water and alcohol injection for detonation control?

First read this.

http://www.htc.net/~tbaldwin/66chev.html

Now can someone explain to me what he ment by water and alcohol injection for detonation control? Did he mean that he just out right injected water into the engine? I understand how this could work, cool off the fuel and air mixture and all, and how it doesn't seem like it would do to much damage, just spilt the H2O into H2 and O, but wouldn't this cause a increase and cyclinder pressure and INCREASE the chance of detonation? I'm confused!?!?!?!?!? argg.....

NEED TO GET OLD...... NEED GEAR HEAD WISDOM.........NEED A BRAND NEW TWIN TURBO 911!!!!........ arggggg!!!!

hehe thanks for all you help

 

Umm, you aren't splitting the water molecule- H2O is still H2O when you're done.

The water just absorbs some of the extra heat to keep combustion under control.

If you spray a little water on a big fire it doesn't put it out, but does help control it a bit.

Alcohol injection (similar to water injection) is very popular on the boosted cars- in addition to a bit of detonation suppression, you get a bit of an intercooling effect from evaporation. www.turbobuick.com has a whole section on alcohol injection on their message board.

-Bob Cunningham

 

Someone even invented a water injection kit for high compression engines that originally were designed for leaded gas.

 

Here's some more info

The government did a lot of research on this back in WWII. They were running into problems with trying to squeeze ever higher performance with the piston engines in planes. The NACA (which was replaced by NASA in 1958) did lots of wartime experimenting with dual-stage supercharging, turbocharging, intercooling, and other ways to get performance out of an engine running in the really thin air at altitude. Lots of the stuff that they did, such as developing precursors to the modern 02 sensor, sodium cooled valves, tests to determine octane rating, and intake manifold flow design experimentation, made it into cars over time. What they were doing was way out on the fringe edge of engine pioneering, and it has all become declassified over time. Interesting reading, and good explanations of the technologies used.

Anyway, good link on water injection here:

http://naca.larc.nasa.gov/reports/1943/naca-report-756/

Index here:

http://naca.larc.nasa.gov/

Click on a year and read away. Ya gotta sift through the aviation-specific stuff to find information that relates to engines, but there is some neat research and good explanations to be found.

- Freed

 

My Grandfather flew in a B-24 in WWII. He told me about the turbos and injection these flying boxcars had to keep the engine performing. It was very interesting, especially that it was done back then.