[Land-speed] Fuel Injector testing

[drmayf]

Well, this wasn't meant tobe  a thesis paper or major effort to 
understand injectors. I simply want the closest in physical properties, 
to gasoline, non flamable fluid I can find. Why? So I don't have to go 
into a major research effort. I am no chemist, but the minimal data I 
looked at seems to indicate that long chain molecules are thicker than 
short chain ones. That would indicate that molecular weight is higher?  
Also, it appeared that density for long chains was higher than short 
chains for organic molecules.   I simply want that fluid so I do not 
have to do a lot of research.  I really do not give a hoot about having 
a  wealth of knowledge about some fluid other than it will work.  
Stoddard solvent is on  my list of those to check out.  To me, the most 
important items are "will it flow similarly to gasoline and not blow up 
in my face if ignited".  These two fluids are used as gasoline simulants 
so they are on my list to check: viscor 16a and 16b. 

So you are probably wondering why I want to do this. Well, every 
injector is off a tad from its brothers.  If I can get egt measurements 
from each cylinder at full bogie, then I know that the cylinder mixture 
is leaner or richer depending on temperature (rule of thumb). If it was 
hotter by a few percent then I might select an injector that flows a tad 
more and put it in that position. So I need to understand the injector 
flow at full boost and full rpm. And I need to use the hardware that is 
on the car because that affects it all as well. And so on. Seems to me 
that would be optimimun. Individual AFR sensors would work also, but  
that seems a bit expensive. Anyway, that's why I am considering this. My 
speed secret (soleful sigh..tongue in cheek) is out.....

mayf

Kirkwood wrote:

>Great question, Mayf and thanks for asking it. I have been wondering about
>it myself for a while. So thinking out loud I have a couple of questions.
>
>
>
>Isn't viscosity more important than molecular weight? Viscosity is more
>about material properties than MW. Or do you think kinetic energy will
>effect the response time of the pintel and is therefore more important?
>
>
>
>It has been easy to find the viscosity of various fuels except for gasoline!
>What do you use for the viscosity of gas?
>
>
>
>In looking at various flash points, Stoddard Solvent is 100F (not as high as
>diesel but with a viscosity which I ''assume'' may be closer to gas). So if
>you cranked up the good old AC in the shop to get into the 70-80F range
>would you have some safety factor? Or is this a too hazardous approach? Auto
>ignition of both gas and Stoddard are similar (in the mid 400F range). I
>realize the goal is a non-flammable liquid period!  Another thought may be
>some of these water-based aviation hydraulic fluids. Water based is being
>required in aviation but again, I don't know the viscosity. For a gas
>substitute, what are the material properties you want as close as possible?