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Crankcase ventilation, deleting air hose?
https://www.slantsix.org/forum/viewtopic.php?t=66315		 Page 2 of 2
Author:  Red [ Sat Nov 27, 2021 9:51 am ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
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In the mid 1960s the Ford 289 was probably the lightest, most compact American V8 in production and it made decent power. It's lighter than a 225!
When I was a teenager, my old man had a '64 Ford Falcon. It had a 260, the "grocery getter" version of the 289) in it. Even that scooted along just fine and was fun to drive.
Author:  Dart270 [ Sat Nov 27, 2021 1:43 pm ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
All I can say is... Vive la difference!! I think of cars as rolling sculpture, and the more creative and unusual the better.

Lou
Author:  SpaceFrank [ Mon Jan 03, 2022 12:50 pm ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
I'm not familiar with the '85 slant's PCV system, but it sounds like there's an air hose bringing filtered air in from your carb's air cleaner, in addition to the actual ventilation line (with the PCV valve in it) going to somewhere on your intake manifold. Earlier slants (circa '70s) used a standalone breather filter on the valve cover to let air in, rather than a separate line to the air cleaner. Much earlier slants (circa '60s) used a primitive combination filler cap/breather full of steel wool (so they only had two holes in the valve cover, but they were both stove-pipes sticking up out of the cover). Swapping to a different valve cover may put you in a better starting position for the modifications you want to make.

If you're open to a little sheet metal work, I don't see why you couldn't relocate the air inlet hose to the driver's side of the valve cover. Just be careful not to route the hose too close to the exhaust runners, or use a hose material that can take the heat. As long as the hose runs upward to your air cleaner (or another remote filter), you shouldn't have to worry about oil splashing into it. This line brings air INTO the valve cover, so you won't be sucking oil into the hose.

From the phrasing of your question, I assume the actual PCV line is not in the way of your coil pack plans? If you need to relocate this one, make sure you look up under your valve cover and take note of the splash shield that Chrysler put there. Since this line does pull air out of the crankcase, you need to make sure you prevent it from sucking in a bunch of oil spray from the rockers.
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Since I am planning on deleting the distributor, I am going to use that hole as an oil fill by putting in a tube with a modern threaded oil cap.
I like this idea. I just made a flat blockoff plate for our distributor hole, but welding up a tube with an oil fill cap from a later-model engine shouldn't be too hard. My main concern is that the distributor hole might be small enough to restrict flow and back up oil in the tube while filling. If you find something that works with minimal fabrication, please post pictures and part numbers!

(We ran into the same problem putting LS coil packs on our slant, so we decided to build a bracket that holds them off to the passenger side of the valve cover. In hindsight this was a bad idea because it made the spark plugs, plug wires, and transmission dipstick harder to access. So now I'm thinking along the same lines as you.)
Author:  MazdaRX8/6 [ Sun Jan 09, 2022 5:59 am ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
It occurred to me at a later date that the second hole in the valve cover, the one that goes to the air cleaner has to be able to blow crankcase gasses OUT sometimes, because when the engine is under full load it will be at nearly zero vacuum, and the engine will be producing maximum blowby. So, under most operating conditions one hole with the PCV valve would work. But not always.

After posting this I got the slant bolted in with my temporary trans to engine plywood adapters and I do not have enough hood clearance to put the LS coils on top of the valve cover. I'm going to mount them over the inrake runners.

I'm going to do as suggested here and move the PCV valve rearward where I have more clearance. I may have to weld another baffle inside the valve cover.

I have not mastered putting photos here yet. I am posting photos on Facebook in the RX8 Swap Commumity.
Author:  SlantSixDan [ Sun Jan 09, 2022 3:32 pm ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
Quote:
under most operating conditions one hole with the PCV valve would work.
No, you want airflow through the crankcase at all times.
Quote:
I'm going to do as suggested here and move the PCV valve rearward where I have more clearance. I may have to weld another baffle inside the valve cover.
Baffle info is in the link here.
Author:  Killer6 [ Mon Jan 10, 2022 5:33 am ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
In order to suck blowby combustion gasses out, You have to let filtered fresh air in, not an option to "one hole" it.
Mounting the coils over the intake means over the exhaust too, I'd pick someplace cooler.
Author:  MazdaRX8/6 [ Mon Jan 10, 2022 11:22 am ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
Quote:
Quote:
under most operating conditions one hole with the PCV valve would work.
No, you want airflow through the crankcase at all times.
Quote:
I'm going to do as suggested here and move the PCV valve rearward where I have more clearance. I may have to weld another baffle inside the valve cover.
Baffle info is in the link here.
Thanks Dan. I would imagine that Chrysler spent a good amount of time and money perfecting the baffle system in the valve cover. I am sticking with the stock valve cover for clearance reasons. I just do 't have that inch I need where the PCV is. I might have to put the PCV in the top of the stand pipe I am planning for the hole that used to hold the distributor. I have to get rid of the PCV and the oil fill cap (I think). Still building motor mounts.
Author:  MazdaRX8/6 [ Mon Jan 10, 2022 11:28 am ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
Quote:
In order to suck blowby combustion gasses out, You have to let filtered fresh air in, not an option to "one hole" it.
Mounting the coils over the intake means over the exhaust too, I'd pick someplace cooler.
I appreciate your concern about the heat over the exhaust manifold, but the LS coils are designed to operate in a hot engine compartment. It doesn't take much of a heat shield and air gap to make the difference. The exhaust manifold is an inch away from the starter solenoid on my Chevy smallblock with a tiny aluminum heat shield. I have am old Ford tractor that the gas tank is less than 2" from the exhaust manifold with just a stamped piece of sheet metal between them.
Author:  SlantSixDan [ Tue Jan 11, 2022 12:35 pm ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
Quote:
I would imagine that Chrysler spent a good amount of time and money perfecting the baffle system in the valve cover.
They did no such thing. They slapped in the cheapest baffle they could get away with and called it good. Their engineers were working toward a goal of commercial adequacy (as defined by the design brief) at minimum possible cost. Read through that paper I posted in your thread about fuel injector angle, and you'll see it come up again and again: lower cost, lower cost, lower cost, this approach was not pursued due to cost, etc. Not the same as your situation where you have the luxury of spending whatever time and money you want to make it work as well as possible.
Quote:
I might have to put the PCV in the top of the stand pipe I am planning for the hole that used to hold the distributor.
Not a good place for it, unless what you do is make a tunnel/tube extending up from the distributor hole, and put the PCV valve in the oil cap atop that tunnel/tube. You'll still have to figure out where to put your crankcase air inlet.
Author:  MazdaRX8/6 [ Wed Jan 12, 2022 11:24 am ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
Not a good place for it, unless what you do is make a tunnel/tube extending up from the distributor hole, and put the PCV valve in the oil cap atop that tunnel/tube. You'll still have to figure out where to put your crankcase air inlet.[/quote]

I have hood clearance toward the back of the valve cover for the breather cap, but not toward the front where the PCV sticks up.
I could possibly reverse the two by making the breather vent from the driver's side of the valve cover and put the PCV in the back hole. Just a thought.
Author:  ProCycle [ Wed Jan 12, 2022 11:47 am ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
Relocate the PCV to the side or front of the valve cover?
Author:  Killer6 [ Wed Jan 12, 2022 5:44 pm ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
Quote:
Quote:
In order to suck blowby combustion gasses out, You have to let filtered fresh air in, not an option to "one hole" it.
Mounting the coils over the intake means over the exhaust too, I'd pick someplace cooler.
I appreciate your concern about the heat over the exhaust manifold, but the LS coils are designed to operate in a hot engine compartment.
Lol. OK......
Author:  Killer6 [ Wed Jan 12, 2022 5:55 pm ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
Quote:
Not a good place for it, unless what you do is make a tunnel/tube extending up from the distributor hole, and put the PCV valve in the oil cap atop that tunnel/tube. You'll still have to figure out where to put your crankcase air inlet.
I have hood clearance toward the back of the valve cover for the breather cap, but not toward the front where the PCV sticks up.
I could possibly reverse the two by making the breather vent from the driver's side of the valve cover and put the PCV in the back hole. Just a thought.[/quote]
That's a great idea, as well as the fill-tube where the dizzy was. The older Slantys had the PCV in back, but unfortunately I believe Your head takes the re-designed cover, not a swap-able quick fix. There should be enough room to mount & properly baffle the breather up on the Dr. side.
Author:  tattoosteve99 [ Mon Feb 07, 2022 2:03 pm ]
Post subject:  Re: Crankcase ventilation, deleting air hose?
I’m late to the party. I can inject a little here. I did away with my factory setup at one time on my 78. Thought I had blown a head gasket as I noticed white milky oil on the fill cap. It turns out without the correct system regular moisture from the air will cause this. I added back the factory pvc and air intake and voila, no more milky oil.
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