PCV system - SIIa

[4flattires]

I was surprised at the minimal posts on the PCV topic using a search, however I am trying to figure out what I'll need to get one set up. I have none now, nor any excessive blowby I am trying to remedy.

I thought I recalled some complex valve diaphragm device written about from somewhere in years past. My big thick green book does not reference anything with the words, PCV, crankcase ventilation, or even pictures in related areas (engine view, carb view).

So....what I have now is:

1. Oil fill tube with an outlet suitable for 3/8" hose, with nothing connected now. What would have been connected to this?

2. Rochester carb, with no external vacuum source. I could tap into the PB booster line however.

3. Valve cover breather tube correctly routes to air cleaner elbow.

Does anyone have pics of how/where their PCV diaphragm is mounted?

Thanks!

Jeff

[Jeff Aronson]

I'll take photos of the one on my '66 II-A's, one that has only a mesh cover on the oil filler neck, and one that actually has the Brit-style diaphragm unit, with a hose running between the Weber and the oil filler neck.

The II-A with the Solex has no PCV valve; the one that came with the Weber has one. The PCV device looks just like the one that was on my early MGB, too.

Jeff

[daveb]

you can see here the way the pipe is routed. there is a hard pipe (probably available from our hosts) that goes from the filler neck around to the pcv valve (funnel shaped bit hiding behind the carb). it is held in place by a few clips and then a larger rubber elbow connects the bottom of the funnel to the carb adapter. if you don't have the carb adapter just use a port in the manifold. you can use the booster port just make a tree at the port, don't tee into the booster line or try to tee it off something else.

http://www.fourfold.org/daveb/roverfs/enginebay05.JPG

http://www.fourfold.org/daveb/roverfs/enginebay02.JPG

http://www.fourfold.org/daveb/roverfs/enginebay04.JPG

[TSR53]

Just updated this category section.
http://www.roversnorth.com/store/c-28-emissions.aspx

Available from stock.

2. RNC473 Metal Line-Oil Filler to PCV Assembly
http://www.roversnorth.com/store/p-2064-pipe-pcv-valveoil-filler.aspx
http://www.roversnorth.com/store/images/Product/large/RNC473.JPG (http://www.roversnorth.com/store/p-2064-pipe-pcv-valveoil-filler.aspx)

[4flattires]

Perfect. Thank you. That solves the dilemma.

It appears I am missing parts #2-8. That along with probably a carb spacer that would allow for a vacuum source. I know my Rochester sits pretty high, and there is no further room upward before the hood.

Jeff

[Jeff Aronson]

My '66 Corvair simply has a hose from the crankcase directly into the bottom of the air cleaner that sits atop the carb. So it doesn't have to go into the top of the carb to enter the carb throat and get sent into the cylinders.

Jeff

[siiirhd88]

I made up a U.S. style PCV system on my late SIII 109. I installed a SIIA type oil fill tube on the right side of the block in place of the blank plate. This fill tube uses a gasketed cap. Using a SIIA valve cover I removed the vented cap and plugged the opening with a freeze plug. I drilled the top of the valve cover and enlarged the hole to fit a rubber PCV gromit. A generic PCV is plugged into the gromit with its hose attached to the vacuum port at the carb base or on a T fitting at the booster port. This supplies the vacuum to the top of the crankcase. For the air inlet, an 11/32 vacuum hose runs from the tube fitting on the 90 degree air filter hose carb adapter to the fitting on the oil fill tube.

Intake manifold vacuum pulls on the valve cover, thru the crankcase, thru the oil fill tube and to the air carb inlet.

I tried various PCVs until I found one that was compatible with my vacuum and blowby.

Bob
'96 Disco SE7
'80 SIII 109
'75 SIII 88 V8
'68 SIIA 109 V8