OK I get the legal thing. I was actually thinking of going with a straight through muffler and a long tail pipe. No cat needed on the 65. How does the air get filtered? I just bought a nice CC filter for the filler cap.

 

What air?


I advocate not using a vented filler cap.

 

This thread has gained my curiosity.

I have a couple of questions though..

How do you gut a PCV valve? This is something I'd like to see pics of. I have many here and different brands. I cannot see how it can be done without physically cutting it apart or breaking it.

Cheaper, low quality PCV valves allow for air to flow in the opposite direction. This is not a problem if an OEM valve is used, whether it be Ford, GM, Mopar, etc. Something to do with a backfire, and engine damage is the end result.

 

I'll snap a pic of one next chance I get, though it's not that complicated. You're exactly right it can't be done without cutting it apart. I speak specifically of this style of valve.
http://marineenginedepot.com/PartIma...Block_1241.jpg
It's really just about having the right fitting. There isn't much out there that does a good job allowing the connection of a 3/8" hose to the 5/8" hole in the grommet in the valve cover. Most older domestic engines use this same style and grommet system, other setups are available and other engines use different styles. It's just about getting something to work. But with these I generally simply grab the old PCV valve and cut the bottom off. Personally I do this on a bench grinder by grinding off the corner all the way around. After I do this the guts fall out and I'm left with what is basically a 5/8" to 3/8" elbow fitting.


I keep seeing this backfire thing come up in writing about PCV valves as a legitimate function of the PCV valve and it's check valve function. This is bogus for several reasons.


For starters I have worked on engines in the aftermath of some MASSIVE backfires. Ever seen a nitrous backfire, google it. You'll see images of complete intake systems blown open. Many nitrous systems are what's referred to as "wet" that is the extra fuel used with nitrous is sprayed into the intake at the same point as the nitrous oxide. Often this point is significantly up stream of the intake valves. This is to allow the use of one sprayer to save money thus the sprayer must be significantly up stream of any intake dividers. Usually just down stream if the throttle valve though sometimes up. So when such a system is in use there is an entire intake system full of oxygen, fuel, and nitrous. When something happens to light that sucker off BANG! The point to this long explanation being that even with that massive of a fiery explosion I've yet to ever see damage extend via any form of PCV or crankcase vent system.


Why, cause it's just not possible, most of all with the system I advocate here. For starters the hoses just can't transfer the flame/explosion. Any big explosion is just going to blow the hoses off. Any small explosion can't maintain a flame down the length of the hose. Most important though. specifically for what I advocate. Fire needs oxygen, and with a good system without a vent there is no oxygen within the crankcase. Thus no fire is possible. I've seen crankcases full of fuel from failed fuel pumps, no fire.

 

I like the idea of no CC intake filter to maintain. I would love to see a vac/boost gauge, tapped into that hose. It would only take half of that kit shown for a 300 six. That check valve looks a lot like the A.I.R valves I used to see.

 

Yup, I wouldn't actually suggest buying the kit. The valve is just a diverter valve from an air pump system. And the venturi part is easily made.

 

OK, Brute, you got me going. When I build my exhaust I am going to weld in a tap and give it a whirl. Couple questions if you don't mind. How far down the pipe should I go? I was thinking a couple three feet. Was that 1/2 NPT, and how far into the exhaust pipe does it need to go? Moroso has a v hole on the upstream side others don't, does that increase the vacuum?

 

Sorry for the delay, forgot about it.

Can't really just weld in a tap, it needs to be at a shallow angle, hard to do with a perpendicular tap.

Where to place it depends on the system, needs to be the point of lowest pressure which is generally the place of highest air speed. Often this is the collector. I'm a fan of well made Y-pipes also and often place then in the Y.

I don't remember the thread size, in the past I've just made them out of tubing from the air injection system.

I've often wondered about the V notch myself and I don't have a solid answer. My general thoughts are with the angle at which Moroso places it the V notch likely helps. I often though find a way to put it in line with the flow. For example when putting together a header placing it in the center of where the 4 tubes meat. Or in the center of the Y of the Y pipe.

Though I guess a O2 sensor bung could work. Put in it a tube that is capped on the end and has holes on the downstream side of the tube.