Kingfish 11 Report post Posted March 5, 2014 I just received Ford Racing aluminum valve covers from Summit and I noticed that the passenger side cover has a grommet for a PCV valve instead of a breather. I was just going to run 2 breathers. I called Summit to order the breather size grommet and the technical guy told me most people run a PCV valve to take the pressure off the crank case. I haven't had a PCV valve on the 69 351W for probably over 40 years. DO I REALLY NEED ONE to take the pressure off the crank case? And how many of you are running a PCV? Thanks for any input, Steve. Quote Share this post Link to post Share on other sites
Brian Conway 264 Report post Posted March 5, 2014 I have the PCV's on my 65 and 69 hooked up. No particular reason just seems simpler; need to fill the hole in the valve cover with something, the carbs are set up to receive the PVC hose and my concession to pollution control. Brian Quote Share this post Link to post Share on other sites
69gmachine 15 Report post Posted March 5, 2014 You need to evacuate the pressure somehow, and the PCV is the easiest way to do it. Are you just venting to the atmosphere now with 2 breathers? Quote Share this post Link to post Share on other sites
Kingfish 11 Report post Posted March 6, 2014 I've been venting to the atmosphere for a good long time. I think with these new valve covers I'll hook up the PCV valve. My old covers had 2 breathers, Steve Quote Share this post Link to post Share on other sites
miketyler 15 Report post Posted March 6, 2014 On my 351C, I have PCV on passenger side, and hose that goes to the breather with filter element on drivers side. I was thinking this was the factory setup on most V8's. Quote Share this post Link to post Share on other sites
j69302 11 Report post Posted March 6, 2014 PCV is actually good for the engine. It will circulate fresh, clean air (from either the bottom of the air cleaner or through filtered breather on the opposite valve cover). Having this hook up will evacuate crankcase pressure which will prevent blow by and oil fumes from making your engine bay dirty/greasy. It will remove moisture from the crankcase, and combustion by products which if left to sit in your oil will break the oil down and try to return it back to its natural raw state. These combustion by products can also form acids in the oils which can eat and etch the main bearing materials. PCV valves are good for your engine. Hook it up. Quote Share this post Link to post Share on other sites
Kingfish 11 Report post Posted March 6, 2014 Everyone: Thanks for all of the good input! I WILL HOOK MY PCV VALVE BACK UP! Kingfish (Steve) Quote Share this post Link to post Share on other sites
Max Power 74 Report post Posted March 6, 2014 PCV is actually good for the engine. It will circulate fresh, clean air (from either the bottom of the air cleaner or through filtered breather on the opposite valve cover). Having this hook up will evacuate crankcase pressure which will prevent blow by and oil fumes from making your engine bay dirty/greasy. It will remove moisture from the crankcase, and combustion by products which if left to sit in your oil will break the oil down and try to return it back to its natural raw state. These combustion by products can also form acids in the oils which can eat and etch the main bearing materials. PCV valves are good for your engine. Hook it up. All good points. While you can just run two breathers and get away with it, just keeping your shiny new valve covers clean is reason enough. Better to burn the vapor off rather than gunk up your engine bay. When I bought my Mustang 15 years ago, it had a fairly tired engine with a bit of blowby, unbeknownst to me at the time. I bought it in Fresno and was driving to Vegas through the Tehatchapee mountain pass. All of a sudden I smell oil while climbing the mountain and started to panic. Pull over and my PCV is popped out of the VC. Turns out the PO had a non vented cap on one side, and the pressure internally built up and blew the PCV out the other. Bought a vented cap for the other side and problem solved. Quote Share this post Link to post Share on other sites