2.4S vs. 2.2S MFI -- DIFFERENCES?

What are the differences between the 2.2S and 2.4S MFI systems? Pumps and stacks only? Thanks.

All S throttle bodies have the same port size on 69'-73' MFI cars, that is they are 38mm where they meet the stack and 36mm where they meet the intake port on the head.

However, the stud spacing differs where the stack meets the throttle bodies. The 2.2 mag stacks and the 2.4/2.7/3.0 plastic stacks all have the same spacing. The 69' 2.0 stacks have a unique stud spacing compared to the above stacks.

So basically, only 2.0 stacks only go with 2.0 TB's. 2.2/2.4/2.7/3.0 stacks can mix and match with 2.2/2.4/2.7/3.0 TB's.

The injector lines and injectors are identical.

All throttle bodies T, E and S have a bore of 38mm where they meet their appropriate stack. They differ only in that the side that meets the head matches that appropriate port. i.e. 36mm for S, 32mm for E and 29mm for T MFI motors.

So what this means is that any T or E throttle body can be bored out to 36mm where it meets the head port and be used for an S setup with the appropriate stack.

One more difference between the 2.2 and 2.4 MFI motors is the cold start enrichment setup. The 2.2 motors had the fuel sprayed in from a fitting in the metal air box above the mag stack. On 2.4 motors the fuel sprays from the fitting in the side of the plastic stack. 2.4 motors also had plastic air boxes.

The 2.4 throttle bodies also had a nipple for a vaccuum line that was used for the vaccuum retard distribututors.

Quote:

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Originally Posted by Bobboloo

All S throttle bodies have the same port size on 69'-73' MFI cars, that is they are 38mm where they meet the stack and 36mm where they meet the intake port on the head.

However, the stud spacing differs where the stack meets the throttle bodies. The 2.2 mag stacks and the 2.4/2.7/3.0 plastic stacks all have the same spacing. The 69' 2.0 stacks have a unique stud spacing compared to the above stacks.

So basically, only 2.0 stacks only go with 2.0 TB's. 2.2/2.4/2.7/3.0 stacks can mix and match with 2.2/2.4/2.7/3.0 TB's.

The injector lines and injectors are identical.

All throttle bodies T, E and S have a bore of 38mm where they meet their appropriate stack. They differ only in that the side that meets the head matches that appropriate port. i.e. 36mm for S, 32mm for E and 29mm for T MFI motors.

So what this means is that any T or E throttle body can be bored out to 36mm where it meets the head port and be used for an S setup with the appropriate stack.

One more difference between the 2.2 and 2.4 MFI motors is the cold start enrichment setup. The 2.2 motors had the fuel sprayed in from a fitting in the metal air box above the mag stack. On 2.4 motors the fuel sprays from the fitting in the side of the plastic stack. 2.4 motors also had plastic air boxes.

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Sorry for the archaeology but... I had in my hand an unmolested 1970 2.2E throttle body yesterday and a vernier caliper, and while I did indeed recorded the port end to be 32mm, the stack end I recorded to be 35mm rather than the 38mm you suggest. The stack on top tapered from 35mm up to 38mm at its top. Having read your post today I will double-check my measurements and correct myself if wrong.

Quote:

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Originally Posted by RobFrost

Sorry for the archaeology but... I had in my hand an unmolested 1970 2.2E throttle body yesterday and a vernier caliper, and while I did indeed recorded the port end to be 32mm, the stack end I recorded to be 35mm rather than the 38mm you suggest. The stack on top tapered from 35mm up to 38mm at its top. Having read your post today I will double-check my measurements and correct myself if wrong.

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Ok I'm back with the facts. On my 1970 2.2E engine, the throttle bodies do indeed taper from 32mm to 38mm as per the info above. But the stack above, part number 911 110 301 0R tapers from 35mm at the bottom to 38mm at the top.

Attachment 618571

I know that the 2.2 and 2.4 MFI pump three dimensional space cams are not interchangeable .