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By Beaver
Alright, so I've decided to replicate what youtuber ThunderHead289 is doing to his Ford 302 with a lawnmower carb and an 02 sensor based electronic fuel ratio balancer that actuates a vacuum leak.

In order to do this I needed access to the ignition timing of my civic because it's the first year to run electronic ignition, I decided to go with Speeduino for this with the hope that it can also handle the fuel ratio balancing based on the output of a AEM wideband UEGO O2 controller by actuating a servo attached to a butterfly valve that sits upstream of the carb inlet (formerly the EGR port)on the AEM intake pipe, a bit like a choke but it would be used to lean out the mixture from the carb or to sit wide open when in normal EFI mode.
I'm also hoping I can turn off the electronic injection in software while the carb is set to run.

Assembled 0.4.3c with VR conditioner, DVR8825, Mega.
AEM 30-0300 X-Series Wideband UEGO AFR Sensor Controller Gauge.

Parts on hand:
AEM intake pipe with K&N filter
Ford Escort Throttle body butterfly valve that fits K&N filter, (will need 3D printed flange to pipe adapter, will need way to mount servo motor to position sensor mount).
A couple servo motors from 3D printers.
Tiny Briggs & Stratton carb about the size of a bobba straw.

Parts to order:
46psi to 2.5psi pressure regulator
Adapter fittings needed to split the fuel line from Honda and go to regulator.
Shut off valve for carb, electronic control would be sweet.
12+1 crankshaft wheel, not sure where to order this
Either a OBD2C compatible Speeduino pinout to ECU adapter or a dead/used ECU to rip apart.

Let me know if there are other bits I might need. Yes I'm aware this is stupid, I'ma do it anyway.

My goal is ecomodding with the option to easily switch to EFI when power is needed. The car is a bit of a junker but I got it to start and it seems to run fine, 5speed, 2 door coupe body. I like to go down to the creek so I'm also fitting 215/70r16 offroad tires under a 2in lift. Lol
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I have a suggestion for potentially even greater success. I took a look at the TunderHead289 video series, and considered the principles he is applying. While he states he did it only to see if highway cruise could be attained with a tiny carburetor — not for economy; the primary factor in his economy improvement is driver restraint. This indicates to me that greater economy could be attained by simply limiting the stock throttle linkage, but also tuning EFI for maximum economy, while also incorporating emissions controls that enhance economy.

The linkage could be two-stage, limited for economy (similar to the lawn-mower carb restriction), with ability to override for power (safety) as found in many "gas crisis" cars of the '70s. Fueling could also be staged, using tiny primary injectors for tight fueling control at peak economy Lambda using WBO2, with coordinated ignition timing for peak combustion efficiency. Functions such as advanced EGR could finally be incorporated in order to reduce pumping losses and minimize octane requirements, possibly transitioning to a carbon monoxide fueling form of high-volume EGR.

There is plenty of potential to keep you busy for quite a long time. ;)
By Beaver
Hey, thanks for taking the time to watch and respond! While I think you're right about driver restraint being the primary thing effecting economy and acting like a restrictor plate, the thing I'm the most curious about is his concept that by using a tiny jet in combination with the hard 90 on the intake it's creating a well mixed fine mist of fuel that atomizes better in the chamber. From what I understand this is the holy grail for magic carburetors. In the 3D printed portion of this I want to have a prototyping area that I can try a couple things. In Luke's design he mentioned the hard 90, my setup will likely use the curved portion of the AEM intake, which is designed to not be turbulent; so I want to have a space I can put a hard 90 directly after the carb. I also want to set it to try this stupid thing right after the carb: https://grav.com/products/14mm-helix-pre-mix-chamber-1

I've reconceived the design a bit and have 2 directions I could go. I'll try to draw it out soon for better illustration, but after watching a more recent video of Luke's I figured out that an idle control valve is the cheap part I'm looking for instead of a 2nd throttle body flappy paddle to balance the air-fuel ratio. I might even end up using a separate arduino to watch the AEM O2 meter/controller then interpret that into PWM signal for an ICV so that this system could be more easily transferred to a distributor car.

(Side thought: couldn't a few Idle Control Valves be set in parallel to act as a drive by wire throttle? If so one of the concepts I have would be to use a few ICVs to act as a programmable restrictor plate/ratio balancer/idle control)

I like the idea of having a programmable throttle, and no matter what I really want access to the full power potential of the engine when needed. Now, I'm okay with cracking the hood and swapping a few bits, but after thinking on it a bit and about what PSIG said about 2 stage linkage I think It might be worthwhile to consider drive by wire, potentially on both the original civic throttlebody and on the lawnmower carb. This would give me the ability to set the Honda throttle as wide or greater than the width of the lawnmower carb plus ICV when in carb mode, but then be able to replace the carb/ICV nonsense with a straight pipe in the intake and run in normal EFI mode for full power.
If I wanted to get real fancy at some point I can imagine an electronically controlled "intake toggle valve" that could switch between carb and EFI on the fly, but it also sounds like an expensive intercooler part or something.

PSIG, I'm really interested in the special tuning I can get into with this WBO2 setup even outside of carb stuff. I just got the AEM meter/controller in the mail and it's probably the most exciting overpriced car part I've ever bought! I don't understand everything you mention about advanced EGR yet but I'll start digging into it! Are you saying I could potentially run tiny electronic injectors in combination with carb or other fuel sources?

I'm interested in HHO but I'd only really want to mess with it after I've got solar mounted on a vehicle to power it. Can a standard O2 sensor deal with hydrogen or would that need to me calculated/metered separately?

Gas fog made from an ultrasonic piezoelectric transducer (cold mist fog machine) is also interesting to me because it's supposed to have ultrafine parts that combust quickly and evenly.
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Beaver wrote:
Wed Jun 22, 2022 1:14 pm
Are you saying I could potentially run tiny electronic injectors in combination with carb or other fuel sources? …
Can a standard O2 sensor deal with hydrogen or would that need to me calculated/metered separately? …
Gas fog made from an ultrasonic piezoelectric transducer (cold mist fog machine) is also interesting to me because it's supposed to have ultrafine parts that combust quickly and evenly.
I would say #1 is to make a scientific plan. A hypothesis and your path to test it. You can have a long list of stuff to try, but it will be random in results if you don't plan ways to show if and how they work (or not) with metrics. Decide on your goals, in order, and make a plan.

Yes, with staged injection, you can run tiny injectors for rapid and fine fuel control, along with standard injectors for higher power operation. This is where you may find the ECM can do a better job adjusting the fuel from one engine crank rotation to the next, than a little carb and a servo. But, that's hypothesis, and it needs proving. What is your first goal with this project? Better economy? To compare alternative paths to economy? Testing weird ideas for validity? Figure that out first and make the plan to reach the project goals.

O2 operates by sniffing the exhaust, and whatever is in it, looking for oxygen. It doesn't care what the fuel is. While Americans are used to "AFR", the basis of all fuels is Lambda, and is the value actually read by the sensor and controller. Stoichiometric for any fuel is Lambda 1.0. If you are using a very specific fuel such as pure gasoline, the controller can multiply by a factor to report AFR for that fuel, e.g., Lambda 1 * Factor 14.7 = AFR 14.7:1. Easy. Unfortunately fuels are rarely pure, and may be mixed (gas and hydrogen or exhaust recirculation), so using Lambda is suggested for almost any tuning purpose these days.

Injector design is optional, and both placement and injection timing are strong influences. Tiny injectors above the throttle is effective, as is injecting after the valve closes to promote vaporization before cylinder intake. Lots to test and play with. 8-) Post when you get your plan together and begin getting to initial results. it will be interesting to see effects, and how you determine what factors are responsible for which results!
I really liked the project ThunderHead289 did, but you really can't take anything regarding MPG away from it. For the numbers to be valid, really you need to test to the EPA recommendations vs a random drive down the freeway.

That said, if you are looking for MPG improvements, you'll gain more from running a lean burn setup than running a carb. The downside is that you will have to remove the cat for it to work and the irony is that despite lower fuel consumption, NOx and other emissions will increase.
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Agreed on the plan to demonstrate with metrics. I don't know that it has to be as complicated as the EPA, but tests do need to be comparable and consistent to show relative gains or losses.

Technically, the catalytic converted does not have to be removed, and it will simply not function as-intended for emissions during mild operating conditions off-road. However removal may be advised, as accumulations in the converter may be ignited such as decel fuel cut that supplies oxygen to a hot converter for combustion. Or the ceramic catalyst may be cracked or fractured by thermal shock if unusual conditions are met, such as spark cut at high loads (cold air & fuel shock), etc. Of course, these same conditions can shock a heated O2 sensor, so … :roll: Check your local laws on defeating emissions and post your plan!

Ensure you have hardware test turned off.


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