Pinto Crankcase Breathers

[Ian Bunker]

Advise needed please. At higher revs my Pinto was pushing oil back through the plastic push in filler cap. The rocker box has "WESTFIELD" cast into it. The breather down on the block was the usual Ford offset metal can and i had a short RAMAIR filter on its outlet.  To cure the problem i have obtained from Burton Power an alloy elbow to go down on the block (ie eliminating the Ford breather box and RAMAIR filter) and a alloy filler cap with a breather outlet. obviously i have connected the two via a suitable length of hose.  Question is will i cause engine pressure problems by not having an open outlet anywhere? Do i need a T piece and the RAMAIR filter somewhere in the line? Any thoughts would be very much appreciated. Cheers IB. 

[Lyonspride]

http://www.burtonpower.com/tuning-guides/tuning-guide-pages/engine-breather-system.html

 

 

The engine defo needs to breath though, it must have a path to the atmosphere via (preferably) a catch tank and air filter.

 

If you don't equalise pressure, it could start to blow seals and even the head gasket.

[BillyPee]

Hi Ian,

 

I don't have direct experience of the Pinto but I have with the Xflow. The Burton Power link from LP is a good starting point for background information. A search online for "pinto breather pcv" and/or "xflow breather pcv" also returns some excellent forum posts on the subject.

 

I removed my PCV valve and replaced with the Burtons elbow. On a Xflow, its also necessary to get a fuel pump blanking plate with an L shaped bracket on the back to stop the crank throwing oil directly up into the elbow. Might not apply on a Pinto but worth checking.

 

At this point there are essentially two options for taking this to an oil catch tank:

1. Plumb the elbow to the catch tank and plumb the oil filler cap take off to the catch tank separately.
2. Plumb the elbow to the rocker cover and the have a single feed from the oil filler cap to the catch tank.

Whichever option you take, put a breather on top of the catch tank to allow ventilation to the air.

 

On my Xflow, I went for option 2 because my catch tank only had two unions and I wanted to use one of them to connect the breather. However, note that it hasn't cured my heavy breathing problem and the oil filler cap still lifts (but the bonnet stops it coming all the way out). It also brought about new problems, e.g. the dipstick started lifting out too. I am hoping to fix these problems with a larger diameter union on the rocker cover and baffling of the rocker cover as per the Burton Power guide.

 

HTH,

Bill

[Ian Bunker]

Thanks very much indeed LYONSPRIDE & BILLYPEE - much appreciated. i have ordered a twin inlet catch tank from a German company with a filtered air outlet/inlet on the top so i propose to feed the oil filler breather and the crankcase breather into the tank - at £30 odd quid with level indicator and hose it seems a good buy. Thanks for your time and trouble. Ian (Pedestrian)

[Man On The Clapham Omnibus]

Pinto engines coming from a car with auto transmission have a different valve from those from manuals I seem to recall. Mine has an oil trap only in the crankcase breather, and no spring loaded valve as that impedes the gasses flowing out to the catch tank. When I bought my Westfield it had a breather from the crankcase and one from the cam cover which were combined before going to the catch tank. It would dump far too much oil into the catch tank so I looked into the problem. I talked to Vulcan Engineering about the need for a cam cover vent and the chap said there is no real need for one, and as the Burton article says, sprayed oil from the camshaft can find its way out via the breather.

 

Logically analysing the situation suggests a breather in the cam cover is not only not needed, but can be detrimental for both the above reason and another which I will come to. As others have said, an engine must breathe out any piston blow by that builds in the bottom half of the engine. There is no source of pressure in the cam cover so why vent it? Any puffing of crankcase gasses found when the oil filler cap is off have come up the oil return channels between the cam chamber and the crankcase and have not originated in the cam chamber. It might even be that a generous flow of these blow by gasses up the oil return channels could impede the oil's journey down to the sump. For that reason I removed the vent and sealed the vent holes in the oil filler cap. Once this is done, of course, the only path to the outside for crankcase pressure is through the crankcase vent and this MUST be of sufficient capacity to allow free passage of gasses and not offer any resistance or excess crankcase pressure will result. Having bunged up all exit points in the top half, I no longer need to drain the catch tank after a few hundred miles as I used to have to.

 

I know this is going against the conventional wisdom but the reason oil filler caps on 'normal' cars have vents in them is to allow air to be drawn in, not to allow gasses out. The positive ventilation system applies a low level vacuum to the crankcase via a connection to the inlet manifold, and the gasses are sucked into the engine and burned. Our modified engines do not do this.

 

Here's the OEM layout from a Granada with a Pinto engine:

 

 

The stubby barrel like item is the valve - get rid of that in favour of an oil trap froma manual car. I opened mine up and removed the spring loaded plunger and then reassembled it as a take-off elbow/oil trap only.

[BillyPee]

Great post MOTCO.

[Man On The Clapham Omnibus]

Thanks BillyPee! I hope that means I can take of my flame suit now - it doesn't pay to hurt sacred cows! 

[Welly Jen]

+1 on what the MotCO says. When I got my car it had a breather from the crank case and one from the can cover. These had both been connected together, bypassing the catch tank. This would have lead to overpressurisation, so I reconnected them both to the catch tank. I then had problems with the tank filling up, so blocked the can cover outlet. This solved it.

My car now has a breather from the crank case only, via a manual car, non valved separator and a hose to the catch tank that goes via the highest point under the bonnet. This has worked very well. I still sometimes see a little oil around the filler cap, so may go for blocking it up too. Reckon MotCO's logic is sound. The catch tank has a breather filter in it so this will let air in as well as gas out.

On a Pinto the crank breather is a long way from the fuel pump blank plate, so a flat pump blanking plate is fine.

Jen

[Man On The Clapham Omnibus]

WellyJen, good point about the route from the breather to the catch tank. Make it rise above everything before it falls to the tank then any liquid oil in the hose will drain back to the sump rather than the catch tank. The oil separator should stop it but belts and braces never hurt.