help...? Air Filter ideas needed...nothing fits!

[DougXKindCoffee]

I've been considering an air box of sorts that would enclose the roll bar
and the carb or maybe an inlet tube and a remote air filter...suggestions?
[image]https://viewmorepics.myspace.com/index.cf...mageID=64876182

 

[Colin8]

That a pretty tight fit for sure. What about a different intake manifold - perhaps there's something available that's shorter that would give you some room?

It looks like you are trying to use the heater air duct as a cold air supply. What about putting an air filter at the forward end of the duct? That would require the duct to be air tight for proper filtration, but perhaps making the carb box easier to fab?

 

[Silverghost]

Ok...I'm only "blue-skying" here...don't laugh too much...what if you had a small spacer made that would turn the carb 45 degrees towards the front - or maybe 60 or 90 degrees? that would give you a lot more space and options for filters, etc. I don't know how that would affect your performance, throttle linkage etc. Something to think about.......

 

[jhorton3]

Wow, that's a really tight spot to put an air cleaner! You might get away with a thin pancake filter, or something from K&N. You might want to consider putting some kind of padding or wrap on the roll bar right there. Reason being whatever you put in will probably bang up against it causing rattling and scuff marks.

 

[bill_powell]

I've been considering an air box of sorts that would enclose the roll bar
and the carb or maybe an inlet tube and a remote air filter...suggestions?
[image]https://viewmorepics.myspace.com/index.cf...mageID=64876182

An inlet tube is exactly what I would do. As an example:

You could also locate the air filter where it would receive a more 'ram-air' effect. I had this for a while on my Midget:

But went to a standard K&N (since I had the room) when I switched out the CV carb for an HIF6:

You may see that I now have the air inlet tube butting up against the K&N.

Just my thoughts~

 

[Gundy]

The K&N conical filter is pretty small and the conical shape helps with tight spots.
Here's mine on a HIF6 single carb.

 

[dklawson]

I was also going to suggest an elbow and inlet tube.

Bill... what's that "non-SU" carb in the center picture?

Doug, what needle are you running in that HS4? I know this is a bit of a thread hijack, but I've just fitted an HS4 to my Spit's 1300 and I know I need a different needle.

 

[bill_powell]

Bill... what's that "non-SU" carb in the center picture?

The PO installed that. It's a Keihin CV (constant velocity) from a Harley Davidson! It worked okay, but was difficult to tune and was <span style="font-style: italic">BLEEP</span> on a cold day. I kept it in place for a couple of months. Naw.

 

[jvandyke]

Re: help...? Air Filter ideas needed...nothing fi

At one point I had mocked up a cold air intake to go around behind the head, in front of the heaterbox, then join with the heater box duct, then have a K&N coin filter sticking into the hole beside the rad (where the stock line is) That was for a Weber carb and I had the carb "hood" for it. I then decided to go SU (the correct decision I think) and just stuck with stock intake bits.
You're already on the right side of the engine bay with an used duct, why not rig something to the firewall and put a K&N cone on it, draw in cool air through a bigger filter? Kinda like what you were thinking. Is there room for a boot on the carb with an angle on it to get pointed up and over toward the firewall?

 

[DougXKindCoffee]

Re: help...? Air Filter ideas needed...nothing fi

Wow,
Quite a few nice ideas and many thanks for the pictures.

I like the idea of an inlet tube... even if THAT runs to an airbox/filter.

will also check on to check the dimensions of the conical filter.. it might fit.

Keep the ideas coming or pictures.. always happy to copy success

Again... thank you for the ideas

 

[Gundy]

Re: help...? Air Filter ideas needed...nothing fi

Minimania.com lists the conical K&Ns and has sizes listed
for different carb applications.

 

[racingenglishcars]

Re: help...? Air Filter ideas needed...nothing fi

Rigid-foam form covered with fiberglass, in the shape you need. Remove the rigid foam and cut the holes to fit.

 

[DougXKindCoffee]

Re: help...? Air Filter ideas needed...nothing fi

The styrofoam idea sounds like the way to craft a box.
My main aim is for better/adequate filtering and not so musch the cold air.
I just have doubts that the current set up is filtering a whole lot.

 

[nomad]

Re: help...? Air Filter ideas needed...nothing fi

I was in the small scale fiber glass business when a pup and if I remember correctly polyester resin melts styrofoam instantly. If you are going to make up a temp form for one off parts go with foamed urethane. You can shape it easily with a electric carving knife and surform rasp's. Saran wrap makes a decent parting barrier as well. Used to shape minor changes in mold's with modeling clay with poly vinyl alcohol sprayed over the clay. Leave's a coating exactly like saran wrap.
KA.

 

[nomad]

Re: help...? Air Filter ideas needed...nothing fi

I should have qualified that post with the words "rigid foamed urethane". I used to get it from plastic's supplier. I would think that for one off's "home foam" thoroughly cured would work.
KA.

 

[Colin8]

Re: help...? Air Filter ideas needed...nothing fi

White, expanded bead Polystyrene foam (EPS) or styrofoam does dissolve readily with polyester resin. For one-off designs, you can use this foam, but the fiberglassing must be done with epoxy resin, which does not attack the foam. After the part is built, poor gasoline, laquer thinner, acetone or similar solvent into the mold and dissolve away the foam. I've seen many one-off motorcycle gas tanks made this way. It's handy since you don't have to worry about release films or draft angles.

As others said, with polyurethane foam you can use polyester resin since it doesn't attack the foam. You do need release film and draft angles in order to remove the mold without destroying it. This method is best if you want to make more than one since the mold is reusable.

 

[nomad]

Re: help...? Air Filter ideas needed...nothing fi

Good to know Colin. I have'nt been around this stuff in quite a while. Is epoxy resin easy to come by for a hobbiest now days?
KA.

 

[Colin8]

Re: help...? Air Filter ideas needed...nothing fi

I usually use West Systems epoxy and buy it from West Marine since they have a local store. There's no relationship between the two companies, only the name is similar. 'W'ood 'E'poxy 'S'aturation 'T'echnique was developed by a couple boat builders who decided to market materials. It's good quality epoxy, but there are many other sources too. Local hobby shops for small quantities or Aircraft Spruce & Specialty Company is another online source for West and other high grade epoxies.

Epoxy is always stronger, has better adhesion and less warpage than polyester resin. But it's more expensive, cures slower and more difficult to sand. Polyester resin and glass fibers aka 'fiberglass' is typically used for cars, boats or other products where strength and weight are less important than cost. Epoxy and glass or carbon fibers are more often used for aircraft or other products where strength and weight are more important that cost.

The fact that expoxy doesn't dissolve polystyrene foam is an advantage for one-off construction.

 

[nomad]

Re: help...? Air Filter ideas needed...nothing fi

Gonna have to look into making up a epoxy carbon fiber laminate!!
KA.

 

[jlaird]

Re: help...? Air Filter ideas needed...nothing fi

They were the Geogon brothers, or something like that, use to race sail boats with them.