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View Full Version : Water injection, EGT's, AFR's and a Petrol V8.....



Sprint
16th November 2009, 10:26 PM
kicked the idea around a lil on the weekend with a friend who is running water injection on his 7.3L turbodiesel F350, that it might be a good idea to trial a water injection setup on a naturally aspirated, fuel injected petrol V8....

am i right in guessing what i'd need as a start would be adjustable water pressure and flow regulators, as well as EGT and AFR gauges?

PAT303
16th November 2009, 10:51 PM
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

Blknight.aus
16th November 2009, 11:03 PM
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.

Sprint
16th November 2009, 11:08 PM
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

Blknight.aus
16th November 2009, 11:12 PM
why not just cheat the sensor or manually tweak it?

Sprint
16th November 2009, 11:31 PM
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.....

Blknight.aus
16th November 2009, 11:48 PM
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.

Sprint
17th November 2009, 07:03 AM
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!

rovercare
17th November 2009, 07:41 PM
Umm, no its a bad idea:D

Blknight.aus
17th November 2009, 07:52 PM
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!

when you get to having a go, keep us posted.

better yet start a new thread with all the goss.

MacMan
17th November 2009, 08:14 PM
Isn't that what slipped liners are for?

Sprint
25th November 2009, 08:54 PM
Isn't that what slipped liners are for?

wtf?

rovercare
25th November 2009, 09:47 PM
wtf?

A slipped liner would cause cooling water to go into the cylinders (water injection:D), don;t think it'd happen on a windsor though, they don;t seem to have the failure rate of a rover motor:angel:

MacMan
26th November 2009, 06:59 AM
A slipped liner would cause cooling water to go into the cylinders (water injection:D), don;t think it'd happen on a windsor though, they don;t seem to have the failure rate of a rover motor:angel:

Yep, that. :twisted:

Blknight.aus
26th November 2009, 03:39 PM
I always thought the slipped liner was to make a ticking noise like an out of adjustment valve so that the mechanic that you take it to who provides you a written quote for $200 to sort out the tick winds up having to replace the block.

MacMan
26th November 2009, 04:09 PM
Dave, expect the horse's head in bed. You've just blown the cover of greasers everywhere. :p

Blknight.aus
26th November 2009, 06:26 PM
dont see how you work that one out....

the mechanic that wrote the quote for "Rectify ticking noise $200" was less than impressed when the legalese people pointed out that he quoted it and he was going to do it.

$200 for a valve adjustment is exxy.
$200 for replacing an engine block is cheap, very, very cheap.

the sheer joy of forcing a rip off merchant into doing a good job was priceless.

MacMan
26th November 2009, 09:44 PM
Sorry, read it too quickly...

That story is gold though!

LOVEMYRANGIE
27th November 2009, 10:41 PM
Water injection, "forced" induction..................

And not a mention of adding a turbo.........

:burnrubber::burnrubber: