CB360 Airbox design

Bucky685

Been Around the Block
I am working on a design for a Airbox on a '74 CB360.
It will bolt into the stock tool box mounting tabs.
It will have brass screen--> uni-filter pre-filter-->a cut up 6" wide K&N pleated filter.(or build a filter from bulk uni-filter foam)

The end caps will be drilled to allow air entry.
From the air box, I will use 2" either silicone/rubber hose to lead upto the Carbs.

Will doing this, solve allot of the tuning problem with pod filters?

Opinions good/bad/indifferent?
 

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While this could work....Im more interested in why? Why reinvent the wheel...use the stock airbox?
 
Green199 said:
While this could work....Im more interested in why? Why reinvent the wheel...use the stock airbox?

I cannot use the stock airbox, with my current frame modifications. Plus this looks better, and I like to design stuff.
Here is to show the "airbox" mocked up as an electrical box.

I was originally going to use it for an electrical box.
 

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I think the intake area is going to be too small, that and you've got a whole lot of different size holes, perfect for whistling at all rpm's :)

I'd redesign it with one big hole in each side, that and if the cylinder filter is the same od as the housing id, effectively you've severely restricted your carb filter area, if you look at pod filters, they've probably got 15-18 square inches of area per carb, in your design it looks like it would be maybe 3-5

maybe turn flanges on the inside of the side panels, and clamp pod filters to the inside of them, make sure the pods are smaller than the inside of the housing, and that should do the trick.
 
That is a bloody great idea. Patent that shit man.

The only concern I have is having too much filtration because of the foam and paper filters, as effective as it may be you don't want to starve the bike for air.
 
Thanks for the input. I'll have to a bit more design work.
I think a filter on just the ends would be better. Then I would have a plenum for the carbs to draw from. This would be more along the lines of a stock air box.


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Why not make the airbox triangular, drawing air from either the top or bottom through a flat filter such as this? http://www.kandn.com/images/l/33-2293.jpg

Then not only does it fit into your frame in a more aesthetically pleasing way (IMO), but there is plenty of surface area, and a nice amount of still air in the airbox for your carbs to suck directly in. This design would make the downward curve or your intake boots unecessary as well.

I'll try to show you what I'm talking about. Give me a moment

EDIT: Obviously, this design would have to be played with and the placement of the electric box could be changed. The red line is filter element... I love your idea and design, but aesthetically I think something like this would look better. Imagine an airbox that just looks like chassis bracing under your seat or something. The frame could even be a sort of endoskeleton for the structure of the airbox.
3e2unaba.jpg
 
Im intrigued. I get tired of the pods no pods debate and have toyed with the idea of an attractive alternative to the stock airbox

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I used soildworks 2012 to model it.
I'm curious to see if my design works as well as I hope!! Shall see shortly!


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Bucky685 said:
I used soildworks 2012 to model it.
I'm curious to see if my design works as well as I hope!! Shall see shortly!


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Definitely interested. Keep us posted
 
I'm interested to see this. Would like to ditch my stock airbox for something that performs as well and is a bit more pretty to look at. I like the curves and shapes of your design. It is sexy looking.
 
PatmanBBE said:
Perhaps you could cap each end with something like this:

HD-0818.jpg
Got a part number for that air filter??
Might have an idea to use that.


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If you look at most stock air boxes they have rubber "velocity stack" shaped I takes. I think you need to incorporate that or else the air flow could be pretty turbulent.
 
gijoe13844 said:
If you look at most stock air boxes they have rubber "velocity stack" shaped I takes. I think you need to incorporate that or else the air flow could be pretty turbulent.
I am planning on adding a velocity stack on the discharge of the air box. The stack will stick into the airbox.


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Bucky685 said:
I am planning on adding a velocity stack on the discharge of the air box. The stack will stick into the airbox.


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Stacks should really be as close to the intake of the carb as possible....there is an equation to determine intake length to catch the correct resonant cycle. Air box design is actually a lot more complicated than it looks. Will it work? Sure...but getting it to work as good as stock is the part you need to do the math on.

Unfortunately it's not as easy as just adding tubes and assuming the motor will pull in air.

I encourage and applaud the effort, just do the due diligence
 
gijoe13844 said:
Stacks should really be as close to the intake of the carb as possible....there is an equation to determine intake length to catch the correct resonant cycle. Air box design is actually a lot more complicated than it looks. Will it work? Sure...but getting it to work as good as stock is the part you need to do the math on.

Unfortunately it's not as easy as just adding tubes and assuming the motor will pull in air.

I encourage and applaud the effort, just do the due diligence

From my understanding changing runner length will effect the hp/torque curve. My runners will prob. be about 3-4" longer than stock.

Images show another idea I have for the air box. I feel this would allow the motor to breath much better, than my previous design. While still allowing for the air to "settle" in the plenum before being sucked up into the carbs.
My elbows will be 45 degree eblows vs 90 degree elbows. This would allow less pressure drop over the 90 degree elbow vs 45 degree elbow.
 

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