Catch tanks and crankcase breathing.

[btcc93]

A bit of help required, I have been working on preparing a car using a Zetec engine on Jenvey throttle bodies, I had fitted a catch tank as per the diagram here with the exception of the return to sump. http://www.burtonpower.com/technical...er_system.aspx However I am told by a scrutineer that I must remove and blank off the small filter. My fairly basic engineering experience lead me to believe this breather filter was essential to prevent the build up of crankcase pressure ?

[dave_samk11]

Since many cars run catch tanks designed by blue peter ie washing up liquid bottles et al I'm a bit mystified by that one I think I would have a second opinion on that one.

Any scrutineers on here?

[redturner37]

Originally Posted by dave_samk11

Since many cars run catch tanks designed by blue peter ie washing up liquid bottles et al I'm a bit mystified by that one I think I would have a second opinion on that one.

Any scrutineers on here?

certainly seems an over complicated system. Previous cars of mine have had washing up liquid bottles, but my current car has a rather posh system, a windscreen washer bottle from a Massey Ferguson tractor. Never had an issue with the scruts. Over to you
N500

[SteveSlowboy]

I would think a pipe fitted in place of the filter, and routed to the rear of the car should be ok. As the other guys have said, plastic bottles seem the norm! On my car I use a 1 litre alloy drinks bottle (of the camping type) with holes drilled around the neck, and the crankcase hose going in to the top and about 1/2 way down inside the bottle. It's been no problems with scrutineering.
Steve

[Bernard]

Rules require a 1 litre catch tank. how it's plumbed aren't mentioned.

[grahamb]

Having ran a Zetec in FWD configuration for quite a few years now, I can vouch for
1) Not using a plastic bottle. They warp with the heat, and usually fall out of their mounting bracket.
2) Using a breathable 1-litre alloy tank (ie Mocal), and empty it regularly (every 10 laps). Zetec's seem to have an ability to throw out huge amounts of oil from the outlet at the end of the cam cover on long left handers, so if I were you I'd block that outlet off, and fit another halfway along the cam cover, vertically would be best. The Mocal tanks have a screw on cap that also allows the fumes to vent (breath), a sight guage down the side, and a plug underneath that allows you to drain the oil on to the floor. (Been there, done that!)

Returning oil to the sump is a very bad idea, because of the amount of moisture (water) that is also produced by the engine. Water isn't a particularly good lubricant.

[btcc93]

The Zetec in question had a total rebuild just a thousand miles back, it ran with the catch tank, which is a stainless cylinder type with a top filter vent, for around 800 miles and nothing reached as high as the sight guage, when I removed the drain plug all I got from it was about 2 egg cups worth of water. It is a silvertop engine but is now fitted with the later blacktop cam cover which seems to have a better baffle and I do not seem to get any oil blown up to the breather take off when I use these later covers. I also have a tank similar to this :- http://cgi.ebay.co.uk/Alloy-1-Litre-...1%7C240%3A1318 which I had on a Mk2 escort years back but this has only 2 inlets/outlets and a bottom drain so would effectively be sealed in this application which would be of no use in reducing crankcase pressure

This is an old photo of the set up I have, the tank has since been relocated aft of the battery and the filter in the foreground is now fitted directly to the top of the tank.