air cleaner with or without snorkel--what's better?

So maybe the engineers in 1975 already had invented cold air intake...I long ago removed the factory air cleaner with intake snorkel and put a neato chrome plated open air cleaner, cuz it looks cool. I doubt my station wagon's performance would be changed much with a closed air cleaner and intake snorkel, but what's the opinions on this?

Can't answer your question, but like your cool looking chrome open air cleaner, I'm certain my custom air cleaner set-up added at least 50 hp...LOL

Looking at the evolution of air cleaners may help you decide for yourself.

The earliest air cleaners were oil-bath type. They were "open" and didn't have a filter element. They worked by directing air down toward an oil reservoir then forcing the air to sharply change direction up. Particles in the air couldn't change direction as fast as the air so they would get slung into the oil. It was adequate for the time but the average consumer didn't care for the whooshing sound. A filter element consisting of steel wool soaked in oil was more effective at filtering out smaller particles and could be contained in a canister with a snorkel that greatly reduced the whooshing sound but it was messy and could draw oil into the engine if it was applied to liberally. So the takeaway from this is that the enclosed air cleaner is quieter than the open element. Quiet is great for the average consumer with his/her commuter/grocery-getter/carpooler but it's of no consideration to the performance oriented gearheads. Speaking for myself, I kinda like the throaty sound of wide open throttle.

A performance engine with a conventional air cleaner and snorkel is like an athlete breathing through a straw; the bigger the straw, the better he can breathe. Consider some factory performance intake setups such as cowl induction where the filter element is essentially open with an enormous snorkel under the hood leading to the base of the windshield. Mcarlo77's setup is quite elegant with the dual cold air snorkels and is reminiscent of some performance packages I remember seeing on some '60s cars. Back in the day, a quick and easy way to increase the breathing capacity of your engine was to R&R the air cleaner cover upside-down so as to simulate an open element.

The classic open element air cleaner with an oiled K&N cotton element is what I use. I like that it's clean, simple, and easy to remove & install. However, I have no control of the temperature of the air going into the engine which I'm ok with because I don't want to have to deal with an elaborate setup whenever I need to do maintenance or repairs.


Hopes this gives you something to think about and, as always, your mileage may vary.

This one I sold when I sold my Black SE

I agree with Zucchi that the bigger the straw, the better it can breathe.  Obviously the cooler the air the better.  Quite a few years ago a magazine did a comparison of factory performance hoods from back in the day.  It was a great read and I wish I saved it.  It compared the Buick GS design with the scoops centered on the hood, the 442 with the scoops close to the front lip of the hood and the cowl induction at the base of the windshield.  All worked well but fell off quickly when 30+ mph and above was reached.  All due to aerodynamics.  As the 442 gained speed, air hit the front grill area and deflected upwards decreasing the amount of air that got into the scoops.  Same issue with the GS, deflected air wasnt getting to the scoops as speed increased.  I personally like the GS hood but never thought it would work that well.  

But the chevelle cowl induction grabbing the air at the base of the windshield got the nod.  There is always turbulent air at that location and the cowl can suck in all it wants.  That was the findings of stock air induction systems.  

Anyway, I dont think anyone will FEEL any performance gain with an air cleaner change.  But we don want to get the best and most air in there as quickly as possible.  An engine is only a pump, more air in, more air out.  I can definitely say that running my 4" L88 cowl induction definitely moves air through the engine bay. Ever since I installed it in the 80s, I cannot use my center dash vents.  The amount of HOT air that comes in from the base of the windshield is brutal. And Im good with that.  As for my air cleaner, I run a 6" K&N on a FLAT base because I read another test comparing air cleaner base designs.  Velocity stack/open won the test and flat base coming in second.  Dropped bases coming in last.  Again, can you feel the difference, definitely not, but I thought if I can fit it, go with it.  

To Joe’s point even if you can’t get cool air in, allowing hot air out of the engine compartment, like out the back of a hood scoop is just as important.

Does the row of perforations across my hood near the windshield let air in or out? Something has clearly changed in automotive design because hoods are no longer made this way.

It doesnt let air into the air cleaner but does let air get into the long plastic vent, by your wipers, on the top side of the cowl. Its for interior ventilation purposes. If you were to remove that long plastic strip and looked inside, you will see your wiper linkage and if you look in the area towards both fenders, there's a vertical tube that extends above the bottom of the area. That tube is where air gets into your interior vents. The reason there's a vertical tube is because water flows in the cowl and exits right above the top door hinges on both sides. Having the vertical tube just doesnt allow water to get into the air flow.

The perforations at the base of the windshield are for directing fresh-air into the passenger cabin. Directing any hot engine compartment air out the back of the hood will make it's way into the passenger cabin thus warming things up all year round.

Performance, drivability and comfort is a give-and-take. Favoring one over the other requires consideration and sacrifices; what is a must-have vs what can you live without. For instance, for flat-out, quarter-mile runs, Joe73's hood-off setup topped off with a velocity stack is the way to go. I personally would find that a bit impractical for going to work followed by a stop at the supermarket when it's raining. Mcarlo77's setup is great for a sleek sleeper that looks like it would still pass emissions testing; to Mcarlo77 – please forgive me if I'm wrong. 35-years ago, I was toying with swapping the hood for a fiberglass one with cowl induction. Many years later, knowing the origin story of the 2nd generation Monte Carlo, I've embraced PCL aspect Chevy was going for and am ultimately glad I didn't go with cowl induction. Besides, most of the miles I put on my car are from slow traffic during commuting times where cowl induction of no benefit.

So, ask yourself what you absolutely must have and what you can live without then go on from there.

Unless your cowl is sealed to the air cleaner assembly you wont get any benefit power wise and that would be negligible at best. But having an open cowl hood cant be beat for helping keeping engine temps down. Hence why I cant use my center dash vents. My 4" L88 cowl is high enough that I can see my passenger headlight when its on while driving.

Joe73 wrote:Unless your cowl is sealed to the air cleaner assembly you wont get any benefit…

…which is one of the reasons I didn't move forward with the project. Even though I was an impetuous young firebrand back then, I looked into what was needed to make that cowl induction functional and thought, "some day…" Looking back with 20/20 hindsight, I'm thinking, "I must have been nuts." Had I come into possession of the car with that setup already done and working, I would have kept it AND maintained it, but putting in the effort to reverse engineer it simply no longer appeals to me. I get too caught-up in day-to-day things like weather stripping, door hinges, better check the rear control arm bushings, I think my power steering pump reservoir is leaking, is that noise something I need to address now… you know, the little stuff that comes with driving a nearly 50-year old car everyday.