It has always bothered me that I have a steel, (built by Joey Cole) hood scoop that is not supplying air to the carbs.
I have two 750 cfm Hollys on a Marine intake. I studied the factory systems, and found that the only one with a seal on the air cleaner was an A12.
So I ordered the closest thing I could find which was a Shaker with Edelbrock carbs and a StageV intake. Of course the rear Holly carb bowl took up all the space, so I had to modify it. My goal is to build a "wa ll" like the A12,and seal the carbs to the scoop.

Metal work is a lost art, stretching, hammering and fitting, takes a LOT of time!

Now I have to fabricate a "wall" with a 1" lip to hold the rubber seal. Then,,,,,cut the metal in the triangle between the metal bracing to let the air in.

Of course I will cut the flat metal to fit the "wall". I chose a Shaker FOR the flat leaving the air cleaner

I need to do something like that for my Hemi, I was going to use the metal aircleaner base to make a fiberglass one then use it to modify for my Holley carbs. Another project on the list of TODO's

Is this for the standard height WO scoop ?

Please explain - "the only factory system with a seal to the air cleaner".

Not getting it either . Didnt the race/scoop setups use a cross ram with velocity stacks sealed to underside of bonnet cut oyt holes ?

Tex

Lynn, when you get done, have it scanned, then 3d print them for other people.

Finally everything fits, I had to trim the air cleaner element in the back where I made a plate to push out for the Holly float bowl, but it seals just fine. Now on the building the wall with the seal AKA A12. The A12 has a slope to the front, I will need to repecate that.

The factory WO/RO 23 system used an aluminum plate the required cutting essentially all of the hood bracing out, indeed, it didn't have any provision for an air cleaner, race only, no good for a street car.

Joey built my scoop to be 3" high. Chrysler tests show that it needs to be at least 2-1/2" high to clear the "boundry layer"

The only fresh air system available before 1969 was the RO/WO23 Super stock available on 55 each Belvedere and Coronet. The system was race only, cutting out most of the hood bracing and no air cleaner.

My goal is to have COOL air coming into the carbs. Right now I have a "bottom breather" Chrome Dome, this pulls air from the bottom, engine temp. For every 10 degrees of temp drop, you gain 1% of HP. So, with underhood/engine temps at 200 degrees, if I pull 85 degree temp air into the carbs, I will gain 65+ HP (engine dynode at 635 HP).

I like the finished product. Pretty neat.

I have one more day off and am spending it wisely. Here I am building a mock up of the "A12 wall". This will be recreated in 18 gauge steel and welded in place. The rubber seal goes on the top lip. I need to give credit to Tommy theChryco. He had the best deal on the parts and made sure I had them before my Christmas break.

I should have posted a photo before of what I am trying to end up with, A12 air cleaner, but for two Holly 750s

I would like to see the modifications to fit the carbs with the base. I have to do something similar with my Hemi with the stageV intake and Holleys. Tim

Tim Look at the first post at the top of the page. The second shot clearly shows his mod to the carb plate to get it to work with the Holleys.

I assume you are making the "wall" out of some sort of high density foam to seal to the hood and allow some flex for engine movement and still stay sealed up.

Tim, here are some shots of the modifications needed to clear the Holly float bowl. You also need to know that the air cleaner element has half the seating room as you are "all up in it" with the Modification. It will still seal, just be careful and go slow.

So now I have a template made from cardboard, (4 hours). Now I will use it to gauge the metal. I have an 8' long 18 gauge piece of steel with a 90 degree bend to the outside for the rubber seal to clip onto. I will use a manual shrinker/stretcher to form the radius at all four corners. Then body work, paint and last but not least, cut a hole in a PERFECT hood!

Well, back to work, not as much time to spend on the air cleaner project, here are a few photo's of the "wall" being created out of metal. Notice the "1" lip at 90 degrees already bent. A manual shrinker, spreader does an amazing job of creating the radius with the lip already on the metal!

Awesome! Keep those pics coming!

👍👍👍

Looks like you have done that kind of work before. Looks too easy - I'm sure it's not.

Ok, why did you trim the lip by where it meets the carb flange? I need to do this mod on mine but I have been hesitant to just cut on a $600 air cleaner base..

To transman, thanks fort he compliment, but no I haven't done this before. And no it is NOT easy, it will try your patients.
The notch cut in the rear carb opening is an example, my mistake.
I thought it was hitting there, it was not, now I have to replace that piece. Part of doing something for the first time!

Are you going to do A-B-A testing at the track to see if there is a difference?

I'd be suprised if your under hood temps are 200* while you're moving...you're still getting airflow. I can't see an outside air supply adding 65hp+ just based on air temps.

Somewhat unrelated...my Coronet was on a string of 10.50 passes one night at QC when the W023 scoop came off in the shutdown. Next pass, no scoop, just a carb and a big hole in the flat hood, car picks up .08 and 1-2 MPH. Only thing I can think is the carb pan sealing to the hood, and the size of the scoop, were creating a pocket of positive pressure and causing a ton of negative areo drag. No more air pan on the carb for me.

Well I have shrinkers/stretchers for 2 different models, that hand one is a lot harder to use than one with a foot pedal. The foot pedal one allows for 2 hands, and if you are on a stool, you don't loose too much balance.

It looks like you are really getting a handle on it.

Do your carbs have vacuum secondaries or are they double pumpers? Keep up the good work. Tim

A39coronet, that is interesting stuff. It is hard to argue with back to back time slips!
No I'm not going to test the car at the track. If I had wanted a fast et, I would have chosen a car lighter than 4175lb.!
I just hate having something on my car for the looks with out it serving a purpose. I also need to always have a project to work on, especially during this time of year. So, just thought you guys might be interested.

astjb2, Your right, I would LOVE a peddle shrinker. I am balancing the long ends on cardboard boxes and trying to work with one hand on the metal!
I have vacume carbs.

I hear you on that...plus no excuse to rush making things during the winter and you can take your time to make it right.

Looking forward to the finished product.

Tonight's progress. When I went to bed last night, I had the radius off. Quite a bit. I was frustrated so went to bed. Tonight after work, with a fresh look, I had every thing "right to the world" in about an hour.
Here you can begin to see why I bought the Shaker base from Tommy, I can just trim away what I don't need and have an excellent "floor to attach the "wall" to.

Leave an edge on the base that is 1/4-3/8, then roll it up, you will get a good lap weld. Even if you only leave the straight sides, it gives you some sort of edge to weld to. Tim

Tim, That is a good idea, it would also serve as a reference to hold the wall in place while welding. But first, I two more radius to build. The one on drivers side rear will have to clear wiper motor, very little room back there!

Well, with the front done, all that remains is to match the radius's in the rear, and hit the overall length. A cardboard template does the trick!

The last bends are critical, they must meet up EXACTLY.

Here it is with the lid. There is a lot of trimming excess of of the Shaker base, welding, body work and paint, but the hard part is done. Two weeks of evenings and weekends! Another week at the very least!

It looks awesome, if you are good with a torch, you may want to try silver brazing. Its low heat and is 60k psi tensile strength. I am not a fan of mig for real precise work.

What are you going to use for a seal to the hood? I have some rubber product that is 3" wide and come is a roll that you could fasten...or look for a P seal

http://www.brownaircraft.com/product-p/t-6400.htm
Tim

Tim,
I purposely had a 1" wide, 90 degree bend in the metal while it was still a straight piece. That way I could use the stock rubber seal for an A12

My goal from the beginning was to make it look as "factory" as I could. This rubber is hollow, and has a compression distance of 1-3/4". This should conform around the bracing. It won't be air tight exactly, but should still allow the carbs to receive mostly cool outside air.

Remember the "notch" that I had to cut out of the base to clear the wiper motor, well that is the next problem to solve. Here is the Kick In required to clear the wiper motor, still working on it.

Well, I have worked through the holidays, and made progress. Here is the finished product, minus trimming and painting.

Lets see the final product! top, bottom, and sides!

Bump

Sorry I know I'm slow. I have the whole thing at a friends to be tig welded. I chose not to use my little 110 mig welder in the basement when he can use his commercial tig welder. Should pick it up this week.

Looks like it is going to be very nice. Good Job!

I know it has been several weeks. In a project like this (creating a one of a kind), you find your limits! Mine were, no tig welder, no bandsaw, not enough clamps, and expertise! So, with the help of good friends, I finished the structure today.

After cutting off the excess metal, we trimmed, then broke the sheet metal to provide a trough. And began to tig weld it together.

Now it is in it's final shape, tig welded, (spot). Then I will "panel bond" the seams, paint and install.

Trial fit.

Very nice. Quite a project!

WAY cool to do this stuff yourself...........

Thanks! I didn't know if I could until I tried! LOL

Any finished photos yet?

Wow! Nice work. Where did you get the hood scoop from?

I'm doing "body work" getting ready for paint. I have to blend in the area in the rear where I had to make a metal extension to clear the rear carb bowl. Almost finished with that. Hopefully this weekend I will get the "panel bond" epoxy in the corners where the wall meets the base. This will seal the air gap where it was spot welded on (tig with silicon bronze). Then it has to be metal prepped (cleaned) for paint.

I got the hood scoop from Joey Cole. He is a master metal worker! He built it from a flat sheet of steel!

Modification to rear carb bowl

Very cool project & nicely done. I am getting ready to start on a similar project but adapting my Shaker hood on my 70' Challenger. I am going to be making a custom drop base to fit to my Indy tunnel ram with dual Dominator carbs & a custom larger/taller Shaker Scoop.

I saw your post. That will be a much larger challenge than what I've done. All I had to do was call Tommy for the base. Making one from scratch will be much more difficult than modifying an existing base. I'll keep an eye on your progress.

Anyone who has done a project that requires paint, will understand the WEEKS that I have not posted progress on the project.
I delivered the welded, finished? air cleaner base to my buddy who insisted on painting it, weeks ago. First comment, "take it home and blend in the outer edges for paint. I did that, then waited.
Today, I got to watch the paint applied to my project. You don't want to know how many hours he spent getting it "ready for paint" after I had spent days on it! But, the finished project is as perfect as it could get.

The air cleaner lid is next. It has too much Red in it. He has mixed an early HEMI orange to match the block. By weeks end, I should have it installed. Guess who is going to cut the hole in the hood to make it all work? Not me!!!!!!

Here's a template if you want to cut the hood like the original WO23.

https://www.ebay.com/itm/1966-1967-WO23-RO23-426-Race-Hemi-Oval-Hood-Template/253393614521?

Here's the plate, the seller is a Moparts member.

https://www.ebay.com/itm/1966-67-RO23-WO23-426-Race-Hemi-Underhood-Plate/253443293644?

OK, I finally finished the air cleaner. The rubber seal was too thick. I found a sheet of 1" closed cell foam. A customer was kind enough to water jet the gasket out. It is done. Except for the HEMI decal on the lid, yet to come!

The details are important. It is a rainy day here in East TN. I spent it putting the final touches on the only cold air system for a 66' with RO/WO23 hood scoop that has an air cleaner!