Technical PCV with OL496

Changing over my intake to the 4x2 OL496 and wonder what is the best way to connect a PCV valve to the intake given the runner set up of the 496. It appears that if I tap the top of the intake I will only be in one half of the intake and wonder how efficient this will be. I supose I could tap both side of the top and tie them together but feel it will look a bit hokey.
Of course, I could just revert back to the draft tube but would rather give the PCV thing a shot.

 

Is there enough room between the valley cover and the manifold to tap into both levels, Tee them together and run the line back towards the road draft tube opening. That would hide most of it.

 

Have you seen aftermarket kits for plumbing PVCs to a gasket ***y that fits under carburetors, I believe they were popular in CA back in the olden days. There must still be some around? I would love one for an AFB.
Oh, and *****in' motor!

 

Possibly Bob, dunno. I will check when I go back out to the shop. Good idea though.

Thanks Bird man. I have seen those but not lately. I will look around, thought I had one here for a Holley 94.

 

I take it that this set up will use all for carbs all the time. This is a little complicated but I would place the manifold on a bench and tape off all the carb bases; poke a hole one at a time in each one and add air and see where it comes out on the head sides. Track everything. You may find that 2 of them will handle all ports. That’s the 2 you can “y” into for the vacuum side of the system. If you find this, take the time to use copper, aluminum, or stainless tubing to make the “y” and form it to use the least amount of rubber hose.
The PCV valve can be at the old draft tube or in the valley cover with a deflector.
If you decide on spacers under the carbs, use 4 to keep them on the same plane.
If you plan correctly you can stump a lot of lookie-loos on what you did.

 

Thanks Jimmy, good points for sure. It appears that there is just enough space in the air gap to fit some br*** fittings in the bottom of the intake. I did the air test and 2 fittings will be sufficient. I will use 3/8 tube, maybe something easy to bend as it is going to be a little tight. Now I need to find the fittings and then I will update this post with the process.

 

vtwhead, if your using 3/8” tube you can also use steel fuel line tubing you can blend and weld/braze it together. Since it’s vacuum you can grind down your welds in the blend of the 2 tubes. I’ve even painted the tubing flat or satin black. Good luck It would be nice to see when your done.

 

I did a PCV on this Red Ram, it had the road draft tube in the valley cover. If you look close you can see the valve plugged in, and the 3/8 tube that curved around and screwed into a 90 in the center of the manifold.

 

Boy, that Red Ram is sure pretty Marty.

 

It sure is, and last I knew he had 28,000 miles on it. That's a lot of driving in a Track Roadster !

 

That would be my thought as well. The beauty of the Olds is that you can use the factory oil baffle for the road draft tube and just put a PCV valve in there, then just run the 3/8" line up to the manifold vacuum.

 

I have never been able to understand how fitting a PCV system with early carbs that are not metered for what is basically an air leak. When PCV systems were introduced they had carbs to match. JW

 

^^^ You are correct but up until the mid sixties almost all carb systems had planned leaks. Most were for the automatic choke systems and all throttle shafts as carbs wore out leaks got worse there too and idle mixture screws were opened up to accommodate it. Same to us adding PCV systems today to engines that didn’t have them.

 

Finally finished the rerouting of the PCV. I ended up using br*** fittings as it is the only thing available in the area and it is easy to work with. What the heck, no one is going to see this anyway. Here is what it ended up looking like.




Not much shows and it should work so we will give it a go and see how it functions. Tomorrow I will install the manifold and then start working on the induction set up.

 

You will now have four cylinders running leaner than the other four. JW

 

That was my first thought as well but running an air test I found a crossover flow to the other runners. Figured it was worth trying it this way. If it does not work, I will resort to the old draft tube. It is not like this engine will see service as it did back in the day. I have been searching for an Edmunds 2x2. If I ever find one, I will be using that and pcv life will be easier. The other intake I have is a 3x2 but it apparently had been cut to fit another engine that had it's heads/block cut as it does not fit well at all, so I am working now with what I have at hand.

 

Looks to me like it should draw evenly a****st the two halves of the manifold.