Hello everyone, I have a question concerning the PCV vale fix on the 235 inline 6. I have already change it over from the down draft tube and have it running out the exhaust. question is is there any reason that I cant seal off the down draft hole and put the the pcv valve from the valve cover into exhaust manifold and then put a whole in the front side of the valve cover to the air cleaner to get fresh clean air. Just not happy with the way it idles can't get it down below 1100-1200 rpms no matter what I do.
You want to put a pcv valve into the exhaust manifold???
What year engine?
Yes the draft tube should be sealed off with a properly functioning pcv system. What kind of pcv system do you have? Factory setup? Homemade setup?
Road draft tubes work perfectly fine, especially for the type of driving and care an antique car gets. Put it back to stock, change the oil at 1 year or 3k mi and don't worry about it. Your engine will outlive you.
Are you saying that when you turn out the idle screw until it doesn't contact the stop, the car stays at 1200rpm?
1950 Chevrolet 3100 (Ol' Roy) 1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1956 Cadillac Sixty Special Fleetwood (The Godfather) | 1966 Oldsmobile Toronado (The Purple Knif) | 1966 Ford Mustang (Little Red) | 1964 Ford Galaxie 500 coupe | 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
Whatever you do, DO NOT follow the instructions on another website about putting a freeze plug and a rubber grommet into the road draft hole and installing the PCV valve there. That creates a massive oil consumption problem due to liquid oil getting drawn into the PCV system. You need to try to duplicate the factory PCV that puts the valve up about the level of the top of the side cover. Any other method is WRONG. You'll need a hose nipple that draws air from the "clean" side of the air filter and supplies it to the valve cover through a sealed oil filler cap with a hose bib on it. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Mike I was just working on mine. I run the vacuum line from the downdraft hole ( that's where the PVC valve is located) to the intake manifold right below the carburator. The air intake comes in the engine through the valve cover where you add oil
P. S. I've experienced no excessive oil consumption.
Give me a minute and I'll get you a great link and a couple photos.
I was never able to get a smooth idle pulling PCV vacuum from intake manifold. The introduction of unmetered air downstream of the carb required slobbery rich mixture for it to idle at all. So put it just past the filter ahead of the carb, allowing the carb to properly meter fuel/air as intended. Idles smooth as butter now.
Matthew 6:33
1952 Chevy 1/2-ton 3100 Late '55 235/SM420/torque tube 3.55 Dalton Highway survivor (using original 216) www.truckwithaheart.com
Please explain how you get vacuum from an exhaust manifold! Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Hello Otto, I have already change it over from the down draft tube and have it running over to the exhaust port on the exhaust side where the old vacum wiper would go. I have a 1960 235. My draft tube is sealed off with the right pcv valve. And the valve cover has the normal cap that has the built in filter from factor.
on the newer 230-250 1963 and up they show the PCV valve on top of valve cover and then going into the top of the manifold, then a fresh air tube from air cleaner feeding back io the other end of valve cover. My question is why can't a person seal of draft tube and copy the 250 style I do not understand the machanics of gas precess of the crankcase.
That is what I have already done but oil keeps coming out onto the top of my valve cover. should I run a sealed oil filler cap with a hose bib on it. To the air filter so it can suck clean air.
Hey Jerry, Thanks for the warning :-) but thats what I did. I would like to fix it like the 230-250 valve covers show The PCV valve at one end of the valve cover going to the intake manifold and the the clean air hose running to the other end of the cover on the side of it. Cand I just seal of the draft tube and do it like the 230-250.
The 230/250 valve cover is baffled so air is drawn down into the crankcase, and then back up to the other end of the cover. Simply circulating air into one end of a stovebolt valve cover and out the other end won't do a sufficient job of scavenging crankcase vapors. It's very simple to duplicate the factory PCV setup by welding a vertical tube to the original draft tube, and eliminating the pipe that goes down toward the road. There are plenty of illustrations of the stovebolt PCV system online and in various service manuals. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I don't have a pic handy at the moment- - - - -could one of the service manual gurus post a photo of the factory PCV setup, please? It resembles a regular road draft canister, but it has a tube that goes up near the valve cover rail to mount the valve, instead of a road tube. Then a 1/2" diameter vacuum line goes from the PCV to the intake (NOT EXHAUST) manifold. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Hi Jerry my PCV valve is about 8-9 inches up from down draft hole. But it goes over to where the windshield wiper would hook up on the exhaust side. so I need to drill and tap a place in the intake between the carb and head like the 250 63 and up is that correct. or maybe about 3 inches in front of the carb. on the round pipe. ?
Just drill and tap that windshield wiper port to take a 3/8" pipe thread and use a fitting that will flow enough volume to support the PCV. Some of the bigger trucks with hydrovac power brakes had an intake manifold with a bigger port in it already. You can put a T fitting in if you're still running vacuum wipers. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
