be/MphgxWidUjo
http://youtu.be/MphgxWidUjo
Rock solid new turbo kits
- Thread starter philp
- Start date
Goat Herder
Member
You still need some kind of a O2 sensor to tell the EFI how to interact? This may prove to be unfriendly with 2 stroke engines? Imagining the 02 sensor getting fouled and or simply clogging up? This thought occurs to me?
Have seen cars/automobiles that burnt too much oil and they would foul up O2 sensors..
Have seen cars/automobiles that burnt too much oil and they would foul up O2 sensors..
Fabian
Well-Known Member
The two engines shown in the video are spark ignition 2-stroke and 4-stroke engines of the design commonly used in model aeroplanes and helicopters. These engines use methanol (with varying percentages of nitro) and very high oil/fuel ratios, typically around 4:1 and as high as 3:1
This high oil content does not seem to be a problem with regards to spark plug fouling or combustion chamber fouling, at least for the last 15 years that i've been involved in the hobby.
The video does not make it clear if an O2 sensor is employed but what is clear is that an electronically controlled micro fuel injector is used and a throttle position sensor and rpm sensor is used.
If only these three components are used, the electronics must contain a map, effectively operating the same as an automotive style system when the narrow band O2 sensor (in closed loop operation) is ignored at anything outside of cruise mode.
I can't see why it would be necessary to run an O2 sensor if solely using a map for ignition and fuel supply.
Maybe my logic is flawed and needs swift correction?
This high oil content does not seem to be a problem with regards to spark plug fouling or combustion chamber fouling, at least for the last 15 years that i've been involved in the hobby.
The video does not make it clear if an O2 sensor is employed but what is clear is that an electronically controlled micro fuel injector is used and a throttle position sensor and rpm sensor is used.
If only these three components are used, the electronics must contain a map, effectively operating the same as an automotive style system when the narrow band O2 sensor (in closed loop operation) is ignored at anything outside of cruise mode.
I can't see why it would be necessary to run an O2 sensor if solely using a map for ignition and fuel supply.
Maybe my logic is flawed and needs swift correction?
Fabian
Well-Known Member
@ Goat_Herder
Maybe this small 2-stroke EFI system more satisfies the technical aspect of your methodology:
http://www.advancedmicroflight.com/EFI/Prod_EFI.aspx
Maybe this small 2-stroke EFI system more satisfies the technical aspect of your methodology:
http://www.advancedmicroflight.com/EFI/Prod_EFI.aspx
Goat Herder
Member
I wanna see a kit for a 50cc model? The closed circuit loop makes sense. The idea of a rather large intake to let as much air in as possible and a injector system that dos not rely on the carb train of thought. A carb that is too large for a given motors ability to work the said venturi properly.
A injector system would not rely on a venturi vacuum to too mix fuel. If these injector systems can be mapped out? That sounds great. I do see a proven point about system tests as in this system is being used on engine craft that varies in elevation in its operation.
The thought of the said system to be smart enough to know to change tuning characteristics on the fly would be a key selling point.
Then again if a fellow just went to larger size cc motors the whole deal becomes more forgiving big time! You change a tiny thing on carburetion to a 50cc and the effect is night and day. Do that to a 150 cc engine and might not even notice a single thing.
Smaller the engine the more that atmospheric conditions greatly effect it.
A injector system would not rely on a venturi vacuum to too mix fuel. If these injector systems can be mapped out? That sounds great. I do see a proven point about system tests as in this system is being used on engine craft that varies in elevation in its operation.
The thought of the said system to be smart enough to know to change tuning characteristics on the fly would be a key selling point.
Then again if a fellow just went to larger size cc motors the whole deal becomes more forgiving big time! You change a tiny thing on carburetion to a 50cc and the effect is night and day. Do that to a 150 cc engine and might not even notice a single thing.
Smaller the engine the more that atmospheric conditions greatly effect it.
If mapped correctly you don't need the O2 sensor, it only serves to make adjustments for emission purposes,EFI runs just fine without the sensor just as mechnical injection worked without it.
I run O2 sensors on two strokes on the dyno, no problem with oil but on an engine used in a vehicle carbon build up can be a problem.
Goat Herder
Member
I saw way too many 02 sensors give out in the automotive field with cars that burnt oil from engines that needed rebuilt! Mebbe they have made some improvements? Those engines ended up running in a closed loop as a result.. Yeah they still ran OK in light of things so I know what you mean.
On a little 50cc motor the atmospheric pressure changes enough from the heat of day and late at night,, that cutting edge response on a motor gets a little compromised. I would like to see a map that adjusts for this?
Last the bigger engines are the more forgiving it is in this particular situation.. Yet the smaller the engine the more changes in atmosphere altitude etc the more frustrating it is.
Would just like to know there is a said map out there that will accommodate this? Finally more about this said accommodating map?
Raining today or its over 110 F out side or its 30 F out side etc.
I made a 50cc Morini motor purr like a kitty with a 21mm PHBG del carby. I see these changes in outside temp etc first hand!
Was just thinking for the whole thing could be programmed to be automated. Rather than remapping it manually for a given situation?
On a little 50cc motor the atmospheric pressure changes enough from the heat of day and late at night,, that cutting edge response on a motor gets a little compromised. I would like to see a map that adjusts for this?
Last the bigger engines are the more forgiving it is in this particular situation.. Yet the smaller the engine the more changes in atmosphere altitude etc the more frustrating it is.
Would just like to know there is a said map out there that will accommodate this? Finally more about this said accommodating map?
Raining today or its over 110 F out side or its 30 F out side etc.
I made a 50cc Morini motor purr like a kitty with a 21mm PHBG del carby. I see these changes in outside temp etc first hand!
Was just thinking for the whole thing could be programmed to be automated. Rather than remapping it manually for a given situation?
Last edited:
tooljunkie
Member
maf would be something to consider.
o2 sensors i have seen fouled are from engines burning a quart of oil in like 100 miles
or the fue reg goes bad and pumps so much fuel the engine barely runs.
tps,map,crank and air temp sensor should be enough to make an efi system with adaptive capabilities.
o2 sensors i have seen fouled are from engines burning a quart of oil in like 100 miles
or the fue reg goes bad and pumps so much fuel the engine barely runs.
tps,map,crank and air temp sensor should be enough to make an efi system with adaptive capabilities.
Goat Herder
Member
I would not mind trying one out one day!
small engine efi http://www.ecotrons.com/Small_Engine_EFI_kit.html
small engine turbo http://www.ecotrons.com/Small_Engine_RHB31_VZ21_turbocharger.html
just run a wet compressor wheel (carb on the intake of the turbo )and one massive jet
small engine turbo http://www.ecotrons.com/Small_Engine_RHB31_VZ21_turbocharger.html
just run a wet compressor wheel (carb on the intake of the turbo )and one massive jet
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