Measuring the effect of air intake temperature in fuel economy

[Buzo]

Question. Did you make any chances to the mixture after installing the coils or did the stock setup do that for you? Could I get similar results by installing a coil on a stock FI setup?

I haven't touched the mixture settings since I started this project. So all data I have taken so far has been taken exactly with the same fuel tables.

I think someone else should try this air/fuel heater. Just because the Oxygen Sensor gets "less lazy" its a huge benefit already.
Hope someone with the stock carb could run the re-fill test with and without the cold intake tube and report the results here.

[Buzo]

New ideas come up after re-reading the thread with your comments. For instance, I was thinking in replacing the vacuum actuator with a electric solenoid, and then I thought, its better just reducing the spring rate, so it needs less vacuum to move the door up. So I did it already and I'm waiting for the next road test to log the change.
I expect to keep the air/fuel hot even during normal acceleration.

[Oldblueaccord]

Buzo

You have over 1400 looks at this thread. Me along with a lot of others are following. I don't comment unless I have something to add to the discussion. So far you have covered about everything I could think of. I wish I had more of you guys where I work. We can't find people who can think in my area.


wp

[Oldblueaccord]

http://www.hotrod.com/techarticles/e...e/viewall.html

do some google search on this guy.


wp

[Dr_Snooz]

Gas vaporization is nothing new (http://panacea-bocaf.org/fuelvaporizationtechnology.htm). It's been rearing its head off and on for decades. Tom Ogle was another "inventor" of gas vaporization). Charles Pogue was another. Unfortunately, just about the time that the technology is ready to go to market, something happens that makes it all unravel (including the mysterious death of the inventor). Hmmmm...

If anyone else is interested, the link for the book is here: http://snooz.cc/secret-page/. It's called "Dave's Book".

The way the author lays out the theory makes the most sense to me. Liquid gas doesn't burn, it has to be vaporized first. Most carbs and FI setups, however, send mostly gas droplets into the combustion chamber. Those don't burn and in turn get blown out the tailpipe, making HC emissions. That's why you need a catalytic converter to burn up all that raw gas. If you heat up the mixture prior to burn, you get much cleaner exhaust and much better performance.

The author was mindful that the technology could get him killed, so he satisfied himself with printing a book and letting the issue go. If any of us turns up in a ditch now, we'll know why.

[Buzo]

Wow 1400 visits, I didn't know that...

OK, It looks like we are going to have 2 subjects now. The first one is the air/fuel heater. I changed the spring of the hot air's vacuum actuator and it worked pretty good.

Here is the new spring size I used, now it requires a very little vacuum for the gate to be kept open.



The chart shows that only 2 times the temp went below 95C, one when I shut the car off and the other during a WOT.

[Buzo]

I started building why I think is the fuel vaporizer to be installed in the TBI' base..

From the hardware store I bought these little nipples. I bought five but I could install only 3. My drill bits got damaged before I could make more holes.
With the electric welder I sealed them.

[Buzo]

Before putting more effort in this little piece decided to run a test in the car just to see how hot it could get.

So I connected the flexible tube from the exhaust manifold source... but found that I can turn it hotter with the direct light of the sun than with this setup.
I idled the car for 10 minutes or so and the air out of the orifices of the vaporizer was around 100F.
The inlet of the tube is at 250F though as shown in the pic.

Any recommendation? I need to make sure it gets hot before I attempt to install it in the car.

[Buzo]

Another option if the gas recirculation pipe doesn't work is to use the coolant lines I have there from when the car was carb'd.
As I have demonstrated with my readings, the intake temp is around 55C, rising it up to the coolant temp (90 C) would be almost double.

But I'll wait to see if anyone have an idea why my vaporizer didn't turn red hot hahaha,

[jbabb]

have you considered an electric style heater like the one that came with the OE carb?

[Buzo]

have you considered an electric style heater like the one that came with the OE carb?

I actually still have the heater stored somewhere, so it would be interesting to test what temperature it can reach. In the car, it works only for the first 15 minutes after start. In the book sketches they pass all the gases of the exhaust through the vaporizer, I am passing only a fraction of it, so that might be the reason why reached so low temp.

[Buzo]

OMG, that little carb heater was able to give me 309F with a current draw of 1.2 A!
Thanks jbabb for the Idea!

Temp > 300F


Current draw:


A couple of water drops turned quickly into vapor:

[Buzo]

Its sad its Sunday. So most of my local yards will be closed today.
I'll go anyway and if I can find another heater I am going to make one out of two by implanting another heat element in the secondary hole.
If not, I guess I can test with one single and see if I get an improvement at least with low engine speeds.

Want to take the opportunity to explain a little bit how the narrow band oxygen sensor feedback works in the megasquirt controller.

The O2 sensor can modify the mix only a certain percentage of the total mix. It is called sensor authority and its currently is set to +/- 15%

So everything starts with 100%
If the mix is lean it will apply 101%, if still lean will increase 102& and so on until 115%. If the mix is still lean, the O2 sensor can do nothing else and will stay in 115%.
If the mix is rich it will substract fuel and will apply 99%, 98 % until reaches 85%, if the mix is still rich, the sensor can do nothing else.
In a well tuned car, The NB O2 sensor will be varying anywhere between 85 and 115.

Wanted to explain that because, if this vaporizer thing works, we should see the O2 sensor authority in the lower 85's and the mix still rich, right?

[Buzo]

This is something that a guy with a stock carb can test. Just give +12V Ignition to the heater and report back what happen.
Just be careful please! I do all these testing with my nose ready in case of the minor fuel smell and a big bottle of coke as fire extinguisher

The only problem is when the secondary opens it will bypass the heater. But its OK because if the secondary opens is because we need power.

[Buzo]

Finished installing the second heater in the carb base and installed it in the car.
About to run the first functional test and will be logging the data to see if there is a difference with the heater on vs heater off.
I got pictures of everything but I will run the test first and upload everything later.

[Buzo]

The test is a complete success!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!!!!!!!

Went for a short drive as usual and found that the car ran very rich!!!!!!!!!!!!!!!!!!

It happened exactly what I stated below. The sensor got to its 85% authority and it was unable to bring it to stoichiometric.
It is the same tune and you guys know per the charts I have posted how the oxygen sensor went up and down at very high speed before.

I don't know what it means in terms of fuel economy yet, but it must be something good. I need to re-calibrate my fuel tables and then I will know because there is no sense to keep running it rich.

I will upload everything in a moment.

The bad news for those with a carbed car is that this is happening after the fuel has been already mixed with the air, so the carb will be metering the same quantity of air.

[A18A]

this thread is very interesting reading

[Buzo]

testing flicker...

This is the oxygen sensor response BEFORE (hot air/fuel)





And this is AFTER (hot air/fuel and two 350F fuel vaporizers in the base of the TBI)

[Buzo]

View of the two fuel heaters through the TBI. I am holding the throttle wide open with my hand.

[Buzo]

Installed in the intake manifold, and my TBI's adapter plate on top

[Buzo]

this thread is very interesting reading

Thanks! thinking more about it, this will not benefit the FI cars neither, unless we can put the heaters where the fuel is injected... Could this be the return of the TBIs?

This is the stock Heater and the spare one I bought. Already dismounted and ready to be added to the secondary.



And here is already installed.

[Buzo]

One more pic showing the TBI, adapter plate and modified heater.

Forgot to say that this 1/2" increase in height didn't affected my filter setup. So I can keep using my air/fuel heater on top.

[Buzo]

The bad news for those with a carbed car is that this is happening after the fuel has been already mixed with the air, so the carb will be metering the same quantity of air.

Actually it can be OK for carbed cars, if some adjustment to the jetting is made. It will need to pull less fuel for the same given amount of air.

[Buzo]

testing flicker...

This is the oxygen sensor response BEFORE (hot air/fuel)





And this is AFTER (hot air/fuel and two 350F fuel vaporizers in the base of the TBI)

Is there any question with these charts?

They are the proof of the success. If we focus in the idling area -where the red line is flat- the oxygen sensor in the top chart was in range to substract fuel and it was able to make the mix lean and rich over and over.

With the fuel vaporized in the bottom chart, the engine is able to burn it more efficiently, so now it looks like is there was excess of fuel. But the fuel injected is the same for both charts!

It means that now we can reduce the amount of fuel injected to make the sensor be in range again.

[Buzo]

Somebody might say that I added an air restriction by putting the heaters there and that's why the car is rich now, well, I ran a test for that and I can change the O2 sensor correction % just by turning the heaters on and off. This chart shows the results of the test. The green line is the O2 sensor authority, adding fuel when the heaters are OFF and subtracting fuel when the heaters are ON. Everything in the same run.

Conclusion: the mix of my car is now rich because its burning the fuel more efficiently.