converting 4.0 EFI to carb

[LITTLE FOOT]

ok like the title says im converting my 4.0l to carb with no emissions crap. im using a 2.9 distributor and getting a carb intake manifold.
has anyone done this and what tips do you have that will make my life easier?

 

[Ozwynn]

why? you would be better off fixing the problem with the fuel injection. this has been brought up before and i think (I am not positive because I would never attempt this) it was decided that the 2.9 dizzy and intake wouldn't work.


you really want to go EFI to carb then buy the EFI 302 in my bronco so I can buy an EFI 351.

 

[LITTLE FOOT]

there is no problem with it. they make a manifold for it and the 2.9 distributor should work if not what one will?

 

[Ozwynn]

I don't recall why it wouldn't work just that it was discussed and argued at length and determined that it would not work, that the carb kit for the 2.9 would not work with the 4.0L despite the claims of the kit manufacturer. for one you would need to either duraspark it or go HEI.

 

[gerko]

Hi there,

I'm working at the moment on it.
a 2.9 dizzy will definately work at a 4.0 V6!

We welded the original 4.0 inlet
made 2 separate rooms, the 3 efi inlets at the front 1 room
and the 3 at the back the other room

Welded a spacer for a 4 bbl Holley 390 CFM on it.

At the moment desperate looking for ARP bolts for the con rods
because we're not sure if thes are the same of a 2.9.
Becuase ARP delivers for a 2.9, but 4.0 not sure yet

Why?!
For ovalracing with contact

 

[stegomon]

hmmm this is cool...i want to see a write up and pics on this

 

[Psychopete]

I am just curious on how you're going about the ignition system since you're using a 2.9L TFI distributor? Is there some way that you'll adapt it to a duraspark or other type of ignition module?

I don't know how true this is, but from what I recall (from his book), Sven Pruett stated that a 2.8L dizzy could be used in a 2.9L WITH the approperiate distributor gear. He claimed you could get them from the Ford dealership but offered no part numbers. FWIW, even though the 2.8L camshaft spins the opposite direction, the 2.8L distributor turns the same way as the 2.9L - clockwise (look it up!).

I think it's feasible!

Pete

 

[2ranger87]

The oil pump drive between the 2.8 and 2.9 dizzy's were different as well. 2.8's were the traditional hex shape, and 2.9's were the "star" shape (almost like a torx bit).

 

[F150hybred]

I'm staying the hell outta this one... as should many others. Its been discussed MANY times over and the original poster should learn to use the search feature.

 

[Psychopete]

The oil pump drive between the 2.8 and 2.9 dizzy's were different as well. 2.8's were the traditional hex shape, and 2.9's were the "star" shape (almost like a torx bit).

Ah, I was unaware they changed that between the engines. I did know the 2.9L had a star shaped drive as I had to make a priming tool out of an old distributor.

What about the 4.0L, is that star shaped as well, or traditional hex?

Pete

 

[rusty ol ranger]

Where did you find a carbed intake for a 2.9?

later,
Dustin

 

[gerko]

O simple

take the inlet manifold of a 2.8
redrill 2 or 3 holes
and it fits on a 2.9

 

[AllanD]

O simple

take the inlet manifold of a 2.8
redrill 2 or 3 holes
and it fits on a 2.9

Never even thought to try that because fuel injection is responsible for ALL of the 20hp difference between a 2.8 and a 2.9.

Not to mention that the 2.9 produces it's torque 800rpm lower (and thus more usefully) than a 2.8.

I still can't understand why anyone would want a carb.

Particularly younger guys...


AD

 

[Sevensecondsuv]

Where did you find a carbed intake for a 2.9?

later,
Dustin

Uh-oh. Dustin's getting excited. This would be sensory overload for him. His two favorite things in life, carbs and 2.9's, coming together as one!

 

[stegomon]

Uh-oh. Dustin's getting excited. This would be sensory overload for him. His two favorite things in life, carbs and 2.9's, coming together as one!

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