Remko GT

This is probably a hard one but here goes:
I have a couple of breathing issues on my modified and tuned BOA 24v Cosworth engine. As standard, the PCV in the RH camcover (when standing in front of the car looking into the bay) is up to the job of ventilating the engine. A couple of weeks ago I realised the PCV in my engine was knackered so replaced it with a known good one (got it from Specialised Engines in Essex). Now it seems it's not adequate anymore (not really a surprise, the pipe where the air needs to go through is about 6mm) and oil is even coming from the vent on the other cam cover which usually is only an air-inlet and other places I'm pretty sure about wouldn't leak if the breathing and thus the crankcase pressure is adressed.
Basically, I am stuck with the following:
Exhaust is too restrictive, effectively causing more piston blow-by and consequently causing more crank-case pressure. Nice for torque though
What I want to know is:
Can you remove the positive crank ventilation valve and replace it with a breather-kit like I see so many times on (big-power) YB Cossies? I am in 2 minds about this. I can see an engine needing this positive ventilation but on the other hand, not an OE one 'cause it's no good on a tuned engine obviously.
My plan is to drill a hole in the sump, make a 22mm connection to it and connect it to a K&N breather kit (I've seen one with a built-in oil separator with baffles) to provide fresh air into the engine (seems a bit overkill but I want to be sure no oil can get out), remove the inadequate PCV valve, make a +/-16mm connector there, combine it with the breather on the LH camcover vent and run that into a seperate oil-catch tank and run it back into the sump via a hole in the sump on the other side.
Unfortutely, I cannot change exhaust yet because of govournment test it still needs to pass but I really need to sort out this breathing problems 1st. Don't want oil running onto my exhaustmanifolds.
Another question I have is: How efficient are those oilcatch tanks? I've read they're basically header tanks with enough volume so the airspeeds drops and the oil is released. I am pretty conviced a baffles tank would be more efficient. Where can I get such a oil-catch tank?
Can anyone post a couple of detailed piccies on cars with uprated breather kits and how you've run them? Even more important: Have you retained the standard PCV valve or ditched it entirely in favour of a uprated breather kit?
Last question: Vent into atmosphere or re-route it back into inlet plenum? My car is not a daily driver so not too fussed about a little smell from the engine bay into the car. Can always open a window, right?

tabetha

The pcv valve only admits air flow at low/idling speeds, when air speed through it becomes a certain amount it pushes the valve against it's seat and effectively closes it, you sound like you obviously have more pressure than the std system can cope with.
There is no advantage to having a pcv valve, it dilutes the fuel with oily fumes, I would just plumb in a system like you describe, always as you say use a baffled tank to catch the oil fumes allowing them to settle and drip down, then place the return below oil level, , you will also need a atmo vent pipe going into this tank right to about 1" from the top, as far from the inlets as you can.
tabetha

Remko GT

Thank you Tabetha, that's a big help confirming what I kind of suspected.
You are correct. We have a lot more pressure than the standard system can cope with. I guess the higher lift cams I have fitted might have something to do with it as well, as well as the superior BOB inlet plenum we made to fit.
With inlet, do you mean the actual airinlet to the heads or do you mean the inlet for the venting system (what I described I want to fit into the sump)
The outlets will be on the back of the camcovers practically against the scuttlepanel and will be the highest point in the engine. I'd say the fact warm air goes up and cold goes down this will help venting the engine, am I right?
The standard PCV would not only fuel but the air as well. That's one of the reasons I am in 2 minds about PCV to inlet. When tuning that's not what you'd want. Foul warm air back into inletplenum.... *shudders*

I got a tip GGR might have a suitable enginebreather and oilseparator kit combined. Anyone have any experience with this kit? Knowing GGR (regular FastFord/Performance Ford reader) it will be a serious piece of kit and could well be up to the job solving my problems. Will be costly though, I guess.

tabetha

Inlet into the venting system.
tabetha

Remko GT

Now I realise what a stupid question that was about inlet...
Ofcourse it makes sense keeping those 2 as far away from eachother as possible.
Thanks again m8, you're being a big help!

Remko GT

I decided to ditch the standard PCV as it was no good. Too restrictive.
Now I have made the hole, wherein the PCV used to be situated, into a hose connection, connected a 17mm hose to both camcovers and ran it into a K&N baffled oilcatch and integrated breather and routed the return through a 10mm hose into the sump by replacing the sump drain plug with a hollow bolt and a banjo connection on the hose. The engine seems to idle a lot better now.
I might upgrade further in the future should the need arise.

tabetha

Glad it's working for you.
I was going to try some of my Dutch on you, but embarased as will no doubt cock it up and make myself look a dick!!
tabetha