Author Topic: Smoke Machine for Finding Air Leaks  (Read 3511 times)

Jordan

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Smoke Machine for Finding Air Leaks
« on: June 16, 2018, 16:30:20 »
Did a search but found nothing. 

Has anyone used a smoke machine for diagnosing and finding air leaks? I have a ticking that you can barely hear which changes frequency based on how fast the engine is turning.  Dan figures it is a leak in the exhaust manifold somewhere based on what he hears and its changing frequency.  I would like to identify exactly where the leak is occurring (exhaust manifold gasket maybe) before I start pulling things apart.  Has anyone used these smoke machines to locate air leaks?  There is a perfect spot on the back of the exhaust manifold in which to plug it in but don't know how useful these machines are at locating leaks. Thanks.
Marcus
66 230SL  Euro 4 speed

stickandrudderman

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Re: Smoke Machine for Finding Air Leaks
« Reply #1 on: June 16, 2018, 17:01:16 »
They are a fantastic diagnostic tool and I use mine a lot.
You won’t want to plug it into the location you describe, rather plug it into the exit of the exhaust. This way you check the entire system for integrity. However, it’s also quite simple to get an assistant to place a gloved hand over the exhaust exit with the engine running and you’ll soon hear any leaks.
The smoke machine works brilliantly on intake systems and vacuum systems too.

mrfatboy

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Re: Smoke Machine for Finding Air Leaks
« Reply #2 on: June 16, 2018, 17:05:27 »
I built a smoke machine to find a inake leak.  It worked really well. Less than $20 in parts at Home Depot 👍
1969 280sl (Aug 1968 build)
Signal Red
4 Speed

Jordan

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Re: Smoke Machine for Finding Air Leaks
« Reply #3 on: June 18, 2018, 17:06:31 »
They are a fantastic diagnostic tool and I use mine a lot.
You won’t want to plug it into the location you describe, rather plug it into the exit of the exhaust. This way you check the entire system for integrity. However, it’s also quite simple to get an assistant to place a gloved hand over the exhaust exit with the engine running and you’ll soon hear any leaks.
The smoke machine works brilliantly on intake systems and vacuum systems too.

Stick, I am not sure where you mean when you say the exit of the exhaust?
Marcus
66 230SL  Euro 4 speed

Benz Dr.

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Re: Smoke Machine for Finding Air Leaks
« Reply #4 on: June 18, 2018, 17:09:49 »
I built a smoke machine to find a inake leak.  It worked really well. Less than $20 in parts at Home Depot 👍

Don't hold us in suspense. How did you do it?
1966 230SL 5 speed, LSD, header pipes, 300SE distributor, ported, polished and balanced, AKA  ''The Red Rocket ''
Dan Caron's SL Barn

1970  3.5 Coupe
1961  190SL
1985   300CD  Turbo Coupe
1981  300SD
2013  GMC  Sierra
1965  230SL
1967 250SL
1970 280SL
1988 560SEC

Kevkeller

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Re: Smoke Machine for Finding Air Leaks
« Reply #5 on: June 18, 2018, 17:52:03 »
Stick, I am not sure where you mean when you say the exit of the exhaust?

I think he means the tail pipe. 
1970 280 SL

mrfatboy

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Re: Smoke Machine for Finding Air Leaks
« Reply #6 on: June 18, 2018, 19:30:02 »
@BenzDr
I was just waiting for somebody to care enough to ask  ;) ;D

Parts Needed (Hardware store, Home Depot, Harbor Freight)

1 - 1 gallon paint can
1 - 1/4 hose adapter
1 - 10 ft tubing (or what ever)
1 - Male air compressor fitting
4 - Grommets
1 - pack of incense (Dollar Store)
1 - Aluminum foil
1 - Makeshift stand (wood, metal, whatever is lying around)
1 - Baby oil

Battery powered upgrade extra parts needed.

1 - pack of Kanthal wire
1 - Tiki torch wick
2 - Bolts
4 - Nuts
2 - Grommets
2 - Battery connectors
2 - Connecting wires


So far I only built the "incense" version.  It did the job so I never got around to building the "battery" version. 

Warning! The "incense" version has an ignition source in the can. Be very careful !!!!!!!!!!!!!

I used 10 feet of tubing so the paint can was outside the garage.



Build Directions.

- Drill holes in can and can lid
- Screw in air compressor and hose fittings using grommets to seal
- Connect air compressor to lower fitting
- Connect tubing to lid fitting
- Connect other end of tubing to fitting of your choice on engine.  For my purpose I removed brake booster hose from intake manifold and attached there.
- Used ~10 pieces of incense (6" length). Wrap in foil around weight to make stand. Use whatever you might have around.

Use Directions

- With your incense stand out of the can, light the bundle, put some drops of baby oil of the incense to add even more smoke.

- Place incense stand in can
- Seal/close lid
- Turn on air compressor about 3-5 PSI (you will have to adjust to find your happy spot.
- Wait for smoke to come out of tubing
- Connect to car
- Look for leaks


The last picture is using the same paint can with some modification.  The idea is that the power source (car battery) heats up the Kanthal wire around the tiki wick that is soaked in baby oil.  You will need to adjust the number of coils to get it correct. Try 9 - 12 coils first.  Less coils will make the wire hotter and burn up your wick. Too many coils will not get hot enough to make smoke.



1969 280sl (Aug 1968 build)
Signal Red
4 Speed

kampala

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Re: Smoke Machine for Finding Air Leaks
« Reply #7 on: June 25, 2018, 10:04:28 »
Mrfatboy - nicely done.   


I used a Cigar.  Blowing into Booster pipe.   Gave me an excuse to smoke one.  :D 

Surprisingly actually worked - found a slight leak at the WRD that I could not feel nor hear.   I bet Mrfatboy's gadget might have found more leaks - nice set-up. 

Saw the cigar trick on youtube - where else.

250sl - later - manual
280sl - 1971 - Auto - LSD

Pawel66

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Re: Smoke Machine for Finding Air Leaks
« Reply #8 on: June 25, 2018, 12:41:08 »
I am very interested in this!

1. Where is the best place in Pagoda to blow the cigar smoke into? Booster pipe - towards the intake manifold?

2. What do you drink while doing that - any particular recommendation to amplify the effects?

3. Do you engage friends to help?

4. Does it work better in the presence of ladies?

But seriously - I am really after the answer to question 1.
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class

mrfatboy

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Re: Smoke Machine for Finding Air Leaks
« Reply #9 on: June 25, 2018, 12:47:51 »
I just slipped off the brake booster hose on the intake manifold and connected there.  Very easy.

There is also a bolt right next to the brake booster hose fitting on the intake manifold that I guess you could remove and connect your own fitting.


If you like the smell of cigars over incense I guess just place the cigar in the can.  Maybe add a little brandy for flavor😜😜😜
« Last Edit: June 25, 2018, 15:50:48 by mrfatboy »
1969 280sl (Aug 1968 build)
Signal Red
4 Speed

Pawel66

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Re: Smoke Machine for Finding Air Leaks
« Reply #10 on: June 25, 2018, 15:29:15 »
Thank you, will experiment!  ;)
Pawel

280SL 1970 automatic 180G Silver
W128 220SE
W121 190SL
G-class