My 1991 Talon TSi Compound Turbo AWD

[cRiPpLe_rOoStEr]

Originally Posted by Logic

Water mist does nothing for combustion speed, but evaporating water in the intake tracts (Water Injection) does allow for dramatically higher compression without ping, thx to Evaporative Cooling.
That's been in use for ages too.

Greater pressure due to the expansion ratio of steam and a more homogeneous thermal conductivity inside the combustion chamber lead to a cleaner burn. No wonder the times I drove a Diesel in a rainy day the better throttle response felt so noticeable.

[pgfpro]

Here is the test I did on pump 87 vs auto paint waste solvent.



This was at a 14.7 stoich A/F ratio. Left side auto paint waste solvent. Right side pump 87 octane. 8-hour burn. Both fuels produced the same amount of heat at the metal test plate.

[Logic]

Originally Posted by pgfpro

Here is the test I did on pump 87 vs auto paint waste solvent.

Attachment 35301

This was at a 14.7 stoich A/F ratio. Left side auto paint waste solvent. Right side pump 87 octane. 8-hour burn. Both fuels produced the same amount of heat at the metal test plate.

The right side does seem darker, indication a less complete burn..?:

Ideally HC+O2=H2O +C right?
So theres no getting away from carbon/soot.
Not Ideal combustion is what gives you CO and CO2 gas,reducing C..?

If It's unburned HCs; that's a different story.
Perhaps they stick and get the C to stick?
The mess seen on the upwind side of intake valves seems to bear out this sticky hypothesis.

[pgfpro]

Originally Posted by Logic

The right side does seem darker, indication a less complete burn..?:

Ideally HC+O2=H2O +C right?
So theres no getting away from carbon/soot.
Not Ideal combustion is what gives you CO and CO2 gas,reducing C..?

If It's unburned HCs; that's a different story.
Perhaps they stick and get the C to stick?
The mess seen on the upwind side of intake valves seems to bear out this sticky hypothesis.

Your chemistry looks good to me but I'm no Chemist lol

As far as a complete burn I really don't know. I'm just glad that this experiment gives me the same results my engine sees.

There is one thing that worries a little bit. My tops of my pistons are so clean it looks like they never have been in an engine. After talking to a Red Bull F1 engineer he said on their hybrid engines today they actually rely on a slight buildup of carbon on top the pistons to act as a barrier coat at maximum power. It will burn most of it off at this point and then at lower power settings it will recoat itself for the next maximum power event. Crazy stuff for sure. Now I might be doing this already when I go from 30:1 A/F to 12.0:1 A/F and I just don't know it.

[cRiPpLe_rOoStEr]

Originally Posted by pgfpro

After talking to a Red Bull F1 engineer he said on their hybrid engines today they actually rely on a slight buildup of carbon on top the pistons to act as a barrier coat at maximum power. It will burn most of it off at this point and then at lower power settings it will recoat itself for the next maximum power event. Crazy stuff for sure.

Definitely crazy. But if you would really need some piston top coating to protect the pistons, wouldn't a ceramic or diamond-look carbon (DLC) coating serve for this very same purpose?

[pgfpro]

Originally Posted by cRiPpLe_rOoStEr

Definitely crazy. But if you would really need some piston top coating to protect the pistons, wouldn't a ceramic or diamond-look carbon (DLC) coating serve for this very same purpose?

I think a lot of coatings are prohibited in the F1 coatings rule.

The other thing I should have made clearer is the Honda F1 engine is very unique in the fact that it is almost a GCI engine. The plug starts the ignition process, but the outer perimeter top of the piston ignites mila seconds after.

I have to be very careful in what I write here because I do have some inside information that could get me in trouble. What I can say is some carbon build up is needed at high load with extreme cylinder pressure. The other thing is a Passive Pre-Chamber can increase heat in the cylinder or decrease heat in the cylinder. During light load FE mode, I want to keep the heat in the cylinder due to very lean conditions the combustion temps drop off drastically. The heat helps with keeping the fuel in gas form and I need the exhaust heat to stay up for the hot side of the turbo to work in its optimal area in FE mode. Now in high power mode I need the Pre-Chamber to pull out as much heat as possible.