Smoke machine

[JohnH]

Here's one I made from an American DJ MiniFog. The regulator keeps the fog pressure down to 5-10psi. It worked pretty well but I was a bit concerned about the amount of moisture that it left in the inlet and therefore cylinders.

Do you reckon it would be ok to use baby oil to create actual smoke?

 

[normspanners]

that looks the business !! how did you couple the pipe to the smoke outlet ?
and yes baby oil might work,veg oil too, also maybe mix a little diesel? to thin it

 

[normspanners]

I see you have formed a venturi with the tee piece,The thing I was concerned was that the back pressure from the manifold as it filled it up its volume up to its test pressure, ie regulator pressure it would end up forcing back out of the venturi tee suction inlet (because a venturi only works when there is flow?) and try and force the smoke/ oil back through the heating element to the pump, did you experience this?
PS Of coarse, if you had a leak it would probably maintain some air flow through the venturi but a small leak would reduce the amount of smoke picked up from the generator?
BUT a very lightly sprung non return valve in the venturi smoke line would stop that happening and be self regulating BRILLIANT! you would fill the engine with dense smoke at first till it reached reg press then the check valve would close until the pressure dropped again and then off to go, more smoke!
IDEAS?

 

[JohnH]

that looks the business !! how did you couple the pipe to the smoke outlet ?
and yes baby oil might work,veg oil too, also maybe mix a little diesel? to thin it

The fitting on the MiniFog is M10x1. All other fitting are 1/4bsp (now adopted by iso as G14 and R14(?)). I got an M10x1 Female to 1/4bsp male adaptor from ebay and all the other fitting from my local builders merchant. The bent feed pipe is a piece of 8mm bundy pipe, you could use 8mm copper pipe. The bung on the end of the white pipe which fits into the intake in place of the air flow meter is a 70mm (2.75") cap from a posting tube (this was the hardest part to find!).

Back pressure doesnt seem to be a problem as thge regulator keeps the pressure down to 5-10 psi and the ball valve reduces it even more.

To use it, you need to block the exhaust with a potato or something similar.

Google diy smoke machine and you will find plenty of hits and youtubes.

Because its only water based fog it condenses out quite quickly, which is why I'm interested if the fog heater unit would work ok with oil.

Its a quite well mage bit of kit. All metal for abnout £30 on ebay. Heres a pic of its guts.

 

[normspanners]

Great thanks, M10 x1 is standard brake fitting but as regards blocking exhaust you only need to turn engine till valves are closed,
Mini fog seems the way2go. allready looking!!

 

[dan.taylor.1]

That's just a stage effect smoke machine by the looks of it, an amdram society i work with have a huge one that'll fill the 200 seat hall in 2-3 mins! The proper smoke fluid is an oil, comes in different types depending what you want it to do, where its meant to sit (up high, down low, full dispersal etc) and how thick you want it. Jem make some good stuff, its about 25-30 quid for 5l but a litre will last for about 20-30 hours continuous run time at full chat on our big machine so a lal thing will hardly use any.

Dan

 

[JohnH]

That's just a stage effect smoke machine by the looks of it, an amdram society i work with have a huge one that'll fill the 200 seat hall in 2-3 mins! The proper smoke fluid is an oil, ...
Dan

Jem "Smoke" fluid is a water and glycol based fluid. The machines produce fogs of varying sized particals. After studying this catalog http://www.martin.com/marketing/files/ProductGuide_2013-LOW.pdf its apparant that all of these "smoke" machines come out of the same Chinese factory, and depending upon the user vary in price enormously. In fact the very slighty larger brother to the MiniFog is listed in this cataloigue.

The fog outlet temperatures on these machines is, according to the catalogue, about 200C which seems a bit low to actually allow a hydrocarbon based fluid to actually burn and produce actual smoke. I have seen various sites on the internet where people have built machines using diesel engine glow plugs and pc power supplies to ignite oil. These may be a better approach to produing an automotive smoke testing machine.

I am tempted to to use a hydocarbon based fluid in the MiniFog just to see what happens. What do you think?

 

[normspanners]

You have it set up, so give it a go!!, I am sure it wont damage anything too badly (but thats easy for me to say!) but I dont think it is actually burnt in there I think it just boils the fluid and it is just the vapours we see, in the same way that if oil or diesel drops on ahot exhaust it smokes like a b*****D but doesnt bust into flames.
air display 'smoke' is just coloured diesel I believe.

 

[normspanners]

BTW Hello JohnH I just realised you are new, glad youve lost your MW virginityto ME! big THANKS for posting, hope you enjoy.

 

[AndyStobbs]

How do you go about rotating the engine until the valves are closed. On a multi-cylinder there is always going to be atleast one exhaust open

 

[normspanners]

On the one with the exhaust open the inlet is closed and vise versa with the inlet valve you just have to turn till the engine seals. if the smoke goes into the cyl with the inlet open it just tests the rings. We used to test the evo's rally cars without blocking the exhausts because they are slip joints and dont actually seal.

 

[MattF]

its apparant that all of these "smoke" machines come out of the same Chinese factory

The design of them all, internally, is very similar. Plastic tank, aluminium heater block surrounded by an insulating sleeve, poxy quality metal dog leg bracket holding the block to the frame and aluminium L bracket securing the thermal switch on the block and lastly the pump. That's pretty much it. Feed goes through the thermal trip to the rest of the components.

The fog outlet temperatures on these machines is, according to the catalogue, about 200C which seems a bit low to actually allow a hydrocarbon based fluid to actually burn and produce actual smoke.

If I recall correctly, the thermal switch on the block is rated around 120 degrees Celcius. It's been a few years since I last worked on one though, so I could be mistaken.

I am tempted to to use a hydocarbon based fluid in the MiniFog just to see what happens. What do you think?

It'd likely be preferable to the usual stuff, for the mentioned application, if you can find something suitable. The usual stuff leaves a greasy feeling residue, if I recall correctly.

 

[JohnH]

Just for completeness, it was this topic http://www.garagejournal.com/forum/showthread.php?t=91216 that got me going, and more specifically I copied the modification mentioned by Ahsai on page 7. Some of the later comments added after I last looked at this thread are interesting.

I just used the "Fog Juice" that came with the machine. In practice it works quite well and detected a couple of very small leaks on the throtle body. The remote control makes it very easy to use when you have your head wedged under an inlet manifold. I see that they are still available on ebay uk for £35, so all in all a good way to get started on this project.

 

[normspanners]

Cheers for the link John

 

[normspanners]

Just come back from lookin at a snap on machine it uses 12v for the heat and produces very small amount of smoke but uses by the feel of it, baby oil with a lavender smell !

 

[JohnH]

Just come back from lookin at a snap on machine it uses 12v for the heat and produces very small amount of smoke but uses by the feel of it, baby oil with a lavender smell !

And how much did it cost?

I think we have been overthinking this, http://www.thesmokering.com/forum/viewtopic.php?t=57747&postdays=0&postorder=asc&start=0

Check out the vids on post 6 or 7. I must admit that I did build something similar using a paint tin and burning some hessian sack. Sort of worked ok, but a bit of a faff getting the sack burning.

 

[normspanners]

And how much did it cost?

£700
Yeh I tried the fire method and smoke matches/tabs but it was not very successful but with actually burning something you then have the mess to clear up plus if you use it inside a car or it leaks inside through a vacuum hose etc you have that stink to deal with. On the vids they call it cold smoke but those chips looked quite hot to me!
I think I am still going to buy a smoke machine for wind noise, water leaks etc after thinking about it seems a good diagnostic tool for various job not only engine diag.