Stock Air Filter

[Guest ratchethack]

It's time for a new air filter for my open-top (home shop made bracket) airbox.

 

The FAQs here & at GuzziTech show a K&N #33-2682, BMC #F45740 (the same one Ferracci uses in their $80 lidless kit) and a discontinued Amsoil #S1938. I found a Fiat number somewhere but no one I checked with either has it or can cross ref. it.

 

I don't use K&N because, although they test out at higher flow rates, they pass particle sizes (as I recall) 2-3X of the most effective "standard" filters, according to a comprehensive test I read somewhere. (Oh, boy - let the winter air filter threads begin... )

 

It's hard to imagine that the only known P/N cross for the stock airbox filter (other than K&N) is BMC. I'm hoping someone has discovered another?

 

Thanks in advance.

 

Ratchethack

[dlaing]

Uni makes Universal size foam that you can cut to fit.

They have a pre filter density and regular density.

I am sure you have heard the arguments pro and con.

I think foam is the way to go if you are into higher maintenance.

It will trap more particulates.

It will flow very well if kept clean and NOT over oiled.

High maintenance is cleaning once per year.

The Universals are cheap enough you could probably toss them every year.

I would not try to stretch the life of one past four or five years.

The only major draw back of foam is that it can degrade and flake off into your engine.

But using your stock box you should lay in a double layer of course and fine mesh, or just corrugated fine mesh to support the filters. This could protect against disintegrating foam mucking up your engine. But replace the foam before signs of disintegration!

The other draw back of foam is that comparing it to brand new clean paper and gauss filters, it does not flow as well....but give it a few months and it starts to pull into the lead.

Protection is superior!

Go for it!

I am using a BMG gauss type, with Ferracci open lid kit...I'll bet my throttle bodies are getting coated by what gets in, not to mention inside the engine.

But it is low maintenance...I think it has been nearly two years without cleaning.

 

addendum:

See here for details on the foam:

http://www.unifilter.com/accessory-catalog.htm

[Guest Thundering Subash]

I'm happy with the K&N I put on my V11 Lemans. It would seem to me that a well oiled K&N should do as well as any other air box filter that fits our bikes. And if you shop around, they're quite inexpensive (around $40 U.S. shipped including the recharge kit). The best part of all, it's probably the last air filter I'll have to buy for it.

 

-Chris

 

 

[Guest jerroldt]

I have been using K&N's for years on Harley's, Guzzi's and various Jap bikes with no problems. My main reason for using them is that they don't wear out. The stock air filters (in my opinion) are more efficient but also more restrictive. When I take a stock air filter out of my car at the required interval, it is choked with dirt and crud which means to me that it is doing what the manufacturer wanted it to do. Since I don't race the car etc. it makes no difference. In the long run, how long does the average rider keep a bike? I have been described on a previous thread as even more anal than Al and I still am to some extent. My current thinking is that an open air box with a stock filter will give me all the kicks that I need and it is functional. I have lavished extreme care on all my bikes during the last 49 years of riding but the next buyer has usually reaped the benefits. Today, I just do normal maintenance and some sensible mods and enjoy the ride.

[Guest ratchethack]

Thanks for the responses, Guys. I take it there's no other commonly available, known cross ref's (yet).

 

As it happens, when I got the tank off, I found a BMC washable filter. I remembered putting it in there as soon as I saw it. I rinsed 'er out several times with hot water and liquid diswashing soap, sprayed it gently and thoroughly with clear water (from the inside out), then gave it about 47 seconds of a blast (also from the inside out) with my hi-power leaf blower, which left it bone-dry and looking nearly new. Now I get to return the brand new MG OEM filter I picked up yesterday to GP Moto.