Intake Manifold Porting Show ‘n Tell

[skinny z]

https://www.youtube.com/watch?v=2sbICMpLiBI&t=106s

Within the testing parameters, the Vic Jr looks to be on the top.

[ChopperScott]

Scott, it is gonna be darn hard to beat that Holley manifold for peak power . That has been established .

Established by Who and on what engine combo ?

This thread covers intake manifold testing on different engine combos...

https://garage.grumpysperformance.com/i ... d-test.58/

The Holley Dorton is ideal for classes that require cast iron heads that require an unported intake manifold. A competitive design but, in my experience, casting deficiencies limit porting without welding and possibly machining. The ports open up nicely to a 1205. On some of these intakes, opening the ports to a 1206 will break through the roof in a few runners. If the runners have enough material to support a 1206, the other problem is runner entry in the plenum. To maintain proper csa and taper, welding may be needed. Eric Weingartner ran into this problem recently...

https://www.youtube.com/watch?v=61brXl7i32Y

[steve cowan]

Scott, it is gonna be darn hard to beat that Holley manifold for peak power . That has been established .

Established by Who and on what engine combo ?

This thread covers intake manifold testing on different engine combos...

https://garage.grumpysperformance.com/i ... d-test.58/

The Holley Dorton is ideal for classes that require cast iron heads that require an unported intake manifold. A competitive design but, in my experience, casting deficiencies limit porting without welding and possibly machining. The ports open up nicely to a 1205. On some of these intakes, opening the ports to a 1206 will break through the roof in a few runners. If the runners have enough material to support a 1206, the other problem is runner entry in the plenum. To maintain proper csa and taper, welding may be needed. Eric Weingartner ran into this problem recently...

https://www.youtube.com/watch?v=61brXl7i32Y

Exactly,
When you size the intake for the application, picking up 10 - 30hp is a bonus. I know guys who have tested as cast manifolds on the dyno with minimal gains and nothing on the track

[ChopperScott]

Holley Keith Dorton Intake Manifold Competition Ported

[steve cowan]

Holley Keith Dorton Intake Manifold Competition Ported

I think you workmanship is first class Scott and I enjoy your videos, how much tapper do you normally put on the intake runner.
For my 383 stuff I work on 3/4" as a minimum.
Anyway nice work

[ChopperScott]

Holley Keith Dorton Intake Manifold Competition Ported

I think you workmanship is first class Scott and I enjoy your videos, how much tapper do you normally put on the intake runner.
For my 383 stuff I work on 3/4" as a minimum.
Anyway nice work

Thank you, sir. Taper is dependent on the manifold and application, within the limits of the casting. If exceeding the limits is necessary, the choice of manifold comes into question.

[1972ho]

Incredible the amount of Chevy intake manifold that are out there and most are of different configurations these last two are SUPER cool.

[ChopperScott]

Work in progress...

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[ChopperScott]

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[ChopperScott]

Ready to run on a 496 BBC with AFR oval port heads...

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[1980RS]

Ready to run on a 496 BBC with AFR oval port heads...

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I've got the 4500 version of that Vic Jr. I picked up at a swap meet for $35 years ago. May need to test it out when I get the L-29 engine going again. Nice work there Scott.

[ChopperScott]

I've got the 4500 version of that Vic Jr. I picked up at a swap meet for $35 years ago. May need to test it out when I get the L-29 engine going again. Nice work there Scott.

Thank you. It's a nice intake and was a pleasure to work with. No odd casting deficiencies or core shift.

Here's a little port work on this Trick Flow R that will be completed with a burr finish...

Trick Flow port work.JPG

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And then this 2900 Victor Jr will be on the bench for a plenum port with burr finish...

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[mt-engines]

What kind of gains are you seeing?

[RevTheory]

Hey Scott, out of the SBC manifolds you've done, what do you think has the longest runners and smallest csa, assuming one has both?

[ChopperScott]

Hey Scott, out of the SBC manifolds you've done, what do you think has the longest runners and smallest csa, assuming one has both?

The manifold that best fits your criteria would be a Super Victor 2925 with the earlier style plenum. Chad Speier has a page on his website with ballpark figures for quick reference....

https://speierracingheads.com/manifold-lengths.html