My 1991 Talon TSi Compound Turbo AWD

[Logic]

Originally Posted by pgfpro

...This Summer I will be finishing testing Gasoline Compression Ignition GCI with this engine. The initial test looks very promising.

Wait-a-minute!
As they don't have a surprised emoj I'm going with:


Rudolf Diesel invented compression ignition people, the fuel was named after the process/him.
So pgfpro is speaking about burning just about anything without a spark plug!

I'm guessing that takes some fine control of boost pressure rather than Diesel type injection timing pgfpro? Both?
Congrats! I'm all ears!

[pgfpro]

Originally Posted by Logic

Wait-a-minute!
As they don't have a surprised emoj I'm going with:


Rudolf Diesel invented compression ignition people, the fuel was named after the process/him.
So pgfpro is speaking about burning just about anything without a spark plug!

I'm guessing that takes some fine control of boost pressure rather than Diesel type injection timing pgfpro? Both?
Congrats! I'm all ears!

Here is last year's test pull GCI on GEM 42

[Logic]

As I understand things; the better the exhaust scavenging; the higher the compression one can run due to a cooler exhaust valve (and chamber) and less hot exhaust gas in the new mix.
(But there also seems to be temperature limit here where vaporization does not occur enough, leading to misfire..?)

Anyway; Perhaps using (and filling) the area of maximum vacuum behind the car to better extract the exhaust (and minimize the vacuum)is of interest to you?

ie: Kill 2 birds with one stone by vacuuming the exhaust out some and filling the vacuum behind every car with exhaust.

There is only one, badly translated, paper on the subject of where best to exhaust exhaust, that seems to point to an exhaust exit just below dead center in the vertical rear as optimal.
The position changes if you prefer downforce.


Taking a 2nd look at this now I NB that the original low position doesn't look bad at all and saves weight, so this is likely just 'nice to know'.
Anyway; The discussion is here:
https://ecomodder.com/forum/showthre...tml#post695293


While I'm at it; here's some original thinking/theory on ameliorating the vacuum at the front of the roof with the high pressure air under the bonnet, using the A pillars as air ducts:
https://ecomodder.com/forum/showthre...ard-41539.html

As a mod this would involve opening the A pillars, as ducts, to the engine compartment air, an aero designed duct more or less above the sun visors and aerodynamically designed slots in the roof in just the right places.

That makes it something for rally teams etc, with an aero research budget, to think about and experiment with, but an interesting idea/theory IMHO as it should cut down on the cooling air going/lifting under the car AND the lift/vacuum above the front of the roof.
I certainly wouldn't start hacking away at a perfectly good, water tight car roof panel on the off chance I'd get this right on the 1st try!
I just thought you might find the idea interesting due to all the heat you need to get rid of.

The 1st post there (and paper) on directing the under hood cooling air backward rather than just letting it flow downward is also worth a look IMHO.

[Logic]

Looking at this:

https://www.youtube.com/watch?v=aoINEoMGf6s

and

https://www.youtube.com/watch?v=z6Pk5g6plNs

I couldn't help wondering what is would take to have a separate, very small, injection system for the pre chambers?
This is superior to getting a richer mixture into the chamber via intricate in (main) chamber aerodynamics is it not pgfpro?
But it also occurs to me that the chamber has to be exhausted of burnt gasses so there's air for the fuel, so perhaps not?

The whole (richer mixture) filling and scavenging of the pre chamber is still 'doing my head in!'
Gasoline Compression Ignition GCI seems easier!??

This makes more sense to me:

https://www.youtube.com/watch?v=ANI0uJfXQiw

[Logic]

Nice!

https://www.youtube.com/watch?v=zKcLteOkpoc

The valve timing by modded/vented hydraulic lifters? to get fast flow over/past the chamber nozzle/vent is there to see.
Then there's the shaped piston head we wont get into now. that spreads that flame front radially and horizontally.

So the fill/scavenge process is like blowing over the head of a bottle to make it 'sing' and the richer mixture is due to the fact that at or around TDC; the piston is hardly moving, making for a richer mixture at that time, as the fuel injection rate remains constant for the stroke.
Then the piston moves away (picking up speed) and the 'blow over the bottle head' effect goes away, leaving the rich charge in the chamber...
ie: Without valve overlap and scavenging and a good banana branch or turbo this wont work!

Hmmm-OK! Yes the penny seems to be dropping at last!
I assume the chambers were loaded with a spray gun for the video?

[pgfpro]

As I understand things; the better the exhaust scavenging; the higher the compression one can run due to a cooler exhaust valve (and chamber) and less hot exhaust gas in the new mix.
(But there also seems to be temperature limit here where vaporization does not occur enough, leading to misfire..?) That is true but when you're at an A/F ratio of 30:1 plus the combustion temps are pretty cool due to the fact that you now have an air saturated combustion. The fuel vaporization is still pretty good due to the low amount of fuel but the heat always does help.

Anyway; Perhaps using (and filling) the area of maximum vacuum behind the car to better extract the exhaust (and minimize the vacuum)is of interest to you?

ie: Kill 2 birds with one stone by vacuuming the exhaust out some and filling the vacuum behind every car with exhaust. I like this and will scope it out this weekend.

There is only one, badly translated, paper on the subject of where best to exhaust exhaust, that seems to point to an exhaust exit just below dead center in the vertical rear as optimal.
The position changes if you prefer downforce.


Taking a 2nd look at this now I NB that the original low position doesn't look bad at all and saves weight, so this is likely just 'nice to know'.
Anyway; The discussion is here:
https://ecomodder.com/forum/showthre...tml#post695293


While I'm at it; here's some original thinking/theory on ameliorating the vacuum at the front of the roof with the high pressure air under the bonnet, using the A pillars as air ducts:
https://ecomodder.com/forum/showthre...ard-41539.html

As a mod this would involve opening the A pillars, as ducts, to the engine compartment air, an aero designed duct more or less above the sun visors and aerodynamically designed slots in the roof in just the right places.

That makes it something for rally teams etc, with an aero research budget, to think about and experiment with, but an interesting idea/theory IMHO as it should cut down on the cooling air going/lifting under the car AND the lift/vacuum above the front of the roof.
I certainly wouldn't start hacking away at a perfectly good, water tight car roof panel on the off chance I'd get this right on the 1st try!
I just thought you might find the idea interesting due to all the heat you need to get rid of.

The 1st post there (and paper) on directing the under hood cooling air backward rather than just letting it flow downward is also worth a look IMHO. Great stuff thank you again.

[pgfpro]

Looking at this:

https://www.youtube.com/watch?v=aoINEoMGf6s

and

https://www.youtube.com/watch?v=z6Pk5g6plNs

I couldn't help wondering what is would take to have a separate, very small, injection system for the pre chambers?
This is superior to getting a richer mixture into the chamber via intricate in (main) chamber aerodynamics is it not pgfpro?
But it also occurs to me that the chamber has to be exhausted of burnt gasses so there's air for the fuel, so perhaps not? Yes to have a active pre-chamber would be awesome but still haven't figured it out yet?

The whole (richer mixture) filling and scavenging of the pre chamber is still 'doing my head in!'
Gasoline Compression Ignition GCI seems easier!?? lol yeah it is very complex on making a passive pre chamber feed the fuel lol

This makes more sense to me:

https://www.youtube.com/watch?v=ANI0uJfXQiw

Honda always has the cool things

[pgfpro]

Nice!

https://www.youtube.com/watch?v=zKcLteOkpoc

The valve timing by modded/vented hydraulic lifters? to get fast flow over/past the chamber nozzle/vent is there to see.Yeah it took a lot of time to make a simple solution to make this work.
Then there's the shaped piston head we wont get into now. that spreads that flame front radially and horizontally. The piston shape does play a major role in making this work.

So the fill/scavenge process is like blowing over the head of a bottle to make it 'sing' and the richer mixture is due to the fact that at or around TDC; the piston is hardly moving, making for a richer mixture at that time, as the fuel injection rate remains constant for the stroke.
Then the piston moves away (picking up speed) and the 'blow over the bottle head' effect goes away, leaving the rich charge in the chamber...
ie: Without valve overlap and scavenging and a good banana branch or turbo this wont work! WOW I'm very impressed on your great explanation. Well done sir.

Hmmm-OK! Yes the penny seems to be dropping at last!
I assume the chambers were loaded with a spray gun for the video? I won't get into details because it was very dangerous how I did this but worth the risk J/K'n

[Logic]

Originally Posted by pgfpro

I couldn't help wondering what is would take to have a separate, very small, injection system for the pre chambers?
This is superior to getting a richer mixture into the chamber via intricate in (main) chamber aerodynamics is it not pgfpro?
But it also occurs to me that the chamber has to be exhausted of burnt gasses so there's air for the fuel, so perhaps not? Yes to have a active pre-chamber would be awesome but still haven't figured it out yet?

I assume its the finding and fitting of 4 micro injectors that's the issue?
And why bother if you still have to 'blow over the bottle neck' to scavenge the exhaust and get fresh air in.

How about these 2 ideas:

For both ideas, the main idea is; Instead of 4 micro injectors you have 1 small injector into a small manifold that supplies both fuel AND air to all the pre-chambers, via small, (injector size?), plumbing.

The manifold might contain compressed air, compressed to somewhat over whatever pressure the turbo is pushing at the time.
From there; 4 micro induction ports, (aka; thin pipes) that go to the pre-chambers via solenoid valves,
pretty much like this guy is doing to actuate his DIY FreeValve System.

https://www.youtube.com/watch?v=E9KJ_f7REGw&t=553s

A question is; will the solenoid valves handle the pressure of combustion, or will it be necessary to also add one-way valves..? (and what/where to get them)

The other (better?) option:
Separate, cam type driven piston pumps that pump air/fuel from the Micro Manifold, at the correct time/timing.
Piston compressors already contain the desired/required one-way valve that would also prevent blowback during compression and the main combustion event.
Perhaps a diesel injector pump might be modded into an 'air' pump..?

Both should exhaust the burnt gasses more completely than the 'bottle neck blow' method, and ends the micro injector search.

The other thing (I've just realized) about a low volume 'Micro Manifold' is you can inject anything at any ratio/s as it's completely independent of the main mixture!
As it only requires small volumes, the injection of exotic gasses like NOS, Hydrogen, Ozone, etc-etc, possibly produced onboard, is more feasible, as is cooling the mixture with the aircon if necessary.

(Now that I think about it; injecting liquid fuel/s before the small compressor pump/s will probably result in complete vaporization, negating the need for possibly having to devise an agitator of some sort in the micro manifold)

Just thinking outside the box...hopefully!?