Methanol injection kit - pump and tank placement

When you fill the tank is the liquid level below the tank's outlet to the breather? Does the meth stop coming out if the liquid level drops to a certain level?

Here is what I think might be happening: At 90F, methanol has a vapor pressure of 0.1 psig so methanol vapor is coming out the breather tube and may be condensing in the filter, so long as the temp underhood is below 149 F. But as temp approaches that it will stay as a vapor.

Personally I think the breather is a fire hazard. But if you cap it, do not fill the tank all the way or you will rupture it from the volume of expanding liquid.
Mike R.

 

[chrisb33]

hmmm...the liquid is definitely above the outlet of the breather but half an inch below the top of the tank.

ok yeah i think it would be a wise decision to just seal the tank and not fill it up all the way.

what if i do this? would this allow room for the liquid to expand and help prevent vapors to escape the tank?

chris b

 

If the liquid level was above the outlet in the tank then vapor pressure was pushing liquid up the tube and out. IT would stop doing that once the liquid level drops below the tube. But as I said, the vapors would continue to come out as well.

I do not see a reason for the cup handle. If you fill it leaving some air space at the top of the tank it will have room for the liquid to expand. Now the other problem is if the tank is completely sealed then it will draw a vacuum as the liquid level drops and your pump will have to work against it. The pump may not even prime. So you probably need a one-way or check valve so that liquid or vapor cannot push out but the tank can draw air in as the level drops.

Really I'm just guessing at this because I do not know how commercial alcohol injection systems are configured.
Mike R.

 

[chrisb33]

hmmm a one way check valve! thats an interesting theory. i might just try that. il try putting a one way check valve with the current set up, putting it in between the breather and the breather tube!

in theory that should work. thanks for the idea!

chris b

 

[chrisb33]

wait, wont a check valve set up just complicate a supposed to be very simple set up? plus, thinking about it more, it might cause pressure inside the tank right?

i got a suggestion to just put a pin hole on top of the tank and it should work because that's how of the shelf tanks from other meth kit brands do it.

that's a simple solution IF it will work. I'd just have to take out that breather tube and seal that hole and put a pin hole on top of the tank.

but honestly im STUCK and dont know how to move forward with this hahaha. I thought that the original design was simple enough until the current issue. dang it! /ubbthreads/images/graemlins/banghead.gif

chris b

 

A small vent hole would solve some problems. But it will emit alcohol vapors. Methanol vapor could accumulate underhood while the car is hot and stationary. Methanol vapors are not as flammable as gasoline vapors and need a much higher concentration in air to ignite. On the other hand, gasoline vapors are denser than air and will naturally move toward the ground and away from the car, while methanol vapors are about the same density as air and will just stay under the hood until the car starts moving again. Maybe that is why those systems are usually put in the trunk: fewer sources of ignition.
Mike R.

 

[chrisb33]

hi mike,

yeah, it could have been so much simpler for me if i could mount that tank in the trunk. but as i said, there are two reasons from stopping me from doing so:

1. my tubes wont reach that far
2. i dont want to mess up the clean sound system install inside the trunk.

although im not closed to the idea of transferring both the pump and the tank in the trunk, id rather exhaust all efforts first in doing making the current set-up work before relocation.

having said that, having a VR4 hood vents mounted on the hood, is it possible for the vapors find its way going out of those vents during idle?

would mixing water like say 70/30 meth/water combination help safeguard me from a potential fire hazard?

 

Hood vents would help a lot. If underhood temps are higher than ambient, when the car is stationary the hot air will be buoyant and will seek to escape through the highest vents taking methanol vapors with it. Also, I expect that mixing water with the methanol would lower its volatility, vapor pressure, and flammability while raising the boiling point, probably in proportion to the dilution. But I don't have any data on hand. You can probably Google physical properties of methanol and find a lot of info on line.
Mike R.

 

[turbowop]

Diluting the methanol may lower any dangers of combustion under the hood, but it also won't make as much power or allow you to run as much boost as if it were 100% meth.

I would run a vent out the top and run a hose down underneath the car somewhere.

FWIW, I have a small vent in the top of my foam filled 3gallon cell, which a has a plastic cap loosely screwed onto it, but mine is in the trunk. I've never had any issues like this.

 

You probably don't have sources of combustion such as 1600 F exhaust or high energy ignition in the trunk either.
Mike R.

 

[turbowop]

That's part of what I was implying with my post. /ubbthreads/images/graemlins/wink.gif

 

capisco!

 

[chrisb33]

i think i have solved the problem. I took out the breather tube and plugged that hole in the tank then placed a pinhole on top of the tank. I pulled a hard run earlier boosted around 1 bar for about 8-10 mins and when i got home, i saw no signs of leakage from the pinhole. i guess that if there were any seepage, they turned into vapors.

however, when i took out the tank earlier, i discovered that the tank was sitting on top of an A/C tube that goes into the firewall which was heating up the tank and the meth inside. I raised the tank about an inch or so to have a good clearance and holy crap! after my run earlier, i touched the tank and it wasnt hot at all (unlike the previous set up where i can feel it hot but not enough to force me to not touch it). I touched the other two cans beside the tank and they were as hot as before (no surprise there).

so i think the seepage in the initial design wasnt a design flaw, i'm almost sure that the meth vaporizes more quickly than it's supposed to be because of the extra heat generated by the A/C pipe where it was sitting on the whole time! but of course, the breather could still be a potential fire hazard because it traps a lot vapors in there.

anyway, the tank will still be under investigation.

FYI, a lot of DSMers put their tanks inside the engine bay where mine is located. although theirs are plastics. So far ive never heard of horror stories about tank placement inside the engine bay and theirs (eclipse's) have tighter/hotter engine bays and normally with no hood vents at all.

although i agree that the ideal tank and pump placement is back in the trunk, im now more confident that tank and pump placement inside the engine bay isnt THAT bad at all. But of course only time will tell, and im sure to post a horror story (knock on wood) if it does happen so that others may learn too /ubbthreads/images/graemlins/smile.gif

now on to my engine rebuild thread! im still stuck as to what turbo to get!!! argggg!/ubbthreads/images/graemlins/banghead.gif

chris b