Stock Dual Snorkel 440 Air Cleaner on 74 Roadrunner

[WileE]

I thought my brakes were hooked to the Holley in the back but they are actually hooked to the only port on the intake, which is in the back right below the carburetor. The PCV is hooked to the only port on the carburetor on the front. So back to my original question, can I Tee off the PCV? NO

That's the correct way. You install the fitting as I said, re-connect the booster hose and connect the thin hose on the thin nipple.

 

[WileE]

I'll break down the questions, IMO as a mechanic

there will be no vacuum loss in the snorkel system. So the point is moot, and the booster is it's own reservoir. All big chryslers had lots of stuff teed in with the factory vacuum port, that's what it's there to do

Yes but poorly. The pcv is a constant open vacuum leak.

lower vacuum signal, possibility of introducing oil vapors into the the snorkel system

True.

I might add, the snorkels default to open operation. What is the concern to make them close when cold. Trying to enhance cold start warm up?
Could just leave them alone

Bingo.

 

[WileE]

May I suggest familiarizing yourself with how a Positive Crankcase Ventilation system operates. It was introduced to internal combusion engines in the early 60's as probably the first emissions control system, diverting crankcase blowby gases back into the combustion chamber.

 

[RR Fan Dan]

lower vacuum signal, possibility of introducing oil vapors into the the snorkel system

Doesn’t the breather exhaust to the air cleaner, under positive pressure versus a vacuum on the PCV. I would think the breather has more chance of getting oil vapors into the air cleaner.

I might add, the snorkels default to open operation. What is the concern to make them close when cold. Trying to enhance cold start warm up?
Could just leave them alone

This is what I needed to know as well. If they fail open, then I don’t need cold start warm up, but I do need air. I have no issues now with cold start or warm up, with no stove pipe or damper. I am going to leave it alone.

 

[RR Fan Dan]

May I suggest familiarizing yourself with how a Positive Crankcase Ventilation system operates. It was introduced to internal combusion engines in the early 60's as probably the first emissions control system, diverting crankcase blowby gases back into the combustion chamber.

I am familiar with how it works.

Edit: Thanks I’ll do that, cause I am confused on how it works.

 

[RemCharger]

Doesn’t the breather exhaust to the air cleaner, under positive pressure versus a vacuum on the PCV. I would think the breather has more chance of getting oil vapors into the air cleaner.

Here's a good view of the principle of operation

This is what I needed to know as well. If they fail open, then I don’t need cold start warm up, but I do need air. I have no issues now with cold start or warm up, with no stove pipe or damper. I am going to leave it alone.

That's what I would do

 

[RR Fan Dan]

I am familiar with how it works.

Here's a good view of the principle of operation View attachment 1827974

That's what I would do

I guess I was wrong. I don’t know how it works. My bad, sorry @WileE

 

[WileE]

I guess I was wrong. I don’t know how it works. My bad, sorry @WileE

 

[RR Fan Dan]

 

[Charlied]

Check the carb to air cleaner circle size.

Carter AFB/AVS and Holey are normally different, but not sure about Carter TQ, which is what would have come on a 74, right?

You’re correct, 74 big block cars with factory TQ came with a dual snorkel air cleaner. I have a 74 satellite t that I bought new and that’s it.

 

[T2R9]

You’re correct, 74 big block cars with factory TQ came with a dual snorkel air cleaner. I have a 74 satellite t that I bought new and that’s it.

Not all of them. Many HP 440 B-Bodies in 74 had a single long snorkel with the trap door like in 72 340's including mine.

 

[T2R9]

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