Thread: Water/methanol injection TD5

Originally Posted by Rick122

Yes, it's easy to tune our engines to lower egt but usually it comes at the expense of performance. Towing a caravan in 45? heat, I think water injection would help keep the internal temps down.

Water injection has nothing to do with "rice".
It was used in the Rolls Royce Merlin engine. It's British...

ok, you are getting off the mark,

1 RR merlin was not water-injected, during ww2 water injection was played around with as a high altitude booster, to compensate for the lower density and cooler air. this was dropped for bassicly doubling up the supper charger then adding another gear to it. so that's a red hearing.

if you are talking about wishing to lower internal temps, you can look at your burn time, fuleing etc first if you wish to go further than that after upgrading inter-cooler and fitting some more airflow ie a fan.

then i would be looking at LPG fumigation which will give you more power and lower egt.

direct water injection can work but the amount off effort for the return is dismal and then there is the risk which is quite substantial and very bloody expensive if it happens ( read will happen)

water to air inter-coolers, are good but have there place, tooling around over sand dunes is not the place

Originally Posted by Rick122

Yes, it's easy to tune our engines to lower egt but usually it comes at the expense of performance. Towing a caravan in 45? heat, I think water injection would help keep the internal temps down.

Water injection has nothing to do with "rice".
It was used in the Rolls Royce Merlin engine. It's British...

Compression ignition works a little differently to spark ignition though.....

More boost or a more efficient I/C will lower EGT's and give more power/torque, the latent heat of vapourisation with H2O reduces compression temps, just what we don't want with diesel.
It will increase charge density, but it isn't the most efficient way.
It's a bit like supercharging vs turbocharging

Honestly, FFS some of you people are so negative. Do some proper research on water injection and then come back. I already have LPG fumigation.

[quote=Rick122;2367910]And you think bigger, more efficient intercoolers are not going to lower combustion temps?


EHHH your point???, of cource thay do, simple maths

Originally Posted by Rick122

Honestly, FFS some of you people must just get up every morning wanting to dispute everything. Do some research. Water injection works, plain and simple. It's been used for years, on petrol and diesel engines. If not on the Merlin, then any number of other aircraft, F1 cars, land speed record cars and bikes etc. If you don't want to use it and are prepared to fit $650 upgrade inter-coolers and $800 exhaust systems and $3000 LPG fumigation kits, then go ahead, don't let me stop you.

there is no production air craft with a reciprocating motor that uses water injection, that has ever lasted. turbo props and jets yes very much so.

all the examples where water injection works and works well is in situations of constant load, the other examples you give are water evaporative, which is a totally different situation again.

450 for a re cored inter-cooler, exchange, 1500 for LPG fumigation. or you can shoehorn an oversized rice burner inter-cooler from eBay for a couple of hundred, or make a trip to U pull-it and grab a relay and a thermo fan why you are there.

but and for your other point, many on this forum have been there done that!!! and Mate you asked the question, sorry if you are not willing to accept the answers, but really that's your issue not mine

Dispute statements based on experience and logic / science..

If you wish to post this "stop gap" measure as a suitable system for a working 4wd then that be your choice..

But what did you really expect? You post something and then expect people to kiss your behind and praise your idea?

Get your ego out of it...

Water injection systems in Diesel 4wdrives isnt the optimum.

Your rant after about $800 exhaust etc was laughable...

Simply put - to optimise your diesel (without altering the engine itself):

• Tune fuel to meet air - up boost if you wish...

• Cool the charge using a sustainable (on a big Simpson type crossing I don't want to have to pump more and more water in) and efficient InterCooler

• Fit a suitable exhaust so it can get the gases out properly (if it can huff it in and not breathe it out it wont play nice)

You need to learn to read 85 county. For a start I never asked any questions, I said I was going to give it a go in reply to the OP who asked about it. Like I said, it's been well proven. What's the difference between water injection and water evaporative, please enlighten. You don't assume I'm going to pump water straight into the combustion chamber do you?

Whilst it can be agreed that Water/Methanol Injection will give you "safe" power - (Post TDC power) with relatively low increase in combustion pressure..

You're talking a 50/50% mix at 20% by volume injection to do it right.

Carrying that on a longer trip will be problematic.

Add that the methanol in bulk is $1.10 a litre and it starts getting expensive...

If you're chasing that sort of power increase... Look at other upgrades - turbo etc..

Or consider moving to a TD5... Plenty of Low EGT TD5s out there pulling some good numbers!!!


Being a diesel mech you shouldnt have any problem tuning your 300tdi up without resorting to this added complexity...

I'll only be injecting at high EGT's, (in order to lower them), after working out what my current maximums are. This should prevent the need to carry lots of water.
Running methanol 50/50 with water is mainly used to increase performance, I'm more interested in the effects of water injection on lowering EGT's. If it doesn't work, it's only cost me a new shut-off valve, which i was going to buy anyway. Apart from that it's only going to cost me my time. I have the rest of the gear already.
I'm not an idiot, I'm not going to fit it without any safeguards. I've had good success before, with petrol cars only admittedly but why not try? I know all the things you mentioned will cure high EGT's and give more power to but I don't have that sort of money to spend at the moment and I'm about a million miles away from everything (well it seems like it anyway!)
Look, it's pretty hard adding posts on here with my small screen mobile trying to convey in words what I'm thinking and I apologise if I've come across as being brash. Peace.