PCV valve delete
 

I am deleting the PCV connection in my 1.8 L turbo build.
Can anyone advise on how to plug the whole that leaves in the valve cover?
The rubber grommet the valve sits in is already gone, shredded apart when I removed it to clean the cover, so just capping the PCV is a bit out of the question without spending a fair amount on a Mazda part.
If I get some sort of rubber cap/firewall plug-like piece will it withstand the pressure it might face from blow by?

The website wished me a Happy Bday a few days ago, so I gifted myself the chance to ask this silly question instead of being creative on my own.

I bought a pop-gun from the 1950s, the one with the little cork in the end of the barrel. I threw the gun away and used the cork to plug up the annoying holes in the head.

Fun fact, the gun looks super real, so if you point it at the cops you get a wicked beat down.

Drill and tap it for a 1/2NPT. Then you can either plug it or put an adapter in it for catch cans.

That must be one huge cork! More like an old fashioned musket ball flint pistol, no wonder it earns a beat down!

The hole is 0.7 inch, 17.75 mm in diam.
That's almost twice a 44!

If you get a new grommet a 1/2" hose barb fits it well.

Probably pretty stupid to just plug it, especially if adding more power.

You can plug the valve cover and let your crank & oil pan seals vent the pressure. :idea:

https://cimg5.ibsrv.net/gimg/www.mia...197e94498.jpeg

"You can plug the valve cover and let your crank & oil pan seals vent the pressure."

Actually, I put a big hole (-8 AN) in the side of the block to vent the pressure to atmosphere through an oil recovery trap, and a feed line back into the sump for the oil return. This follows what Mazda did for the turbo B6T engines in the 323 GT and GTX.
There remains the vent on the other side of the valve cover to vent pressure, as well.

And, thinking of Midtenn's byline to one of the revered ones on this site, another one, Savington, (Andrew), has made clear that if you are going to vent the valve cover to atmosphere you do not want to do it with the PCV vent, you want to do it with the one on the hot side of the head. He has clearly stated that on the race track, the PCV side dumps a lot of oil and is better to be blocked.

If it were a street car I would not block it, if I had not installed a vent to atmosphere port on the bottom end of the block I would not block it. But the head will be vented, the seals will not be doing the job.

In that case, I think Midtenn's on the money with the 1/2" NPT and plug :bigtu:

Since you almost asked:

Vent to atmosphere from block. Used a boss or landing Mazda left on the casting.
ORB connector a tight fit in behind alternator, but it will work.

https://cimg4.ibsrv.net/gimg/www.mia...b4fa04467.jpeg

Then the condensed oil return to the sump was placed close to the bottom, in a space that clears the internal braces and strengthening bits, and externally fits between the 2001 engine mount (that follows the black line) and the cross member. ~ Filled oil level is marked by the short horizontal line.
A bit small a diameter, but the easiest size to fit. Used a -6 AN bulkhead part, with copper crush washers and gasket maker to seal it in place.

https://cimg7.ibsrv.net/gimg/www.mia...70c11c774.jpeg

Neat. You just drilled that out? Does the engine go longways or sideways? Seems a miata might dump oil out that hole depending on which way you are going? That looks a lot lot lower than the original breather location if I'm not mistaken, because I thought that was above the mount bosses. At least if it's sideways you are off power when the oil sloshes up there?

I'd like a heated catch can with a programmed drain valve to the pan after coolant temp hopefully flashes out all the water and other nasty bits, an extra hole in the block to assist the head draining is just icing on teh cake.

That does sound magnificent, but the closest thing I have found is the coolant heated Radium catch can. It adds a lot more plumbing, and they are very pricey. I have not brought myself to buy one.

Yes, the boss I used is about 1.5 inches lower than the one Mazda left of the 1.6 L block, which was just below the oil pump to oil filter feed line that runs visibly along the block. But they stopped having that boss on the 1.8 L engines. I will end up learning if it is too low. But there is a substantial windage tray, and it sits above that, which should help a bit.

I was thinking of making a catch can that sits on top of or near enough the exhaust to heat things up.
im not totally sold on the idea of returning the crank case vented oil back into the pan though.
seems like it would be fairly contaminated with combustion byproducts besides oil and oxidation.