Engine breather set-up for Zetec

[Mike65]

I've had a blacktop 2 litre in my Mk1 Cortina for a few years. Went over to twin 45's last year but need some advice on a breather set-up. I've obviously got too much pressure as the gaskets have started leaking. Currently only got a PCV but no breathing from the cam covers. Recently drilled an outlet into the cam cover but it blows out way too much oil and don't know where to send it. Don't want to tap into the inlet manifold as I think it will upset the carbs.

Any advice would be appreciated guys.

[katana]

Have you 'gutted' the PCV valve? If not and not connected to the inlet manifold it won't be opening so wouldn't function as a breather hence the excessive crankcase pressure. The single cam cover breather will be insufficient for a 2.0L motor. If you don't want to tap the inlet manifold then its either gut the valve so it vents atmospherically and run hoses from it and the cam cover to a catch can with a vent to atmosphere. I'd say you'd want at least 2No 1/2" ID hose vents, 3No would be better - all routed 'uphill' if possible so fluid oil will drain back whilst oil vapour is condensed within the can that can be drained periodically.

[robert maguire]

Good info there , thanks.I nearing end of my Zetec mk2 escort build and am considering the final bits like breathers etc

[Mike65]

Thanks for the reply Katana. When you say gut the pcv, I guess you mean stop it operating as a valve, just as an outlet from the crankcase. ? I'm going to run one hose from the pcv outlet and one from the valve cover, both into a vented catch can. Judging by the amount of oil that blew out of the valve cover when I revved the engine hard, looks like I'll be emptying the catch can often (?).

[colr6]

Have you got the hole in the cam cover inline with the throw of oil off the cams that might be a reason for blowing so much oil out. Maybe a splash plate below the hole will stop that.

[katana]

'Gut the valve' = Yes stop it functioning as one way valve. The Zetec has a breather standard as far back on the offside rear so oil fling should be minimal - more likely the constrained crankcase pressure was forcing the oil out - it shouldn't need draining more than every couple of months IMO

[Mike65]

Thanks guys. I'm using that Retro Ford BDA cover, it's expensive but fab. Its got a baffle inside but I reckon Katana is right, all the time I got the PCV in, I got too much pressure in the crankcase. I've ordered a neat 1/2L breather catch can and will hook it up next week. This weekend I'll remove the PCV and see if I get less oil blowing out the valve cover. Got the pipe stuck in a Coke can for now.  Let y'all know.

[Mike65]

So following the good advice above, I 'gutted the PCV' on the basis that it was not connected to a vacuum source and therefore permanently closed. This was certainly causing too much crankcase pressure which was causing the oil to pump out of the only opening, my valve cover outlet.  See the pics how I got the valve out of the PCV. Put the empty PCV back in, blasted the car out on the A23 for 5 miles and Bingo - no oil pumped out anywhere. Just waiting for the oil catch-can breather to arrive so I can put the valve outlet pipe into something a bit more proper than a Coke can.  Thanks for advice guys.

Pic 1, cutting off the bottom of the PCV with a hacksaw.  Pic 2, the valve and spring out.  Pic 3, just a quick file and pop the empty PCV back in.

[mk2 mike]

Good tip there. Will have to have a look on my zetec before it goes in this weekend.

 

 

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[Mike65]

Finally finished the job, fitted a breather catch-can (£35 off ebay). One hose in from the valve cover, one from the empty PCV. Given the car a fast blast for 1/2 hour and absolutely no oil blow. Result.  One tip: I wanted to route the hose round behind the engine and needed to get some 'bends' into it.  I cut 2 lengths of a wire coat hanger and shoved it into the hose, then it could be bent into any shape and the bends stay there. Don't know if it's a first, but it works great.

[robert maguire]

Nice job.I am near finishing my Blacktop to mk2 escort and have no breathers connected up yet.Looks like ebay one as yourself. I just have the crank metal breather box left open at bellhousing area and nothing yet on the cam cover one but no oil presses out but in saying that I am not on the road yet.Just revvin in the shed !!.Any Ebay item number for the can you bought??Thanks

[Mike65]

I ran mine for over a year with no breather but it gradually started pushing oil out of the engine gaskets, crank seal etc. cos the internal pressure was too high. The ebay item no. is 12184093998 and cost £35 from 'aclubuk'.

[colr6]

Don't want to sound ignorant but do these engines suffer with excessive crankcase compression for a reason or are they like that ??

[mk2 mike]

I'm going to fit my zetec tomorrow (1800 silvertop) I have a breather tank and there's two outlets (back of engine and cam cover) where is the valve mentioned above? Will I need to do the same mod?

 

 

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[katana]

Depends if you are still using a similar manifold as the stock one ie. has a vacuum hose connection. This hose lifts the valve within the can connected to the crankcase. As highest vacuum occurs at idle or low speed, this is when crankcase venting occurs and any fumes get burnt via the induction system in all 4 cylinders. If using DCOE type carbs or Jenvey's you'd only normally have one vacuum source so overloading one cylinder with the fumes / oily nastyness. If you can hook up all of the inlet runners to a common pot with a pipe to the valve it 'may' work but can't be guaranteed.

I believe these engines have a relatively large bore to stroke and like to rev, so ring blow by is greater than older designs. My main experience is high rpm bike engines where crankcase compression can be a massive problem and add a turbo / supercharger where boost also pushes past the rings and oil will literally piss out of any gasket / seal. On a 1200cc engine inc. a turbo, I ended up with a dash 10 and a dash 8 hose from the lower crankcase, a dash 10 from the cam cover and another dash 8 off the std cam cover breather that normally goes to the airbox so in excess of what is provided for a 2.0 Zetec!

[mk2 mike]

I'm on twin 45s. I'm almost certain from memory there's no vacuum connection

 

 

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[Mike65]

I've had a good chance to get my head round this now. When I fitted the 45s I lost the vacuum to the PCV that was originally on the downdraught Weber. I did the old school trick of running a hose from the PCV and hang it under the car. I had no outlet at the top as the Retro Ford BDA cover for the Zetec is on the left side and very close to the twin Weber linkage. So I blocked it off thinking the PCV would be enough.   Big mistake. The PCV doesn't operate with positive pressure in the crankcase, only with a vacuum lift from a source (such as the inlet manifold).  I tapped into the inlet manifold to do this but it played hell with the carbs so I blocked that off too.  6 months down the line and the engine was pissing oil out of every gasket and seal.

I now know (from useful info above) that taking out the valve in the PCV AND opening the valve cover outlet and running both into a breather catch can has solved the whole issue. It's not sufficient for modern emission engines but fine for our old stuff. I was worried I had blown out a gasket or crank seal but the engine is now oil tight and dry again. So is my garage floor!

[mk2 mike]

I have exactly this issue. Front crank seal (possibly rear too) and sump gasket all leaking spraying oil all over.

 

I've got the cam cover breather connected to the breather tube at the rear of the block via a t piece then going into a catch tank.

 

Is the valve inside the big black box under the exhaust manifold??

 

Anyone got a pic of it in situ for me please?

 

I'm hoping my problem is this not the crank seals need doing.

 

 

 

 

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[colr6]

It will be be under the inlet manifold as its operated by vacumn

[mk2 mike]

Actually in the manifold? I'm on twin 45s with the weber manifold so not standard.

 

Or in the block under the manifold?

 

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[colr6]

In the block under the manifold

[mk2 mike]

I'll have a look tomorrow. Cheers!

 

 

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[colr6]

I'll have a look tomorrow. Cheers!

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Should be easy to find there normally black amongst all that orange...LOL

[robert maguire]

The breather box is in the block under ex manifold but PCV valve is on manifold..Thats on my Blacktop anyway.

[mk2 mike]

My pcv valve was under the exhaust manifold in that black breather box. Took it out earlier I'll gut it out tomorrow.

 

While I was in the garage I had a closer look today. There's evidence of oil leaking from both front and rear crank seals, sump gasket, and rocker cover gasket.

 

I'm hoping this will solve it.

 

 

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