EFI for small engines

Hardware inside and outside of the ECU
hojnikb
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Re: EFI for small engines

Post by hojnikb »

jbiplane wrote:
Sat Aug 17, 2019 6:14 pm
This 2 pictures are from Speeduino forum
The first picture CIMG0931.JPG
shows typical Chinese kits started from 250 USD. Cheap, but very unreliable.
The second like.jpg
shows how it should be. It miss only crankshaft position sensor.

1. Is it possible to make ~Stm32 ECU with 2 injection and 2 ignition channels under 100 USD for end user? Should work for 2 and 4-strokes
I saw numerous attempts like https://www.nanoefi.com lasted for 5+ years, but nether finally sucseed.

2. Very good option many want to use starter gear dents for pulsing signal. An additional signal can be taken by different methods.

3. If ECU will small enough it can be placed on throttle body minimizing harness.
Can anyone with first hand experience tell me, what kind of reliability issues do these have?

I'm seriously considering converting my gy6-50 to EFI as sort of a test bed for efi tinkering. These aliexpress kits seem to be the only ones ready made for this specific engine.

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Re: EFI for small engines

Post by jbiplane »

hojnikb wrote:
Sun Dec 22, 2019 10:14 pm
I'm seriously considering converting my gy6-50 to EFI as sort of a test bed for efi tinkering. These aliexpress kits seem to be the only ones ready made for this specific engine.
I have ~5 kits from ecotrons abandoned in scrap. A bit more workable is https://aliexpress.ru/item/32767252274. ... c201969a56 but not for 50cc, at least 125

My electronic guy created 2 different ECU based on Speeduino, but for internal use with our engines.

I hope one day see NanoRusEFI project here :)

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Re: EFI for small engines

Post by Abricos »

why do you want to make a bike ... if you can use the finished product ...


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Re: EFI for small engines

Post by hojnikb »

jbiplane wrote:
Mon Dec 23, 2019 1:46 pm
hojnikb wrote:
Sun Dec 22, 2019 10:14 pm
I'm seriously considering converting my gy6-50 to EFI as sort of a test bed for efi tinkering. These aliexpress kits seem to be the only ones ready made for this specific engine.
I have ~5 kits from ecotrons abandoned in scrap. A bit more workable is https://aliexpress.ru/item/32767252274. ... c201969a56 but not for 50cc, at least 125

My electronic guy created 2 different ECU based on Speeduino, but for internal use with our engines.

I hope one day see NanoRusEFI project here :)
there seems to be a 50cc version as well
https://www.aliexpress.com/item/3278607 ... 309az12iXW

What specifically was wrong with the units ? Pump faulires, injector issue, ecu... ?

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Re: EFI for small engines

Post by jbiplane »

What specifically was wrong with the units ? Pump faulires, injector issue, ecu... ?
Problems are numerous, unpredictable and each time differs. One my friend burn 16 smartcoils with his Econtron.
Sometimes ECU can hang up. Sometimes unprotected ECU outputs burn out. Sometimes loosing fuel output signal.

I can sell all my ecotron collection (new and packed) for 50% of original price.

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Re: EFI for small engines

Post by infinityedge »

russian wrote:
Sun Aug 18, 2019 7:24 pm
One cylinder system chip tle8080 https://www.infineon.com/cms/en/product ... e8080-3em/

Also see https://www.infineon.com/cms/en/applica ... arter-kit/

I have no idea how to make a PCB survive vibration, I am a software developer. I wonder what would be the temperature if you get closer to engine, our stm32 is only rated for relatively low temperature.

What would be the cheapest test mule engine setup with one or two cylinders but high revs? A Chinese scooter or something cheaper already with EFI so that I can play right away?

A budget for R&D would be nice :)
There are high-temp STM32F versions available that should be compatible with RusEFI:

https://www.mouser.com/ProductDetail/ST ... YioQ%3D%3D

https://www.mouser.com/ProductDetail/ST ... Batg%3D%3D

For vibration, the traditional solution is epoxy staking:

https://workmanship.nasa.gov/lib/insp/2 ... aking.html

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Re: EFI for small engines

Post by AndreyB »

STM32F413VGT3 LQFP-100, 100 MHz 320kB RAM Maximum Operating Temperature:+ 125 C
Interesting stuff!!!

STM32F423ZHT3 LQFP-144, 100 MHz 320kB RAM Maximum Operating Temperature:+ 125 C

Thank you!
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Re: EFI for small engines

Post by kb1gtt »

The fr4 PCB material is typically the limiting factor. The stm has low enough thermal resistance that the fr4 gets to hot before the stm gets to hot.
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Re: EFI for small engines

Post by mck1117 »

The last digit of the part number indicates the temperature scale. For example, the STM32F407VGT6 that comes on the F4 discovery board is rated for -40 to +85C. The STM32F407VGT7 is identical but rated -40 to 105C. Most of them only come in the 6/7 flavors, but a few (as you've discovered) come in 3, which is good up to 125.

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Re: EFI for small engines

Post by infinityedge »

kb1gtt wrote:
Sat Dec 28, 2019 11:13 am
The fr4 PCB material is typically the limiting factor. The stm has low enough thermal resistance that the fr4 gets to hot before the stm gets to hot.
They have higher temp rated fr4, or you can go crazy and do a single sided, all-SMD design on aluminum backing.

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Re: EFI for small engines

Post by kb1gtt »

Yes you can pay for many things. Most people look to design for low cost china MFG and assembly. Those will generally be lower temperature PCB's.
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Re: EFI for small engines

Post by infinityedge »

kb1gtt wrote:
Mon Dec 30, 2019 12:21 am
Yes you can pay for many things. Most people look to design for low cost china MFG and assembly. Those will generally be lower temperature PCB's.
dirtypcbs, pcbcart, and seeedstudio will all do small batch Al boards at a reasonable price and I've seen a few chinese pcb shops with high temp fr4 for not that much more than normal fr4. Yeah, it's more expensive than bog standard fr4, but not by all that much and if you're shoving a pcb on the engine, you gotta do what you gotta do.

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Re: EFI for small engines

Post by kb1gtt »

What is a ball park price for a 100mm square alum substrate board?
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Re: EFI for small engines

Post by infinityedge »

kb1gtt wrote:
Mon Dec 30, 2019 4:24 am
What is a ball park price for a 100mm square alum substrate board?
Around $40-50US for a 10-pack of 100mm by 100mm boards.

(Single sided of course, multisided alum boards are a PITA to do vias for so the price skyrockets)

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Re: EFI for small engines

Post by hojnikb »

jbiplane wrote:
Wed Dec 25, 2019 8:18 am
What specifically was wrong with the units ? Pump faulires, injector issue, ecu... ?
Problems are numerous, unpredictable and each time differs. One my friend burn 16 smartcoils with his Econtron.
Sometimes ECU can hang up. Sometimes unprotected ECU outputs burn out. Sometimes loosing fuel output signal.

I can sell all my ecotron collection (new and packed) for 50% of original price.
is ecotrons even in any way related to aliexpress kit ?

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Re: EFI for small engines

Post by jbiplane »

hojnikb wrote:
Thu Jan 02, 2020 10:28 pm
is ecotrons even in any way related to aliexpress kit ?
Yes, they have on ali 2 vriants of kits. For most of cc it is ecotrons, for other simplified ECU taking in accout only 02 sensor.

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Re: EFI for small engines

Post by jbiplane »

This solution from Stihl works perfectly for small 2-strokes. Without lambda, automatic calibration, bateryless, mechanical fuel pump of crankcase pressure variation. I would be happy produce throttle body if someone will make working board for.
Attachments
!!! Session 1.3_Zahn_Stihl AG presentation.pdf
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Re: EFI for small engines

Post by AndreyB »

Please try articulating your proposal a little bit better. At the moment it's really unclear what you are looking for, unless you make an effort to explain better I am absolutely failing to understand you.

We have microRusEfi boards available for sale at https://www.ebay.com/itm/rusEFI-microRu ... 3532119947

For software we have viewtopic.php?f=5&t=1642
https://rusefi.com/s/howtocontribute
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Re: EFI for small engines

Post by kb1gtt »

I recall he was saying something integrated into the butterfly. Very minimal setup. I agree it needs more details. For example, DI vs manifold injection. I think he was thinking manifold. As well, is this electric start or pull start? How many cyl's, etc. What are the general parameters? Do you have a particular throttle body you are thinking of using as a starting point, what is the LWH of the PCB, etc. We need more details about what you desire, and why you desire it.
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Re: EFI for small engines

Post by jbiplane »

I used Megasquirt Ecotrons and few Speeduino on small engines and they behave worse than carburetors.
I have clear vision how make happy this category. If someone help me I will full tests and mechanical part
to bring this solution on market. If make good and cheap solutionit will really hit the market.

Valerii Rutkovskii
jbiplane@gmail.com
www.flame-power.com

Image
EFI integrated to throttle body. Mainly for up to 15000 rpm 2-strokes, though 4 strokes and wankels supported
Very efficient power supply to minimize electricity consumption and heating

Enclosure milled alum case with central hole. It is bolted to throttle body by fed screws.
At the center of board located magnetic sensor to perform contactless TPS functionality.
Image
Enclosure cowered by plastic transparent lid to increase range of Bluetooth (wifi) on board.

No wire connector, 2 bunch of wires 500mm long goes left and right of case. Unused wires would cut off.

One side all outputs + Power:
2 ignition channels (for smart coils)
2 injection channels (relatively small injectors squirting about 2,5 ms per revolution)
Hardware regulated PWM pump
Power
Power ground

Other side all inputs:
Crankshaft position sensor
Camshaft position sensor
Fuel Pressure Sensor
Cylinder temperature, under spark plug
Wide band O2 sensor, only for calibration
On/off button wire
Couple of sensor grounds
Map onboard
IAT on board, in cold PCB corner

Very useful functionality is to use existing starter geared wheel without missing tooth and
something additional…

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Re: EFI for small engines

Post by infinityedge »

Ural motorcycles used a similar idea for a few years that was made by Electro Jet:

http://www.electrojet.com/products/

And Walbro seems to also be doing something similar:

http://www.walbro.com/wp-content/upload ... _PS_EN.pdf

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Re: EFI for small engines

Post by jbiplane »

infinityedge wrote:
Wed Mar 11, 2020 10:41 pm
Ural motorcycles used a similar idea for a few years that was made by Electro Jet:
And Walbro seems to also be doing something similar:
Both of this solution non-programable and require battery. You need to buy from those company 1000+ articles to get adopted for you engines.
So I thiked someone can help me make RusEFI nanoboard... Open to cooperation

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Re: EFI for small engines

Post by Abricos »

jbiplane wrote:
Thu Mar 12, 2020 12:36 am
infinityedge wrote:
Wed Mar 11, 2020 10:41 pm
Ural motorcycles used a similar idea for a few years that was made by Electro Jet:
And Walbro seems to also be doing something similar:
Both of this solution non-programable and require battery. You need to buy from those company 1000+ articles to get adopted for you engines.
So I thiked someone can help me make RusEFI nanoboard... Open to cooperation
RusEFI MRE
https://www.ebay.com/itm/333532119947

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Re: EFI for small engines

Post by kb1gtt »

jbiplane wrote:
Thu Mar 12, 2020 12:36 am
Both of this solution non-programable and require battery. You need to buy from those company 1000+ articles to get adopted for you engines.
How do you EFI with no battery? I expect you will need many high speed RPM's before you have enough energy from a magneto to power the injectors. I expect low speed RPM when pull starting. How do you generate the PWM'ed fuel pressure with out a battery?

I have done contact-less magnetic angle sensors. I think you will not be happy with this solution. You need to keep the PCB sensor and magnet very accurately co-axial aligned. It can be difficult to keep them aligned. I had certain levels of success by drilling a hole in the PCB and mounting the magnet from below. However this still requires the chip is placed very accurately on the PCB. Another issue was the difficult prediction of how strong the magnet fields need to be. Most OEM's use POT's for the position sensor. I would suggest you consider the same. They are much easier to design with. See my below page, which shows some of the stuff I did with the magnetic sensor.
http://jaredharvey.com/Files/projects/o ... /index.htm

I once did a schematic for Frankienstien in Dia, see the source files below.
https://sourceforge.net/p/daecu/code/HE ... chematics/
The end result looked like this.
Image

Could I get you to make a similar system level schematic? I fear you are missing pieces of the power supply scheme. If you drew a schematic like this, I think you may notice problems with your approach. I think it can be done, but I think you will need a battery. It might be possible to make this work with a very small battery, but I think you will still need a battery.

I also fear the boot time, and crank angle sync. I think your crank angle sensing method will be difficult. How do you plan to detect the crank angle?

Smart coil? Do you mean a coil with an internal igniter? What do you mean when you say smart coil?
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Re: EFI for small engines

Post by jbiplane »

>How do you EFI with no battery?
Exist few solutions, but at moment small battery is OK. In Megasquirt2..3 use few variants of PWM fuel pump regulation
the simplest with fuel pressure sensor. At moment small pump eat 24watt. It too much for most scooters. If PWM
reduce consumption to max 15w it would be good enough.

>contact-less magnetic angle sensors
Already got some to integrate
https://ru.mouser.com/ProductDetail/ams ... QjJw%3D%3D

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Re: EFI for small engines

Post by kb1gtt »

Pull start? Electric start? Crank decoder plan? I need more details.
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Re: EFI for small engines

Post by jbiplane »

kb1gtt wrote:
Thu Mar 12, 2020 9:46 pm
Pull start? Electric start? Crank decoder plan? I need more details.
Should work mostly for pull start, electric starter should be supported as well.

Decoder. It would be fine if for some users worked with one dent + scooter inductive sensor(existing on most scooters)
but it mostly will with geared wheel and inductive sensors from cars. Says 60 with one missed.
Many users want use as trigger existing starter gear wheel 54...85 dents + some additional input.
Some users want CAN support and stepper motor iddle.

But all this is options. Most important in first version support of pull starter, custom geared wheel with missed tooth, pwm modulation of fuel pump, as low energy consumption as possible (impulse power source), use coils with internal trigger. Options only to have ability implement in future.

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Re: EFI for small engines

Post by kb1gtt »

I see desired sequence like this.
1. turn on engine run switch
2. fuel pump PWM's to some pressure and consumes ?? mJ.
3. ECU blinks some kind of light or beeps or does something to let you know it's booted, fuel pressure is ready, priming pulse has been delivered etc. Injector consume ?? mJ, and fuel pump also turns back on and consumes ?? mJ.
4. you pull start cable
5. when single cam pulse comes along, you send a 5V or 12V level signal to the coil. Coil has igniter which bumps this voltage up to around 400V for the primary side of the coil. As well the injectors causes the pump PWM to kick back in.

Do you have a throttle body that can be purchased from Ali or similar?
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Re: EFI for small engines

Post by jbiplane »

Yes, you have very correct understanding.
>I see desired sequence like this.
>1. turn on engine run switch
>2. fuel pump PWM's to some pressure and consumes ?? mJ.
Yes, most spread motorcycle fuel pump use 43psi or 3bar pressure. This pressure is comfortable, but in future possible decrease it to smaller value up to 15psi or 1 bar. Distances and hoses length in small engines very short. For 43psi this pump have performance 35lph, my biggest 30hp engine in a full consume 12 hp per hour max, in realty up to 5 liter per hour in normal flight, so energy wasted by the pump.
Seems new pump with 50 lph models like
https://aliexpress.ru/item/32913333564. ... web201603_
declared 1,7 A for 12V or 20W (dont tested personally)

This eat less than 35 lph pumps I tested before. 2A for 12V or 24W
https://aliexpress.ru/item/32899157341. ... web201603_
This 20..24 W is too much for scooter generator which generate max 50W in a full rpm.
If PWM decrease pump consumption to 12w or less it will already acceptable, the less the better.


Instead of mechanical pressure should used Fuel Pressure Sensor like
https://aliexpress.ru/item/32998009174. ... web201603_
or https://aliexpress.ru/item/33035893349. ... web201603_
Megasquirt 3 supports this type of regulation and in Tuner studio it can be regulated
or any of
https://aliexpress.ru/item/400026315970 ... web201603_
A lot of variants to choose

>3. ECU blinks some kind of light or beeps or does something to let you know it's booted, fuel pressure is ready, priming pulse has been delivered >etc. Injector consume ?? mJ, and fuel pump also turns back on and consumes ?? mJ.
Yes, blink and sound together which means engine ready to start.

>4. you pull start cable
Yes. About 20% of enfines will have electrical starter, but it should work the same like pull starter.

>5. when single cam pulse comes along, you send a 5V or 12V level signal to the coil. Coil has igniter which bumps this voltage up to around 400V for >the primary side of the coil. As well the injectors causes the pump PWM to kick back in.
Yes. 12...18V battery will be on board

The best suited for 125...250cc throttle bodies are https://item.taobao.com/item.htm?spm=a2 ... =19#detail
I have 5 in hands. I can CNC mill throttle bodies. The most popular is 24...32mm

PS. One offtopic idea is to use just dosing pump without any injector nozzles. Just meter correct quantity of fuel to carburetor body.

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Re: EFI for small engines

Post by kb1gtt »

Are there TB's with injector bungs that would be of interest? Also is that pipe thing the place you would connect a MAP sensor?

What is the battery plan? External or small cells on the PCB? I think it looks like external is they wall to go. So 12V electrical connection is required or should we consider something different?

As well the FAI injectors are of interest. Those are good for small engines. I can not seem to find an explanation of how they work right now. From memory I recall they are gravity feed fuel supply. The injector activation is a bit backwards. You energize the injector, which pulls back a spring loaded plunger. Then when you stop energizing the injector, the spring generates very high pressures which will atomize the fuel nicely.

https://item.taobao.com/item.htm?id=564941959397

http://www.fai.com.cn/en/product/33.html
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