To fog or not to fog (Colonoscopy for your engine)

[tkrfxr]

Tabbed browsing is a bad thing.
It fills your head with ideas, and having just read this post on colonoscopy,
http://forums.iboats.com/showthread.php?t=446174
right after all the stuff that comes up on fogging, I could not help myself....

This is a project for a technical school, perhaps a teaching mechanic, or a high school shop class. The idea is how to answer the question of fogging....

If the cylinders of an engine can be examined and photographed through the spark plug holes with one of these;
http://www.fiberscope.net/servlet/the-Videoscopes/Categories
particularly this one;
http://www.fiberscope.net/servlet/the-175/PORTABLE-FLEXIBLE-USB-VIDEOSCOPE/Detail

Then a study could be designed, where comparison of engine cylinders can be made before and after storage, with and without fogging, and determine if fogging has any impact on rust, engine life, or operating performance....

Perhaps the length of time the engine is stored is important, or the lattitude, climate, etc.

This could even be funded with research grant from a fogging oil manufacturer...

What do you think? Colonoscopy for your engine?

 

[Alpheus]

Re: To fog or not to fog (Colonoscopy for your engine)

I have one of these sitting in my garage.

http://buy1.snapon.com/catalog/item...group_ID=21604&store=snapon-store&dir=catalog

I never fog my engine but I could make a video of my engine when I put it away and then another in the spring for comparison...

 

[tkrfxr]

Re: To fog or not to fog (Colonoscopy for your engine)

I have one of these sitting in my garage.

http://buy1.snapon.com/catalog/item...group_ID=21604&store=snapon-store&dir=catalog

I never fog my engine but I could make a video of my engine when I put it away and then another in the spring for comparison...

I would love to see exactly what you can see if you look through the spark plug port....and what it means....can you see shiny flat machined piston steel? can you see rust if it is there?

if you give a little crank over to an engine that has been stored for 3 or 6 months, would you see rust in the walls of an unfogged, or fogged cylinder?

Just wonder if you can determine if and when fogging is necessary...or which may be the best way of doing it...

Do the manufacturers even know these details?

Would they like this information? or would they pay to get it? and would they freely tell the consumers?

Mercruiser does recommend fogging by saying "Follow this new fogging procedure when laying an engine up for storage."

http://www.boatfix.com/merc/Bullet/01/01_15.pdf

but the procedure is laborious and has consequences...the procedure requires that you run the engine at 1300 rpm. If you are running on a hose, and the boat is out of the water, some engine manuals say not to run at higher than idle speed....you must have really good water flow....

 

[Bluestream]

Re: To fog or not to fog (Colonoscopy for your engine)

If there is a downside to fogging an engine before storage I would like to know what it is?

Metal exposed to moisture will rust, Oil coats the metal and prevents rust. Some people have the idea the the way to store and engine is to turn it off. That's not enough, it needs to be protected against rust and that is done with oil.

The "new" procedure is not that new. Lots of shops used that method 20 years ago to store outboards. At 10:1 you need to run the engine a long time to get enough oil in to do a good job, 5 mins of running might burn one liter of fuel oil mix and there therefore 100cc of oil. Problem is most of that would be burned off in combustion. Its better than nothing though. Also, this leave a 10:1 mix in the fuel system, and that can make for hard starting in the spring..

 

[John_S]

Re: To fog or not to fog (Colonoscopy for your engine)

When I did my heads for a vortec upgrade, leaving the old heads off just overnight produced a fine coating of rust by the AM. The cast iron block makes a good heat sink for water to condense on. It cleaned up fine, and kept it oiled until the new heads were installed. Brake cleaner took the oil off before install. Now, how long it can go before pitting or ring sticking? That's not an expeirement I need to do.

 

[KJSmitty]

Re: To fog or not to fog (Colonoscopy for your engine)

If there is a downside to fogging an engine before storage I would like to know what it is?

Very true.

Whether called snake oil or not I pull my fuel filter and fill with Marvel Mystery oil then run the engine for about 5 until it starts smoking a bit. Then I shut down pull the plugs and fog each cylinder with fogging oil. For me, the oil in the fuel mixture isn't the fogging rather a way of lubing the injectors and upper fuel system - basically a heavy dose/localization of stabilizer.
Come spring I change the fuel filter and stroke her up. It will smoke a few minute yet never once has it been hard to start. Just my technique - and due to it taking just a matter of minutes and absolutely no downside, I just do it.

tkrfxr,
It would be interesting to see if any rust formed. I would think your study would provide the best data if performed in different climates and different intervals of storage etc.. Then again, many other variables could skew factual data. Different oils/packages could far better is just one thought etc.

 

[tkrfxr]

Re: To fog or not to fog (Colonoscopy for your engine)

I have one of these sitting in my garage.

http://buy1.snapon.com/catalog/item...group_ID=21604&store=snapon-store&dir=catalog

I never fog my engine but I could make a video of my engine when I put it away and then another in the spring for comparison...

We will look forward to your video.

 

[Alpheus]

Re: To fog or not to fog (Colonoscopy for your engine)

I will be making it in a week. I will post it here when its done...

 

[Subliminal]

Re: To fog or not to fog (Colonoscopy for your engine)

As nice as it is to get into the cylinders, I'd think the carb, with all its tiny little parts, would reap even more benefit from fogging.

 

[JetBote]

Re: To fog or not to fog (Colonoscopy for your engine)

As nice as it is to get into the cylinders, I'd think the carb, with all its tiny little parts, would reap even more benefit from fogging.

How does it help the carb if you fog through the venturis?

Use a fuel stabilizer in the fuel tank and run the engine long enough to allow the treated fuel to flow through the carb.

When the engine sits during the winter, if possible, go bump the starter once every two weeks. To don't have to start it, but turning the motor over allows the rings to scrape the cylinder walls, and relieves the tension on valve springs that may be sitting compressed for months on end.

 

[Simoniz]

Re: To fog or not to fog (Colonoscopy for your engine)

Well, Ive got 5 litres of TWC 3 Oil from my jetskiing days so I just run my engoine at a fas tidle while pouring about 50cc into the carburettor. When the engine stalls and the whole vicinity is obscured by smoke, I know my engine is dripping with rust resistant oil and Im happy.

 

[JimS123]

Re: To fog or not to fog (Colonoscopy for your engine)

If there is a downside to fogging an engine before storage I would like to know what it is?

Metal exposed to moisture will rust, Oil coats the metal and prevents rust. Some people have the idea the the way to store and engine is to turn it off. That's not enough, it needs to be protected against rust and that is done with oil.

The "new" procedure is not that new. Lots of shops used that method 20 years ago to store outboards. At 10:1 you need to run the engine a long time to get enough oil in to do a good job, 5 mins of running might burn one liter of fuel oil mix and there therefore 100cc of oil. Problem is most of that would be burned off in combustion. Its better than nothing though. Also, this leave a 10:1 mix in the fuel system, and that can make for hard starting in the spring..

I used to help my Grandpa "fog" our motors each Fall back in the 1950's.

I have the original owner's manuals for several of my motors, Evinrudes and Johnsons, dating back to 1953, 1955, 1957 and 1968. I also have an Evinrude owners manual for their Rowboat motors, covering motors they made back to 1909. That particular manual is dated May, 1927.

They all recommend fogging prior to off-season storage, though they don't specifically use the term "fogging". So, to say its not a "new" procedure is an understatement.

 

[45Auto]

Re: To fog or not to fog (Colonoscopy for your engine)

When the engine sits during the winter, if possible, go bump the starter once every two weeks. To don't have to start it, but turning the motor over allows the rings to scrape the cylinder walls, and relieves the tension on valve springs that may be sitting compressed for months on end.

The above advice is about the WORST thing you can do to a stored engine. It's the equivelent of pulling an aircraft engine over by hand during storage without starting it.

From Lycoming Bulletin L180B:

Pulling engines through by hand when the aircraft is not run or flown for a week or so is not recommended. Pulling the engine through by hand prior to start or to minimize rust and corrosion does more harm than good. The cylinder walls, piston, rings, cam and cam follower only receive splash and vapor lubrication. When the prop is pulled through by hand, the rings wipe oil from cylinder walls. The cam load created by the valve train wipes oil off the cam and followers. After two or three times of pulling the engine through by hand without engine starts, the cylinders, cam and followers are left without a proper oil film. Starting engines without proper lubrication can cause scuffing and scoring of parts resulting in excessive wear.

If you're really interested in engine preservation, pay attention to what people do for aircraft engines.

The paragraph below is also from the Lycoming bulletin. If the humidity affects aircraft operated CLOSE to lakes, rivers, etc, what do you think it does to boats that are operated IN those lakes, rivers, etc with water in their exhaust systems??

Our experience has shown that in regions of high humidity, active corrosion can be found on cylinder walls of new engines inoperative for periods as brief as two days. In engines that have accumulated 50 hours or more time in service in a short period, the cylinder walls will have acquired a varnish that tends to protect them from corrosive action; such engines under favorable atmospheric conditions can remain inactive for several weeks without evidence of damage by corrosion.

Aircraft operated close to oceans, lakes, rivers and in humid regions have a greater need for engine preservation than engines operated in arid regions.

From Continental bulletin SIL99-1:

ENGINE PRESERVATION
Corrosive attack can occur in engines that are flown
only occasionally regardless of geographical
location. In coastal areas and areas of high
humidity, corrosive attack can occur in as little as
two days. The best method of reducing the
likelihood of corrosive attack is to fly the aircraft at
least once every week for a minimum of one hour.

You can read the Lycoming bulletin here:

http://www.lycoming.textron.com/support/publications/service-letters/pdfs/SL180B.pdf

The Continental bulletin is here:

http://www.tcmlink.com/pdf2/SIL99-1.pdf

 

[chaparall villain 2]

Re: To fog or not to fog (Colonoscopy for your engine)

well i fog mine every year with napa engine fogging spray .. i work next to a machine shop and i know what happens to cylinders and valves that set unprotected .. there is always intake valves open pn some cylinders and exhaust on others ... sitting allows the air and moisture to do its work over the winter .... i just run mine till its warm then just above idle i squirt the spray back and forth between the two front barrels of carb until it almost dies then to the other side ... once its smoking a little i shoot it full force into both until the engine dies ..... at spring startup she smokes for a minute or so but she always comes to life quick .... cheap enough insurance

 

[CVX20SPRINT]

Re: To fog or not to fog (Colonoscopy for your engine)

It's so cheap and easy to do I don't understand why anyone would take a chance with their expensive toys.Cylinder walls are only part of it,so I don't know how much good video of them will do.Rusted crank and rod bearings(2-strokes) can be a whole lot more expensive.They need protecting just as much or more than the cylinders.Fogging coats everything inside the motor, unlike pouring oil in the spark plug holes and turning it over.
Another good thing about fogging is that once you fog it you can forget about it until you need it again.Even if it is years instead of months.Everything of mine gets fogged before it goes into storage(2 and 4-stroke).

 

[JetBote]

Re: To fog or not to fog (Colonoscopy for your engine)

Lycoming? Please. Not saying my method is best, but it's been working for my mills for years and years.

 

[Alpheus]

Re: To fog or not to fog (Colonoscopy for your engine)

Lycoming? Please. Not saying my method is best, but it's been working for my mills for years and years.

I bet Lycoming has spent more money/time on this issue than all the marine engine manufactures combined...

 

[JetBote]

Re: To fog or not to fog (Colonoscopy for your engine)

I bet Lycoming has spent more money/time on this issue than all the marine engine manufactures combined...

You can't be serious with this statement.
While airplane engine manufacturers have a lot more on their shoulders, as their piece has to keep an object from falling out of the sky, you can't honestly expect lycoming to put more research into fogging than ALL THE OTHER MARINE MFRS COMBINED. Can ANYONE cite where an engine builder had to go more than a standard cylinder overbore on a rebuild, due to not fogging in an off season, proving there wasn't any other cause to amplify the corrosion, ie; water in the cylinder.

 

[haulnazz15]

Re: To fog or not to fog (Colonoscopy for your engine)

Lycomings research costs are probably significantly more because aircraft engines normally operate fewer number of hours than a marine engine. I don't know the repair procedures, but I'm not sure how much boring of cylinders that aircraft mechanics do.

In any case, these are two entirely different styles of engines, so the point may an apples/oranges situation.

 

[Don S]

Re: To fog or not to fog (Colonoscopy for your engine)

Why do MARINE engines always have to be compared against Automotive and Aircraft? They are neither.
Wouldn't it be better to compare your marine engines and/or procedures to other marine engines and keep with apples to apples and not apples to oranges.
Now it's fogging oil, not just engine oil.

As far as using it goes
If you are too lazy to spend 2 minutes to fog your engine, then don't. You are the one that will suffer................... If you are happy without, fine. Who cares.
But there sure are a bunch of engines every spring that crank slow and have rust on the plugs and won't start. Come back in April and May and watch.