[hayden1992]

So ive almost finished making a custom airbox, and have just noticed a hose going from the rocker cover to the airbox i did some googling and found that its called a PCV.

My question is do i need this? Can i block it off? Or am i to put it back into the airbox

Any suggestions will be much appreciated.

Cheers Hayden.

[Gwagensteve]

Yes you need it.

For the purpose of emissions and the longevity of the motor, it should be connected to the filtered side of the box. Out of interest, what filter are you using?

Steve.

[hayden1992]

K&N filter

[Gwagensteve]

Oh, that's a shame. Seems like a lot of work to end up with a terrible filter. Is it a part # you can replace with a proper filter element?

[hayden1992]

How is it a terrible filter?

What do you mean?

[Gwagensteve]

K&N filters do not filter sufficiently for a vehicle in an off road environment. This is well established knowledge. They approach the effectiveness of a standard paper filter when they are very dirty.

The efficiency of their filtration is also dependent on how well the user cleans and oils them, which is obviously a problem.

They might, just, be OK for a road car. Maybe. They are certainly inadequate for a car that sees off road conditions.

If you are determined to use a K&N, use a pre filter like a donaldson, a sock over the filter, and run the largest possible filter. Any filter works better the slower the air passes through it. A bigger filter means more area so the air moves slower.

viewtopic.php?f=17&t=12199

[hayden1992]

Okay, could you recommend me an after market filter?

[missmyljdaze]

Steve didn't mention - the best thing about K&N filters - is their P.R. and marketing department.

Best bet, like Steve said, is get the biggest surface area filter you can find, with a pre-cleaner of some type if you are planning on doing dirt tracks.

As for the PCV system, if you block it off you will most likely find yourself blowing seals and leaking oil everywhere.

The PCV hose needs to be piped back into your air cleaner, even better - hook an oil separator/catch tank into the PCV hose between the engine and the air cleaner.

No point feeding oily fumes back into the engine - especially if the fumes go anywhere near a MAF sensor.[if your zook has one]

[Gwagensteve]

hayden1992 wrote:

Okay, could you recommend me an after market filter?

No, because they're pretty much all competing with k&n for nonsense horsepower/efficiency claims.

Find a Oem style convoluted paper filter that fits.

Even better, use a factory designed centrifugal airbox (many Japanese commercials use a very well sealed designed centrifugal box, which are adaptions of the donsalsdon cyclopac design) my favourite is from a 1980's Hiace. The box seals very well, and the filter has about twice the area of a 1.3 filter.

[greavesyzook]

Haha lol another lad that's got Steve talking about the k&n!!

[greavesyzook]

viewtopic.php?f=17&t=12199

Read this dude

[Gwagensteve]

That thread was already linked in my reply.

You have to get up pretty early to beat me hating on crap&n

Steve.

[sideways]

Hey Hayden, I'm Hayden!

There are paper pod filters, I'd look at them if you want to build something pod filter based. I do like the idea of a pod filter as once they're clamped on there's no way for them to leak, you just have to find a good one.

[hayden1992]

oh i already had made the box to suite a 3inch k&N filter

its like 150mm wide i believe, and i also put a pipe on the lid now for the PCV

i should have done more research than i did

[claytox]

Would like to see some photos of said airbox if possible