Engine Breather

Managed to get out in the car over the Christmas break, I was keen to see how my PCV valve worked - I was looking to see how much crankcase depression I was getting in various engine conditions - my measurement method was a digital manometer hooked up to my dipstick tube. Didn't get very far before I realised my first simple in-line valve was giving me too much depression, it wasn't able to control the pressure. The downside of this is that in extreme overrun I could potentially suck the oil into the intakes.

Time for Plan B, I had picked up a diaphragm type PCV valve, only problem was finding somewhere to fit it, no room on top of the intake manifolds.

After some pondering, decided to use my redundant distributor mounting, This needed a bit of machining to make it suitable, I also added a fixing point to hold the valve in place.

Not sure where I originally picked up this valve.

The valve pushes into the modified distributor housing and is held in with a small cap head bolt.

Fits quite neatly on the side of the block

Plumbed into the intakes via some 1/2" tubing pressed into the end of the manifolds.

Checked everything was fitted ok and started the engine, my pressure gauge was showing a 15 mbar depression at idle. Took it out for a drive, subjecting it to various operating conditions, the valve seemed to pretty much maintain a constant 15 mbar depression +/- 10 mbar. The original engine breather is now the fresh air into the engine crankcase and is fitted with a small restrictor to create the depression. With no restrictor it would be like having an air leak post throttle in the intake system.

Didn't get much else done, really need to trial fit my front upper wishbones - once I know they fit of I can get on and make another set with the thicker wall tubing and then ream the internal bores to the correct size.