Zetec Crank Breather

[CMA]

Do those of you that have a 2.0 Zetec fitted have the crank breather blocked off or piped to a catch tank?

What about the cam cover breather? To the catch tank or to atmosphere using a little filter?

[kevp]

Hi.
Both to a catch tank.

[CMA]

Cheers Kev.

Seen alot say block it, including people reporting that Dunnell also advise it gets blocked. GBS (Robin Hood) also advise to block it too.

Does anyone know if there is a breather adapter that's not as big as a house (unlinke the standard mondeo thing)

[stylussprinter]

Cheers Kev.

Seen alot say block it, including people reporting that Dunnell also advise it gets blocked. GBS (Robin Hood) also advise to block it too.

Does anyone know if there is a breather adapter that's not as big as a house (unlinke the standard mondeo thing)

Dunnell definitely didn't advise me to block it but it's not very big anyway (about 6 inches x 3 inches and very close to the block) . Raceline also say to keep it and both my cam and block breathers run to a 1 litre bottle in the driver's side cavity , sitting on the fibreglass ledge out from the bulkhead. It has two pipes in plus air holes at the top . Never gets much in there unless you overfill the sump , mostly watery oil around 10mm deep after an event or two but the dipstick never seems to move from fill to fill.

[Craig-Chap]

I'm doing something slightly different. I have removed the vac operated gubbins from the separator box, joined this and the cam cover breather using a T, and I will then be joining this to a plumbing fitting on the back plate of my filter. But mine doesn't run yet, so this could be a terrible plan. Time will tell!

I didn't want to block it- those breathers are there for a reason, I'd quite like my crankshaft oil seals to remain in one piece.

[stylussprinter]

Absolutely correct BUT don't put them into the air filter if that's what you mean't --- simply run the standard block breather and cam cover breather in their own pipes into a catch tank that has vent holes --- really easy and a T piece may push that watery oil back into the engine and that you don't need.

[CMA]

Cheers all for the replies.

Obviously if the crank is getting pipped into a catch tank you'll need to remove the vac operated gubbins (PCV valve). Otherwise it would be the same as blocking it as there would be no vaccuum to open the valve.

It wasn't a direct Dunnell quote, just from what others had said on other forums.

Personally I'll probably keep it. But was just after what the collective thoughts were and what other options were about.

Running the pipes to the filter back plate is basically as it used to work in the Mondeo. So won't cause any harm just wont give you nice clean fresh air to burn so you'll probably loose a tiny bit of power and soot up the inlet side a bit too, which is fine on a production car.

[Craig-Chap]

The thinking was that I might gain a bit by having a small vacuum in the crankcase- and I won't have to muck about checking/emptying catch tanks. I'm not too bothered about the oil mist etc, if the engine isn't shot there shouldn't be much to worry about. Hopefully! If it does chuck a lot out I'll fit a catch tank at a later date.

[kevp]

Hi Craig

Cant think what you might be gaining from a partial vacuum. In theory you could without 1 of the breathers (engine block?) as they are both interconnected. However its easy to vent them to a catch tank.

In the early days I just used a plastic drinks bottle strapped to a chassis rail. I never had to empty mine even after a few years of sprinting.

[Craig-Chap]

Engine torque is produced by the difference in pressure between the top and bottom of the piston. Lower crankcase pressure = more power- this is partly why people run multiple scavenge pumps on dry sumped engines. Although I will be pulling such a small vacuum I can't imagine it'll make a huge difference, and my engine is basically standard anyway.

Good to know that they don't chuck much out, I didn't think they would.