View Single Post
triplesn8s triplesn8s is offline
Registered User
Join Date: May 2004
Location: Tallmadge, Ohio
Posts: 78
Question MFI Manifold & Stack Identification & Modification

I am seriosly considering a Megasquirt retrofit into my '72 2.4 MFI setup with 'E' cams. I want 32mm ports. In doing a port size check I found the following:

Head intake ports 30mm (An unpleasant '72 anomaly, valves standard size) I can enlarge them, no problem.

Intake manifolds 30mm at the head but can obviously & easily opened up to 32mm, ~36mm at the stack.

Plastic stacks 911.110.316.1R 30mm at the manifold! In other words it goes from 30mm at the bottom of the stacks to about 36mm at the top of the manifolds to 30mm at the bottom of the manifolds. Tres bogus IMHO.

The question is do the plastic stacks have enough wall thickness to port out to 32mm recognizing I will have to blend a fair way up the stack to make sure the diameter is never less than 32mm?

What are my other stack options? An 'E' set? Are they actually different? What should I pay for the stacks only less manifolds? Anyone with a set to sell?

I know my webers are OK but you can't beat programmable FI for that last 10% of power/drivability. Besides the stock MFI stuff looks way cool & minus the original MFI pump I believe it is lighter than the Weber setup.

Apologies for the longwinded questions but I am new to 911 performance applications.


Bill McCauley
'72 911T Coupe
'80 TR8
'78 TR8
'75 Jensen Healy
'00 Triumph Sprint ST 955i
Old 11-22-2004, 12:23 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)