| Author |
Message |
    
Djkaplan
| | Posted on Thursday, November 08, 2007 - 05:03 pm: | 
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Here's my budget catch-can, btw. I've posted this many times. Forgive me if anyone is getting tired of looking at it. It's a huge fuel filter with the paper media inside pulled out and a little K&N on top. The yellow thing is a pot scrubber I shoved in to act as an oil mist separator.
Here it is mounted on the frame...
With the bodywork on... fits nicely.
The whole story...
http://www.badweatherbikers.com/cgibin/discus/show.cgi?tpc=3842&post=446814#POST446814 |
Jc000
| | Posted on Saturday, November 10, 2007 - 06:38 pm: |
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Hey Dj, I have been studying yours and others solutions for a while actually. The problem is, I don't really know enough about what I'm doing to understand how to best tackle the problem.
Like, I don't know what an oil mist separator or fuel filter is. I get the concept of simply routing the hoses into a beer can or something, but I am wondering more about these optimized setups you and others are running. |
Djkaplan
| | Posted on Monday, November 12, 2007 - 02:34 pm: |
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All an oil mist separator is supposed to do is give 'spooge' something to cling to so it can settle to the bottom of the catch-can. It's not absolutely necessary, but it helps keep blowby gases from blowing oil mist past the filtered vent.
You can make the can part out of anything that will hold liquid. Beer cans, coffee cans, tomato paste cans, shampoo bottles, softdrink bottles... anything. You don't need a fancy filter to properly vent a catch-can, but it keeps things cleaner. The only reason I used a big automototive fuel filter (with the paper media taken out) is because it was cheap and had the proper size fitting for the breather tubing. It was also easy to install a simple drain made out of vacuum fittings on a plastic fuel filter.
It took me few tries to get something that vented properly without clogging or coating the inside of the tailsection with oil. I almost resorted to actually buying a catch-can at one point, like a normal person would. |
Djkaplan
| | Posted on Monday, November 12, 2007 - 04:10 pm: |
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Here are some pics from the archives... great stuff!
And the ultimate...not cheap and not practical, but you gotta admire the eccentricity!
Check out the archives for more interesting stuff. |
Punkid8888
| | Posted on Tuesday, November 13, 2007 - 08:03 am: |
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I just finished my own version of catch can.
Total cost was 12 bucks I think
3ft of 3/8s hose
2 3/8s Tee fittings
and a 8 dollar mini racer cone filter from the auto parts store.
It actually came out better then I thought. I used a small 8oz bottle that my posi additive came in for my truck as the container, then made a very small bracket to mount in behind the heal gaurd. The filter then sits up against the tail frame rail visible (still not sure if I might try to hide it)
I dont have any pictures yet but will try to get some posted. I also have only put about 30miles on the bike since I did it (really cold out lately) I am wondering how often it will fill up an 8oz container.
Anyone else have any insight into how often they empty their catch can? |
Jc000
| | Posted on Tuesday, November 13, 2007 - 01:59 pm: |
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Hey dj, I like Mikef5000's solution:
http://www.badweatherbikers.com/buell/messages/476 23/291947.html
My question is, if I'm not routing back into the air filter, how would I vent? I'm not sure how or why I am venting.
Forgive my ignorance! Let's say I'm using a prescription bottle. I would connect my two breather hoses and run them into the top (???) of the prescription bottle lid. How would I vent, and where is the optimal place to put a vent?
Is this making any sense? |
Djkaplan
| | Posted on Tuesday, November 13, 2007 - 03:41 pm: |
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"I'm not sure how or why I am venting."
There is a slight pressure in the engines crankcase when you start the bike up. This pressure is caused by blowby from the rings at idle and expansion of the air inside as the engine heats up. The internal volume of the crank continuously changes as the engine runs because the pistons are only separated by 45 degrees on a common crankpin. This means that there is a time when both pistons are rising or falling together, changing the internal volume pretty drastically. This constant cycle of pressure and vacuum in the crank and the whirling cams and gears in the cam case whips up quite an oil mist in the heated air. There is also water that condenses in the oil (from the heating and cooling when starting and stopping the engine) that will heat up and evaporate out of the oil. A certain amout of the oil mist and water will emulsify into a white, pasty mixture we call 'spooge'. This moisture and spooge needs to be evacuated from the crankcase volume. What the catch-can catches is water vapor and spooge (or if the bike is stock, it's sucked back into the carb or FI to be burned off in the combustion process). If you check your breather lines with the bike idling, you can feel air under pressure being blown out. This pressure stops as you rev the engine because the increased combustion pressure actually helps seal the rings better against the cylinder walls (unless the engine is really worn, then you get pressure all the time).
The catch-can catches the spooge and water but it must also let air pressure out. The easiest way to do this is to vent the top of what ever you feed the breather tubes to. You can see how some people just stuck a tube loosely in a can so the spooge settles to the bottom and the pressure is let out at the top. The problem with this is the air that's vented still carries a bit of oil mist in it and it'll oil up whatever it hits. There are two ways to help this - put somthing for the spooge and oil mist to collect on like stainless steel wool (or a plastic pot scrubber) and seal a small filter on the catch-can vent. The catch-can vent filter actually filters stuff from the inside out, not the outside in like an air filter for the engine.
There are a few stratagies that will help with any catch-can. Keep the breather lines running downhill all the way to the catch-can. Gravity is free and it's always there to help, so no sense fighting it. It also helps to keep the lines as short as possible. Spooge collects on the inside of the tubing, and when it gets cold, it will really clog the lines up. If the line are short and stay near the engine, heat will help keep the spooge from congealing and make it easier for the slight pressure to push it into the catch-can.
Don't connect the engine breather lines to the transmission vent line and run them to the same catch-can. Pressure from the breather lines will force water and spooge into the much lower transmission vent fitting near the starter - not a good idea.
Whew... |
Djkaplan
| | Posted on Tuesday, November 13, 2007 - 03:49 pm: |
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"Hey dj, I like Mikef5000's solution..."
A neat set-up, but if you try that location on the frame, make sure your knee will have enough room. If you externally vent it in that location instead of running the vent lines back to the intake like Mike did, place the filter on tube in a remote location so what ever oil mist does make it past the filter won't get on your right knee. |
Djkaplan
| | Posted on Tuesday, November 13, 2007 - 04:09 pm: |
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Here is graphic evidence of 'spooge'.
http://www.youtube.com/watch?v=-4z8MohZD10 |
Jc000
| | Posted on Wednesday, November 14, 2007 - 08:51 am: |
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Good stuff, dj I have a much better handle on this now. Thanks! |
Gentleman_jon
| | Posted on Sunday, November 02, 2008 - 06:20 am: |
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nice post,Danny.
 |
Buford
| | Posted on Tuesday, January 06, 2009 - 12:16 pm: |
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Why is a can needed at all? Here is my simple tube which exits right at the muffler exhaust outlet:
http://www.youtube.com/watch?v=zK7ZNstTnys |
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