Water/Methanol Injection...

[Ccmano]

I'm curious if anyone has ever tried water/methanol injection on an LT5? It's supposed to significantly increase the octane rating (25%) and allow for much more agressive timing. Of all people, MAM is offering an electroncally controlled kit for $590. Thoughts....?
H

[jonszr1]

i believe that ron aka cuiesenarte vet had one on his car .spelling on his handle is most likely wrong. i wonder about using one also . sure would be nice not to have to back timing down due to fuel. corey made a very conservitive aproach to timing in tuning my cars to to ca ugly fuel . in fact i do 2 parts91 to 1 part 100 oct when i go to the strip .just to be safe .i have done this ever since popping a head gasket at the strip . i wonder if detonation plays a part in some of the head gasket problems that happen . maybe someone with motor motor expertise can chime in .

[LGAFF]

As you probably know this is used mainly on Supercharged engines.....funny this tech was used on WWII fighter planes as a way to get a short burst of power when in a dogfight. Would be interesting to try not, sure why the kit costs so much.....its actually a washer fluid injection system.

[Locobob]

As Lee stated water injection is typically used in forced induction applications. I haven't seen any hard evidence of it being effective on a naturally aspirated automotive engine. If anyone has such evidence lets see it.

[Ccmano]

From what I have read it has the same benefits for NA engines as it does for boosted engines. Particularly high compression engines. The key appears to be retuning the engine for more timing that would not be supported without the injection. Simply adding the system without retuning will do little or nothing.
There appear to be several benefits:
The water cools the air charge and makes it more dense, like driving your car on a cool morning. A major benefit to prevent heat soak on hot days or after running hard. This by itself allows for more timing.
The methanol has the effect of an octane booster. Several reports I've read state that it brings the effective octane to about 116. This is apparently the major factor in allowing for very advanced timing settings. It is claimed that engines up to 13 to 1 compression can run on 91octane pump gas without pinging and with full timing advance.
Modern systems now use electronic controllers based on MAF, vacuum or other electronic engine control criteria to progressively inject. Allowing for optimum tuning under all load conditions.

Attached is an article in HotRod magazine that examines the issue in todays context, in their case both for boosted engines and for high compression muscle car engines that their readers tend to have.
http://www.hotrod.com/techarticles/e...ion/index.html

Given the sensitivity of our engines to timing and heat soak, I suspect there may be some gains to be made. I know that chip tuning done by Dominic has shown that optimum timing advance cannot be reached on pump gas. This is because the pre-ignition sensor picks up ping and instantly retards the timing, this gets worse as the engine gets hot. In theory, this system should allow maximum usable timing advance without fear of engine damage due to pre-ignition. Couple that with a cold, dense air charge and what "SAE literature refers to as `micro explosions' as the water/methanol mix flashes to vapor that helps break up the fuel droplets even further, giving a more homogeneous charge in the combustion chamber." We may have something worth investigating further here.

I'd like to hear further discussion on this.
H

[jeasen]

I use alcohol injection on my Turbo Buick motor. It allows me to run over 20 pounds of boost on pump gas. 20 pounds of boost on a 8 to 1 compression ratio makes the compression ratio close to 20 to 1. So alcohol injection work well.
Instead of using alcohol injection has anyone considered running our LT5 motors on E85? It would seem to me that with 16 injectors all we would need is a chip burned for E85. E85 has way more octane then our 11 to 1 compression ratio would ever need so timing could be increased also. The new injectors work with alcohol so why not use E85?

[Locobob]

Originally Posted by Ccmano

Given the sensitivity of our engines to timing and heat soak, I suspect there may be some gains to be made. I know that chip tuning done by Dominic has shown that optimum timing advance cannot be reached on pump gas. This is because the pre-ignition sensor picks up ping and instantly retards the timing, this gets worse as the engine gets hot. In theory, this system should allow maximum usable timing advance without fear of engine damage due to pre-ignition. Couple that with a cold, dense air charge and what "SAE literature refers to as `micro explosions' as the water/methanol mix flashes to vapor that helps break up the fuel droplets even further, giving a more homogeneous charge in the combustion chamber." We may have something worth investigating further here.

I'd like to hear further discussion on this.
H

I suppose that is what it comes down to: Does the LT-5 significantly benefit from running more timing than is possible with pump gas. This would be a most interesting dyno/tuning experiment.

[Paul Workman]

YOu take me back a while, Hans. I fooled with water/Methanol back in the mid 80s; a 11.25:1 CR 427 BBC. When it worked, it worked! But, the control system was rude, crude, and socially unacceptable - unreliable and difficult to get "right".

What I took away from the whole deal was it had a lot of potential, but at least at the elementary level (read: cheap n crude) it wasn't practical (for me at that time). And, I wasn't fooling with timing so much as attempting to come up with a method of just running that beast on pump gas. It was a cantankerous SOB for sure, and in the end, I gave it up for lent. That said, when it worked it was a beautiful thing!

Timing advance: With regardt to water/methanol, is advanced timing key to performance, or a necessity due to (much) slower burn rate?

I was reading about timing advance and the LT5 on pump gas. One of the points made was there was an optimum** timing. At some point advance became too much of a good thing - beyond which performance actually falls off. But, this is fodder for another thread, I suppose.

**Optimum timing was affected by the usual gang of suspects: engine temp, air temp, humidity, etc, etc.

Anywayz, tiz an interesting thread, Hanz. U taken the Z up to the Palomar Mt observatory yet? A nice twisty road for sure!

P.

[jonszr1]

how would one controll the amount of fluid that gets injected ? would it go off vacume or somehow patch into the computor?????

[Ccmano]

Originally Posted by jonszr1

how would one controll the amount of fluid that gets injected ? would it go off vacume or somehow patch into the computor?????

Generally manifold pressure, rpm and in some cases injector duty cycle. Depends on the system. However, the basic systems simply use an on/off control. There is nothing progressive about them. Reach a certain boost level or manifold pressure and they turn on, drop below and they turn off. We're talking very small quantities, a fine mist.

There are two problems with ethanol. The first is simply availabilty. Outside the midwest, availability of E85 let alone straight ethanol is very limited. The second is the corrosive properties. While the newer injectors we install are good, the rest of the fuel system was never designed for it. Even today, new cars designated for E85 use have specialized fuel system components. I suppose it could however be done. E85 alone is 105 octane.
H