K24R Oil Filler Cap Breather

[s2driveruk]

i'm in

[QuattroFever]

another great idea! Im interested!

[Rusty]

Cheers chaps, should have the design sorted this week

[A80Avant]

could be interested as well.

is this to replace the 13mm exit at the back of the head?

[Rusty]

Yes. I'll need to get the ID of a 1/2" NPT adaptor, as the thread troughs are 18.5mm, I'd guess at about 15mm diameter.

The design gives an aperture equivalent to an 18mm diameter pipe and the NPT thread can then join to an AN barb or pipe of up to 3/4" (19mm) hose. However, even if it just used 1/2" hose, the beauty is that it won't get clogged with oil under hard acceleration, as the OE one does, and wee oil into the breather system.

In conjunction with a swirl pot, fed by a 30mm pipe from the crank case, a Fumoto based retun and the option of a catch tank, I think my breather work will be nearly done

[A80Avant]

nice!
at the moment though my tank was ordered with x2 13mm inlets and one 19mm outlet along with a drain.

i would either have to reweld the oil tank, or use reducers for the pipes you are making in order to get them to fit to the tank

[Rusty]

Where's 13mm come from block is 30mm and head is 14mm so can use 5/8" oil hose. 13mm is smaller than factory even.

[A80Avant]

I use a 13mm samco hose to connect the head pipe to it's metal continuation towards the block (at the back of the head). If the pipe itself is 14mm, thats fine as the samco fits.

However 5/8= 18mm. So a 5/8 samco hose wouldnt it be too big for the head pipe?

[Rusty]

No, 5/8 x 25.4 = 15.9mm.

Where does the other 13mm come from? That's too small for your power car IMO.

[A80Avant]

i need to look into those thread sizes and equivalents grrrr i just did a search and got those values for thread sizes and they are driving me nuts!

when i ordered the catch tank, that is what i had done (unfortunately) since i still use the OEM metal pipes. So for the back of the head (pipe that drains the cyl head down to the block) the size of that is 13mm (or 14mm, no big diffeence). The larger metal pipe (OEM) the one connected to the PCV valve and one way valve (+N80 valve for the fuel fumes), is 19mm. I had to reduce that to 13-14mm in order to fit my second catch tank inlet. Then my tank outlet is 19-20mm and was supposed to be connected to the pipe that goes to the MAF.

Ideally my 2 tank inlets should have been larger, i know. But having said that if i connect both inlets to the tank, my rubber head cam cover gasket does not leak under boost, so for me its only a matter of getting rid of the oil that collects in the tank for now, to see if that will enable a better separation(as the tank is a proper separator,with mesh and holes etc)


is this wrong by the way?
http://www.holley.com/data/TechServi...ad%20Sizes.pdf

where can i find a proper metric to AN to US equivalent chart?

[Rusty]

The original pipe that runs from the head is the one that causes problems. Best to replace that with a swirl pot.

The N80 valve can be directly connected to the inlet nipple using 8mm hose, that then means that the PCV valve can go, as there is no longer a strong vacuum attached to the breather. In turn, you can then run a 30mm hose from the crank case to the swirl pot and a 16mm hose from the head, or a 19mm using the breather I'm designing.

If this doesn't solve the oil issues you're having then I'd be very suprised. The swirl pot would have to be connected to the Fumoto valve. If you get the swirl pot setup correctly then the catch tank is all but redundant on the road and will catch very little on track.

To clear up your confusion -

NPT thread sizes are not the diameter of the pipe and are misleading a little. NPT is a pipe thread, and I can only imagine that the size quoted relates to the ID of the pipe onto which the thread is cut, thus the thread is larger, due to the thickness of the pipe.

AN fittings use the following hose -8 = 1/2" -10 = 5/8", -12 = 3/4"

My design will be tapped 1/2" NPT and can use an adaptor to fit -8, -10 and -12.

[A80Avant]

the tank i have does have the features of a cyclone. It is made by this company

http://www.saikoumichi.com/

and if you see the design is suppose to work as a separator. I imagine my problem is that it gets overwhelmed by that pipe at the back of the head!

I like the idea that JP has that still uses the turbo's vaccum on the PCV system. will that solution you are considering leave the option open for a return to the turbo/maf side?

[Rusty]

I've not done a vent to atmosphere tank for over 18 months. All my tanks are custom designed to fit the S2 and feed back to the turbo inlet.

[A80Avant]

ahhh i see! even better then!

only problem is my left hand drive configuration which needs any tank to have opposite inlets/exits!

[Mcstiff]

Have you looked at the breathers on the NA 2.0s the adapt to the oil filler.