NOOB 283 chevy vent/PCV Question?????

I've got an old 283 that i'm putting in my 57 chevy truck and need some insight. There is a metal "tube" that bolts on and exists the rear of the block near the distributor. I'm assuming it's some kind of crankcase ventilation for when the older motors didn't have a provision for a PCV valve. Anyway, the tube is in my way as far as new exhaust, etc... I can easily modify and redirect it, BUT i was just wondering....If i install a PCV valve in the new valve covers can i just eliminate it all together? Knock a freeze plug in the hole? Cut it off short and weld it shut?

Thanks in advance for the advice. Sorry but no pics. Camera took a dump.

 

Yes, you can block it off as long as you use a PCV valve in the valve cover.

 

You can also cut it off short, put grommet in, and run the PCV off the draft tube...

 

or redirect it to the back of the carb.

 

That's called a "road draft tube" and it uses the flow of air across it to pull fumes out of the crank case. You can't modify it, or it won't have good flow across it, but you can put a rubber grommet in the hole, stick a PCV in it, and route the tube right to your carb for a crankcase vent system. If you do that, make sure you still have the fresh air vent sticking out the front of your intake. That's what I did on my 283 and it works great. Your other option is to plug it if you are going with a later style valve cover that has a breather in one, and pcv port in the other. If you do that, then you also have to plug the intake fresh air port.

Good luck,
Matt

 

Rather than punching a hole in the valve cover, use the road draft tube port with a adaptor and use a PCV valve tied into the intake manifold.

 

It's for blow-by. Just put a freeze plug in it and use those vlave covers you were talkin about that have the pcv set up in them. Same Same.
The law makers in all thier wisdom thought that PCV would be better than a road draft system,but it's all the same. Even if you route it to your carb, It's still gonna go out the tailpipe anyway, so WTF? now your lil 283 is burning it's blowby oil... BFD! All the same..

 

Sounds good! I was thinking that would work. Thanks for the fast advice.

 

This is the fitting that Chevrolet used in that same hole when they first went to a PCV on 67 Chevelles etc. It's available on the Chevelle parts sites. You will need an inline PCV valve. The 67 Chevelle PCV valve screwed into the base of the carb. with a hose between the 2 pieces.




Piece of cake and no holes in the VCovers

 

you can run into the header which evacuate the crankcase ... that is how it was done in the 60-s ... JD

 

Did just what Tommy said on my tripower 327 with Vette valve covers and intake breather and it works terrific!

-Dave

 

Perfect! Building a 283 right now, was wondering how to fix this. Thanks

 

I am working on a 63 impala (engine is a 1964 283) and im planning on using the road draft tube (no pcv). The pound-in breather in the lifter valley was too large and wouldnt clear the aluminum weiand intake im using, so I cut about a third of its diameter out (cutting the long way), and capped/welded sheetmetal back over what I cut out. It clears my intake now.

My question is, I dont have a fresh air vent in the front of my aftermarket intake. I was planning on just using a valve cover breather. It didnt even cross my mind about no longer having the manifold fresh air vent. Is this ok?

 

Not completely. Road draft systems allowed ambient air to be drawn into the motors. Ambient air with no or poor filtration. Over time, the grit that found its way into the crankcase shortened bearing life.

PCV systems are actually the best thing to come along for the longevity of your lower end. I retrofit PCV systems onto older engines just for this reason.

 

Made this puppy on the lathe and mill. Screw in PCV is a Nissan item. If you use the road draft port for your PCV you must retain the baffle "can" in the lifter valley.