# CB desert sled

Discussion in 'Some Assembly Required' started by Luke, Sep 6, 2012.

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TOO much air is just as bad. Try running a bike without an air cleaner, they blubber and bog just run like crap.
Usually even running those stupid little UNI filter socks makes them run terrible and requires re-jetting that often is never right.

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If the outlets are 1" and the inlet is 2" as he stated, then the area of the openings are exactly the same...

1" outlet = 0.5" radius, squared= 0.25 x 3.1415 {Pi rounded off} = 0.785375
2" inlet = 1" radius, squared= 1 x 3.1415 = 0.785375......

He might well be just fine....there is however the length of the tubing on the in and out lets...that could disturb air flow some...play with it.

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I think your calculator is broken... 1 x 3.1415 = 3.1415!
4. ### RedRaptor22Been here awhile

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Volume, shape and baffling has a lot to do with airbox efficiency too, nowadays most bikes have airboxes tuned so that between after one intake pulse the air is still moving into the airbox at faster than normal speed so that it crams into the next intake port to fire vs just getting sucked in by vacuum alone....but that would involve lots of computer simulation and dyno time to achieve.

I think whats going on here is going to work fine, like others said, you don't want too big of an opening or you will lose serious amounts of mostly bottom and mid range power that tuning will not fix.
5. ### DRjoeLong timer

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Yep a 1" hole has the same area as 2" hole

I think the pain killers are getting to you.

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I forgot to add the divide by...dohhhh

If you take the 3.1415 and divide by 4 you get the 0.785375
OR if you take the four 1" outlets at 0.785375 and times them by 4 the you get 3.1415....so my point being 4 outlets at 1" diameter is the exact same size as one inlet of 2"....

I deserved the jabs...

I do still agree that the flow based on TUNED flow could be the issue...but it is not a bad place to start.
7. ### Mr. FishermanPROUD 2B Riff Raff!

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Good discussion.... Just wanted to make sure the beast can breath at WOT... Though knowing Luke, it has been thought through thoroughly...

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And besides, this being an ADV build, the only equation relevant here is: N = C + {fb(cm) . fb(tc)} + fb (Ts) + fc . ta
9. ### Mr. FishermanPROUD 2B Riff Raff!

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Nothing is going to go wrong Luke is going to nail this. I just wish I could be there when he crosses the finish line. I'll just have to settle for watching his SPOT during the race and seeing the pictures (Allan, that's you ) after it's over.
11. ### LC GarageOn Any Sunday

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E=mc2

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f = ma
13. ### LC GarageOn Any Sunday

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This equation reminds me of flat tracking the old SL350, which unlike my Bultaco 350 Astro that was quick, twitchy and reacted instantly to input, riding the SL350 at speed required thought and planning. It was similar to snow skiing, you were very aware of your mass and momentum and somehow trying to gently direct that mass without scrubbing off too much speed. Kind of like doing ballet with an anvil.

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Quoted for posterity.
15. ### Rich667Been here awhile

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Nice work! thats alot of dedication working out in the cold.
16. ### drc42Rally Dreamer

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I have one of those, works very well. I used it to bend up 3/16" aluminum for my DRZ rally bike last year.

short video of me using it

odd... can't seem to get the video to embed.....
17. ### ducnutLong timer

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Some good ideas, there, as I've been looking at buying the HF 20T press. I don't need anything HD, just something to press balljoints, bushings, bearings, etc.
18. ### LukeGPoET&P

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I made a little more progress, recently. Unfortunately I had hoped to get the bike barely running this month but I'm not quite going to make it. It may only be a week or two late, so it's not too bad.

The carbs needed some screwing around. The air intake for the enrichener/choke draws from outside the carb, so I had to make up some hoses to route these to the airbox. The fuel line in this picture was too stiff, and I ended up switching to thinner vinyl hose. The wood under the carbs is drilled to match the float bowl caps so they rest in place. An essential tool if you're working on these things alone.

Next was closing up the airbox. The TIG torch made short work of it.

Here it is installed on the bike. The filter will be enclosed on the sides but should be accessible from the top.

The frame needed some mounting tabs for the rear subframe. The TIG mostly works well, but I sometimes I still spaz the starts.

With a lot of help from Rick the subframe was mostly finished. A couple of the welds are incomplete and it needs some gusseting, especially at the tails, but all the hard work is done.

Time for more posing.

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So awesome...

It looks like it's seat time!

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