Mechanical Water Injection?

[38flattie]

I didn't want to clutter the other current thread, so thought I'd start a new one.

Is anyone running a mechanical water injection system in one if the blown  vintage classes?

Is anyone aware of such a system?

[RichFox]

When I ran in the class I used a sealed can with one line in from the intake manifold and a line out the top from below the water line. Build boost, squirt water into the top of the carb. Simple.

[jl222]

  We ran one in blown gas altered for years before going to new pump type system. We ran a small air #3 or 4 ''boost'' line from intake manifold to a 3 gal aluminum water tank [1/4'' thick and bolted down water lid] then to Enderly fuel jets and nozels [with a # 3 or 4 line] just before impellers [two blowers] at the time. The water has to be injected on the intake side of blowers with this type of system as pressure is not above boost pressure. I like it because it also cools the blower. With the Enderly jets it's easy to change the amount of water. We ran about 20% of fuel flow [ just water no alcohol] because alcohol would put us in fuel class.
 This would be even better for roots type blowers because of their low efficiency and smaller intercoolers if even used.
  Some tractor pullers [John Deer type] inject up to 3 gal min but at real high boost [ like 175 psi] and no intercoolers
because they  stage their blowers [one blower into another blower into another blower] and with all that plumbing going on
there is no room for intercoolers.

  JL222

             
 

[38flattie]

Thanks guys!

Sounds easy, and it's all controlled on boost-no boost, no water!

[hotrod]

The only problem with that sort of system is if it sets up a siphon action.
You need to make sure the reservoir is placed below the outlet. If placed above the outlet point, once the flow starts it will continue after the engine is shut off due to gravity and residual boost pressure in the reservoir.

The two common ways to resolve those issues is to put a low pressure anti siphon valve in line between the reservoir that is spring loaded to close unless there is a differential pressure of 1 psi or so.That will delay the water flow slightly as you come into boost but will positively shut off flow when you shut down the engine and boost bleeds off from the reservoir.

Some folks who have not taken this safety measure have found that when they attempt to restart the engine it is hydraulic-ed by water that has dripped into the intake after engine shut down.

Or you can use a positive shutoff valve either manual or an electronic solenoid valve that closes when the ignition is cut.
If you are not running high boost you can use anti-siphon valves designed for use in aquarium air bubbler systems, which have a light spring to force them close if the air pump stops.

Larry

[38flattie]

jl222, what kind of boost were you running? I'll be at about 12lbs, and am wondering if the 20% is a good starting point, or maybe less for me, as I imagine you may have had more boost?

Edit: Nevermind, I just thought more about it- 20% of fuel is 20%, regardless of boost. BW

Hotrod, thanks for the info. I'll do that.

[NathanStewart]

I know your concern is the "no computers" rule but you could simply run a Hobbs switch or even a WOT switch to activate an electric pump and use a "modern" high pressure system.  The key to good performance with water injection is atomization.  A high pressure system with a good atomizing nozzle would work great for you. 

Email me if you need parts or more info: nstewart@aempower.com

BTW I think we started a conversation re: water injection on the HAMB a while back but I don't remember hearing from you with more questions.  I'd be more than happy to finish up the convo now. 

[38flattie]

Beef Stew?
I didn't follow up, because at the time, I was planning port EFI, with water/methanol injection. Even then, I was eyeing the salt flats, and found out that EFI wasn't allowed. I kind of put that part of the build on hold, until I could figure out what I was going to do.
About a month ago, I committed to the salt build, rather than the hotrod.
So,... here I am!

I will contact you for parts AND info .Thanks! I've got a Scott 4 barrel injection system- I'm just trying to decide on that or a 4 barrel.

Could I add a 1" riser between the carb and the blower, and put the injector there?

[oz]

I once saw a system using a bottle with a vent in the top and four small capiliary tubes running into hypodermic needles that were inserted into the intake rubbers (4 cyl bike) and apparently different sized needles were used to meter the water which was sucked up with the vacume effect.bottle being below the carbs of course.
did it work I dont have the foggyest idea but seems feasible.

Cheers Oz

[hotrod]

Could I add a 1" riser between the carb and the blower, and put the injector there?

That sort of injector plate is a common way for folks to add water injection to conventional carburetor NA engines. I would not expect any special problems in a blower application.
If the blower sucks through the carburetor, the water will also help cool and seal the blower rotors and improve its efficiency by reducing temperature gain during compression.

Larry