Best dual plane intake for small block Windsor

southcross2631 · Jan 10, 2020

I am starting on a 333 inch small block Windsor for the southeast gassers super stock class. class rules state stock or replacement dual plane intake only ,no air gap styles.
No sheet metal ,no tunnel rams. It can be a single carb, 2x4 or 3x2 intake. Must use holley forward mount carbs. 2x4 setups must use side float carbs. Can use 1 inch spacer.
Which would provide the most top end charge? All cars are stick shift ,spec rear tire, lbs. per cubic inch.
I will be using a 65 Comet or a 64 Comet wagon .

LILCBRA · Jan 10, 2020

Here's a dual plane shootout by Car Craft from 2013.

Dual Plane Intake Manifold Comparisons - Car Craft Magazine - Hot Rod

A well-designed dual-plane intake can improve torque, add horsepower, and make that otherwise stock engine look a little more aggressive. This is why we have decided to provide you with several Dual Plane Intake Manifold Comparisons.

www.hotrod.com

Of course those were only single carburetor manifolds.....

And here is who they determined to be the winner.

404 | AirFlow Research

www.airflowresearch.com

LILCBRA · Jan 10, 2020

Scratch that - it looks like that Titon manifold is only for SBC.

southcross2631 · Jan 10, 2020

No composite manifolds are allowed. Remember this is nostalgic racing.

Adieu · Jan 10, 2020

My ported Edelbrock Performer RPM works wonders on the 308ci mill in my Mustang II. I also ran a Weiand Stealth at one point.

southcross2631 · Jan 10, 2020

What rpm 's did they drop off at ? I am looking for at least 7500 with my cam, 8,ooo would be ideal. I have read some test's on the performer rpm with the center cut down for higher rpm's and then a 1 inch spacer will help also.
I have everything for my new engine for this project and it is sort of a change of direction as it was built with a parker single plane in mind. Now it is going into a different car with different intake rules.

2Blue2 · Jan 10, 2020

The limits of dual plane and 1 inch spacer become apparent before 8000rpm I imagine.
Always liked the Edelbrock stuff so Im with 74stang2go and voting the RPM performer.
Would like to see a pic of proffered Comet, I got a soft part in my heart for them.

Adieu · Jan 10, 2020

southcross2631 said:
What rpm 's did they drop off at ? I am looking for at least 7500 with my cam, 8,ooo would be ideal. I have read some test's on the performer rpm with the center cut down for higher rpm's and then a 1 inch spacer will help also.
I have everything for my new engine for this project and it is sort of a change of direction as it was built with a parker single plane in mind. Now it is going into a different car with different intake rules.

In my car, the Performer RPM really doesn't, but I shift at 6000rpm.

The Stealth was on a different car that didn't get raced, so I don't know on it.

LILCBRA · Jan 10, 2020

I was going to say the Eddy Performer RPM, but then did a little Googling to come up with that article. Then that Titon intake had me wondering so I looked it up. I imagine the rest of that article was all done on a SBC.

When I bought my intake I did a little research then too. What I was finding at that time was either the Eddy RPM or the Weiand Stealth work very well. It's been a while now, but I think the RPM just edges out the Weiand. I also think the RPM comes stock with the center divider milled some? Maybe it's just the Air Gap....? Anyway, I found that when I bought my RPM Air Gap knockoff manifold and did the same to it when I was still working in a shop. With my 306 it'll get up and move from the dig. I haven't gotten it to the rev limiter, so I don't know how well it would respond up to and beyond 6k rpms. But if you're interested in seeing what I did with the knock off manifold, the link to a post is provided in my sig as well as a post with dyno vids and numbers for my 306. Maybe they could help a little?

southcross2631 · Jan 30, 2020

My neighbor has a Fox with a performer rpm that noses over a 6500 ,but that could be his cam and heads.
He has offered it up as trade for my Parker style ported intake. I guess I will take him up on it.
I am gathering parts for the Comet. I have my engine parts back from getting balanced. I have located a 57 Ford wagon rear end housing.
My input shaft for my top loader is at Liberty getting upgraded. I found some 5 lug hubs and spindles.

LILCBRA · Jan 30, 2020

Out of curiosity, will the class allow an Offy 360? It's a split single plane. I had one on my 302 to begin with before swapping to the Air Gap knock off that I have on the car now. I can attest to it pulling to 7k rpms as I bounced the rev limiter with it once before dialing it down to 6000 - 6500 rpms. I still have it if you can use it, definitely cheaper than Summit, they're asking $400+.

2Blue2 · Jan 30, 2020

southcross2631 said:
I am gathering parts for the Comet.

64 Comet wagon is so cool! Gonna be a fun build. Curved side glass is rare.
Roof rack will help carry slicks to track right?
Looking forward to this build. Be sure to post lots~o~pics.

Heres Dyno Dons wagon for inspiration!

southcross2631 · Feb 12, 2020

I have traded for a Performer RPM intake and in the middle of porting it to match the ProMaxx heads. I am trying to get up in as far as possible to reach the lumps and bumps in the ports.
I am up in the air about cutting the center divider out. I am allowed to run a 1 inch spacer. I have read articles about cutting out part of the divider. I have even read and article about cutting the whole plenum out and trying to make it as close to a single plane as possible .
The rules read porting is allowed as long as there is nothing showing from the outside. So I can cut holes in the bottom of the intake and port it out and weld the holes back up. Basically everything but cut it in half and weld it back together.

southcross2631 · Feb 17, 2020

after many hours of grinding and acid porting here is my intake manifold. Ground off the name and model too.

2Blue2 · Feb 17, 2020

Acid porting?

southcross2631 · Feb 20, 2020

Acid porting is a procedure that has been used for years to hide grinding marks after porting cast iron heads or exhaust and intake manifolds on round track race cars.
It's called undercover porting in that type of racing. In my case their is no rule against it and on aluminum it's a very effective way to open up the ports on a dual plane intake as muriatic acid is applied to the areas you can't get to with a grinding bur.
Just be careful as it will eat the manifold. After reaching the desired size of the ports then spray water to neutralize the acid. If you do any grinding on aluminum and don't lubricate the grinding bur it clogs up with aluminum. then to clean the bur you let it soak in some acid and the aluminum will start foaming up and the bur will be clean. The aluminum will be gone.
you can buy the muriatic acid in gallons at most any hardware store. Just be careful and use it in a well vented area and wear rubber gloves and a face shield.

2Blue2 · Feb 27, 2020

I know this boat sailed but

Offenhauser 360 degree single plane for Dominator carb oh wait it had to be double p right?

LILCBRA · Feb 27, 2020

2Blue2 said:
I know this boat sailed but

Offenhauser 360 degree single plane for Dominator carb oh wait it had to be double p right?

That's the intake I asked about earlier, I have one sitting on a shelf in my carport right now. I replaced it with an Edelbrock RPM Air-Gap knock off....

2Blue2 · Feb 27, 2020

LILCBRA said:
the intake I asked about earlier, I have one

yup my brain is muddled from thinking of 1050cfm with reversion plate on small block ford with umpteen to one compression

southcross2631 · Feb 27, 2020

The only manifold now that I will swap out would be a dual plane 2x4 intake like the old Cobra intake that will take 2 Holleys. that way I can run 2 660's .

Best dual plane intake for small block Windsor

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I wish I didn't have all of these balls in the air

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will be trying this sex one when I can find it

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will be trying this sex one when I can find it

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will be trying this sex one when I can find it

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