Water Injection Thoughts

[Greg Hermann]

>For those considering the use of normal fuel injectors for water injection,
>consider adding some lubricant to avoid the corrosion problems.  For straight
>water, nothing beats dirt cheap machinist's cutting oil - completely water
>soluble.  About 3 tablespoons per gallon (memory serving me right) and it
>makes the milky white lubricant that you see around all machine shops. Enough
>to lubricate but not enough to effect combustion.

Good idea here.

>If you are running some alcohol or other joy juice, consider adding synthetic
>castor oil ( two cycle oil ) in a small percentage.

I assume you mean add it to the fuel. Even so, watch it with this stuff
around Dino oils--mixed they turn to soft plastic and plug things like oil
passages, with obvious serious side effects (sorta like plaque in coronary
arteries!)

>
>A last thought on evaporation.  The evaporation rate of water is very low
>below its boiling point 100c stp.

Suggest reading a steam table. It all depends on temperature and PRESSURE.
under boost, higher boiling point, under vacuum, lower. Latent heat of
vaporization decreases slightly with increasing temp/pressure.

Latent heat of V for H20 is about 980 BTU/lb,, for methanol about 500
Btu/lb--50%, not 25%.

 alcohol
>will absorb less than 1/4 the total heat that water will.

No , see above!
What alky (methanol ) does is give you more heat of combustion from a fixed
amount of oxygen.
>
At less than wot, this would not cause a loss of
>power.

But it would damn sure cause a need for wider throttle opening to make the
same power, which is WHY the pumping work would be less!! Just another way
of achieving what a stratified charge motor does.
>
  Consider effective
>compression ratio.   Static effective compression ratio is the cylinder volume
>at intake valve closing divided by the chamber volume at piston TDC - a number
>that is considerably less then geometric

About a point or MAYBE 1.5 points less in most normal, streetable cases of
cam and rod length.

Even more significant is effective EXPANSION ratio. (To power output and
eff., not to det.)

Best, most rational  approach to this I have seen is Porsche's--calculate
effective displacement and effective

 Too much, too much, too much is never
>enough anyway.

AGREE!!!!
>
>For perspectives sake - think about PC magazine - where the goodness of the
>review is factored by the bigness of the advertising spread.

And Car mags DO NOT EVER do this??

>I am cynical

AGREE, AGREE, AGREE!!!!! ME TOO!!! :-)

Regards, Greg