Form and function: found it with K&N

[Healey Z]

I have tried a number of air filters on this L28 in attempt to have good air filtration, functional air horns, a hose for the valve cover and a solution that looks correct (old British) for the car. I saw an ad in the local craigslist for these air filters ($40) and I was shocked to see they were the absolute perfect fit, with air horns and took little effort to add the hose for the valve cover.

[Rainman]

Nice find!

[Zedyone_kenobi]

Did you consider running a T so both carbs could help suck those fumes? Not really needed just curious. Love your car

[Healey Z]

Hey Zed,

I did consider it, but wanted to keep it simple and not have a point where the hose went near the throttle linkage. Since it is only providing fresh air for the PCV system, I figure the volume isn't sufficient to cause an airflow imbalance. I have seen other original manufactures systems with multiple carbs that have the breather going to a single carb.

I just receive my colortune, which will allow me to check the color of the flame in the cylinder and get a proper air/fuel mixture, which I hope to do here shortly. With any luck I will capture some good pics or a short video.

[Z train]

Wash the filters at short intervals.

[doradox]

Wash the filters at short intervals.

You and K&N don't seem to agree. What is your reasoning?

http://www.knfilters.com/cleaning.htm

Steve

[gnosez]

After all the work that's been done on my engine I saw no reason in the world to inject dirty oil vapor et al into my very clean triple intake so I installed a simple catch can. Why did you route your valve cover exhaust to the BACK side of the air filter where there is no element to catch anything? Yes, this was the way it was done on the original airbox but that's not a reason to compound a bad design process.

[Healey Z]

Bad design? If the engine is operating properly, air should be flowing in to the valve cover, not out to the carbs. I'll see if I can find this explained.

[Healey Z]

I found it in the 1972 FSM. What you say is true, if the motor is ready for a rebuild, which mine is not.

[240260280z]

John was referring to the slurry that comes out of the crankcase vent.

The PVC system on a stock Z has a single stage collection element and this system is supposed to circulate just vapors for re-burning however; it seems the system does not do it well.

The vapor/liquid separator stage is just a baffle and wad of mesh gauze inside the crank case below the vent hole. The mesh is supposed to trap the liquids but it seems that some pass through and cause the slurry (i.e. water vapor from condensation inside the motor when the engine is cold and also volatile gases from the combustion process).

John is recommending that a second stage "catch can" should be added to capture the elusive liquids that pass through the mesh gauze and also to catch any vapors that condenses due to the temperature drop experienced outside of the crank case.

Edited December 23, 2011 by Blue

[Healey Z]

Hey Blue, that is not a pretty picture. Glad I already ate breakfast

I think gnose touched on both parts of the PCV system; gases from the crank to the intake and air into the valve cover from the air cleaner.

In my automotive experience (Z motor new to me) having this system work correctly is important to the motor operation and life. Do you have your catch can prior to the feed back into the intake?

[240260280z]

Not on my beater, it is stock, but I will on my new install.

As John said it keeps the intake cleaner.

btw the hose to the top of the valve cover has a spark-arrester inside for safety.