Thread: Hi-Ram Tunnel Ram

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what about the Manifolds Hi-Ram Tunnel Ram, in stroker engine 383?
the Carburetors edelbrock 1500cfm?

Originally Posted by ra7tnast

what about the Manifolds Hi-Ram Tunnel Ram, in stroker engine 383?
the Carburetors edelbrock 1500cfm?

Way to much carb.
Here is the old carb forumula for size.
Carb. CFM required = CID X MAX. RPM,then divide by 3456.

^^^^ that's right! (actually VE*CID*maxrpm/3456 where VE is volumetric efficiency)

Sometimes a quicker rule of thumb is CID*2 i.e. 383*2 -> 766cfm

this shortcut assumes max rpm~7000 (3456*2) and 100% volumetric efficiency (most motors are 80% to 95% efficient).... a 750cfm carb should suffice unless you're looking to spin the motor much over 7000rpm.

This is for minimum cfm required.... you can go larger but if you go too big the vaccuum signal will be too weak at lower rpm.

2 cents,

Chris

Yeah but the plenum volume of a big tunnel reguires a lot more wetting out than you might think.

Why do you want to run a tunnel ram?

Kitz

Originally Posted by kitz

Yeah but the plenum volume of a big tunnel reguires a lot more wetting out than you might think.

Why do you want to run a tunnel ram?

Kitz

I was wondering when someone was going to talk about "wet flow".

Originally Posted by kitz

Yeah but the plenum volume of a big tunnel reguires a lot more wetting out than you might think.

Why do you want to run a tunnel ram?

Kitz

Because it just looks freakin COOOOOL!

A guy in Saskatoon built a small block Ford with a dual-four tunnel ram (cause it looks so COOOOOL!) and he put adapters and dual Holley two-barrels on it. Most people don't notice the diff, and he can drive the thing with no problem. Sorta like the triple carb flattie manifolds with the center carb blocked off.
Must be a farm boy!

thank you all