'383' Stock Intake Manifolds vs. Edelbrock Performer

[440 Cuda]

We've secured an Offenhaser 360* Dual-Port Intake for our 383.

Never thought about trying one, but we will give it a go.

http://static.speedwaymotors.com/RS/SR/Product/5606015_L.jpg

 

[YY1]

What's the internal design of that? Is it just a plenum, or are their runners?

IIRC, there's a Weiand that looks real similar to that.

 

[440 Cuda]

YY 1

Here is a description of the Offenhauser 360* Dual-Port.

Basically, the 'Dual-Port' Dual-Plane Intake is designed as '2' separate manifolds.

The Primary Throttle's are directed into smaller ports, which are the lower runners
in the Intake Manifold.

The Secondary Throttle's are directed into larger ports, which are the upper runners
in the Intake Manifold. This section of the Intake stays cooler and provides for
denser air.

The theory >
Was that under 'normal driving conditions', the smaller ports would provide for better
response 'off idle' and provide for improved Fuel-efficiency in the lower RPM range.

And that the 'split port-runners' would provide a 'Ram Effect' when the Secondary
throttles are opened up, and approaching high RPM's.

Was it a gimmick.

http://www.offyparts.com/images/offy_works.JPG

 

[440 Cuda]

Offenhauser #6015-DP

The Dual-Port was a 'lug'.

It did not work well at all with the 'stock' Carter AFB {566 CFM}.

It was expected that it would be very responsive in the low-end, due to the small lower runner-ports
off the Primaries which would create a higher-velocity effect.

From 'Idle' {850 RPM's} to 3000 RPM's it did perform adequately as the RPM's increased.

But as soon as we hit the middle of Mid-Range, the Engine seemed to starve out.

 

[strokie]

That's in another post. Possibly also posted by member "440 Cuda".

- - - Updated - - -

FWIW the Weiand action plus is still available new...and it's relatively cheap.

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I'd like to see the numbers for the Performer RPM.

As per many tests Performer RPM is one of the best...

 

[440 Cuda]

Strokie

This was just a test with the 'Old School' Intakes.
And we were using the 'stock' Carter AFB #4999S {566 CFM}.

 

[Bee1971]

Yes , it’s a four old post but a great comparison

1971 Superbee - #s Matching Drivetrain

Running the Weiand Action Plus 8008 on my 383/432 Stroker with Edelbrock E Street Heads 75 cc and Comp Cams XE 275 HL Cam

I love the torque of the engine off idle as I can roast the tires all day long , even getting on the gas at 15-25 mph - Auto Trans - 3:91 Sure Grip

Would there bee any advantage on the street switching over to the Edelbrock RPM Intake ? It’s not tested here , and I don’t want to make the switch over say 5-10 HP on the street based on the height of the intake etc , coil location , factory kick down and running the factory dual snorkel air

But if it’s 20-30 HP ? Difference well

Shift around 5500-5600 Rpms

 

[Big bill]

This is some really good info .