plenum divider on single plane intake

[chevy art]

read many posts about single and dual plane intakes and it was mentioned about a single plane with a plenum divider installed)(sideways)?, could someome explain this for me and hopefully some pics. thanks Art in NY

[F-BIRD'88]

Increases plenum velocity to any 1 cylinder as the plenum is cut in ½. Tends to help low speed drivability and throttle response on street driven cars.. Usually a bit of a peak power penalty on single carb manifolds as carb flow capacity is ½ to any 1 cylinder..
If multi carbed may not see top end power penalty, or minor power penalty.
Reduces egr effect of valve overlap at idle and low rpm.

Plenum divider is longitual.

[Tom68]

read many posts about single and dual plane intakes and it was mentioned about a single plane with a plenum divider installed)(sideways)?, could someome explain this for me and hopefully some pics. thanks Art in NY

We did it on a Cup engine in the 80s, didn't get past the dyno. 1:1 throttle linkage, separate 5 and 7.
Doesn't work, not on paper nor on the dyno.

Weiand had a low single plane that came with longitudanal dividers, they didn't ship it with a flat plane crank though.

[Geoff2]

They came about because folks bought single plane intakes...only to find they lost a lot of low end tq. The 'fix' was a divider to halve plenum volume. A band aid fix.

[Tom68]

They came about because folks bought single plane intakes...only to find they lost a lot of low end tq. The 'fix' was a divider to halve plenum volume. A band aid fix.

Holley even recruited the great man to signature a crappy single plane "torque manifold" . Having said that, Zora never had a decent manifold for his Hemi heads that I can find.

image.jpg

[Walter R. Malik]

They came about because folks bought single plane intakes...only to find they lost a lot of low end tq. The 'fix' was a divider to halve plenum volume. A band aid fix.

Holley even recruited the great man to signature a crappy single plane "torque manifold" . Having said that, Zora never had a decent manifold for his Hemi heads that I can find.

image.jpg

Zora did not simply "signature" that manifold design. He supervised and did a lot of personal testing on the theory of that design for the Mopar, Chevrolet and even AMC engines using a Holley dyno and air flow room.
It was quite involved and did work at towing engine speeds.

[Tom68]

They came about because folks bought single plane intakes...only to find they lost a lot of low end tq. The 'fix' was a divider to halve plenum volume. A band aid fix.

Holley even recruited the great man to signature a crappy single plane "torque manifold" . Having said that, Zora never had a decent manifold for his Hemi heads that I can find.

image.jpg

Zora did not simply "signature" that manifold design. He supervised and did a lot of personal testing on the theory of that design for the Mopar, Chevrolet and even AMC engines using a Holley dyno and air flow room.
It was quite involved and did work at towing engine speeds.

Any idea how good it worked ?

[agertz1]

More work=more filling ? Well maybe, what if divider could smoothly telescope, up from the floor of that single plane ? Control it with mechanical
linkage or manifold vac. ? Would need enough rigidity not to bind or degrade.
Art.

[1980RS]

If you have to put a divider in your single plane intake, you probably have the wrong intake on the car.

[HQM383]

If you have to put a divider in your single plane intake, you probably have the wrong intake on the car.

Agree. There will always be a market for those that want race type parts but don’t need them. These divided singles would have targeted that market to at least improve their single plane experience where they would use it most often. Probably needed the great man on board to work out how not to make it worse than no divider for the end users expectations.

[ClassAct]

If you have to put a divider in your single plane intake, you probably have the wrong intake on the car.

And the carb used way too big. One does shit like that because they buy carbs based on CFM rather than venturi and throttle blade diameter

[1980RS]

If you have to put a divider in your single plane intake, you probably have the wrong intake on the car.

And the carb used way too big. One does shit like that because they buy carbs based on CFM rather than venturi and throttle blade diameter

I know my 850 style FST vs worked great on the 358 with the dual plane, we will see what is does with the ported Vic Jr. then the ported Super Victor. It will be an interesting test to see how the carb works on those intakes.

[Walter R. Malik]

Holley even recruited the great man to signature a crappy single plane "torque manifold" . Having said that, Zora never had a decent manifold for his Hemi heads that I can find.

image.jpg

Zora did not simply "signature" that manifold design. He supervised and did a lot of personal testing on the theory of that design for the Mopar, Chevrolet and even AMC engines using a Holley dyno and air flow room.
It was quite involved and did work at towing engine speeds.

Any idea how good it worked ?

Better torque from 1,200 RPM to 3,600 RPM than anything that was tested, (2 plane or small single plane), which would still have some power remaining at 5,000 RPM on O.E.M. engines ... not high-performance or race engines but, for trailer towing vehicles going down the highway.

[Tom68]

Zora did not simply "signature" that manifold design. He supervised and did a lot of personal testing on the theory of that design for the Mopar, Chevrolet and even AMC engines using a Holley dyno and air flow room.
It was quite involved and did work at towing engine speeds.

Any idea how good it worked ?

Better torque from 1,200 RPM to 3,600 RPM than anything that was tested, (2 plane or small single plane), which would still have some power remaining at 5,000 RPM on O.E.M. engines ... not high-performance or race engines but, for trailer towing vehicles going down the highway.

I remeber it in magazines at the time, they raved about the ingenuity, but I don't recall seeing actual comparisons.
SP2P was similar era, that was claimed to create such great cylinder fill af low revs that it caused detonation, hard to imagine on thd old low comp motors.

[steve cowan]

On my Jim McFarland CD he said they put a divider in a victor junior and on the dyno it ripped out,so they didn't bother after that.