4.0 swap...

[NickMBroncoII1987]

What year 4.0 v6 would work best in my 87 bronco II 5sp manual

 

[Josh B]

It may well depend on what motor was in it, due to matching the transmission case

 

[RonD]

I don't think BIIs even came with anything but a 2.8l or 2.9l V6, both used same block as 4.0l

So 1990-1994 4.0l with computer and engine wiring harness would be easiest swap, it will match transmission pattern in BII, but.................
If you can get the transmission with the 4.0l it will be a better setup, assuming both were 4x4, manual or auto

1995 and up 4.0l engine/computer can be used just adds extra layers of additional parts needed
1994 and earlier use OBD1 60 pin computer, 1995 and up used OBD2 104 wire computer

 

[NickMBroncoII1987]

I have found a 1995 4.0 engine/computer and wiring harness. What are the extra layers of additional parts Ron?

 

[lil_Blue_Ford]

You’ll probably need the dash wiring for a 95 donor, that would have OBD2 and the scan tool connector is under the dash rather than the engine compartment. Not sure what else.

Either way you’re facing adapting a lot of wiring, even with a 90-94 donor. Hope you’re comfortable with wiring.

 

[NickMBroncoII1987]

I think I will just bite the bullet and replace the heads on my 2.9. I've already got plenty of rebuild parts on the way. I was hoping the 4.0 swap would be easy. Are there any complete write ups on the to-do's on the 4.0 swap 91-94 models

 

[Josh B]

Here's a general view of the tech articles, you can pick about any route you want from there

Ford Ranger Tech (1983-2011) - The Ranger Station

DISCLAIMER: Activities and vehicle modifications appearing or described at The Ranger Station and it’s pages may be potentially dangerous. We do not endorse any such activity for others or recommend it to any particular person – we simply describe … Continued

www.therangerstation.com

 

[lil_Blue_Ford]

I think I will just bite the bullet and replace the heads on my 2.9. I've already got plenty of rebuild parts on the way. I was hoping the 4.0 swap would be easy. Are there any complete write ups on the to-do's on the 4.0 swap 91-94 models

Unfortunately, the first gen (83-88) are less than ideal swaps to the 4.0 because the wiring harness is so different. The 89-92 had a different harness (89/90 for the B2) and since the 4.0 started in that generation, it’s almost a plug and play swap. Not so much on the older ones. By no means impossible, but a lot of people either don’t like wiring or shouldn’t be touching wiring.

Depends on what you’re after really. My choptop on 35” tires needed more engine, the 2.9 didn’t like it. So I went 4.0 with that. My 88 is going to run 31” tires max (probably 30” tires though) and not be more than a mild off-roader so the 2.9 is adequate (wiring isn’t really a problem for me). I’m intending on giving the 2.9 some help, free floating rockers and stuff. Think some mods to the 2.9 will make it work to suit my needs and I don’t have to do the wiring.

 

[gaz]

@NickMBroncoII1987 ,

I sourced an OHV 4.0l with SFI computer from a 94 Explorer, the complete engine bay and cab wire harness, all sensors, the dash and steering column for my 87 BRONCOII.

Though I prefer the original Gen1 dash, I wanted the install to be simple plug and play. After driving the Explorer, I pulled everything I felt would help. If you need the torque then going 4.0l is a nice option; great parts support, drops right.

4.0l Explorer swap ISSUES:
• wiring harness are runs different
• 4.0l steerting column needs the firewall cut for the shape difference.
• the OHV 4.0l does not have an adjustable valve train.
• the 4.0l will need more exhaust flow than the 2.9l.
• the 4.0l will use more fuel unless you take steps to make it more efficient.

Benefits of 2.9l:
• better fuel economy.
• adjustable valve train.
• no swap.

 

[NickMBroncoII1987]

I'll be sticking with the 2.9. A few questions about the availability of parts...
Performance cam?
Newer style rocker arm setup?

 

[PetroleumJunkie412]

I'll be sticking with the 2.9. A few questions about the availability of parts...
Performance cam?
Newer style rocker arm setup?

No performance cam out of the box, however I'm guessing yours is really worn. They were known for soft cams that eventually die.
Edit: actually, there may be a performance cam. I think. Check the Brit performance sites for Taunus/Cologne/Sierra/Merkur. I.... can't remember tho.

FE block lifters fit, so more non shitty lifter options out there.

I have a set of free floating rockers on mine. Haven't run it yet. Can't report.

They respond well to a microsquirt ecm. I have the base tune uploaded in the 2.9 forum. Factory ecms tune is poop.

Merkur intake leads to better throttle response.

Headers still exist. JBA are worth the coin.

Factory pistons and rods are capable of boost. Skogen Racing in Norway has Factory 2.9 blocks running 14+ psi with good tuning.

Guessing your heads are fine if it made it this far.

 

[NickMBroncoII1987]

Im going to try and run the 2.8 pistons in the 2.9 motor with reground cam. A guy on here was telling me how to do this and now i cant find his messages. We assembled the rotating assembly the the bottom of the 2.8 pistons are hitting the crank... I assume i need to get the 2.8 rods as well? Or do i need to run a 2.8 crank?

 

[PetroleumJunkie412]

Im going to try and run the 2.8 pistons in the 2.9 motor with reground cam. A guy on here was telling me how to do this and now i cant find his messages. We assembled the rotating assembly the the bottom of the 2.8 pistons are hitting the crank... I assume i need to get the 2.8 rods as well? Or do i need to run a 2.8 crank?

@gaz

 

[NickMBroncoII1987]

Yes Thats his name! Thank you PetroleumJunkie412

 

[PetroleumJunkie412]

I've thought about the 2.8 pistons on my build. Forged pistons for the 2.9 don't exist.