Just installed newly rebuild '74 Olds 455 in the 1950 88. Motor has 10.5/1 pistons, aluminum heads, updated cam, 850 cfm Brawler carb, etc. Seems to have a big problem starting, idling, blowing blue smoke, etc. Appears to be a problem related to PCV valve.(?). Can the PCV valve be removed and/or replaced? I am wondering if the PCV outlet on the valve cover can be plugged and some kind of filter adapted to the oil filler tube? Any help would be appreciated. Thanks.
I'm new to the use of this forum, so hope I got this right.

 

First, I'd cap the pcv line and make sure it is the problem. Are the valve covers baffled?

 

If you end up wanting to replace your pcv, here's a suggestion - https://mewagner.com/

It's an adjustable valve that you tune to your specific engine specs. I've had one on my motor for a few years now and it's a set-and-forget proposition.

 

As I understand it, if you have a nasty cam that does not provide normal vacuum when running, you need a special PCV valve. Not sure if that would cause your symptoms though.

 

Thanks for your reply. I need to check about the baffles on the valve covers. Will also try capping the pcv line. I also plan to take the cap off the oil filler tube to see if that makes any difference. Will get back with you on the results of these changes.

 

Interesting. I'll check into it. Going to try a couple of other things first. Thanks

 

I am also concerned somewhat about the cam and that may enter into the problem. I am going to try the pcv route to see if that is the problem. Also converted to disc power brakes on the front which are not working well at all, but that is a problem to be addressed later (vacuum?) Thanks for your suggestion

 

Get a vacuum gauge and let us know what your manifold vacuum is at idle speed.

 

In checking on the pcv valve setup, I found that there are no baffles in the valve covers although the plug used in the valve cover has a restrictor in it (1950 Olds reproductions made for Chevrolet which I adapted to the 455). Also, there was no pcv valve in the circuit, the valve cover had a direct line (tube) to the carb. I plan to remove the carb to make sure all the vacuum lines are attached properly, put a pcv valve in the tube running from the valve cover to the carb. The other valve cover is plugged, so no ventilation going through the motor. Would removing the cap on the oil fill tube provide the ventilation needed as a temporary measure (test)? Although I rebuilt the motor, I employed "professionals" to finish setting up the motor - install carb, etc. Big mistake. Not only did they not set it up right, I don't know what else they did or didn't do that may also cause problems. Thanks for your help.

 

I think you're on the right path. You can make your own baffle plate. Bet the engine ran poorly with that massive vacuum leak.

 

Having manifold vacuum hose going directly into a valve cover with no PCV valve would cause a huge vacuum leak. Probably the source of your problem. You do need a breather somewhere either at the oil fill tube or in the other valve cover.

 

Someone posted pics of their engine with the PCV valve in the oil fill tube and breathers in each valve cover. That would keep the PCV vacuum from pulling in oil.

 

interesting idea. I would like to know how they set up the pcv valve on the oil filler pipe if you remember where you saw it. Did they fabricate some sort of plug for the pipe with the pcv valve in it or a hose running to the carb with the pcv somewhere along the hose, or something else??

 

That is my thinking as well. Haven't had a chance to try out that scenario yet but hope to this week

 

Breather in each valve cover. Went from pcv i modified onto oil fill tube to an inlet to a catch can, out the can to pvc port on carb.

 

OK. I see how that works. Thanks