Questions for WVI guys

[methaneb]

I wanted to make this a separate post so as to not get lost in / interfere with the general WVI discussion.

Water Vapor Injection looks like it would be a huge benefit for my gas guzzling Chevy Pickup. I tried a little experiment on it today and it seems promising. Here's the dilemma.

The truck has a Throttle Body Injected 350 5.7L. The intake manifold is very similar to that of a carbureted vehicle, and has the same style of air cleaner. I cut away the air cleaner housing beyond where it seals to the filter, and put a K&N filter on it.. so the filter is exposed all the way around (I am planning to add a hood scoop to push cold air to it) . The only place to tap in before the throttle body would be in the air filter lid... but I would have no way to restrict the air filter to create much vacuum there.

However, there is a very strong vacuum source beyond the throttle butterfly, where the PCV gases are pulled into the intake manifold. I wonder if maybe I could hook up a T fitting to that line, so that that manifold vacuum would be divided between my WVI system and the PCV system. I could then tap the WVI fresh air intake into the PCV fresh air intake much in the same way. That way the the manifold pressure is not altered by the system.

Anyone familiar with these motors? Does this sound viable? Typically the flow of a PCV system slows down the more the throttle is opened, but the manifold vaccuum on this truck remains fairly strong all the way up to full throttle (there is some noticeable loss, however).

The key downside to this, is that the WVI system would be MOST active at idle, and LEAST active at full throttle, which is somewhat backwards behavior... but I don't know how else I would do it.

Anyone got any ideas?

[redrat100]

If it were me, I would not plumb into the PCV vacuum for a couple of reasons. You already mentioned that "...the WVI system would be MOST active at idle, and LEAST active at full throttle, which is somewhat backwards behavior...". That alone is reason enough because you want it to be more effective at higher rpm. Secondly, and more importantly, by using PCV vacuum you run the risk of backstreaming moisture into the crank case and fouling up your oil. This could be an expensive lesson...

If installing a venturi is not an option then you could do what I did. Use a ram air scoop infront of the radiator to pressurize the WVI bubbler. Mine has worked fine that way for several hundred miles. Sitting at a light there is no airflow through the bubbler but at high speeds it bubbles like crazy.

[Roland Jacques]

The key downside to this, is that the WVI system would be MOST active at idle, and LEAST active at full throttle, which is somewhat backwards behavior... but I don't know how else I would do it.

I assumed my 2001 5.7 intake manifold pressure would be go down on acceleration, but according to my ScanPro, it says the opposite is true. 4 psi at idle and 8 PSI on acceleration, and higher RPMs. I'm thinking there should be a way to regulate into the manifold enough not to through a code... but I too am not sure how.

[methaneb]

I'm going to try to tap the input from the WVI bubbler into the air cleaner lid, and use a separate filter for the air intake. Hopefully there will be enough vacuum generated to pull some air through. I can mask off some of the air filter surface to try to generate more vacuum within the air cleaner as well.

The vacuum from the manifold is WAY too strong... it pulls the sponge up to the top of the container despite being fitted very tightly in the container. Left unattended, this could very easily let liquid water into the manifold.

[Helz_McFugly]

yea, you dont want to hook into a vacuum line. it would only pull vapor at idle. and as you said, it will suck water into it. unless its a very ridged container, it could implode it and suck it dry.

[spicerman]

I know that story by heart!!!!! That caused me much anxiety! Helz is right!

I hooked a vacuum gauge to my PCV port and it does go down or is less under load then at idle.

I think you can create a venture if you put a cone like Helz showed on his dodge, but on the 5.7 you will have to be a little creative. I'm going to try to put one in the hard plastic hood that mounts to the throttle body. I have already removed the square vortec box that is mounted on the back and blocked that opening off with a 2" large coin shaped piece of 1/4" thick plastic. I put a 3/8" hole in the center of that "coin" and clamped it in place with the existing rubber connector that held the vortec box. That will be my new in for my HHO.(You could also use it for WVI.) The steam comes in at the top right above the throttle plate. Here is the tricky part.. That chamber assembly that goes from the round rubber corrugated hose and connects to the throttle body starts out round and goes oblong. If you put in a piece of metal of plastic about where the votrec box came in and at the same angle, and force all the air to flow off to the opposite side so it would have to swirl around before it entered the throttle body, That would create a venture and be a vortec too. Then both the steam and HHO will be under vac. I could eliminate my pump and just draw it in through the metering valve