Air cleaner help

kevins2 · #1 (**permalink**) 02-09-2012, 03:12 PM

I'm working through the details for my ERA 427 and will be having an FE 428 built. Talking with Keith Craft and am told that most of their Cobra customers are using the oval Cobra air filter. From what I've read, although it looks good, it is very restrictive - the 1.75" high filter is rated at 475 CFM, which somewhat chokes the carb (probably will go with a Quickfuel 780. I don't want to use a turkey pan (requires an even smaller filter, which probably offsets the benefits of cooler air). There is also an option of adding a 1/2" spacer under the carb which solves a potential fuel problem in high temps and also may help with fuel flow a bit (ok, so maybe I'm reading too much and over-complicating this stuff). One option would be to go with a K&N 3" filter in the oval Cobra air filter but that may not fit under the hood. So, looking for ERA specific solutions to the air filter issue. I've read a bunch of threads but haven't seen any good solutions that were specific to the ERA clearances. Anyone using the oval Cobra air cleaner with good success? Other options I should consider?

Thanks,

Kevin

B.M.B.C · #2 (**permalink**) 02-09-2012, 03:31 PM

Easy, just go 8 stack efi and do away with large pancake style filters......

King- cobra · #3 (**permalink**) 02-09-2012, 03:33 PM

The oval Cobra air cleaner will not clear the rear of the hood inner structure. I found a Cobra air filter about 2/3 the normal size and it works great. Let me know if there is any thing I can help you with.

DanEC · #4 (**permalink**) 02-09-2012, 04:47 PM

What intake are you planning to use? That will make a difference in the heigth of the filter element you can squeeze under there. I'm running the dual S&H air cleaners on mine and know they are restrictive. I just hope with 2 - 600 cfm carbs and air cleaners that it will suck enough air in to allow it to rev over 5000rpm. But I'm probably about 8 or 9 months away from knowing. I would think the oval air filter housings would flow fairly well because they do have a lot more surface area due to the greater circumference. Also, some of the original cars ran a larger, round air cleaner that was around 14 inch diameter. They should flow reasonably well also. I think they were used on 428 police interceptor motors, as well as some other motors.

If you have Keith build your motor, be sure to try and get down there when they dyno it. That's a thrill.

gsharapa · #5 (**permalink**) 02-09-2012, 04:53 PM

I have one of Keith's 496 FEs with a Quickfuel carb and I use this turkey pan with K&N setup and works very well. It has a flat base and the filter is 9 inch by 2 3/4. They make a 9 by 2 1/2 also, plus the 9 inch Extreme top. You will notice mine is on a single plane intake that Keith milled down alittle bit but if you are running a dual plane you will have more room. You could run the filter setup without the turkey pan also. Oh yes, the Quicklatch setup is great as you just push the button to take it off. C & S Performance in Plano, Texas makes them and sells them. I think Jegs has them also.

Pman1961 · #6 (**permalink**) 02-09-2012, 04:56 PM

Craig's Cobras sells a dropped base oval filter which I will be considering. Check out their website under the 'parts' link.

kevins2 · #7 (**permalink**) 02-09-2012, 05:13 PM

King-Cobra - I'm surprised the oval filter won't fit in the ERA. I've seen enough photos of Cobras with that setup, maybe none were ERAs - thanks for saving me that trouble. I would be interested in the details of your smaller version as I haven't come across that.

DanEC - If I do go with Keith Craft the intake they typically use is the Edelbrock Performer RPM Port Matched (taken from their crate engine description). A large round air cleaner might be the way to go.

Gary, thanks that looks like a nice setup - I'll certainly consider it.

Pman1961 - Check out this thread before you do a dropped base.

Air flow

There is a post in there where a dropped base seems to work well and another further down that indicates a dropped base setup gave poor numbers on a dyno because some of the filter was actually blocked.

Thanks for all the good info. Keep it comin'... I appreciate it.

Regards,

Kevin

tboneheller · #8 (**permalink**) 02-09-2012, 06:33 PM

Quote:

Originally Posted by King- cobra

The oval Cobra air cleaner will not clear the rear of the hood inner structure. I found a Cobra air filter about 2/3 the normal size and it works great. Let me know if there is any thing I can help you with.

It fit on mine after I trimmed the inner rear of the hood.

ERA 778 · #9 (**permalink**) 02-09-2012, 06:47 PM

Page 75 of the ERA assembly manual shows how to cut the structure of the hood for the oval air filter, but you should check for hood to cleaner contact as well, I would think.

I'm using the S&H unit with a K&N filter on a Keith Craft 428 with a QuickFuel carb on a Blue Thunder intake with a turkey pan. The S&H package protrudes up into the hood scoop just a little.

I would like to go with a larger filter, but so far I've had no trouble cranking up to 6200-6400rpm. I usually run out of road or intestinal fortitude before the engine runs out of air.

Hey gsharapa: where did you get the rubber gasket/trim material for your turkey pan? I need some!

Hal

Bobcat · #10 (**permalink**) 02-09-2012, 06:49 PM

If you ask ERA , they will trim the inside hood support so an oval filter will fit before you have the car painted .... they did that for me . Makes life a whole lot easier .
Actually , I running now without an air cleaner since I added a 1" , 4 hole tapered spacer .... car runs much better with that spacer . Next step is to compare how it runs with the smaller filter I have to use to get the hood closed .
Bob

kevins2 · #11 (**permalink**) 02-09-2012, 06:53 PM

Thanks, I'll check the manual and ask ERA about that. I'm having one of their local painters paint the car so would have to do that in advance if that's the way I go.

Hal, I hear you on the running out of road and intestinal fortitude comment. Keith Craft's 428 "Street" Crate engine is 550 HP. I'm going to "mild" it down to about 450 HP and I'm sure it will still be stupid fast.

Regards,

Kevin

kevins2 · #12 (**permalink**) 02-09-2012, 06:57 PM

Bob, so you were running with the standard Cobra oval (1 3/4" high filter)? Sounds like it was very restrictive if you noticed a huge difference when taking it off. I'm not clear on what the spacer does...can you elaborate a bit more? Sounds interesting.

Regards,

Kevin

ERA 778 · #13 (**permalink**) 02-09-2012, 07:20 PM

Kevin, I thought putting 550 HP on the street in one of these little beasts would be way too dangerous. So, I asked Keith for a "stump puller" that would be a little better at just getting underway so to speak. We ended up with a MUCH SAFER 520 HP !!!

Hal

gsharapa · #14 (**permalink**) 02-09-2012, 07:35 PM

ERA 778

The trim I put on the turkey pan I had from years ago to trim aluminum inner panels on a Component Craft Cobra I had. Not sure where I got it but I found this company that makes all kinds of trim as I was going to put some that actually sealed to the hood.

McMaster-Carr

kgs365 · #15 (**permalink**) 02-10-2012, 07:54 AM

then why are you worrying about the air intake restrictions?...

Quote:

Originally Posted by kevins2

Thanks, I'll check the manual and ask ERA about that. I'm having one of their local painters paint the car so would have to do that in advance if that's the way I go.

Hal, I hear you on the running out of road and intestinal fortitude comment. Keith Craft's 428 "Street" Crate engine is 550 HP. I'm going to "mild" it down to about 450 HP and I'm sure it will still be stupid fast.

Regards,

Kevin

undy · #16 (**permalink**) 02-10-2012, 11:19 AM

No restriction here... proven flow on the chassis dyno. 482" Pond motor from Keith w/ 2 of Barry's 750 Quick Fuel carbs on top.

kevins2 · #17 (**permalink**) 02-10-2012, 11:28 AM

Quote:

Originally Posted by kgs365

then why are you worrying about the air intake restrictions?...

Because even if I lower compression a bit to get to 450 hp, I think the engine still needs to breathe properly to run right

kgs365 · #18 (**permalink**) 02-10-2012, 12:28 PM

set up as your thinking about...i have the small stelling air cleaner and turkey pan ...and its running and breathing fine....do i have have every ounce of HP/TQ probably not but i'm at or north of 400 rwhp (dyno'd at 480 hp) and it moves all 2,600 lbs just fine and i dont notice any engine weezing or coughing asking for more air...just saying ...

Quote:

Originally Posted by kevins2

Because even if I lower compression a bit to get to 450 hp, I think the engine still needs to breathe properly to run right

patrickt · #19 (**permalink**) 02-10-2012, 12:51 PM

Kevin, kgs365 is more right than wrong, and I run a Turkey Pan with the KN filter in the little S&H air cleaner. I have done "informal" highway performance testing (because my Turkey Pan is removable). There is no noticable difference between any configuration (TP on, TP off, air cleaner on, air cleaner off). I say put it together so that it looks good to you. You will have the performance you crave, trust me.

kevins2 · #20 (**permalink**) 02-10-2012, 01:10 PM

I'm sure you guys are right and I'm probably reading too many posts...

Thanks for your help.

Regards,

Kevin