When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I recently had installed a crate engine into my 1963 driver. I kept the 327/340 intake and exhaust manifolds and valve covers to keep an original type look (not for judging purposes of course). The mechanic is concerned that the valve covers do not provide for a PCV valve. He is concerned that, in time, without relieving the pressure, leaks will develop.
Is his concern valid? If it is, are there vented aluminum finned covers that look similar to the original.
Had a similar problem with my 61. Someone put a later 350 engine in it, and I put the finned covers on. When I took it for a good drive, it would spray oil out the oil filler tube. I had to put on chrome covers and add a PCV valve to stop the problem. As far as finned covers with the PCV, I haven't seen any yet, you would have to use later year covers.
Yes his concern is very valid. You could go without a PCV valve, but I would advise you to use one. This does indeed relieve pressure and will help in reduction on small oil leaks. Now you have some choices. You could put different valve covers on. You could drill out your original covers and put breathers on them. I don't know what your oil fill is like on your year. If it is a breather then you could possibly find a spot on your intake manifold to put a PCV valve there. That is what I am going to do this winter.
"Are there vented aluminum finned covers that look similar to the original."
Yes there is. Corvette Central makes some I believe, but they are very expensive. I am not 100% sure if that is where I saw them, but I know they are out there and expensive. I like my finned covers and really don't want to change. I do want a PCV valve on my car so I am taking the intake manifold off and seeing if I can find a place to put one. I have an aftermarket intake on my car. If you are running original, I would recommend doing something with the valve covers.
From: One thing is for sure this kind of discourse and BS would not be tolerated on the NCRS forum. Ohio
Re: Need Vented Valve Covers? (plaidside)
Check the swap meets and EBAY . There are a lot of old style Corvette valve covers with aftermarket breathers on them. I got a set at Carlisle for 50 bucks with nostalgic old Moon breathers. :cool:
I have a pair of "staggered hole " 7 fin aluminum 327 valve covers for that very purpose....each side has a "horn" for breathing. I can send a pic or two if you are interested....I had them on a 66 327 for the same reason..they came off a 63 fuelie....... :chevy poortom
Hey Dick, What type of breathing was the original engine doing? Wasn't there a metal pipe attached with a long bolt next to the distributor. Early editions had a long pipe that went down along the bell housing on the passenger side to remove crankcase pressure. Later editions had a similar pipe but only about 5-6" long that a rubber hose attached to that went somewhere (carb back, oil fill tube, etc), can't remember. If you have used the 340HP intake I believe it should have this provision hole in the manifold and just do it like it was. I don't think PCV's came along till 67. It's been a long time and if I'm wrong someone here will correct me..Frank
Breathers on the valve covers (like the ones on the Ebay covers) will relieve crankcase pressure, but they will just blow an oil mist all over the top of the engine. Your original block had the provision for the crankcase ventilation intake pipe in the block to the left of the distributor, but your newer crate engine block doesn't have this hole (assuming it's based on a post-'68 block). You can use the later finned aluminum valve covers from a '69-'70 Z/28 or '70-72 Corvette LT-1, which are still active GM parts and have the holes for the PCV valve on the front of the left cover and the PCV intake pipe on the rear of the left cover, and the elbows, hoses, and valve that go along with them and have a fully-functioning PCV system that won't blow seals or put an oil mist all over the top of your engine.
It is easy to machine a PVC hole in the valve cover. I have one on the 62. Just fly cut the fins and machine the correct size hole. I forgot the dimensions but you first purchase a PVC valve gromit and then machine to fit. If you are worried about the valve cover just buy a repo and machine it.
If you need a place to add oil then you can machine the other cover to accept a removable vent cap. Works great.
Your correct John. Now I remember that the hole for the pipe was in the block. Sorry Dick. You could open up the covers in the rear by the fire wall retaining most of the orginal look and use aftermarket attachable breathers (90'ers). If they spray get ladies tennis wrist sweat bands. There elastic and fit over the breather. Easily replaceable and/or washable....Frank
Here's what I did and it has worked flawlessly for 20+ years. On the right bank valve cover just forward of the distributor and on the upper (intake manifold side) face, which is smoothe, just drill a hole for a rubber PVC grommet and install a pvc valve for any small block chevy. I use a vented cap on the breather pipe and no additional baffles in the valve cover. It works great and doesn't suck any oil. I drive it a lot so I can tell you it works fine and you don't have to machine any fins, it looks stock, and you hardly notice the pvc as it is hidden toward the back of the valve cover. My plug wires run over this area so you don't even notice it. Happy Motoring! :seeya
on the pics I sent ya the breather horns are hollow and we filled them with steel wool and threw it away every second oil chance..inexpensive and with a new engine shouldn't be that often....cheap trick that works and keeps the motor pretty..... :chevy :chevy poortom