I have a bee in my bonnet and this thread is purely for my own curiosity and thirst for info. I've found a number of threads pertaining to increasing and improving the performance of a 300 inline six, but not much eloboration. Good reference photos!


I'd like to build a tri-carb intake manifold and will be implementing my existing knowledge of V8 performance to an inline six:

1. rectangular runners: rectangular tubing, mandrel bent and laser cut seats for the carbs to be mounted on
2. longer runners for increased low-end: taking my cue from a high rise intake manifold
3. polishing and grinding plenums for the usual reasons
4. 1/2 inch riser for each carb
5. blending each runner, so one carb feeds two intakes at a time

I'll be building this out of steel and have it electroplated/ galvanised for rust prevention. Am I missing something? Or bad idea?

What carb would be ideal for such a set-up? Rochester 97's (favored amongst many hot rodders) or Weber single barrels? Or a triplet of standard Carters/Motorcraft carbs?

I also intend to fab up a header and add a performance cam and performance ignition set-up to the mix.

Would this work?

Any advice and tips would be muchly appreciated.

 

Check this thread:

https://www.ford-trucks.com/forums/6...s-running.html

 

I'm going to be building something similar on my 300. I'm also building my own headers. So I'm going with a single mounting flange for the header and intake.

I'd skip the whole electroplating or galvanizing idea. If you want to have it coated go with a ceramic coating inside and out. And there's not really any reason to polish the intake plenums.


I'm going with some mandrel U-bends exhaust tubing for my runners. I'm going to try and flatten out the sides on them some. Might not be perfect but it'll be a little easier/quicker for me. Mine going to be a daily driver not an all out drag car so it should be fine.

My plan is 3 separate plenums for the carbs. I haven't decided yet if I'm going to divide the plenums to separate the ports or not. I'm going to build the plenums out of some sheet metal and am going with 1/2" plate for the carb mounts/risers.


Personally I wouldn't mess with rochestors or Weber 1V's ( Now if you are talking some DCOE's or IDA/IDF's 2V's then sure! ) . For my set up I'm going to run 3 Autolite 2100 2V carbs. The Autolite 2100's are super simple, perform good and very reliable. Then once I get the supercharger set up finished/engine for it built I'll be swapping over to 3 Holley 4412 2V carbs.

When you build your take lots of pictures and post them.

 

"Longer runners for increased low end"? really? I always thought they were longer for better top end like the high rise and tunnel ram intakes on V8s.
How about 3 side draft carbs. each on it's own 2 into one. Three S&S carbs from Harley Davidson maybe?

 

Longer runners are good for torque. That's one of the reasons the Ford EFI truck intakes have such long runners.

I think the V8 tunnel rams are more about plenum volume then it is runner length.

 

what about a set of three glass bowl holleys? they'd look pretty sweet!

 

Not much of any performance to be gained with three glass bowl Holley's.

The Autolite 2100's are a good performing simple/reliable carb. And they came in enough different sizes to size them to your engines need.