hood clearance / taller intake

[sigmfsk]

I got a PM asking about hood clearance and thought to put the info here (copied mostly from my posts in LV's build thread here:
www.bluesmobiles.proboards.com/index.cgi?board=owners&action=display&thread=56&page=4


Here's one way to see the clearances involved with a 440 in the stock location:



The distances are from the top of the valley tray holddown brackets to the hood.


Here's another way:

A 440 with a stock manifold and stock dual snorkel air cleaner housing fits under the hood. Not much clearance, but apparently enough:



A dual snorkel has 1/4" drop base:



So let's say you want to install a new intake that is 1.5" taller than stock. To have the top of the air cleaner housing at the same height, relative to the end rails, one needs the air cleaner housing to have a 0.25" + 1.5" drop base = 1.75" drop base.

You could use this intake with a 2.0" drop:

www.ecklerscorvette.com/corvette-air-cleaner-base-1965-1972.html

Here's some info on it:
> Most generic parts store 14x3 chrome air cleaners have a base with a
> drop something between 0" - 1.25". There are a rare few out there with
> a 1-3/8" drop. If you're like me, this isn't enough, even though it is
> close. Here's the solution:
>
> This air cleaner I bought is a reproduction part for:
>
> -1970-72 LT1 Corvette/Camaro
> -1969 Camaro Z/28 (302ci)
> -1966-69 Corvette 427ci 1x4bbl (L88)
>
> This air cleaner will work with a dual-feed Holley carb, like a double
> pumper, because it was designed by GM to work with the above
> engines, which did come from the factory with dual-feed Holley carbs. It
> has a HUGE 2.00" drop!
www.thirdgen.org/techboard/carburetors/529713-ultimate-drop-base-air.html

But you may like to use the standard cop monaco dual snorkel air-cleaner.

The standard dual snorkel air cleaner won't fit unmodified, but you could cut the bottom out of it, and mate that 2.0" drop-base housing to it, and then it would clear the hood, and everything would look fairly stock, as the air cleaner top would be basically in the same place as stock.

your friend in free-flowing intakes,
arthur

[countrybunker]

Thank you arthur!!

Great info! I knew you did some measuring under the hood before, but couldnt remember if it was with the stock location.

Im tempted to see what it might take to modify the air cleaner to sit lower...

[countrybunker]

Its not looking to promising....

Been looking into the drop base air cleaner deal.

It looks like ford racing also makes a drop base that works perfect for mopars.
www.dodgecharger.com/forum/index.php?topic=83085.0

This seems to be it-
www.fordracingparts.com/parts/part_details.asp?PartKeyField=10855

Firgured take the drop base, modify it to the bottom of the dual snorkel air cleaner, and good to go.. But if the air horn tube in the carb is closer then 1.5" to the top of the air cleaner, the carb wont work properly.

Next would be getting an aftermarket air cleaner lid, along with the ford drop base. To eliminate the problems with the air horn. K&N has a filter top in order to use.
www.knfilters.com/universal/X-stream.htm

But they dont seem to carry a 13" top.

Also with the higher intake, and drop base, it seems the top of the air cleaner would be just about back in the stock location. Which is right up against the hood. Seems kinda pointless with the filter top if its shoved in the hood insulation..

Damn you mopar!! lol

[Lord Vadus]

I've been looking into a low-rise intake and, near as I can tell, for those of us who want to run a carb setup with a dual snorkel intake, the best option is the Edelbrock Performer 440 Intake Manifold - 2191 as its a low-rise intake.

[sigmfsk]

It seems that we have a solution to:

q1) how to use an unmodified air-cleaner housing with a taller intake manifold?
a1) use the eckler base I refer to earlier. It has a 2.0" drop base, and works correctly with holley carbs.

q2) how to use the mopar cop dual snorkel housing with a taller intake?
a2) get the dual snorkel housing, cut the bottom out of it, and attach the eckler base I refer to earlier. So it looks stock from above.

Country, LV, do you disagree with those answers? Or is there another question we're trying to answer?

[countrybunker]

May 31, 2013 22:02:22 GMT -5 sigmfsk said:

It seems that we have a solution to:

q1) how to use an unmodified air-cleaner housing with a taller intake manifold?
a1) use the eckler base I refer to earlier. It has a 2.0" drop base, and works correctly with holley carbs.

q2) how to use the mopar cop dual snorkel housing with a taller intake?
a2) get the dual snorkel housing, cut the bottom out of it, and attach the eckler base I refer to earlier. So it looks stock from above.

Country, LV, do you disagree with those answers? Or is there another question we're trying to answer?

I dont think it will work with the dual snorkel. The carb wont work properly acourding to another forum. When you lower the dual snorkel, the top plate of the assemble will be right on top of it, if not even be able to fit down all the way.

[sigmfsk]

Jun 2, 2013 8:45:24 GMT -5 countrybunker said:

I dont think it will work with the dual snorkel. The carb wont work properly acourding to another forum. When you lower the dual snorkel, the top plate of the assemble will be right on top of it, if not even be able to fit down all the way.

Hi Country:

The only possible problems I see are:
1) not enough clearance between the carb vent tube and the air cleaner lid
2) air cleaner housing lid too tall (hits hood).
3) not enough room for air to pass through the filter to the carb (meaning, inside the air filter, the base of the housing is rammed up against the lid)

Let's say we need 0.75" from the top of the vent tube the air cleaner lid.
forums.corvetteforum.com/1578892445-post6.html

Here's a good pic for reference that shows if we have at least 1.25" or so of clearance between the carb and the air cleaner lid, we'll have 0.75" of clearance on the vent tubes:


We know that the corvette L88 standard air cleaner is 3.0" tall.
forums.corvetteforum.com/c3-tech-performance/1012966-hieght-of-l88-air-cleaner.html
forums.corvetteforum.com/c3-tech-performance/2926537-l88-air-cleaner-base-dimensions.html

so with a 2.0" drop base, that gives 1.0" of clearance if the air cleaner housing was flat.

The stock L88 lid wasn't flat:

www.ecklerscorvette.com/corvette-air-cleaner-cover-l88-1967-1969.html

but it looks less intrusive than the dual snorkel lid that dips down 1.0" at 5" radius:



At 5" radius, the top lid has a drop of 1.0"






The shallowest cross sectional area between the base and the lid inside the air cleaner is 1.25":



But if you turn the lid upside down, you'd get some more clearance, and be a bit hod rodder.

Here:
www.bluesbrotherscentral.com/forum/topic/8176-angle-between-440-dual-snorkels/#entry104384

I wrote about an article showing that the dual snorkel causes significant air restrictions even for a stock 440 [air restriction causes loss of 10Hp at the rear wheels] but you can get all the air you want, equivalent to the power of an open element by using

> ...the old-timer's trick of flipping the air cleaner lid

www.moparmusclemagazine.com/featuredvehicles/mopp_0007_1971_dodge_charger_440/viewall.html


I think the thing to do would be to determine:
1) do you want the dual snorkel housing?
2) do you want the dual snorkel lid?
3) do you want the dual snorkel lid upside-right?
4) do you want the base of the dual snorkel the same distance as stock from the top of the lid (meaning, would you accept a 4.0" tall air cleaner, which, with the lid in the stock location, would mean that the base would be lower than stock.

Depending on what you select for these things, I think it wouldn't be hard to fit a 1.5" taller intake.

[countrybunker]

Saw another idea for the dual snorkel assembly to improve air flow, on another board. Nothing I would do, as I wouldnt want to ruin it. But....

Drill some holes in the base.

[sigmfsk]

Jun 16, 2013 20:24:26 GMT -5 countrybunker said:

Ouch! Well, it's another idea in the kit bag to get the thoughts going. I bet there'd be lots more air-flow simply by turning the lid upside-down.

[Lord Vadus]

Mine has an opening in the back from where the lean burn module was; by leaving that unfilled I get an extra area for it to pull air and it doesn't look like Swiss cheese.