Looking to replace the single horn air cleaner on my '68 442 with a high flow air cleaner. Not sure if I would need to get a drop base or not as there does not appear to be much or any room over the stock cleaner under my stock hood. Any one used an aftermarket air cleaner that flows better and fits under the stock hood?

 

If appearance is at all important, you can just use a taller element rather than going aftermarket. That's what I did on my '69. It leaves a 1/2-in. gap of exposed filter between the lid and the housing -- plenty of room for fresh air to get in.

EDIT: Oh, and before you ask, mine has plenty of clearance under the hood.

 

Thanks but definitely looking to go aftermarket. The single horn is the limiting factor, not the size of the filter. I definitely feel it over 5000 rpm and at 7400 ft elevation I need all the air I can get.

 

You may be misunderstanding me. The exposed area between the lid and the housing effectively converts the air cleaner to an open-element without giving it that high-school hot-rod look.

EDIT: Whoops! Never mind, I just looked at your avatar.

 

Why not get some under the bumper scoops to add more air and go to a double air horn. As in ram air system.

 

Ha my avatar is one of my late father’s drag cars. I have a driver ‘68 with a 550 hp 455. Sorry for the confusion. Still not quite sure what you are suggesting. All the air has to come in through the single horn though correct?

 

Sounds extremely expensive. Looking at the K&N X-Stream assembly or similar, but I know there’s not a lot of room under the ‘68 hood. I may just have to start ordering parts to see what fits.

 

This is a 4" K & N on a stock 68 442. OAI would be better on hot days. But moving provides good flow. Been considering the OAI for a while but this car is too clean and very close to a numbers car to alter.

 

No, there will be a gap all around the top of the air cleaner lid:

 

I get it now. That is an interesting idea for sure, or I can get a K&N x-Stream filtered lid for the top. Either way looks a little goofy but you can bareLt get your head under the hood of a ‘68 anyways so it’ll be hard to see. Thx fellas.

 

You can get a cheap ram air system for about $100 but you can make your own a lot cheaper . I think maybe around $40. Oh and 1968 Hurst had ram air under the bumper scoops. Flex hoses up to twin snorkel air cleaner canister.

 

I’m listening. I’ve seen the original OAI parts for big bucks but haven’t seen a knockoff or diy version. My motor was tuned with a 1” spacer under carb and I couldn’t even fit that under my stock hood. I’ll start with trying the taller element and go from there.

 

Spectre i think is the name of a ram air system. Cheap as it gets after market. My buddy put it on his 65. I have one but haven't used it yet.Clean air off front of car is always better than engine compartment and it is because of cooler air charge.

 

A single snorkel is incredibly inadequate for a 550 HP big block, regardless of altitude. A single snorkel air cleaner housing in stock configuration is only good for a 300 HP engine or less. Dual snorkel is good for 390 HP or less. Dual snorkel with a flipped lid is good for 640 HP. Air Filter Horsepower Shootout ! Engine Masters Ep. 27

If you want to spend absolutely nothing but a few minutes of your personal time, just flip your factory air cleaner lid. That will instantly give your engine better breath-ability. Likely all it will need for now....


( Love the fact that they took the time to put the Olds insignia on the inside of the air filter lid.)

If its good enough for Jack Watson's 1968 Hurst Olds test car, its good enough for any of us.... He is one of the Gods of speed. He is the creator of the Hurst Olds. (At approximately the 5 minute mark they open the hood.)

 

And if you combine the flipped lid with the taller element ...

 

That is exactly what I needed fellas. Thank you.

 

Flipped the lid and test drive today. HUGE difference from 5k-6k. Using the stock 14 x 3 filter. Don’t think I can fit a 14x4 under my hood but might check to see if someone makes a 14 x 3.5. Thanks again for the suggestions.

 

We used to this as kids, bet you can really hear the carb now.

 

Hows the power on that thing? I forgot what Robbie told me it made for power?

 

https://www.dailymotion.com/video/x693421
Vertical air

 

Good post for info but lacks ram air test where you have a pressure system. Also was not tested real world with a hot engine compartment with hot air being induced to carb. So basically worthless. The one thing track tested by me is raised tube same as a velocity stack 5inch gained two tenths in et. Now you can say something changed by the swap but this was a round robin run stopped only for a swap. The normal air cleaner was a
​​​​​​on a open top element and a three inch filter. The tube got the clean air from hood scoop. The kn got hot air engine compartment.😂 My .02 kn is not as good as they brag about. Flip lid better than single air horn. Carry on.

 

Bernhard wrote
The test confirmed what a lot of racers already new vertical air flow on a NA engine makes HP.
What I find interesting is that the factory engineers flipped the lid on the factory ram air cleaner.

 

That does seem a little counter-intuitive, doesn't it?

 

Not that hard to understand. They did that to squeeze out the extra hp that even with what ram air leaves on the table. But in hot weather i think you will not get same results. Those engineers were not doing round robin test with hot engine compartments. IMO They were doing these type test in optimal conditions. Just like dyno test.

 

Motor runs great. Robbie’s dyno showed 370 hp at elevation (I think 540 something corrected).

 

Nice Numbers congrats

 

They ringed the car out all day, they obviously felt there was an advantage in flipping the lid. Its hard to beat a open carburetor, this is proven every time I walk through the stock and super stock pit area.
The bumper mounted ram air ducts work some say they are worth .10 and 1 mph. I have know way of validating this claim at this time. A lot of factory muscle car hoods just don't work well even though they are very cool.

 

I doubt they ringed them out all day long. Flipping the lid is not a open carb. It is a un restricted air cleaner filter. You are right a open carb is hard to beat.

 

Bernhard wrote:
Yes flipping the lid is not running a open carburetor. The point was all the GM muscle car air cleaners & hoods were designed to sell cars first and performance second. The ram-air works but does it work better than a open carburetor with the hood lifted up in the back? That is how a lot of stock and super stock cars run on the west coast. They were testing the car hard ,much harder than running a bracket race and going rounds all the way to the final. The ram- air was turned into a open cold air pick up drawing air form the engine compartment as well out side. That tells me that the ram-air could not meet the needs of the engine as well with out a flipped lid.
I would guess that the flip lid and ram air might be the quickest set up.