Best PCV hose connection? Intake manifold or Carb?

[Great68]

I was just wondering what would be the better location for the PCV hose to plug into. Right now I have it going into the back of the intake manifold, but a friend told me it is better to put it to the carb because this way it more evenly distributes over all the cylinders.

It makes sense. What do you guys think?

 

[D.Hearne]

Either way is good.

 

[Ozsum2]

What D said.

 

[Ronstang]

For once I will disagree with D. Hearne. If you plumb the PCV into one runner in the intake like most threaded ports are in aftermarket units then you are fouling only one cylinder and it can affect the plug and overall cylinder temp of that single cylinder so it is always better to plumb the PCV into the carb or a spacer underneath it that will distribute the gases to all cylinders.

 

[Route666]

I agree with Ronstang.

Although, unless you take the source from the very middle of the intake charge of the carb, it will most likely still effect some cylinders more than others. Most likely this will be a lot more negligable than being hooked to the manifold, but it still exists.

 

[D.Hearne]

For once I will disagree with D. Hearne. If you plumb the PCV into one runner in the intake like most threaded ports are in aftermarket units then you are fouling only one cylinder and it can affect the plug and overall cylinder temp of that single cylinder so it is always better to plumb the PCV into the carb or a spacer underneath it that will distribute the gases to all cylinders.

That's really only going to happen if you have a really bad blow-by problem or if you have no valve cover baffles to shield the PCV valve, if that's the case, then yes, it needs to go into the carb base. I've plumbed it both ways, and never seen a difference either way. Use which ever port is convenient.

 

[Max Power]

Agree with Ronstang.

 

[Ozsum2]

Still agree with D. I really shouldn't matter. I run mine off a carb spacer.

 

[BobV]

I agree with your friend, better at a central point, like under the carb.

When the new engine went in my car, I ran the PCV to the intake runner on an old Shelby intake. Cylinder #8 sparkplug was always extremely lean, and #3 was somewhat lean. The rest of the plugs were perfect. Later changed to a carb spacer setup, and all cylinders are now even. The extra "air" being pulled thru the PCV will lean out one or more cylinders if hooked up to a runner

 

[oz]

When I started my newly rebuilt 302, I had a PCV plumbed from the valve cover to the threaded port going to runner #8... well the PCV sucked oil (no baffle) so I got a lot of white smoke from the left pipe until I disconnected this PCV...
...so I would recommend attaching it to a carb port if one exists. The manifold is always the second choice if needed.

 

[WORTH]

I was just wondering what would be the better location for the PCV hose to plug into. Right now I have it going into the back of the intake manifold, but a friend told me it is better to put it to the carb because this way it more evenly distributes over all the cylinders.

It makes sense. What do you guys think?

I agree