Currently working on a definitive test with the ported iron heads in regards to various single four intake manifold variations or mods.  I suspect that paticular intake modification (slotting) does standout more when the heads are ported than if used on stock heads.  From what I have observed, modifications to the intake manifold needs subsequent increases in head flow to realize any significant benefit.  Once the heads have been ported though, then the stock intake must be modified for more flow or an aftermarket intake used.

Lorena, Texas (South of Waco)

The Stromberg 97’s are generally rated at 155cfm when used individually.  Concensus has the Stromberg 81’s at 125cfm while the Stromberg 48’s are 170cfm.  The Strombergs with ‘LZ’ on them are rated at 160cfm.  The 3X2 intake manifold testing that was performed recently was with the Stromberg 97’s.  You'll have to remember that when the carbs are used in multiples, the cfm rating drops.

Lorena, Texas (South of Waco)

Ted: That's interesting information. I'm sure most of us thought that a 3 carb setup,( in this case, 3- 97's), that the flow total would be approximately 465 cfm. In say percentage terms approximately how much flow does a Tri Power setup lose?

Paul

The ECZ-B intake can be modified to make good power but it takes a lot of work. We modified this intake before the B-T intake was available. Windows were cut in the upper runners to allow access to port turns. Floor was rounded to improve ramp to lower runners until the heat chamber was found. Holes were brazed and patches welded into ports. Made 425HP on 330 cu in Y.

Ted, I still have this intake if you're interested in a test.

http://ford-y-block.com 

20 miles east of San Diego, 20 miles north of Mexico

I’ll take you up on your offer on that cast iron intake.  That particular manifold would represent the extreme end of what could be done with the iron intake manifolds.  I’m thinking that particular manifold is best tested on the mule engine with the angle milled heads just to take advantage of the increased compression ratio the engine will be seeing with those heads.  The following set of ported heads drops the compression ratio back to the 9.2-9.5:1 range which would negate some of the benefits of a highly ported intake where it would try to normally shine in the upper rpm ranges with the higher compression ratio.  But I’m in a position to test that intake on both sets of heads anyhow so the compression ratio can also be properly evaluated.

Lorena, Texas (South of Waco)

Using numbers from some FE testing that was done in the past on a Superflow dyno, I’ll just throw 19% out there as the number for the cfm reduction when using three two barrel carbs.  Based on this, the 465cfm for the total of three Strombergs would net 376cfm when used together on a 3X2 setup.  If anyone has any more definitive information for this, let’s hear it.

Lorena, Texas (South of Waco)

Wow. So then there is probably a lot left with the 573. The Demon 98s are 205cfm each (498ish for 3) and the Stromberg throttle bodies for efi are about 255 cfm each (620ish for 3).

I was checking out the Demons the other day. They use a Y for the examples in the instruction book.

I wonder when the new Edelrock 3-2 manifold will be available. They say spring 2010 in the catalog.


Lawrenceville, GA

Ted, John:

Gary Burnette had a B manifold extrude honed a few years ago.  Maybe that one is still around and available for testing and comparing with John's extreme manifold.

John - "The Hoosier Hurricane"

That one is on my 56 Sunliner.

-Gary Burnette-

Besides what Gary is using on his vehicles, he has been generous enough to already send me an assortment of intakes for testing including an extruded iron intake and an extrude honed aluminum Blue Thunder.  This is on top of the extrude honed Blue Thunder intake I also have which was previously ran on the Church Brothers Thunderbird.

 

I’ve already done some preliminary dyno testing with the extrude honed intakes and these actually don’t perform as well as some of the hand ported intakes that are also here.  Gary and I have batted this back and forth and have come to the conclusion that the extrude honed intakes may be too slick on their insides thereby allowing some of the fuel to drop out of suspension before getting into the combustion chamber.  Gary has given me the go ahead to scuff up the insides and see if that helps.  The plan is to run the extrude honed intake again in the near future on a set of heads that will take advantage of the increased flow in the intake and then immediately ‘rough’ up the runners and rerun the manifold again to discern the difference.

Lorena, Texas (South of Waco)