Where to run the valve cover vent tube?

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clementine

clementine

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Hello FABO!!
I have some old valve covers I like and have the PVC worked out. I am looking for solutions to the breather tube coming off the drivers side. My question is....if im running EFI would it be better to run the breather hose down to the header collector or into the wheel well or into the air cleaner. I ask because if I do have some blow by anomaly then all that nasty haze/smoke is going into the TBI..not good? I have a routing plan and I have a couple pics of the fitting I found that I could drill up into the lower part of the air cleaner. Using the knockout would put the fitting into the EFI unit so using that is out. Suggestions?
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As the engine runs with a PCV system, the air is pulled from the breather/oil cap into the engine by the PCV valve.The PCV is mounted in the opposite valve cover thru the crank case and into the intake either thru a port on the throttle body/carb base or direct port of the manifold.
So your idea is correct to pull from the base plate of the air cleaner pulling filtered air into the breather cap.
 
Drago looks a lot like my daughter's Texas rescue dog Maxine. Big feet, short legs, will herd anything.

As for the vent, stock in 67 has the cap inlet outside the air filter. On the snorkel of a silenced air cleaner, and on the housing of an unsilenced air cleaner.

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I always thought this was odd as then you are pulling unfiltered air into the crankcase.

Other (earlier???) years just had a cap on the inlet of the valve cover that allowed fresh air in. (had oiled mesh inside to catch particulate)

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Dana67Dart said:
Drago looks a lot like my daughter's Texas rescue dog Maxine. Big feet, short legs, will herd anything.

As for the vent, stock in 67 has the cap inlet outside the air filter. On the snorkel of a silenced air cleaner, and on the housing of an unsilenced air cleaner.

I always thought this was odd as then you are pulling unfiltered air into the crankcase.

Other (earlier???) years just had a cap on the inlet of the valve cover that allowed fresh air in. (May have had oiled mesh inside to catch particulate)

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Yes very similar markings although Drago is all leggy.

So as this is not stock situation, and Im running an un silenced air cleaner, do you think drilling into where my picture has that fitting will be fine? it would be filtered air. The valve cover has a baffle in the area of the breather.
 
Only issue I can see is it will be a slightly lower pressure area then outside if the air filter (air creates a slight restriction) and the possibility that oil droplets could get into the inlet of the EFI.

IIRC the PVC could become overwhelmed under certain cercomstances like WOT and excess blowby gets sucked into the carb / EFI and burnt.
 
The thing is, the air filter bonnet has ALWAYS been the correct place, a baffle on one valve cover, plumbed as you propose to the filter bonnet, and the pcv on the opposite vc.

Issues:

Some aftermarket baffles are not up to the task, and many factory vc (generally not necessarily Mopar) had additional baffles below the hose connection baffle

Engines with excessive blowby WILL put oil laden air back into the filter bonnet

If you connect to the header, you will need one of the check valve fittings, you cannot just plumb the hose right in. There are diagrams here and there on how to build these. Basically, they use smog pump check valves

BUT IF YOU WANT to get "down and dirty," (And I doubt this is legal in WA) just hook a hose to the thing and run it down "under the engine" "road draft tube" style
 
That hose is an INLET and supplies filtered air to the crankcase for the pcv system. Run it to the air cleaner. It’s amazing how much oil/blowby you’d have to pump in to the throttle body of an efi system for it to care at all. Ask anyone with a turbocharger.
 
You can even buy a remote filter for it and not run it to the air inlet at all, but at WOT, if you do actually have blow-by, and the filter is too small, it will make a mess.
The common use of the term blow-by, does not necessarily have to be confined to applying to combustion gasses blowing past the rings.There can be other sources that masquerade as blow-by.
Such as; the crank picking up the oil and whipping it up, an overly rich mixture, overly exuberant oil-squirters, or just plain old inadequate baffling under the valve cover. Besides that are; vertical scratches in the cylinder walls, unusual oil drainage from the top end, possibly even late ignition timing.
If it was me, I'd be doing a LeakDown test, to see how bad it really is.
 
The engine is a fairly new rebuild, or so I was told, and it seems to act like it judging by the first start up. not smoking except the usual 'first start' burn off. So this is where things are at. the chrome air cleaner top is getting blasted and will get a wrinkle paint finish. enjoy and thanks for the input!

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That looks really nice. What are you using for fuel delivery? Looks like some kinda TBI.
 
RustyRatRod said:
Last I checked, I'm still me, yeah. lol I've read a lot of good about the Sniper stuff.
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I still dont know if Im supposed to set my timing at 0 and let the computer do the advance or set at 12 and go. but it did start right away, I have no run/learn time on it as Im still squaring everything else away. Running the hyperspark, the sniper coil and their ignition box, so added costs there, but fingers crossed that the hemmoraging has slowed on this build.
Thanks for the encouragement. next up....getting the gauges to work, hopefully a wire not hooked up and not the IVR. I do not have my head wrapped around that fix despite all the threads I have read about it. Keep you updated.

Thanks again for the response.
 
I can't detail the procedure here, but the timing can not "advance" electronically, it can only retard. Think about it. There is no such thing as time travel. LOL. What happens is that the computer generates "delay gates" (pulses) which turn off the timing trigger coming in. This re tards the spark. As "more advance" (less retard) is needed the delay gate gets smaller

What you are going to get into here --and you have to do some searching and research--is what is called "rotor phasing" because in a normal distributor, the trigger/ spark event as compared to where the rotor is pointing---is determined by the position of breaker points or the trigger device. But with EFI the computer MOVES that because of the trigger delay. So the rotor position needs to be ?? physically timed so that the rotor is mid point on the cap contact with "about midpoint" in the timing curve---so that as timing is moved from "advance" to retard, the rotor is still in range of the contact.

I am NOT CERTAIN but it might be that the computer can delay the pulse one dist. revolution, so it can get the pulse "advanced" enough. Don't take that as "gospel" it just seems reasonable.
 
67Dart273 said:
I can't detail the procedure here, but the timing can not "advance" electronically, it can only retard. Think about it. There is no such thing as time travel. LOL. What happens is that the computer generates "delay gates" (pulses) which turn off the timing trigger coming in. This re tards the spark. As "more advance" (less retard) is needed the delay gate gets smaller

What you are going to get into here --and you have to do some searching and research--is what is called "rotor phasing" because in a normal distributor, the trigger/ spark event as compared to where the rotor is pointing---is determined by the position of breaker points or the trigger device. But with EFI the computer MOVES that because of the trigger delay. So the rotor position needs to be ?? physically timed so that the rotor is mid point on the cap contact with "about midpoint" in the timing curve---so that as timing is moved from "advance" to retard, the rotor is still in range of the contact.
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Well, Ill get it to the point of moving before worrying too much about how it runs. But judging by what you said, I think 12 initial is good starting point. I followed the instructions, oddly enough, and there was a part about phasing, and I put the cap thing on the dist. and its pointing at the #1 and the timing marks are showing 12*. I dont know if once running Ill do the 'advance it until it pings n back it off' or some version of that, but that will be a great day once this thing moves under its own power. F**#$ng marathon this one.

Thanks Del. Hows the snow over der aye?

Good info on the 'retard only' situation.
 
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