What kind of h20 injection

[OsaurusRex]

What kind of H20 injection are u using for a whipple, 5.7 engine.. any suggestion of witch one to buy?

[sack]

could someone enlighten me of what you are refering to? water injection? and what is it for? and how does that work? is it very beneficial in certain cases?

thanks!

[00Silverado]

Originally posted by sack
could someone enlighten me of what you are refering to? water injection? and what is it for? and how does that work? is it very beneficial in certain cases?

thanks!

Water injection is used when you are using a supercharger to cool the intake charge. Usually people who dont have intercoolers use this to run more boost so their engine doesnt ping. James B is running water injection

[thruster1015]

water injection is to intercooler as
nitrous is to supercharger


sort of speak... its like the cheap way to make an intercooler

[Boosted-Z71]

Go to www.carollsuperchargering.com, & take a look at their web site, (gasseous intercooling) I have a gen 4 setup on my truck and they are very nice. You can adjust when they inject the water & alcohol mix along with how much you inject. I was running 10 psi boost on my stock internal motor last year with no problems. And I am pretty sure this is the same setup that James is running.

Boosted-Z71

[James B.]

Hey, you guys have good memories!

I am running the Carroll GenIV system. It's 100% reliable and issueless - works great.
Here's a history of my progress with it.

Aug 3, 2002:
http://www.pacific-audio.com/performance/messages/185657.html

Aug 4, 2002:
http://www.pacific-audio.com/performance/messages/185756.html

Aug 8, 2002:
http://www.pacific-audio.com/performance/messages/186392.html

Aug 12, 2002:
http://www.pacific-audio.com/performance/messages/186942.html

Aug 12, 2002:
http://www.pacific-audio.com/performance/messages/187091.html

Aug 14, 2002:
http://www.pacific-audio.com/performance/messages/187454.html

Current configuration is the 2.5" pulley, making 9-10psi boost with the 15GPH nozzle.

[sack]

o.k. i see what you mean, but where are you injecting the water? i'd never think to inject it into the engine or into the supercharger. so where?

[James B.]

I inject into the intake air path right before it enters the manifold. It is possible on a twin-screw supercharger (Whipple/Lysholm) to inject a small amount before the compressor. The supercharger has very close tolerances on the rotors and the water actually helps it seal. This gives you a bit more boost by minimizing these losses. I run only one nozzle. You would not want to inject more than a flow rate of about 5gph into the compressor. For the H2O injection to be effective it needs to be able to absorb heat in the intek air - the most heat is obviously on the discharge side of the compressor.

[sack]

alright, that makes some sense, is it on all the time? or only when you want it(like during a 1/4 mi race)? if it is on all the time you would need a lot of water.

how big of a water tank is it?

and wouldn't you think the water would be bad for the metal? or get absorbed into the gas charge before it goes into the cylinder making a worse combustion? or does it evaporate before it even reaches the valves?

[James B.]

Originally posted by sack
alright, that makes some sense, is it on all the time? or only when you want it(like during a 1/4 mi race)? if it is on all the time you would need a lot of water.

how big of a water tank is it?

and wouldn't you think the water would be bad for the metal? or get absorbed into the gas charge before it goes into the cylinder making a worse combustion? or does it evaporate before it even reaches the valves?

First, it comes on in response to boost. Most systems have a 2-Bar MAP sensor and are triggered at a setpoint well into boost. The water is only injected when boost meets or exceeds this setting. The system I have has two stages, stage 1 runs the pup at a reduced speed (pressure) and begins at 5psi. Stage two kicks in at 8psi. at full pressure.

Second, the tank I use is one gallon. I use about 3/4 gallon water to 25 gallons of fuel.

Lastly, the water is intended to abosrb heat. The better it can be atomized the more effective it will be. Finer droplets of water stay suspended in the intake air better and have a greater overall surface area, maximizing evaporation. Some liquid water does reach the valves. In fact, if you're going overboard on the water injection it is possible to not only lose power but also get the intake runners so wet that water blows by the valve seals and ends up as rusty crud on the indside of the rocker covers. For the same reason, water injection isn't the greatest thing for engines only driven short distance where the coolant barely gets to fully warm up. (My commute to work is 3 miles.) The amount of water being injected is not enough to cause hydrolock or engine damage. It can also cause misfires if the system is being used correctly. It's easy to get set up and tuned right.

[K-9]

You guys might want to look in to this.


http://www.designengineering.com/