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Registered
Join Date: Dec 2020
Location: The Swamp and NC
Posts: 486
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Now for something completely different Part 1
The long term goal..Holley carb on a '83 SC, type 2300 2 BBL. 350 CFM, manual choke.
Why? Simplicity, cost, performance.
1. I'm a good fab guy.
2. Very easy to adjust for A/F ratio. Lots of parts to customize the Holley.
3. Will prove out the system set up before going to Holley Sniper EFI system.
4. I have experience going this route on V8s but using larger CFM carbs.
The CFM numbers I have found here show the 3.0 have a max build out flow of 329 CFM so I am in the right size for the small 2300 carb.
The Problem, the long runners are good for torque but bad for fuel fall out. The heads have the injector well tear drop design to force fall out to cool the back side of the intake valve.. Ford used the same head design starting in '96 because cooling the valve was more important than atomizing the fuel, 6 pintle Bosche injectors be damned, just make funny shaped chambers and pistons to remix fuel in the cylinders. Ford used an intake valve seat of .080 wide to dump the heat. I have a set of SC big valve heads and Porsche uses a .040 seat width which is good for performance but bad for dumping heat so the tear drop injector dump design in the head runner on the long side radius.
Here is a solution I have used that I got from Chrysler big blocks, big cams ran poorly on the street so they made intake gasket sets the had window screen in-between 2 gaskets, the problem was that the screens worked great but cut down CFM because the screen created 25% blockage. When you got to the drag strip a quick change out to a regular open gasket and back to max flow.
The SC head needs a 3mm flare expansion at the end of the runner and at the beginning of the head to compensate for the 25% reduction from a screen to get the fuel back to a "fog" before entering the cylinder which has been the down fall of the central single carb set up. I have checked with 2 tier 1 builders one of which has done it back in the day and the result was high torque but rough drivability because of fuel drop out.
Flame on gents..
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