Thinking about putting a PCV system on the new 235 that I have for my 37 Chevy p/u but would also like to have it where its not that noticeable,was wanting to keep the road draft tube but block it off and try to put the PCV in it some how so if anyone has done it please post some pictures. I have tried to make the present 235 look like a 216 and would like to keep that look.
Might be helpful, might not. http://devestechnet.com/Home/PCVInstall I would think you could weld a cap on the end of the road draft tube and use the grommet method on a hole drilled on the top of the road draft tube.
I'd drill a hole in the side of the road draft tube a bit down from the top and weld in a bung for the PCV valve and put a freeze plug or something similar in the end of the draft tube. I've seen a lot of them (and done a couple on customer cars) that had the road draft tube cut off about an inch from the piece that goes in the block and a fitting welded in the stub of the tube for the pcv. I think some guys use a rubber pvc grommet stuck in there to do it but we were doing those in the 70's .
Will start looking for another road draft tube to modify,I am using the original 37 tube that has the oil fill cap on it which will make it a little harder to do. Looks like I will have to go to the later style 216 valve cover with the fill cap so it can breath.
On my wife's 216 I did exactly what you're looking to do. Look in the Inliners social forum for the post "TECH- PCV Valve for Inline 6".
The oil fill tubes from 55-mid 60s V8 will also fit your block. Personally like the chrome one shown below. I believe that it's from a 350 horse 327 about 1965. I think that these are reproduced. Eddie
That isn't a PCV. its simply a vapor hose that lets the blow by be directed into the air fuel mix. A PCV is a metered vacuum leak. From the inside of engine thru a PCV valve and hooked to a manifold vacuum port.
I used that page as a guide to install mine. It had a freeze plug in the hole and the valve cover was hacked into when I bought it. Here's what it is now:
I guess some people love the smell of gasoline vapors mixed with burnt oil, but not my wife! When we bought her mostly-stock '51 3600 that was one thing she didn't like about it. Pull the truck into the garage, shut it off, and almost instantly, the tell-tale sign of worn rings wafts from the 216 valve cover and fills the garage. She hated the stink on her clothes, too. Well, I knew I'd eventually rebuild the motor (that's another post), but I needed a quick fix--a pcv valve! I loved the stock look of her engine, so I didn't want to ditch the road draft tube and plug it with a pcv valve. What to do? Can you see the pcv valve in this picture? How about a closer view... You might notice the extra tubing running up the front of the engine, or maybe the plugged vacuum port down near the oil pan. The pcv valve is inside the road draft tube canister, with the vacuum line running down the tube and around the engine to the intake manifold: I didn't take a lot of pictures as I was building this (I'd rather just get it done!) but I can describe how I did it. This project uses a Standard brand pcv valve #V237. This valve has the correct vacuum rating for a 216/235 engine. Start by removing the road draft tube from the engine. Drill out the 3-4 spot welds that hold the cap on, remove the cap and clean all the gunk out of the canister. Remove the "gunk trap" and we're ready to begin. If you have a lathe, or access to one, this is going to be easier. I machined a holder for the pcv valve, with 2 o-rings on the inside to seal the valve, and one o-ring around the outside rim to seal the holder inside the road draft canister. There is a cross-drilled tube that connects to an X shaped base which is plug welded to the bottom of the tube (the tube is open from the pcv socket and is plug welded closed at the X base): Manifold vacuum pulls vapors past the X base (which is at the bottom of the road draft canister), though copper pot scrubber mesh (not shown) that is wrapped around the tube, into the holes in the tube, and up through the pcv valve which is installed at the top: Insert the holder into the canister with the connectors facing the road draft tube: Any oil mist collects on the copper mesh and drains back into the crankcase past the X base. Everything needs to be sealed so that the vacuum only pulls vapors from the crankcase and not outside air. You can just press the road draft cap back on as there's no vacuum present in the canister above the pcv holder. Also it makes it handy to clean the pcv valve. Snake a rubber vacuum line up the road draft tube and connect one end to the pcv valve. The other end connects to a hard line coming from the intake manifold. You can route this any way you like; I made mine connect to the rubber hose right at the level of the road draft tube mounting clamp by drilling a hole in the side of the tube. It stays hidden this way. I also placed a vacuum port in the hard line (see photo above) so I can connect a vacuum gauge while I'm tuning the engine. Very handy! Now that we have the vacuum side all done, we've got to get fresh air into the crankcase. The best place to draw air in is through the slots in the valve cover, but we don't want to pull dirty air into our engine! I made a simple filter out of a 3"x20" piece of 16g sheet metal and some fabric store batting (sorry, no pictures of this part, but I think you'll get the idea...). I drilled 2 holes in the sheet metal base for the valve cover studs, aligning them so I covered the valve cover slots but not the oil fill hole. I threaded a nut down each stud for the base to sit on, above the rockers and close to the top of the valve cover, and another nut on top to hold it in place. You will have to play with the position of the base so that your valve cover fits correctly. Once the base is on, cut a piece of 1" thick batting (the open-weave nylon stuff, not cotton batting!), 4"x21" to sit down over the studs on the metal base. This batting should be thick enough to press against the inside of the valve cover, sealing the slots but allowing air to easily p*** through. Over time this batting will become oil misted and really collect the dirt! Now you've got filtered air pulling into your engine, replacing the crankcase vapors which are being pulled into the manifold for re-burning. This setup works extremely well on my wife's truck and has totally eliminated the burnt oil/gas smell in the garage. She enjoys driving it now and, you know the saying, "happy wife, happy life"!
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