Topic: Air filter, type sandwich

[70CB750]

Very simple replacement of those pods the bike came with.

The side plates are 1/4" - aluminum, the filter is 6 bucks Purolator from PepBoys. 

Pipe nipples I turned from the stem of an old sunbrella, they stick into the filter 2mm to position the paper element.  I turned them to be a press fit, but peened the plate around them on the inside to make sure they stay there.

The rubber connectors are pieces of an old radiator hose - I want to replace them with something better looking eventually, maybe urethan and thinner walled too, but it works like this.

Two bolts hold it together sandwiching the paper element - hence the name - I should have used metric, but didn't have any on hand.

[70CB750]

Assembled and installed.

[Scott S]

 Now THAT'S ingenuity!

[Rigid]

A couple spacers inside, on the bolt shanks, would provide the proper tightness on the filter for sealing but not crush it.  I like the look.  I am amazed no one has written you a lengthy prose on how that won't work at all and your engine will seize? Citing issues like; no velocity stacks inside your filter to "distribute the pressure drop evenly and to smooth the incoming air" :-)

[ekpent]

A couple spacers inside, on the bolt shanks, would provide the proper tightness on the filter for sealing but not crush it.  I like the look.  I am amazed no one has written you a lengthy prose on how that won't work at all and your engine will seize? Citing issues like; no velocity stacks inside your filter to "distribute the pressure drop evenly and to smooth the incoming air" :-)

Its early Rig,those comments may still come. Better get my Jiffy Pop next to the microwave just to be ready.     

[Dimitri13]

Looks nice and all...

But.
But.. But...

THE TURBULENCE!

[johnrdupree]

I thought about doing something similar on my 550 but with there just isn't enough room, the down tubes get in the way.

My idea was similar to yours but used 4 of the stock, center intake trumpets (they're straight, the outer two are angled) and .060 aluminum with a rolled edge to match the outline of the filter.  It would have basically been a homemade version of a Henry Abe airbox with a modern filter.  Maybe I should go buy a 750 so I can try it out.

I second the need for spacers on the rods to keep from crushing the filter.  And all that 1/4" aluminum has got to be heavy.  Do you have the assembly supported in some way or is it all just hanging off the carbs?

~john

[70CB750]

The spacers are not necessary, the filter element is harder to crush than it seems. As far as the weight and support, I measured the distance filter to frame and keep an eye on it. So far it  holds without a change.

As far as  the Turbulance and air velocity   - it uses same jets as pods, I expected rejetting to be necessary, but the power and seat of the pants evaluation is excellent so far.

[Duke McDukiedook]

A couple spacers inside, on the bolt shanks, would provide the proper tightness on the filter for sealing but not crush it.  I like the look.  I am amazed no one has written you a lengthy prose on how that won't work at all and your engine will seize? Citing issues like; no velocity stacks inside your filter to "distribute the pressure drop evenly and to smooth the incoming air" :-)

no velocity stacks inside your filter to "distribute the pressure drop evenly and to smooth the incoming air.

Uh huh, yeah. That. ^

[Rgconner]

A couple spacers inside, on the bolt shanks, would provide the proper tightness on the filter for sealing but not crush it.  I like the look.  I am amazed no one has written you a lengthy prose on how that won't work at all and your engine will seize? Citing issues like; no velocity stacks inside your filter to "distribute the pressure drop evenly and to smooth the incoming air" :-)

no velocity stacks inside your filter to "distribute the pressure drop evenly and to smooth the incoming air.

Uh huh, yeah. That. ^

I recommend Menthols... smooooth. 

[Terry in Australia]

That looks good mate, well done! This same situation came up a couple of years ago, someone posted a pic of a filter very similar to yours that they'd made, and that was the inspiration for Tintops "anti-pod". How does the paper filter stand up to rain? Cheers, Terry.

[72500john]

instead of aluminum make the parts from unobtianium..will be way cooler!
seriously..nice job!!

[70CB750]

Thanks, guys. Technically I could make nipples to connect to carburetors directly, but hole saw and drill press has its precision limits.

In the rain - hmm - never rode it in heavy rain. I think/hope it will do ok.

[wedoo2]

I like reading these air box replacement threads.  One of these days I will come across one that will help me get rid of that stupid %@#$ thing on my 550.  The damn things just needs to be about 3 inches shorter.

[Mantree]

Just a thought what about covers over the sides so It is not pulling water in the rain.  I have pods and the only time they give me troble is in the rain when the 2 outer filters get wet but I supose you would still get good dry air from the potlrtion under the tank

Sent from my SM-G900V using Tapatalk

[seanbarney41]

I have gotten good and wet with an old school Henry Abe breadbox with un-oiled UNI foam filter material.  It resulted in no major running issues, just some minor spittin' and sputterin'.

[Stev-o]

So, whatever happened to the sandwich, Prokop?

[Terry in Australia]

When I had my first K1 I didn't know how wonderful the OEM airbox is, but I still blamed my old round K&N pods every time my bike sputtered in heavy rain, until one night I saw my wet plug leads arcing against my frame. Ooops..........

[enwri]

A couple spacers inside, on the bolt shanks, would provide the proper tightness on the filter for sealing but not crush it.  I like the look.  I am amazed no one has written you a lengthy prose on how that won't work at all and your engine will seize? Citing issues like; no velocity stacks inside your filter to "distribute the pressure drop evenly and to smooth the incoming air" :-)

Its early Rig,those comments may still come. Better get my Jiffy Pop next to the microwave just to be ready.     

Alright, I'll do it. That actually looks pretty good, tubes have almost the length of the stacks, just missing the bellmouths on the filter side of the plates. The bellmouth does flow much less "turbulently" than a sharp 90 degree edge.

[70CB750]

Stev-o:  sandwich is boxed away with Dorothy.  I will probably put it back after I rebuild her.

I may even adapt the sandwich plate to use stock rubber boots.

As far as riding in the rain.  Bringing PZ from Barber I was on US40 and US81 for hours, most of it in rain and Dorothy started to die above 4000 rpms.  It felt like she had no power in higher rpms.  When I finally decided it was the air filter, I poked holes in it with a knife and the problem went away.

But that was really extreme, with heavy traffic around me the air was full of water.

[evanphi]

I may even adapt the sandwich plate to use stock rubber boots.

Probably best idea since you get the benefit of the stacks, but nice high airflow. Or even some machined stacks (but price goes u^uuuuuuuup).

At least we know that this is possible!