[Murf]

Could anyone post the "as cast" port sizes at the head mounting surface of the HSD & Hurricane/Tomahawk? I haven't seen them anywhere. Very informative thread, btw.

Thanks, Murf

[Steve C.]

Murf, I can't provide the actual dimensions on the Tomahawk port openings but will confirm they are small. As I understand it was done so as to be able to market the intake for use with unmodified factory heads if desired. In a way, similar to the Performer intake has small openings. It takes some work to port match and blend the runner for something like a FelPro 1233 gasket(2.200" tall). And the number 1 port/runner needs additional attention in blending. They will go 2.300" tall but doing so only leaves about a 1/8" or so above the opening for seal.

[gearbanger]

What about the "Northwind" intake? It looks good, supposed to perform with a victor and fits under the hood of more cars. And it is supposed to have pleanty of meat to port match to higher flowing heads.

I haven;t seen any in circulation though. Anybody running one?

[Steve C.]

The Northwind intake was susposed to come available with two differant port opening sizes, a RAIV size which I presume is a FelPro 1233 gasket that is about 2.200" tall, and a larger 2.300" opening. That said, I have only read comments regarding the taller port version and don't know if the smaller size made it into production. But their higher flowing heads typically have 2.300" or taller port opening. That can be a tuff nut for the Torker II intake without welding. The Performer RPM intake will work with the taller port opening as will a Tomahawk intake (or Holley Street Dominator intake) but as mentioned the Tomahawk intake will have only about 1/8" or so above the port to seal.

One person had the Northwind intake, but found his hood would not close on his 2nd Gen Firebird with a air cleaner installed. He got rid of it and replaced it with a HIGHLY modified Holley Street Dominator intake, his testing indicated it gave up about 15 hp to the Northwind intake with the change. But because the HSD is about the same height as a factory intake he can now use a air cleaner.

It appears limited testing has been done, or at least shared and posted on the various Pontiac boards. KRE's class clown on the PZ board has stated it compares to a Victor intake. And here is some testing done by Dave Bischop:
http://www.sdperformance.com/newsStory.php?newsID=53

Pontiac Enthusiast magazine article available on line, title "North Winds Of Change":
http://editions.amospublishing.com/P...num=32&s=North Winds Of Change

And a word of caution, the method of measuring the manifold height within the article, and height comparision photo presented, are VERY misleading. Lots of discussion about that on line.

[Skip Fix]

I can tell you neither a Tomahawk or a T2 will seal a 2.400 tall port as KRE CNC E heads have. A 2.3 the T2 on some but not alot at the top, probably not the Tomahawk. Both need weld. The original Holley Intake the Tomahawk was based on will just barely seal a 2.400 port.

My T2 does OK for just a 3/8 spacer and a real Shaker base Cliff

For you all looking at the Tomahawk Cliff has found some issues using a Q jet and no spacer, I have some flow number here years ago and what it does with different carbs. The Holley is more centered so the primary bores can flow easier into the front runners on it with it's shallow plenum.

[torqjunki]

To keep your intake ports from getting to thin on top, just run a thicker intake gasket, or two intake gaskets. Most intakes have extra material on the bottom side of the port if you need to lower it a bit. This will also get the intake up off the valley pan and the thicker gaskets will help heat soak. May need to elongate the intake bolt holes a little.

[Murf]

So, none of the currently available manifolds fit the RA IV port without work, correct?

Murf

[440GP69]

IMHO all these intakes need work before bolting on and going
T2 has Small runners that have their runner bend up near the plenum then a nice straight shot at the IV which for a Single Plane is one that will produce a Lot of Torque and decent top end with minimal low rpm loss, I Really Like the T2 if i can Do a Full Port Match all the way up the runners and some plenum work, Good Street Its capable of over 665hp on pump gas!
But it isn't capable of really tall intake ports i believe 2.3 is the tallest
The RPM is also a Good Intake and can be Port matched to a 2.4+ intake port and can flow 340-375+cfm
I built a 470 Pump gas motor with 87cc e-heads ported to 322 @ .650i 242e old faithfull
Ported RPM, 2" headers 10.23:1 made 568hp at 5600 and 588tq at 4300 and i heard of a guy making 580 with one on pump gas and 350cnc e-heads
The Tomahawk is a decent intake, Ive seen a Fuel Injected 467 with a Port Matched Tomahawk and 330cnc E-heads at mid 10's comp with a mid 240'si 250's ex hyd roller make 592hp near 6k and 575tq so all three can do the job
I'd use a Ported T2 though FWIW
Oh and if you use a Tomahawk They NEED at least a 1" spacer with Q-jet!
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