Thread: Water injection, EGT's, AFR's and a Petrol V8.....

You used to able to buy a factory water injection kit for the 2.25ltr but I don't know if it worked,it used a 50/50 water metho mix. Pat

its not going to net you a lot of advantage on a standard rover donk on standard fuel.

theres a couple of schools of thoughts as to when your supposed to use it and how.

the first is the "raise the compression of the low compression engine" school

and the second is the "lower the combustion temperature of the overcooked engine" school.

unless your talking about spraying the intercooler which is something entirely differnt and not at all related to a NA engine.

in this case its a 302/5.0L Ford Windsor V8.....

part of the theory we were kicking around is that with water injection and the resulting effects on intake air temp, combustion chamber temp, etc, you should be able to disable the EGR function and alter ignition timing , hopefully to a positive result in terms of power/economy

why not just cheat the sensor or manually tweak it?

cheat/tweak it in the sense of the el cheapo "chips" you get on EBAY? i think i'll pass on that one.... all it does is force more fuel in..... i can achieve a similar result by refitting the crappy tridon 80deg thermostat (or removing it altogether)

the reason it was put forward is because people have been achieving some interesting results in the states with water injection on forced induction diesels, so there may be some benefit doing a similar thing with a NA petrol engine.....

in the diesels your working on the latter school, help cool the over cooked engine deal.

what youre aiming at realistically is the former school where your trying to raise the compression ratio. to really get the gains from it you also need the fuel to deal with it.

I would think that for the effort you're likely to go through more gains would be made by a port n polish with gasket matching on the intakes and cleaning up the exhuast.

my money says that if it doesnt steam the flame front out then it'll start getting knocky unless you retard the timing and thats going to cost you power. you might pick up a cleaner exhuast and engine out of it tho.


There is some ancedotal evidence that early race cars ran better when it was raining but my thinking is that it was the overall cooling of the atmospheric air that gave the advantage rather than the water being ingested by the engine.

All that said.

Other than for diagnostic/decoking reasons Ive never tried misting the intake of a running engine done smartly its not going to kill a petrol engine and you might pick up a pony or two and at the end of the day on the track sometimes its that extra pony on tap at the right moment that makes the day.

ID suggest that for preliminary testing you could use the vac advance point on the 3.9's intake plenum as a water entry point its fine enough and with enough airflow that it should nicely break up a water stream for intake (its also after the MAF so you wont kill that.)

on the edit.

my bad not a rover engine.. eyeball the rover engine for the vac advance pickup point and find a similar location downstream of the MAF or equivelent in ford language.

Originally Posted by Blknight.aus

ID suggest that for preliminary testing you could use the vac advance point on the 3.9's intake plenum as a water entry point its fine enough and with enough airflow that it should nicely break up a water stream for intake (its also after the MAF so you wont kill that.)

on the falcons theres a handy spot on the intake pipe where a resonator usually resides, which is usually plugged with a 2" welch plug..... how handy is that!

Umm, no its a bad idea