Ford Mustang: Water injection on C8 302

I use water injection on my supercharged '89 LX. It will help to
control detonation but I wouldn't think you would have a severe problem
at a 10:1 CR. If you haven't done so you might try and back off the
timing and make sure there isn't a buildup of carbon in the combustion
chambers and double check the overall tune of the engine.

When used on a N/A water injection lowers combustion temperature which
in turn stabilizes the burn process and controls detonation. This
doesn't occur without paying a price in reduced performance. Lower
combustion temperatures reduces horsepower. Also, the water takes up
space in the cylinders which decreases the amount of air and fuel burned
further lowering horsepower. To help get back lost power you can
increase timing but the major benefit is you can run the engine on lower
octane fuel. A side benefit is the water will remove carbon from the
combustion chambers.

Instead of spraying a mist I suggest using a setup that works like the
carburetor does. This will meter the water better, prevent bogging and
make the system much simpler and cheaper to install.

Scott Williams wrote: 

First thing, dump the Edelbrock Carb (good for the plug and play guys,
terrrible for just about everything else), replace it with a Holley
650dp. Second, part of your problem is the .060 overbore of the
cylinders, as the walls on the 302 block are thin enough as it is.....As
for the water injection, sure a slight water injection spray will help
just a bit, but not to the point that your going to see added
HP......Your still going to have to use the super unleaded gasoline to
keep your motor happy, even with backing your distributor advance down
just a bit...........................


Bill S.



Scott Williams wrote:
 

He's complaining about the high cost of gas and you tell him to get a double
pumper? Maybe I'm missing something here.

"Bill S." <net> wrote in message
news:jQi%a.79012$srv.hcvlny.cv.net... 
or 
warm 
82 
detonating 
cure my 
in 
of 
would 
more 
Gap, 
or 

If you back off your timing and put 89 octane in the car will it diesel? If
it diesels that means you _need_ at least a high enough octane gas to stop
it from dieseling. If it pings on lower octane, but never diesels then you
can work with it.

Start by retarding your base timing and unplugging the vacuum advance
(remember to plug the line). Go for a couple quick drive and blast down the
street at WOT. You want to keep backing down on the timing until you no
longer ping at high revs at WOT. You will likely need to adjust your carb
after that to get your idle back where you want it, so do that. Then plug in
your vacuum advance. Go for a drive and listen for pinging, namely at part
throttle. Turn the screw in the vacuum port with the allen wrench 1 turn
counter-clockwise, and go for another drive. Repeat until the pinging is
gone. Performance will suffer from this, but you may be able to run on 89
octane, 87 if your really lucky.

I know what it's like. My first car was a '67 Galaxie 289, which ran on 87
octane and would rev out the wazoo. My second car was a '68 Galaxie 302
(great grandma's car) which needed 89 or it would diesel and ping. I didn't
like paying more for the same amount of gas with the '68 so I tried to make
it run on 87 but couldn't. I got it running pretty good, but it would still
diesel sometimes. Finally I said screw it and put 89 in and tuned my advance
to get the most from it. The kicker is that the 289 was faster on '87 than
the 302 on 89! The 289 also has 200,000 miles on the original engine and
transmission, whereas the 302 has 97,000.

I couldn't justify paying for 93, or especially 94 octane, especially in a
10:1 compression daily driver. 93 is a 4 point jump from 89, and you
probably don't need that much for 10:1. If it were me I might get all ghetto
and fill it with 10 gallons of 89 and 10 gallons of 93. LOL

Anyway, if you haven't tried already go ahead and do the timing procedure I
mentioned on a tank of low octane gas. You can try 87 if it doesn't diesel
on it, but if it does move up to 89. You may have already tried that, and
that's why your looking at water injection, but I just wanted to make sure
before you go through the hassle of water, which I've heard more bad stories
than good.

Cory

"Scott Williams" <net> wrote in message
news:com... 
or 
warm 
82 
detonating 
my 
of 
would 
Gap, 

Hey Cory,

Believe it or not, a properly tuned holley 650dp will actually get
better gas mileage than that 650cfm Edelbrock unit sitting on his car


Bill S.



Cory Dunkle wrote: 

Thanks for the advice. I'm in CO and premium IS 89. regular here is only 85.
Sucks!!! I'd have to get octane boost.
"Cory Dunkle" <net> wrote in message
news:Qgq%a.4399$gnilink.net... 
If 
the 
in 
didn't 
make 
still 
advance 
ghetto 
I 
stories 
cure 
in 
more 
or 

I was just using the mist as an example. How do you inject the water though?
I've seen electronic controlled setups for Turbo EFI motor's, but not for my
more vintage setup. Is it like a nitrous plate?

Scott Williams

"Michael Johnson, PE" <com> wrote in message
news:com... 
or 
warm 
82 
detonating 
cure my 
in 
of 
would 
more 
Gap, 
or 

Yikes! That does suck. Give the lower octane a try anyway, if it doesn't
diesel when you turn it off there is hope of getting it to run well on it,
though it won't be as peppy as on 89.

Cory

"Scott Williams" <net> wrote in message
news:com... 
85. 
stop 
you 
carb 
plug 
part 
89 
87 
than 
a 
procedure 
diesel 
and 
sure 
compression 
a 
the 
of 
down 
use 
Air 
seats,