The Stovebolt Site Forums The Shop Area Engine Shop 283 breather?

Have an early 283 installed in my 51 3600 with what looks like a breather opening behind the dist cap in the block. Kind of a small dome fitting with a tube at90 degrees to put a rubber hose. Its open now and the engine runs fine but the garage gets real fumey and i suspect this is the reason. Where does this go?. The valve covers and manifold were replaced with aftermarket edelbrocks at rebuild and there is already a breather tube coming from one vc to the front of the carb. Can I cap this mystery openingit? Do i plumb it to the air cleaner? Thanks a lot the info on this site has made my project possible
Aubrey

no, you can't block it off, that's the PCV connection

Bill

There is a very easy install to put a PCV valve kit on that motor eliminates that pipe, plugs that hole and you will have solved the problem. Believe Eckler classicChevy.com sells this kit for about $30.

If your valve cover already has the PCV valve in it, and the oil filler cap is vented, then you can simply install a freeze plug in the block in that hole. That's what I did on a 57 283 I recently rebuilt and it is fine. It did not have the baffle/ filter inside any more and was pulling oil through the opening.

If there is no baffle/filter inside the block that goes to that hole then if you put a PCV valve there you will suck oil out of the engine into the intake.

To follow up on RR's advice you will need the baffle that connects to the other end of the vent opening if you don't have any other venting. See photo for an example.

Early SBC valley breather

thanks for all the replies. RR i have a breather tube coming out of my passenger side valve cover that is connected to a tube coming out of the front of my qjet. the oil filler cap is definitely vented how can i tell if there is a pcv valve in the fittings between the vc and the carb? if i read your advice right if there is a valve here, i can put in a freezer plug on the outlet and forget about it.

if there's a valve in the line you should be able to see it, they don't fit inside anything, they're a separate small metal unit the hose connect to, see the pic I posted above, that one is threaded on the carb end with a hose nipple on the other end

Bill

If the hose is going to a fitting on the front of the Qjet then it is likely attached to a vacuum port. Without the PCV valve in place the engine would likely not run very well (if at all) at idle due to having a wide open vacuum leak.

Also, where they hose meets the grommet on the valve cover there should be a metal ring that you can see. If you pull the hose and metal ring out of the rubber grommet you should see that the pcv valve is in the end of the hose.