I have a 1963 327 with a hole behind the intake manafold. As I recall this is the draft tube for pressure build up in the crankcase. The motor didn't come with the draft tube and I would like to retain it along with the fill tube in the offenhouser intake. Any idea where to get a replacement or can I fab any pipe to go out the opening and run down the back side of the engine. I do like the idea of valve covers with no vents. Is this a bad idea and if not what should i do for the draft tube?? Thanks may be simple but I am new at all this engine work. Thanks Ed and for all the help in the past

You can easily adapt a PCV valve in that hole to a port on the intake manifold. Th engine needs some sort of vent and the PCV valve is much better than going back to the road tube.

Definetly go with the PCV, if you like the look of the tube weld it shut and make a hidden PCV.It's a much better system, probably the first emmisions control device.

Hello,

Im not sure of the year they changed but the later 60s had a pyramid looking device in that hole that did connect to a pcv valve.

There is also a filler neck with a pcv (corvettes and other 350 horses i think) and a breather in back.

Make sure you use the oil seperator that fits under the intake or you will have an oil burning Problem.

One last note of interest ( at least to me)
Most people using the old block convert to the pcv valve in valve covers. You can plug the rear vent hole with 1 1/8 or 1 1/4 freeze i dont rember which, I also put a 1/4 in allen head cap screw in the bolt hole that bolts the breather down (witha little lock tight). One of my customers had a block that was drilled all the way into the oil galley below. It had a massive internal leak! Since then I plug them all.

If you put the valve in the valve cover I always look at the cyl heads around the push rod holes 68 up heads are cast for breathing slots along the valve cover rails. 67 down are not forcing the push rod guide holes to be the vent holes also (along with the oil drain holes in the head) this sometimes builds a vaccum in the valve cover area preventing oil drain back. Sometimes a real hard to find problem. By the time you pull the covers looking for oil the pressure evens and the oil drains.

sorry to ramble on
Thanks
Jeff

You can either the road draft tube that dumps behind the engine or the type that vents to the carb from Corvette suppliers like Paragon, Corvette Central, etc.

I looked at the site from Corvette central(this motor did come from a 63 Corvette) and they show tubing going to the vent hole to a pcv at the back of the carb. This I believe would allow me to use the 3/8 pipe plug in the back top of the manifold for the power brakes. I can easily turn a plug that will be a press fit into this draft vent hole and thread a hole in the center for a barbed fitting for a vacumm line to the carb. My only concern is, will I need another place for return air or will it bleed through the oil filler tube. I do like the suggestions and they are better then I was expecting. Ed ke6bnl

That sounds like the way to go, less work for me and clean, do you need a vent somewhere else to make up for the vacuum you pull out of the crankcase. Ed

I have the same 63 327 motor and it wars removed from the origional car. The PC valve fit into the rubber groment in the block hole and a flexible tube went to a spike that was in the base plate for the 4 GC Qjet. The intake boss was for the power brakes.. This is much better than the old down draft tube which could make for a very dirty bell housing.

Trees

I copied the mid-60's Chevy PCV system for my '59 283. I bought a steel PCV adapter made for mid-60's SBC & put it on my block where the draft tube had been, & ran a tube to the rear of the carb base. There was a PCV valve in there somewhere (this was 30 years ago). Replacement air came through the oil filler tube filter cap.

The draft tube motors I believe also had a canister that bolted in the lifter gally that needs to be there for the tube setup to work.
I would use the filler neck with the PCV in it,this way you get your old covers but better crankcase evac system.The road draft tube don't vent when the car is not moving as there is no passing air creating a vacuum.

I am sold on the suggestions and I will be going with the pcv valve as a replacement for the draft and I will retain the look that I was going for. Thanks agian Ed

Well I picked up the rubber grommet and it fits fine and it is a simple solution to the problem, then went through may gasket kit from a head gasket replacement and there was another one. These were all great solutions to the problem and great sources for me to research further thanks, hope this may have helped someone else out also. Ed ke6bnl

For starters let me claify that I am not an engineer nor do I claim to be a mechanic. I have over 50 years of experiance building street rods/customs.
The subject of engine ventilation, ie: draft tubes/PCV is one of the most misunderstood subjects in the modified car world. The racers and uninformed come unglued when you mention SMOG EQUIPPED ENGINES. The fact is that if the engine is not vented correctly it will blow gaskets and oil.
The '63 327 in question originally had a fitting placed in the hole mentioned, to which a hose was attached with a PCV then to a vacuum port, the breather cap on the fill tube must be a BREATHER type to complete the loop.
I have a '36 Ford w/full race 59AB flathead that has a PCV as do my '56/57 Birds (312 CID) 59 Ford
4x4 (312 CID) 39 Plym Conv. (350 CID)....Bill

My 327 also has a PCV valve with a hose dumped towards the street. I did this because I thought if i plugged it into a vaccum port on my carb i would run "dirty air" back through my engine. I assumed by dumping it that my engine would be cleaner internally. Am i correct?

I think the question has been answered very well. The most recent ? about a "DIRTY" engine is the most misunderstood part about a properly vented engine. It has been my observation that PCV equipped engines run cleaner and last longer, moving air through the block minimizes internal condensation and the formation of acids, thereby keeping the engine cleaner.

How you accomplish the deed is up to ones personal tastes, you just have to keep in mind that you have to have vacuum on the line that has the PCV and you MUST have fresh, filtered air, being drawn into the inner part of the engine.

A group of us went on a rod run last summer, one of the cars was a very nice '49 Chevy Coupe, first time out. After about 60 miles the car was blowing oil, we stopped along with several other cars. The engine did not have a PCV, nor did it have any ventilation. The difference of opinions was pretty wild, from broken rings, etc. I brought up PCV which started a heated debate. After another 60 miles the fellow was going to call for a tow truck, thinking the engine was burning up, he reconsidered and continued the run. Upon arriving at the destination the fellow came to me, we went to a parts store, purchased the necessary supplies and installed a PCV. No smoke on the return!!!!

I understand that the fellow has since replaced the valve covers with covers that have ports for the PCV and replumbed my installation to make it neater.