Chevy 283ci, what is this for?

[evilways]

This is not my engine; I am using it for an easy reference. Mine actually has a cap that is bolted and has a port for what might be vacuum. This is at the rear of the block behind the dizzy and to the side. It seems to be part of the block?

What the heck is it for? can it be plugged?

[CG]

Road draft tube for crank case ventilation. Before pcv valves.

[thirdstreettito]

Originally Posted by CG

Road draft tube for crank case ventilation. Before pcv valves.

Would that make that specific 283 a pre-58(59)?

[primered_junk]

That is a crank case vent system, which has a cannister under the intake in the valley area. The oil fill tube, and the vent were the PCV system of the 60's. If your going to use a modern system you can plug it, I would use a freeze plug. The rubber grommet is not repopped, but I have found some that work, for that you'd also need the 3/8 steel line etc that was used to connect it to the vacuum source. I would plug it, and use the modern stuff, if not going for the original look, I would plug the oil fill on the intake too. Improper crank case vents tend to cause oil leaks.

[powerbench]

if memory serves me , there is a canister that is bolted into the valley of the block that slides intothe lower portion of that hole......i guess you could pound a frost plug into the hole to cover it, but you would have to run a set of valve covers with pcv valve holes in them ,or ealry 327 oil filler neck with a tube on it to avoid push out valve cover and oil pan gaskets

[powerbench]

327 had 'em too thirdstreet, pcv valve used to screw into the base of the carb ,they just ran ahose from the canister to the carb

[evilways]

Thanks so much. I already have a performer intake so the oil fill is gone. I also have valve covers that have the PCV valve in it too. So I will just plug it and be done. Thanks to all

[special-K]

Make sure both valve covers are vented.The passenger side goes to the air cleaner or just put a breather in the valve cover.

[evilways]

Yes both are vented, one with the breather and the other with the PCV.

[ChevLoRay]

Ahh, the memory of seeing a car in front of me, with their road draft tube emitting smoke at night, as it was illuminated by the headlights of my car. Any blow-by was gonna come out of that tube. If it was really bad, you'd see oil dripping from it and some evidence after you moved from that spot.

We fussed about PCV stuff, back in '62. California even required a crankcase ventilation system be retrofitted to cars made back to '55 and registered in CA. Seen some funky stuff...