Crankcase breather hose on 64 230SL

[Rick Katucki]

The 230SL I am "resurrecting" has a piece of hose that runs from the top of the valve cover and over the side of the motor.  It is open to the atmosphere.  There is a rigid tube that is plugged on both ends and looks to have run from the valve cover to a fitting on the intake manifold at the throttle body.  I have not yet addressed this issue but assume that the crankcase breather hose should be connected to the intake manifold via the abandoned (plugged) tubing. I assumed that the the breather was disconnected because it was somehow interfering with the engine.  There is not an obvious amount of blow-by at the open end of the breather tube when the engine is running nor oil smoke at the tailpipe. [/size]
BUT, yesterday I saw pictures of a 64 230SL on bringatrailer.com. Photos of the engine clearly showed the same crankcase venting modification as I have on mine.  Anyone know if this is an 'accepted' modification for that year model?

[clunker]

[ I am just reposting the original question in full size font / appears to be an html glitch ]

The 230SL I am "resurrecting" has a piece of hose that runs from the top of the valve cover and over the side of the motor.  It is open to the atmosphere.  There is a rigid tube that is plugged on both ends and looks to have run from the valve cover to a fitting on the intake manifold at the throttle body.  I have not yet addressed this issue but assume that the crankcase breather hose should be connected to the intake manifold via the abandoned (plugged) tubing. I assumed that the the breather was disconnected because it was somehow interfering with the engine.  There is not an obvious amount of blow-by at the open end of the breather tube when the engine is running nor oil smoke at the tailpipe.
BUT, yesterday I saw pictures of a 64 230SL on bringatrailer.com. Photos of the engine clearly showed the same crankcase venting modification as I have on mine.  Anyone know if this is an 'accepted' modification for that year model?

[Garry]

There were two types of breathers on the 230, one was a metal fixture from the rocker cover and the second was a rubber one.  See photos.


The metal fittings were the earlier ones mine is a ‘65 and still had it then they went to the rubber connection through the remaining years.

[Pawel66]

This is a close up of the later solution Garry describes.

[Charles 230SL]

..and here's an earlier one; production date of my 230sl is Apr '64

[Rick Katucki]

Thank you for the photos. I will gather the parts and set it up correctly. Curious to know how it will affect the engine as I don't know why it was altered in the first place.

[Pawel66]

You ay want to read this passage on the venting: https://www.sl113.org/wiki/Engine/Lubrication#ValveCover