Do you have the electronics skills to design a good home made smoke machine?

[Arthur Wood]

All we need to find vacuum leaks in a complex engine is a smoke machine that works. All it needs to do is... a. Emit lots of smoke that won't clog up an engine when it condenses, and, b. Constantly push that smoke at a couple of psi for about a half hour.

We made a smoke machine to work on a friend's kid's old bimmer but the smoke machine we made failed to generate enough smoke. And now I need a smoke machine.

It seems so simple, and yes, we've seen the "cigar in a can" and "burning rags in a can" videos but they all have problems of not generating enough smoke for a long enough period of time.

Our machine generates smoke for a long time but not enough smoke! :(

It's 3 holes in a new paint can with glycerin in a soup can inside.

The top has a 12VDC diesel glow plug which gets red hot. It is stuck into the glycerin in a soup can. That generates the smoke.

We push that smoke out regulated at about 3 psi with an air gun mounted on the side.

There's just not enough smoke.

Do you know what fluid would generate more non-sticky smoke? Or do you know of a hundred dollar smoke machine that can do the two thing? a. Emit lots of smoke that won't clog up an engine when it condenses, and, b. Constantly push that smoke at a couple of psi for about a half hour.

[Phil Hobbs]

Cheers

Phil Hobbs

[trader_4]

That's what I was telling him about in the other thread here, that I've heard people have used one of those disco smoke gizmos. Seems you should be able to rig up something to pipe it in. Plus, with a boom box and some songs, you can have a business at parties and weddings as a DJ.

[Arthur Wood]

I thank you for coming to my aid, and I apologize for not having "believed" in your previous suggestion. (See below why.)

For some reason, I had thought that the "party foggers" had a big opening at low pressure (like the size you can put your hand through) but this one in the Amazon picture seems to have a one-inch opening with a tiny 1/4-inch nozzle.

Is that right?

If so, I don't see why it's not perfect for the task - if it generates the smoke at enough of a pressure to get us a couple of psi for a long period of time. It has to be in the goldilocks range of a few psi (maybe 2 to 4 psi?).

The output is 2000 CFM, which seems like a lot. Is there a way to *convert* that to PSI?

The "wired control" might even be useful for one-man operation while debugging a vaccum leak on an engine.

The machine holds 0.5 liters (1/8 gallon) where a gallon of the fog juice (propylene glycol perhaps?) is $20 which means the machine, over time, is cheaper than the fluid used to make the smoke!

So I do agree, for forty something bucks, it's about the same cost as what it cost me to make that tin-can smoke machine that didn't work.

Any idea how to calculate the PSI out from the 2000CFM spec?

[Tekkie®]

Arthur Wood posted for all of us...

From reading replies you don't any research on anything before posting, then you argue and ask more questions. Are you a previous poster under another name?

[rickman]

How did you come up with that number?

Not really. Most likely they are using a fan designed to move air against very little pressure, like the "muffin" fans in a PC. They will move a decent volume of air at very low pressure, but the air flow falls off very quickly as the pressure increases. The only way to know for sure is to get the spec sheet of the fan.

Here is a spec sheet of a typical DC cooling fan.

Notice the flow goes to zero at pressures around 0.1 inches of H2O. Your 2 psi would be 55 inches of H2O.

Maybe they are using a different type of fan, but I don't think you are going to get 2 psi from one of these machines. Maybe you could rig your compressor to it to boost the pressure.

The same cost for something that also isn't likely to work without modification.

See above...

[etpm]

You can calculate the PSI if you know the viscosity of the fluid and the size of the orifice the fluid has to pass through. So you will need to guess at the size of the orifice on the party smoke machine and then look online for about 5 minutes to find a page that will let you just plug the numbers in. I am pretty sure that searching for a "conversions" web site will provide you with a solution. Why do you need 2 to 4 PSI? Eric

[trader_4]

IDK, I'm not the manufacturer.

You'd think that when it's going into a limited space, ie your car, that the PSI would rise. It doesn't have to rise much.

There is no way, without knowing about the design and specs of the blower. I think if you google you'll find car folks that have done similar. And if you buy it for $30 and it doesn't work, you can become a DJ. Or sell it on Ebay and get most of your money back.

Me, I'd fix the known issues and not worry about whether there are other vac leaks or not, until later, if it is still throwing lean codes.

[micky]

Why are you concerned with PSI. AIUI, you only need enough pressure to get the smoke out of the machine, or out of the hose**. Plainly it has that much pressure, or the machine wouldn't function for its original purpose.

After that the smoke just has to float around near the vacuum leak and the vacuum will suck it into the engine.

If anything too much pressure would make the smoke zoom by the leak without stopping. LOL Well, not unless it was r eally fast, you'd still probably see some of it get waylaid and sucked into the engine

**Or are you saying it needs enough pressure to get through the hose? The pictures don't show it being used with a hose, but if it doesn't have enough pressure to get it through the hose, then skip the hose and just blow from the machine to the engine. You can put the machine on a chair or stepladder if need be. You can hold it closer to the engine if need be.

The pictures show the smoke going out 3 feet or more. That seems like enough pressure to me, and a bigger problem is likely that there is too much smoke. Is that why you want to use a hose? If there's too much, cut a hole in a big piece of paper near the engine so that only so much can get through the hole. It's not like you have to do this for 50,000 miles, only long enough to find the vacuum leak.

No.

Typically, fog is created by vaporizing proprietary water and glycol-based or glycerin-based fluids or through the atomization of mineral oil. This fluid (often referred to colloquially as fog juice) vaporizes or atomizes inside the fog machine.

[TimR]

I have one that looks just like that.

We bought it for Halloween.

We tested it inside, it filled the entire basement with smoke. We were afraid the neighbors would call the fire department. Lucky we didn't have alarms there.

It has a heater, a fan, and a bottle of glycol. Pretty simple.

[trader_4]

You do need enough pressure to force it through wherever you inject it in the car through the whole vacuum system. I don't think you need a lot of pressure, but it's still different than just dumping smoke out an opening onto a floor.

That isn't how it works. You're pumping it into the vacuum system of the car and looking for where it comes out. But the other alternative is an interesting possibility too.

[trader_4]

Keep talking like that and I may buy one.

[trader_4]

Funny, I was wondering the same thing. Does the name start with a D?

[Clare Snyder]

Not really possible to be really accurate. You could determine how much poressure is required by calculating the velocity of the fog escaping from the nozzle size and roughly approxemate the pressure utilized to force that flow, but that won't tell you the pressure capability of the system. (it might put out 2000 cfm of smoke at

1/2PSI, and be capable of pumping 1000cfm at 2.5psi, for example.

[Clare Snyder]

They don't use a fan. They use a liquid pump to squirt the fluid through the heater, which vapourizes , producing steam pressure. No fan. I have onem and I've had it apart. The poressure is reasonable, but I'd say less than 5 psi. Commercial smokemachiners run somewhere around 1 - 2 PSI maximum.

The only olproblem I see is getting the HOT smoke (really more like steam) into the fuel system you are testing. It will melt a plastic hose attached to the output - so you need an adapter that acts as a cooler as well - which WILL reduce the pressure somewhat.

\

ou are

[Clare Snyder]

Again, you have NO IDEA what you are talking about, Micky. The smoke is pumped INTO the system, with the engine not running - under a low pressure to force it OUT through the leak.

Gettin in deeper, Micky

[Clare Snyder]

A fluid pump - no fan. Look again. The heater heats up to the required pressure, turning on the "ready" light. Pressing the switch turns onthe pump, forcing the fluid through a heated nozzle, creating smoke which billows out under it's own pressure. No air is added.No fan is used. At least not in the one's I've had apart and the one I own. (a pretty standard unit)

[Clare Snyder]

You thinking the same guy that argued about tire mounting and ballancing???

My thought too. Mabee his twin brother from a different mother???

[trader_4]

Hard to imagine that these things inject hot steam level smoke that can melt car components onto a dance floor. Just sayin........

[trader_4]

Uh oh, Micky, I don't think Clare likes you.....

Watch out, he'll have you in his blocked bucket next.