Originally Posted by realcanuk

Been running water meth for years and never have any issues from detonation. I know most here go on about how pure meth is best, but I use what I think is best for me.
Could a make a few more HP with pure meth? Maybe, but I'm not out to set records. I just agree with what's been posted and think the cooling of water adds some safety.
Added bonus is it's easier on the meth system and my alky pump has never had an issue, where many of those that run pure meth seem to have to rebuild every few years.

Originally Posted by JoeNova

Water cools far better than methanol could ever hope to.
Charge air temps have a lot less to do with preignition and detonation than people think. Methanol does a slightly better job of cooling charge temps because it evaporates more readily than water, but water absorbs twice as much heat energy as methanol when it is converted to gas. It also takes twice as much energy to raise the temperature of water at room temps as it does methanol. Water wins in the cooling department, hands down.


The second problem is that methanol still burns. It might cool charge temps slightly, but its still going to ignite and produce heat. The water will not. Methanol's only benefit here is that its 'slightly' cooler than gasoline. It will still force heat into pistons, it will still cause rings to expand. For guys running cast pistons and tight ring gaps, water wins here too. During compression, the temperature of water is raised high enough that it flashes to steam before ignition. This removes so much heat from the cylinder that it makes detonation or pre-ignition almost impossible. Methanol is still able to detonate in this situation. It will remove some heat, but if it has evaporated, it takes far less energy to raise its temperature, and therefore its still very possible to obtain pre-ignition temperatures during compression.


So for guys running cast pistons that need to stay cool to prevent cracking, and tight ring gaps that need to stay cool to prevent expansion, water beats methanol every time.

If you have forged pistons and preferable ring gaps, methanol is the way to go.
If you are out of fuel injector and need supplemental fuel to make more power, methanol is the way to go.
If you have a wild combo but the CFM flow of your heads isn't up to the task, methanol will cool the charge air better and allow more power for a given port size.

But for pure cooling purposes, water is king.

Originally Posted by BLOWNBLUEZ06

I agree that water has a higher latent heat of vaporization than methanol but I don't agree is that water beats methanol hands down.

Originally Posted by typeav

I didn't get your statement clear, are you for Water / Methanol mix or Pure Methanol ?

Originally Posted by BLOWNBLUEZ06

I agree that water has a higher latent heat of vaporization than methanol but I don't agree is that water beats methanol hands down. What has to happen in order for water to do its job? It has to change phase to a gas. If it doesn't change phase, then it's not nearly as effective as methanol or ethanol. Even if you spray it in a fine mist, much of it will hit walls and turn back to larger particles. Sure, the combustion chambers are hot enough to boil water, but when you increase pressure on the compression stroke, what happens to the ability of water to change phase? It's decreased tremendously and so much of it doesn't change phase until it's blown out the exhaust port, after the pressure drops. It also has time working against it. Methanol enters the charge pipe and the air charge temperatures are almost always enough to begin the phase changing immediately. That's not the case with water. At 15psi boost water should begin boiling at 250 degrees. If we were dealing with much higher temperatures at low pressures, I agree things would be drastically different. I'd love to know and see how the test models were set up back in the WWII days. I would love to come up with a good way to quantify all the data between various levels of methanol and water.

As for Methanol being a fuel and there being an issue with the fact that it burns, I say "so what"? The burning of the fuel isn't what causes the heat in the first place, it's the quick rise in pressure.

Never enough time to discuss these things.

Originally Posted by typeav

I didn't get your statement clear, are you for Water / Methanol mix or Pure Methanol ?

Originally Posted by stevieturbo

I'm sure he is for testing to see what is better for each and every individual user

Higher percentage of water requires much finer control over quantities used at any given time

Higher percentage of methanol...to 100%...is pretty idiot proof and requires little control over flow. Just dump loads in

It's quite easy to see why most choose the latter.

Originally Posted by chuntington101

Water doesn't help cooling intake much at all. As you say you need pretty high IATs to get the water hot enough to change phase (but don't forget it still abosorbs a stupid amount of heat no matter the phase!). In the WW2 days OATs would be more than high enough as the aftercooling was primitive (if they had any at all).

With modern intercooling the real benefit of water, and what the like of WRC teams use it for, is controlling the flame front speed and effectively having amazing dept. control.

These guys used to meter the water like fuel. This allowed high comp engines that would run over 3bar back in the day. They used to say that was on pump fuel to! They were able to do this because they could keep the flame front speeds down and stop dept. using the water.

In real world terms, and as Steve said above, without loads of testing and very fine control of the flow you are never going to see these kind of benefits. plus it's not as easy as meth!

Originally Posted by BLOWNBLUEZ06

That's my thoughts as well. I'm just not a big fan of running H20 and nobody's convinced me otherwise. I've seen lots of big talk, but the fact is that I've never watched an impressive pass happen in a car, walked up to the owner and asked his setup and heard "water injection" come out of their mouths. Ever since I got involved with his car, ALGZ06 (Albert) has beat the **** out of his 3700lb C5Z on the track and street for years, running 9.1x's and 9.0x's before it finally broke a rod. He's running E85 now but still spraying some meth. I'm not opposed to listening to how others achieved their success, but I'm not inclined to change my methods before I see something impressive happen.