4.0 retrofitted with a distributor?

[Shran]

Are you sure though guys have ran a 5.0 on a 2.9 ECM? How does the ECM deal with 2 more cylinders?

2.9 ECMs (actually, virtually all 1980's EFI computers) are very unsophisticated... the 2.9 batch fires its injectors and there's only two sets of them - each set of three fires at once. They all share a common power and ground. So to run two more... you just add another injector plug to each batch. For all the computer knows, nothing has changed - it still thinks it only has "two" injectors. Every other sensor on that era of Ford is more or less interchangeable, wired the same, and most even have the same plug... the programming in the computer itself and the clutch/auto trans wiring is the only major difference.

I'll be watching this thread, it's an interesting subject. I read on another forum this morning that 4.0 heads will fit a 2.9 block but you have to swap them from side to side, among other rumors. Hope someone can shed some light on this.

 

[adsm08]

I read on another forum this morning that 4.0 heads will fit a 2.9 block but you have to swap them from side to side, among other rumors. Hope someone can shed some light on this.

I would believe that. Not sure why you would have to turn them around though, the heads are symetrical. The head gaskets, head bolts, and exhaust manifold gaskets are all the same.

 

[rusty ol ranger]

If 4.0 heads fit a 2.9 this could open up a whole 2.9 renissance. By (cheaply) eliminateing their only real weak point.

@Shran that makes sense. I didnt think about the batch fire thing.

 

[RonD]

Probably not the best swap, lol
Lowering compression with bigger chambers, and not sure either intake manifold would work

4.0l OHV had same head issue if overheated

 

[rusty ol ranger]

Probably not the best swap, lol
Lowering compression with bigger chambers, and not sure either intake manifold would work

4.0l OHV had same head issue if overheated

Why ya gotta burst my bubble man?

 

[85_Ranger4x4]

Why ya gotta burst my bubble man?

And if it was that easy people would have been doing it decades ago.

 

[adsm08]

And if it was that easy people would have been doing it decades ago.

If it was that easy AllanD would have done it in 1990.

 

[Rowdy Fitzgerald]

If it was that easy AllanD would have done it in 1990.

That's what I was thinking too lol. But then again, maybe people just always figured it wouldn't work...

 

[rusty ol ranger]

That's what I was thinking too lol. But then again, maybe people just always figured it wouldn't work...

I always heard it wouldnt.

But i never really had a reason to look into it.

I did find new "improved" 2.9 heads online the other day though...

FORD 2.9 NEW FULL - PROMAXX Performance Products

ProMaxx Performance developed/designed this cylinder head from the OE casting 86TM. This is a direct bolt on cast iron cylinder head to replace your factory casting. Year: 1989-1992 Models: Bronco II, Ranger Engine Size: 2.9L V6

promaxxperformance.com

248 for a head aint bad imo

 

[bobbywalter]

yeah...batch fire and injector sizing are old hat. along with running the 302 on the 2.9 pcm....or early 3.0.


so fitting the batch fire harness eliminates any issues as long as they would fit the 4.0 injectors

in the general.... the fitted injectors matched to the engine do just fine as the map and spark tables are not huge...total timing otoh is at times.


the 4.0 drive housing fitted with a dizzy top is what is needed... the drive and deck heights and holes are different...close but not perfect...

the drive shaft sizes are different as well... the pin ends are the same.


in any case the 4.0 is already setup for edis. so megjoltinator deluxe...is the easy button.

 

[1990RangerinSK]

And if it was that easy people would have been doing it decades ago.

You sure rusty's old enough for people to have been bursting his bubble decades ago?

 

[bobbywalter]

You sure rusty's old enough for people to have been bursting his bubble decades ago?

yes.....


i am 48...pretty sure he is 10 years older then me...

 

[Dirtman]

Uhhh I may be dumb but umm wouldn't batch firing the injectors just be dumping raw fuel down the exhaust?

Batch firing plugs... yes. But injectors?

 

[85_Ranger4x4]

Uhhh I may be dumb but umm wouldn't batch firing the injectors just be dumping raw fuel down the exhaust

Not if the intake valves are closed.

 

[Dirtman]

If it sprays on the intake stroke it's just a normal injector.... if it sprays on the compression stroke it would flood the engine.... if it sprays on the power stroke it would do god knows what.... if it sprays on the exhaust stroke it's dumping fuel out the tail pipe.

So when is the the batch fire injector spraying that isnt going to be dumping fuel out of the exhaust?