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View Full Version : PCV/Breather/Nut?


AHorseThief
09-23-2011, 09:37 PM
My 327 was sounding vac leaky lately. I tracked it down to the PCV valve. Checked the hose running from the PCV to the carb and it was good so I got a new PCV. The good news is that the new PCV fixed the vac leak sound.

Bad news is that I decided to upgrade the engine breather from the existing 3' of hose to an actual filtered breather. My PCV is currently on the valve cover, like so.

http://farm7.static.flickr.com/6179/6176386921_1fe986e006.jpg (http://www.flickr.com/photos/goofyat210/6176386921/)

The hose is where the PCV should go on a '68 327 (I think) on the block behind the distributor. My plan was to cut the existing hose to length, install the PCV inline, and put a breather where the PCV currently sits. When I pulled the hose to add a hose clamp I found this.

http://farm7.static.flickr.com/6178/6176914804_58848cbb63.jpg (http://www.flickr.com/photos/goofyat210/6176914804/)

It looks to be a nut with a bolt coming through it from inside the engine block to act as a plug for the vent hole. Anybody have any thoughts here short of tearing the engine down? For now I'm planning on running with the PCV on the valve cover and no breather, but I don't see that being the way to go long term.

As a bonus, I get to bust out the welder to fix this sweet spot I happened to notice on my tire carrier today. Hurray for POs!

http://farm7.static.flickr.com/6178/6176386839_cf68bb358d.jpg (http://www.flickr.com/photos/goofyat210/6176386839/)

subzali
09-23-2011, 09:42 PM
Dude, I think you have a winner for the biggest stumper seen in a while.

AHorseThief
09-23-2011, 09:45 PM
What's the prize?

SteveH
09-24-2011, 07:54 AM
The 'draft tube' solution (just letting the fumes blow out of the crankcase and through a tube below the the truck) is the redneck solution, but it's been done. It's not as efficient at cleaning the crankcase as a positive vacuum deal. You sure don't want pressure in the crankcase, no matter what.

Is there a big port near the bottom of the carb where you can pull the PCV fumes into the engine (for reburning)? - some carbs and spacer plates have a port (ostensibly for power brakes...) - but maybe you can tie into that?

AHorseThief
09-24-2011, 09:40 AM
The PCV currently is connected to the carb. Everything on the PCV side of the house is in order. What I don't have is a path for the fresh air back into the crankcase.