I have a '62 283 that's mildly warmed over(bored to 292, mild RV cam etc). It has the road draft tube port at the rear of the engine beside the distributor...but I don't have the road draft tube, nor do I have the ventilator canister in the lifter valley. I'm planning to run corvette valve covers and a dual 4 manifold with an oil fill tube which is already bolted on it. I have been told that if I run a PCV conversion from the road draft tube port to one carb, that I will create a vacuum leak. Is this really true? My understanding is that GM went to the PCV system and used the road draft tube port in the early PCV years. I can't imagine GM would use this with if it caused a vacuum leak. Secondly, does anyone know what dual 4 manifold will work with the ventilator canister? I think the one I have will hit the canister. My understanding is that the ventilator canister is necessary as without it, oil splashing around the lifter valley will get sucked into the PCV hose and into the carb, clogging the PCV. I know just using a road draft tube would be easy, but this engine is going in a deuce roadster and I don't want to smell fumes etc from the RDT.
There are plenty of Chevrolet dual quad manifolds on eBay, ask one for a photograph of the underside and see if it might clear the manifold. A California 61 MAY have had a PVC so ask if the manifold is date coded a 61. The PVC's were mandatory in 62 and I'm not sure dual quads were offered in 62 with the 327's. You may be able to do a little cosmetic surgery on the canister to flatten the top to clear. This is another option. Some Chevrolet front oil filler tubes have a threaded fitting on the side near the top it also has a twist seal cap on it. It was for the PVC of that year ( I believe 1969 it was there) you could use one of those and plug the rear hole with a cup freeze plug. You will need a breather on one of the valve covers if you do that. That hose should go to the air cleaner so the engine does suck unfiltered air. Good Luck.
All PCV valves are inherent vacuum leaks when open. The valve is designed to close off at periods of high vacuum so at idle there is no loss of vacuum.
Use the cannister AND the elbow that bolts into the block for a PCV valve to connect to that should connect with the PCV valve to the rear of an intake or into the base of a carburetor. Both of those items are getting expensive, even on E-Bay. Hit your friends up first, then local car guys, before going to E-Bay for the cannister or elbow. A factory OR aftermarket dual quad intake should fit with the short cannister; keep in mind there are long and short cannisters. 55-56 are longer, 57 on are shorter. Be sure the cannister is boiled out, and you use a new breather cap; they get crudded up. The cannisters are available new from the corvette restorers, but are really expensive. Don't drill into your intake manifold, or Vette valve covers; it can be avoided so easily. You probably already knew all of this, but if you did't.....................................I am Butch/56sedandelivery.
I found the ventilator canister reproduced on a corvette website for $50. Where can I get the elbowyou're referring to? I haven't been able to find that. The corvette website says 55-67...I didn't know there were different lengths for the canister.
No it will not create a vacuum leak, yes to PCV. You just put a grommet on the hole for the road draft tube and stick your PCV in there. Note: the baffle in the lifter valley for the road draft tube won't clear some intakes and has to be removed, Mr gasket makes a baffled grommet for a PCV valve that you will have to use in that situation.
The 55-56 265's had a very short , oil splash pan, riveted underneath the intake manifold; that's why they use a long cannister, there's more room; the pan's only about 4 inchs wide.. The pan got longer in 57, so the cannister got shorter. Only the shorter one is re-popped. The elbow is strictly a used item.The short will work with any manifold. Aftermarket manifolds don't have a pan at all, and can use either one. I've seen some cannisters beaten to conform. I am Butch/56sedandelivery.
Side note: I have an elbow on my 283 with a hose running to the rear of the car....which would eliminate any smell.
Your lucky you have the early block. GM figured out the conversion for you. No drilling of anything, just run the stock filler tube and breather up front. Install this kit in the hole and bolt in the canister baffle. Of course you can make your own versions of this factory stuff. Listen to Butch/56 and his wealth of knowledge. https://www.ebay.com/ulk/itm/311576897861 https://www.ebay.com/ulk/itm/351678731541
That's the kit I was looking at. Corvette central also repops the canister. I just don't want to buy the canister if it won't fit under my manifold.
It should, those manifolds usually don't have a lot of material hanging down in the valley. On The fitting to go in the road draft tube hole. You could fab your own piece with a short piece of tubing that would fit in the hole a soft plug and a piece of tubing welded to the side to fit the pcv valve to. . I used to see guys cut the road draft tube off and make a fitting out of the piece that stuck in the block too. Or if you want to keep things simple check this kit out and then figure out how to do it yourself for under 10 bucks. http://www.classicchevy.com/chevy-pcv-valve-kit-small-block-with-metal-elbow-1955-1957.html I think that is what I did on the 283 I had in my T bucket in the mid 70's.
I got weak and decided to post. Warmed over 283 buy a smog pump, drive it with fan belt, suck side to breather or tube, blow side to outside air
So I was at the Monroe swap meet yesterday and found the elbow I needed. (See below). My question is does a PCV valve go between the elbow and the carburator? Or is there no actual PCV valve in this system? I'm running an oil fill tube with a breather on the front (and a ventilator canister in the lifter valley).
This is way easier than you're making it. If you don't have a canister, take a freeze plug, drill a bunch of small holes in it. Hammer it in the valley side. Wha-laa! Instant baffle canister. I always put one hole low so any oil that might get caught in there can drain back. Next, they sell a baffled PCV valve cover grommet that fits the block hole perfectly. Your choice of angled or straight PCV valve goes right in, hook up your hose and Shish-boom-bang! You're done. I've done this on several 283s and never had any problems.
You still need the valve. You can put an inline valve in between the elbow an the carb but there is also one that can be screwed directly into the carb base and then its just a hose to tge elbow. The screw in ones were on factory 283 after 63 I believe. I'll find the part number on my extra ones and post it tomorrow.
I bought this PCV Retrofit Kit from an Ebay vendor. It fits into the road draft hole and the valve attaches to the base of my Edelbrock carburetor with a supplied 90 degree fitting. Works awesome! Hosted on Fotki Hosted on Fotki
Any word on how it works out hooking the PCV to the back of the carb by the secondaries instead of using the port on the front that Edelbrock spec's for the PCV hook-up? Looks better with a hose off the back than going around from in front.
I had already been driving around for a month before I noticed in the carburetor instruction booklet that they recommend using the front port for PCV and the rear port for brake vacuum booster. I'm still using the rear port and have noticed no adverse effects. It definitely looks cleaner this way and that's how GM did it when they changed over to PCV valves. The crankcase must be venting adequately because I have zero oil leaks and I've been driving my truck 99% daily to work since getting it road worthy in early January.
I'm planning on running the Pcv in the road draft inlet. The canister is in the valley. Running no hole Cal Custom 9 fins, and I built a top fill thermostat housing, so there is no room for a breather tube. So I built a breather to run on the top of the timing chain cover. It's not finished in the pic, I still have to weld the mount to the timing cover and polish everything. The breather is drilled and will have a screen and filter inside.
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