Air filter restrictions?

Melzer · #1 (**permalink**) 03-27-2003, 04:04 AM

This has probably been visited several times before, but I'll beat this horse one more time......

Currently running an oval 'Cobra' air cleaner on my 427 with single street demon 4v. Contemplating switching to a Stelling & Hellings with the K&N element for appearance as well as better air intake.

Would the Stelling & Hellings offer less air restriction?

Now for the turkey pan.....how difficult is it to install one on this demon carb? The carb body is fairly large as compared to a Holley. Has anybody installed one with this setup?

thanks,

Mel

Zderf · #2 (**permalink**) 03-27-2003, 06:48 AM

Here's a recent thread on this topic:

Big RPM drop with stelling /helling

There have been many in the past, some of which kept coming back to the K&N "Xtreem" assembly.

Zderf

Melzer · #3 (**permalink**) 03-27-2003, 08:28 AM

Zderf....

Thanks for the heads up on the Stellings post. I'm gonna take a shot at the Stelling & Helling cleaner.

Hey, what about the turkey pan...think it will fit?

Mel

Tinker51 · #4 (**permalink**) 03-27-2003, 08:48 AM

Not sure if this is applicable since you are running a big block but this was my experience. A friend had a pretty hot 289 built using a Holly 650 that was running around 370 hp on the dyno with no air filter. The motor was for a Sunbeam Tiger and we were curious what would happen to HP when we put the air cleaner on. A Tiger air cleaner is smaller but essentially the same as the oval Cobra cleaner. We put it on with a K&N element and ran it again on the dyno. No difference in HP. Go figure.

Todd Hedges · #5 (**permalink**) 03-27-2003, 01:03 PM

Take a look at the engine picture in my gallery.
428 with Holley 4150HP - 750CFM.
Has a K&N filter and top with a "no-name" base to lower
the filter around the top of the carb for hood clearance.

Hope this helped.

wilf leek · #6 (**permalink**) 03-27-2003, 02:01 PM

FWIW, I use the K&N # E-1963 filter on my oval air cleaner. (about 1 3/4" tall element). Engine is a 408 windsor stroker, revving to 6000, so I guess airflow requirements are substantially similar to yours.

No difference on dyno with/without the filter, also no significant manifold vacuum difference between the two at WOT. Thus I conclude that this air filter is not restrictive.

I have always wondered about those tiny H&S filters on the original cars. In theory they are way too small. Any comments from the cognoscenti?

Melzer · #7 (**permalink**) 03-28-2003, 05:39 AM

Todd,

Where did your Stelling & Hellings lid disappear to? Did you need to eliminate it for clearance?

Mel

speed220mph · #8 (**permalink**) 03-28-2003, 07:03 AM

Wilf, I'm about to find out if the Stelling and Helling air cleaner is restrictive compared to the replacement K&N. As soon as I receive the K&N's, I'll stick one on my flow bench, then flow a Stelling and Helling air cleaner and get back-to-back numbers.

Zderf · #9 (**permalink**) 03-28-2003, 08:35 AM

Quote:

Where did your Stelling & Hellings lid disappear to? Did you need to eliminate it for clearance?

Mel,

The top you see on Todd's air cleaner is the K&N Xtreem lid which actually flows air. That is how the smaller diameter and height K&N Xtreem assembly achieves such high flow rates, and speaks also to its hefty price. I too have that same assembly on my FE big block (see my gallery), and noticed a big difference the minute I installed it. It's a great concept that actually works.

The drawback? Its does not appear authentic or original. Oh well....

Zderf

ronzara · #10 (**permalink**) 03-29-2003, 09:22 AM

How did you get the "COBRA" oval filter base to fit your Demon Carb??
I tried the combo and the neck on my base was too small to fit over the Demon. Thanks
RZ

George Snyder · #11 (**permalink**) 03-29-2003, 01:13 PM

ronzara,
You will need this plasitc adapter spacer ring.

Bud

Michael C Henry · #12 (**permalink**) 03-29-2003, 07:18 PM

Why would anyone with a single four, ever want to go with a little Stelling and Helling air cleaner? I have dual fours and it's them or the oval. I'd buy an extreme top if I could get in 8 1/2" but 9" is the smallest they make. Hell I'm thinking about buying two 9" and grinding the edges where they meet so as to get some more air in the top where the air scoop is supposed to be getting cool fresh air. Go to Finishline the Shelby distrib in Vegas Those cars all have large and tall ( enormos) round air cleaners.Why get all bunched up over authentisity it aint authentic CSX-2 or 3is it?

Pete C · #13 (**permalink**) 03-29-2003, 10:06 PM

Michael, I agree and have been trying to figure out how to use the xtreme on my dual S&H air cleaners. I run a large one on my 347 stroker Mustang and my guess is that the FE Cobra needs to breathe better than the S&H cleaners with the K&N elements will permit.

Cheers, Pete C

Michael C Henry · #14 (**permalink**) 03-30-2003, 03:13 PM

My car came with the S&H's But with the two pieces of perferated metal and foam element. I had to cut the metal rings to make a slight taper on one side of each cleaner. The hood comes over the front 1/3 of the front aircleaner and the rear air cleaner hits in rear of scoop.I have K&Ns in hand and all this s--- started with trying to make a little clearence for the K&Ns. A lower intake and a single four should be able to get a massive aircleaner under the hood.
In the days of Gallaxeys you could run the element for the tripower or dual four in the oval aircleaner. You could even stack elements. Take that with the current technoligy and you can buy any brand of hi-flow elements.If I was scratch building a car .I'd go with multiport FI- a large single four air door and cover it up with a big air cleaner.I really like personal improvements- modifactions and functionality.If it doesn't work then why?
Do you think that the race cars of that day were the same for each race. If they thought of an improvement that may even be legal they wouldn't appy it?Heck read the Daytona Coupe story. when it was turned over to that brit that Bondurant went and made a deal with other cars for fat NASCAR tires. Those cars were in constant evolution ,untill Ford took over and managed it into the ground. In the authenticity game it's all or nothing and they look at numbers.

Cobrabill · #15 (**permalink**) 03-30-2003, 05:50 PM

K&N filters work.However,the extreme tops cost you horsepower.

Bart Carter · #16 (**permalink**) 03-30-2003, 07:57 PM

Quote:

Originally posted by Cobrabill K&N filters work.However,the extreme tops cost you horsepower.

Can you elaborate?

Cobrabill · #17 (**permalink**) 03-30-2003, 08:21 PM

Dyno tests.I have personally seen two where 5-10 hp was lost.
I have yet to see(or hear about)a positive test using the extreme lid.

Prevailing theory is that the air entering the thru the top disrupts air entering thru"normal channels"-the side(s).

A major magazine did a test a while back.And the tests weren't good.But for some unknown reason,the test of the "lid" was not published.

Again,prevailing theory is that the mag. gets too much ad money for said company.

ronzara · #18 (**permalink**) 03-31-2003, 12:34 AM

This may sound odd, but......
I had an '88 Mustang GT with some decent mods..... I added a K&N filter, and LOST a noticable amount of Torque. I did see more top end, but Lost the "feeling" of a lot of take off power.

RZ

PS: George Snyder ... where would I find such an adapter???

mickmate · #19 (**permalink**) 03-31-2003, 12:56 PM

Very good visual on flow of air into a carb. Now pour something into the middle and see how smoothly it flows. Carbs are designed to pull air in over the sides and flow it down through. I believe you would need a serious redesign of venturis to accomodate the changes being put on top of it. But what do I know?