The Stovebolt Site Forums The Shop Area Engine Shop Vents in Valve Cover

I noticed there are two 1" slots in the top of the straight-6 valve cover on my 216 engine. Anybody know the purpose of the slots?

It would seem like any water run-off from the cowl vent hose might splash into the valve cover.

Thanks

They are part of the crankcase ventilation system. Air goes in those slots and out the draft tube.

I appreciate it. Thanks!

Somewhere I have an original GM instruction on making those slits in a cover that doesn't have them. They were indeed for ventilation. The cowl drain is conveniently positioned to feed into the back slot!!

My '49 3100 has a '55 235ci. I was noticing that my cover has the vents closed off with RTV. Would there be any reason for this or should I remove the RTV?

Thanks,

Ronnie

I would not remove the RTV that seals your slit vents....BUT.... you should make sure that you have some source of fresh air for the crankcase..... look at the possibility of using a vented valve cover cap.. the ones with a metal fiber inside the cap that once oiled slightly will trap dust and grits....from the air going in....

What kind of draft tube do you have....?

You might want to read the other recent thread on crankcase ventilation.

Bob C.

As to the cowl vent I merewly put on a longer hose which drains to one side of the engine.

Thanks Bob,

I agree the vented, filtered cap is the way to go. As far as the down draft tube type...I didn't know there was more than one type. Mine looks the same as the one on Hutchtruck.com . But I definately need to do more reading.

Thanks,

Ronnie

To my knowledge there are at least 3 type.

The most recent had only one opening and that was for the PCV elbow that threads in the hole and points the PCV vertically.

Some model had no provision for the PCV to be intalled and where vented downwards by a 1 inch sheet metal tube.... usually dripping with oil on the open end.

An earlier model... also with no provision for a PCV had a screw on cap....sorts squaring in appreance.... it allowed owners to pour engine oil directly into the crankcase and also had the large 1 inch sheet metal tube angled downwards.... on tired engines that vent pipe would puff smoke and drip oil.....

Bob