Air Cleaner discussion

[Fury440]

I used to invert the pie plate, this vastly increased air flow and let some of the neat sound effects out at WOT.

 

[CBODY67]

Back when HOT ROD was testing a new '68 Road Runner, they took the air cleaner off for a 1/4 mile test. Engine bogged down . . . when the air flow sucked the underhood fiberglass insulator into the carb. They had to fabricate a metal strap, held in place by the air cleaner stud & wing nut, in order to keep that from happening again. There were pictures to document that situation!

Enjoy!
CBODY67

 

[fury fan]

CFM are CFM, but lower vacuum drop means "less" and more vacuum drop means "more".

Enjoy!
CBODY67

Yes, CFM are CFM.
But the flowrate is a resultant of a variety of conditions, and inlet pressure is one of them.
Change the inlet pressure and the CFM changes.
The problem arises when we try to use CFM at 1 set of conditions and use it as-is in another set of (unknown) conditions.

You can use that CFM to compare filters, but not to know if that filter is capable of flowing enough for a carb/engine.

 

[fury fan]

...
My thoughts are that Ma Mopar was having some financial issues and compromised the exhaust and air intake to save some money. These cars had a single exhaust with 2 inch pipe and the Q-bert nosed air cleaner. You could buy a chromed open element (bottom) air cleaner from Hustle stuff.
...

All the OEMs practiced cost-cutting where possible, and had since probably the 1930s (or whenever priced-based competition came into play in the auto market).
Putting single exh and single snorkel on a 350hp New Yorker helped keep it quiet (required for the market segment), but also helped keep the cost down compared to the competition, who was doing the same thing. IIRC there were some Mercurys with 429s and 2-barrel carbs.

As for the snorkel, I'm curious if the area of the snorkel is about equal to the area of the 2 venturis in the 2-barrel carb.

 

[Marv]

I went to that process today @Dsertdog and I had the same thoughts.. Will the snorkle limit the airflow and will have negative consequences for the mixture? Will there be a loss of performance?

Although with my 350cui Pontiac engine with a 1406 4bbl Edelbrock sitting on an Edelbrock intake and not with a Mopar engine.

I got rid of that standard chrome Edelbrock open filter element and put a correct 1968 4bbl GM single snorkle aircleaner on top.

Result..... Absolutely no changes! Engine starts when turning the key like it did before, it idles, accelerates and performes through all RPM stages as it did before!
Accelerates as it should to 70mph, leaves 20ft marks on the concrete and after all the speeding it idles smoothly through city traffic on a 85° day.

For spacing between air cleaner and carb I used Pro-Flo Series Round Air Cleaner Spacer (3/4") and the stock cleaner housing sits perfectly on that spacer

So my conclusion is, just give it a try, later Pontiac 455 H.O. engines had dual snorkels the Chrysler 440 engine was also sold with duals on the high performance models, why should a single snorkle limit a 383 that was designed to work with that set up anyways!

 

[Dsertdog]

I went to that process today @Dsertdog and I had the same thoughts.. Will the snorkle limit the airflow and will have negative consequences for the mixture? Will there be a loss of performance?

Although with my 350cui Pontiac engine with a 1406 4bbl Edelbrock sitting on an Edelbrock intake and not with a Mopar engine.

I got rid of that standard chrome Edelbrock open filter element and put a correct 1968 4bbl GM single snorkle aircleaner on top.

Result..... Absolutely no changes! Engine starts when turning the key like it did before, it idles, accelerates and performes through all RPM stages as it did before!
Accelerates as it should to 70mph, leaves 20ft marks on the concrete and after all the speeding it idles smoothly through city traffic on a 85° day.

For spacing between air cleaner and carb I used Pro-Flo Series Round Air Cleaner Spacer (3/4") and the stock cleaner housing sits perfectly on that spacer

So my conclusion is, just give it a try, later Pontiac 455 H.O. engines had dual snorkels the Chrysler 440 engine was also sold with duals on the high performance models, why should a single snorkle limit a 383 that was designed to work with that set up anyways!

View attachment 313465

And you know, I would expect that. Although my experiences have been different.

I would hazard a guess that if you were to run the car on a chassis dyno or at the track you would notice a small power difference between the air cleaners. Notice I said small. Once the engine compartment heat soaks, the air temp remains consistent and the carburetor cannot adjust for it.
Your stock snorkel has a lot more air intake area than the 2 inch tube on my stock air cleaner.

I don't believe there's enough air flow through my little snorkel tube to make the AFB happy. Perhaps the average adult driver who seldom floors it except to enter traffic from a highway on ramp or pass a slower vehicle might not. I admit the Polara does this pretty well! But low end with the car...ehhhhh not so much.
The single tube top is the same top on the 2bbl engine and probably works great with the smaller carb.

I've moved on from this thread and need to get the top and filter for the open element so I can compare. That'll be somewhere in the future.

Of course anyone who wants to keep discussing it can certainly do so. I'll report back once I've gotten the open element system installed.