Don't bother at the moment.
Hydrogen does work great as a hydrocarbon catalyst or as fuel in itself, indeed in the US you could drive one end to the other on Hydrogen fuel with delivery stations along the way and the WA Gov were running a 100% Hydrogen powered bus trial here in Perth for a few years but it was uneconomical in scale IE not enough users to justify the Hydrogen price.
For the 4.8 you will need too much engine bay space, too big a fuel cell bank and most of all too much electrical power (50 Amps or more) to run the Fuel Cells for onboard generation of sufficient HHO for that size engine to make a difference worth doing.
...and the other posts are correct in that most of the Ebay or backyard solutions are, unfortunately, Snake Oil. The ones that are somewhat efficient and safe are BIG $ in the scheme of things and don't run on just water, they use a chemical mix
There is a bottom line however and that is this... A lot of us spend waaay too much dollars and time on stuff that is either fun, a hobby or just out of plain curiousity so if experimenting with HHO is of an interest to you then I say go right ahead. You can always pull it out if the novelty wears off... just don't do it if you are expecting to recoup the $ and gain astronomical power increases etc
:headwall:I have sat in a truck with the fuel cell on and got a 30% improvement on economy and 5% power improvement and we travelled 2500km and used 2litre water and improved fuel from 20/100to 14/100 fully loaded so Im impressed but not fully sold because petrol a different senio so thats why Im asking the question if anybody has put one in a 4.8 petrol
the fact that the name HHO has stuck shows it's only idiots with no chemistry knowledge whatsoever do it..
2x H20 + ELECTRICITY = 2x H2 + O2 + HEAT
look up what hydrogen fuel cell really is, what you do with those is mix H2 with O2 on a very expensive reaction surface to generate electricity and water as an output
these HHO things use a LOT of electricity to break water into H2 and O2.
so if you could get more energy out of burning it than what it takes to break it apart you could use a hydrogen fuel cell to power one of these HHO things. and use the extra spare electricity to do whatever you want. and you would only need a little bit of water recycling in the system.
why isnt anyone doing this? BECAUSE IT TAKES MORE ENERGY TO SPLIT OXYGEN AND HYDROGEN THAN YOU GET FORM BURNING IT.
If you aren't bright enough to understand that you shouldn't be messing around with explosive gas.