Is the 2.8 the same size as the 4.0???

sveppi · Post by **sveppi** » Sat Feb 19, 2005 3:54 pm

Hi I was wondering, the 2.8 V6 motor from a ´82 Bronco, is the block the same size as the 4.0 motor?? I currently have a 2.8 w/carb. and I´m thinking about replacing it for a 4.0 w/carb. All I need to know is do I need to make any modifycations, and is this swap simply plug & play operation or do I need to do any serious modifycations?

regards
sveppi

ranger5.0 · Post by **ranger5.0** » Sat Feb 19, 2005 9:56 pm

The engines external dimensions are similar as in bellhousing bolt pattern and motor mount placement but the heads , intake and the exhaust are different. I am not sure if there is a aftermarket carb intake for the 4.0L. The 2.8L has a solid lifter cam that runs in the opposite direction than the 2.9L and the 4.0L. Gear drive versus chain drive. So it might not be as much plug and play as you may want. BTW I thought that 83' was the first year of the Ranger-BII chassis.

DBrown · Post by **DBrown** » Sun Feb 20, 2005 4:29 am

I don't think you can get a carb setup for the 4.0L unless someone has started making an after market piece. I would just wire it to keep EFI.

sveppi · Post by **sveppi** » Sun Feb 20, 2005 4:47 pm

damn, so they never made any 4.0 engines with carburator? so the biggest V6 motor that was manufactured with carb. is the.. what.. 3.4 ???

ranger5.0 · Post by **ranger5.0** » Sun Feb 20, 2005 9:53 pm

In ford motors it is the 2.8L. Ford tended to use the 200 cu in inline six in the mid-size cars and the 300 cu in in trucks. The 2.8L was a german ford design that started out as a 2.6L and was bored and stroked to the 2.8L motor. You can build up the 2.8 and put the lowest gears in the truck to put it in the powerband or install a carbed 302.

85ranger4x4 · Post by **85ranger4x4** » Tue Feb 22, 2005 4:06 pm

3.8L V6 from some mustangs and early 80s cars is the biggest carbed V6 (I think). If you are really worried about sticking with a carb but want lots of power then probably go with the 302 because the 3.8 and the 302 have the same bellhousing (I think) so you would have to change all your drive stuff anyways.

As for me, I went FI and swapped in a 4.0L and I am very happy with it. It just needs new O2 sensors...and a new tranny now because my old one (which was already on the way out) was helped along by the new power.

The wiring really wasn't even all that bad, I just made sure that I gathered up a COMPLETE harness from the vehicle that the motor was from (94 explorer)

Exhauster · Post by **Exhauster** » Fri Feb 25, 2005 8:05 pm

hi, does the 4.0 fit without hitting the firewall or wiper motor on the intake? i have an 88 with a toasted motor and the heads and intake are missing.... i figured this is a good time to change it over.... can the 2.9 intake and distributor be used on the 4.0?

ranger5.0 · Post by **ranger5.0** » Sun Feb 27, 2005 8:20 am

Yes it fits, but the 4.0 has coil packs and no provision for a distributor.

Exhauster · Post by **Exhauster** » Sun Feb 27, 2005 8:23 am

i was looking at a 4.0 from a 91 aerostar and it has a plate covering the hole where the distrtibutor would go.... i'm wondering if i can just ust the intake and distributor from a 2.9 on the 4.0?

DBrown · Post by **DBrown** » Mon Feb 28, 2005 7:21 am

I never tried it but I am going to go out on a limb here and say no. the odds are against that from working. I would just wire the motor. you are getting a better system buy going MAS air anyway. the top end is where all the power is made and you could end up "shooting yourself in the foot". remember that there are things like piston to valve clearence, compression ratio's, bolt location, intake fitment......such as deck height and intake size to think about. so the odds of you being able to use the 2.9L top end on a 4.0L bottom end are slim to none. also the 2.9L had issues with cracking heads from over heating so that will be another down fall........to make this short with out getting into a lote of theory and measurements it is better to keep the 4.0L complete then try to hybrid something together....think about it some guy stood there for days scratching his head figureing out how to get the best performance/life out of that motor......why change it when you can get really good numbers out of it in stock form?

ranger5.0 · Post by **ranger5.0** » Mon Feb 28, 2005 9:46 pm

I would pull the cover plate and see if there is a distributer gear on the camshaft. If so, then I would leave the intake and drop the 2.9 dist. in. I wouldn't change the intake because it would have to have more air flow. The wiring would be close to the same but the 4.0L would have a crank sensor. For that reason I would use the 2.9L wiring harness too. You may have to get a upgrade on your computer to accommadate more fuel flow. But I think you should get away with out it though since the ECM doesn't know what size the motor is, it does what it is told to by the information sent to it from the sensors, Where there is a will there is a way

Good Luck.

DBrown · Post by **DBrown** » Tue Mar 01, 2005 6:40 am

I can't remember all the specs but I am pretty sure this is the problem you will run into. I was messing with a 3.0L at the same tie so I might be messing up some numbers.

2.9L = 14lb injectors
4.0L = 19lb injectors

your computer will probably fight the sensors and run the motor lean.....in other words boom.
if this was a 2.9L and you were going to run a 3.0L ecm I would say it might work or if you would run the 3.0L with the 2.9L ecm. but for me the displacement is too far off. and I would not want to ruin a perfactly good 4.0L. the wireing isn't that hard and I would wager that you will spend more time trying to get around it then just doing it. I plan on wiring another 4.0L swap in the next few weeks for a friend and I am thinking I can get it in the first shot this time.

ranger5.0 · Post by **ranger5.0** » Tue Mar 01, 2005 8:31 pm

Doesn't the Regulator at the end of the fuel rail control the fuel pressure to the injectors

so as long as the pump puts out enough pressure and volume I don't see a prob. The O2 sensor reads the mixture and would be able to tell that it was lean and add more fuel. The temp, knock sensor, oil press, air flow sensor, speed sensor ( if so equipped) all use the same principles as "water hot" and " engine knock" and "lotsa air coming in" and "oil pressure up" All you are doing is tell the computer the info it needs to run. Besides I wouldn't use a 2.9L rail and Injectors on a 4.0L engine.

DBrown · Post by **DBrown** » Wed Mar 02, 2005 9:01 am

you can't use the 2.9L fuel rail on the 4.0L, they will not interchange. the fuel rail is bolted in between the upper and lower plentium as kind of like a spacer. what I am getting at is that all electrical parts have a certain resistence that the ecm reads. so you might have a problem when you plug in the injectors or other sensors. kinda like not pulsing or pulsing but not delivering enough fuel, or the IAC not opening far enough to control idle. if any of this senses wrong it will kick back to the ecm causing a trouble code and the motor to not run right. for this reason it just makes more sense to me to rewire. it might work and I'm not discourageing someone from trying it if thats what they have to do to get it in but the easiest way would more then likely be to just rewire.

Exhauster · Post by **Exhauster** » Sat Mar 05, 2005 11:54 pm

this problem is solved..... i found a different complete motor and electricals.... got a 93 aerostar that is turnkey running....now i'll just have to figure out the wiring and what all i'll need.... my understanding is that i use my 2.9 clutch and flywheel, with the 4.0 starter? 2.9 or 4.0 mounts? do the aerostar ex manifolds work? anything else i might want to keep off the aerostar? was thinking of keeping the rear end too... looks like an 8.8, i have an 8.8 trac-lok and ring and pinions are cheap on ebay