Water Meth Inj for intake heat soak

[ralmo94]

As many know, the gmt 400 OBD2 big block trucks suffer really bad from heat soak. Sit at a stop light a couple times in the summer and IATs skyrocket and power goes way down.

I have a water Meth kit, to aid in this, the problem is I only need it to come on when IATs are above something like say 120? It can tie in to the MAF or the MAP. I had it hooked up to the MAP, but towing I was at too low of vacuum and it sprayed too often.
I was thinking I could have more control and spray less with it connected to the MAF, as the MAF can read more airflow than I flow WOT.

Also when I used it before, I didn't have the IAT, where it was cooled by the water Inj.

Planning this out better, I'd like it to come on during heat soak, and very little spray, the controller is variable.
My thoughts for temp engagement is to use an e-fan controller that powers the unit on. I could locate the sensing bulb touching the intake.

Before any replies, I know these water Meth units are usually only used on forced induction and mostly diesel. I don't plan to run meth, only distilled water.

Anybody have any thoughts?
Let me know what you think. If I get to it before I go out of town again I'll report my experience.

Any tips are welcomed.

[steveo]

my thoughts are that this is insane

an engine should produce far less heat at idle than when it's under load.

if the car only heat soaks at low RPM when not moving it's a coolant or airflow issue. insufficient airflow over the engine or radiator, or coolant moving too slow so not enough movement through the thing getting hot

instead of an elaborate water misting system how about just re-tool the damn cooling system or airflow so it goes away

or is it possible your manifold itself isn't heat soaking and your IAT is just in a bad location

better analysis of the problem and re-engineering to solve is always preferred to a band-aid like spraying a programmed amount of water at it

of course if you must use that meth system, they usually use a 0-5v map sensor input, right? so why not just put a temp sensor there with appropriate resistors so it reads like a map sensor and then the system mists above a certain IAT.

[ralmo94]

Coolant Temp stay rock solid between 178 -183, Coolant is not the issue, issue is engine bay is completely full, not enough airflow over the engine. I failed to mention that I did relocate the IAT in the air filter box. I also thought a body lift might help with airflow and heat evacuation..

This will work from a 0-5v, or Frequency of the MAF. It is designed to inject more with more load. If hooked up to a 0-5v temp sensor, when it heat soaks it could inject full at idle and possibly hydro lock. Thats why I thought about the MAF, for variable input, with sytem only powering on at a certain temp.

There is nothing "wrong" as far as I can tell, just too much under hood heat. I also thought about a scoop, not sure I want to cut a hood though.

[steveo]

if you dont want a hood scoop just pull all the crap off between your hood and windshield so it can escape there

[kur4o]

Meth injection with distilled water is useless. The main reason is that water you are spraying will likely be at the same temp as engine bay. It won`t cool enough incoming air. It will also gives tons of white smoke at the tailpipe. At least the valves will be cleaned from carbon deposits and shine like new.

The reason methanol is needed is that when alcohol evaporates it ingest heat and cools the air making it more dense, with more oxygen content. So to make it work you need a real methanol in that injection. Wrapping headers with thermal barrier will also bring underhood temp down, or cutting vents in fenders or hood and adding E-fans.

[ralmo94]

if you dont want a hood scoop just pull all the crap off between your hood and windshield so it can escape there

I think the only thing there is a rubber seal

[ralmo94]

Meth injection with distilled water is useless. The main reason is that water you are spraying will likely be at the same temp as engine bay. It won`t cool enough incoming air. It will also gives tons of white smoke at the tailpipe. At least the valves will be cleaned from carbon deposits and shine like new.

The reason methanol is needed is that when alcohol evaporates it ingest heat and cools the air making it more dense, with more oxygen content. So to make it work you need a real methanol in that injection. Wrapping headers with thermal barrier will also bring underhood temp down, or cutting vents in fenders or hood and adding E-fans.

The manufacturer claimed it still had cooling effect with straight water. I didn't think about that being the same temp, low slow flow, makes sense.
The manufacturer recommended using the blue window wash that only has meth and water in it, or a can of heat mixed with water. If it works as I think it should, I'm not afraid of buying the meth.

I pulled out the splash shields in the fender wells, that helped, but with summer traffic it needs more help. It's acceptable empty, but towing it is a problem. There is a factory e fan, when it comes on it just blows radiator heat into the engine bay though. I don't have headers yet, I plan on it though. Didn't know if it would be worth it to wrap the manifolds until then?

Sounds like the body lift is actually the best solution to the problem. I already have the meth kit mostly installed though, was thinking it helped I might as well use it.

I Appreciate all feedback

[steveo]

because of evaporation i think even warm water would help. its called evaporative cooling. i just think its too elaborate. although if you're looking for off the line power when hot i guess it would do it but at that point might as well get some meth

[Thorwon]

When I installed the 5.7l Hemi in my 2007 4 door wrangler I had a lot of cooling issues. Not cooling the engine but heat build up under the hood.
The Hemi fills the complete engine compartment up. There's just no where for the hot air to go.

I started by wrapping the exhaust, removing the inner fenders and installed splash guards for the exhaust manifolds. That helped a lot but what helped the most was the hood louver.
I know what you mean about not wanting to cut the hood. When I installed mine the jeep was 3 years old. I stood and looked at it for an hour before I could make myself drill the first hole.
That fixed the heat issue until I started towing my 17 foot Chris-Craft boat. That thing is heavy. At that point my heat build up came back. That's when I found out the 545RFE trans makes a LOT of heat.
I ended up putting a remote mount trans cooler with fan, mounted horizonal under the jeep.

This is the louver I used.
0111 rugged ridge luver.png

[LeMarky Dissod]

... There is a factory e fan, when it comes on it just blows radiator heat into the engine bay though ...

At what coolant temp does that electrical fan start blowing?

[Fast355]

My IATs will get to 170-180F fairly easily around town with the factory GM air box.

[ralmo94]

At what coolant temp does that electrical fan start blowing?

Stock was set to some stupid high number like 260.
I believe I set it at about 185 last, maybe 190. Would have to check, haven't looked at that part of the tune in a year or more.

Edit. Stock was 260.

[ralmo94]

My IATs will get to 170-180F fairly easily around town with the factory GM air box.

Is that with the van? Do you suffer from heat soak lack of acceleration also? What do you got now a 383?

[Fast355]

Is that with the van? Do you suffer from heat soak lack of acceleration also? What do you got now a 383?

Yes the 97 Express. It has a ~500 hp 383 in it so lack of acceleration is relative. Even on E85 it probably loses a good 50 number tq/hp due to heat soak until it has been rolling a couple of miles and the IATs drop. Even when it is 40*F outside the IATs will heat soak up to 120-140F idling around town. The 96+ vans might as well have an open cone filter under the hood. They run maybe 10F warmer than ambient at 70-80 mph on the highway but heat soak badly as soon as you slow down. GMs air box design sucks on the vans. The older G-vans were not quite as bad but they also have high IATs with the air intake drawing hot air off the ac condenser. The vans have heat soak related fuel boiling issues as well that GM never corrected even in the LS powered vans. On a hot restart it is typical for them to stumble and run crazy lean. You can actually hear the fuel boiling in the TBI or fuel rails in the summer after you shut the engine off. The boiling fuel sounds like a perculator on top of a hot woodstove.

[ralmo94]

Seems like my truck don't like to cool down once it gets heat soaked. Every time I stop for gas I leave the hood open the whole time until I'm ready to roll again. Seems to be the only thing that helps so far.

Not sure if I'll get time to wire the meth back in or not. Too busy working on junk farm equipment. And I leave town again Sunday morning. The week off sure went by quick.