2.9 Motor build up

[Broncopower33]

Just about ready to send my 2.9 motor into the shop to get rebuild. Does anyone have any good up grade parts to put on the motor? I use this b2 for 4 wheeling and would like to be able to get the max power out of the motor, but keep in mine I live in California, so my wonderful state makes things hard for me when it comes to smog. I read the info on this web page, but looking to see what works?

Thanks

 

[Beanmachine7000]

I would say it's not even worth rebuilding the 2.9... If you really wanna waste the money on a rebuild, find a 4.0 block and rebuild it... If I were you I'd just get a 4.0 junkyard engine and swap it in, it's so easy, and such a giant improvement... For the price of a rebuild you can easily buy a low miles 4.0 and M50 and the swap is super easy... If you're heart is set on rebuilding the 2.9 pretty much the only thing you can do is rebuild, it's already tuned pretty much to it's peak from the factory... It makes more hp per cubic inch than a H.O. 5.0...

 

[username]

Do you have any info on doing a 4.0 swap that you might be able to email me? I am really considering a 351W swap but I like to keep my options open.

 

[snoopdoggie]

Do you have any info on doing a 4.0 swap that you might be able to email me? I am really considering a 351W swap but I like to keep my options open.

Just look in the Tech Library

 

[Broncopower33]

I just finnish a 4.0L in my other bronco II. To tell you the truth, the wiring the motor is a big deal. I started off with a 91 explorer 4.0, and putting in the motor was ez part, same motor mounts, same everything, just the wiring is different. But if you can get pasted the wiring side of it, it is a great hp upgrade. I was looking to stick with the 2.9 in my other b2 just because I did not want to go through the same problems I had with the 4.0 upgraded. Something to think about.

 

[fastpakr]

If you've got the time, you can do a good condition 4.0 swap for a fraction of the cost of an engine rebuild.

 

[Beanmachine7000]

I just recently went from a BII 2.9 to an Explorer Sport 4.0 and honestly, I will never have another 2.9 again... I can pull a hill in 4th gear by my house that I could barely get up in 3rd in the Bronco... No contest...

 

[Broncopower33]

Ya I hear ya, the power of the 4.0 is awesome. My b2 does not even feel like a b2.

 

[Beanmachine7000]

If you've done a 4.0 swap why do you even want to keep the 2.9? You know how to do it now, it should be easier this time, lol...

 

[Broncopower33]

You would think, just not up for the fight again. If I did not live in California I would try the 302. But I hear it is hard to get it smoged.

 

[tbuddy]

whats so bad about the wiring i would like to no, seriously,. id assume ud put the engine wiring from the 4.0 on, as well as the computer from the 4.0, but could u go into more detail with the wiring

 

[Beanmachine7000]

You have to re-pin the engine harness to match the dash harness from the 2.9... look in the tech library...

 

[RacinNdrummin]

What you can do to the 2.9 is this...

Get a MAF 3.0 computer and maf sensor from a taurus/ranger/aerostar, verify the pinout, but it should be the same, add a pigtail for the MAF sensor.

Send your cam to Delta camshaft and have them grind you up their RV grind and some new lifters.

Gasket match your lower intake to the head, and your upper intake to the lower intake, can easily be done with a dremel.

If I remember correctly, you can use the flat top pistons from a 2.8 in the 2.9 for a compression bump, however I could be wrong.

Dont waste your time porting the heads, chances are youll replace one in the future and you wont wanna go through the hassle of porting another head, plus the benefits are very little for the amount of work put into them. If you have the heads done, use 88tm castings or even better the world products castings. The 86tm heads have a VERY bad rep for cracking, the 88tm's crack too, but not as often.

You could have a machine shop turn you up some rocker arm spacers to get rid of the springs on the shafts, this will free up a couple of HP.

Get some headers on it, and make sure you have a nice free flowing cold air intake and thats just about all you can do short of boosting it.

 

[Broncopower33]

Thanks for the info on the 2.9..... That will give me a starting point. As for the question above, about the wireing on the 4.0. You can pretty much forget any wire that is under the hood. Bring in every wire from the 4.0 fluse box head light wires, every thing. And then you start converting the 4.0 wire harness into the 2.9. I am not againt 4.0 upgrade, I am all for it, the only thing I am saying is to be sure to look into it, before jumping in. Take good notes and pictures will help. I am really glade I did the 4.0 in my b2, it was just a lot more work, than what I thought it would be, based off of everything I read. I think the best thing to do, is to buy car with the 4.0 and put it side by side with the b2.

 

[UnderMedikated]

Get out of California while you can!

 

[LittleHorse]

I was under the impression that engine swaps were ok in Cali as long as you kept all of the emissions equipment with the engine and the engine came from a model year equal to or newer than the vehicle it's going into? So wouldn't that mean you could do a 5.0 as long as it came from a vehicle made after the BII?

 

[Beanmachine7000]

I was under the impression that engine swaps were ok in Cali as long as you kept all of the emissions equipment with the engine and the engine came from a model year equal to or newer than the vehicle it's going into? So wouldn't that mean you could do a 5.0 as long as it came from a vehicle made after the BII?

Actually I don't think any engine swap is legal into a BII... Doesn't the engine have to come from the same model, from the same year or newer? I think since the BII only ever came with a 2.9 that would mean anything is not legal... Luckily where I live if it goes and if it stops it's legal, lol

 

[LittleHorse]

Actually I don't think any engine swap is legal into a BII... Doesn't the engine have to come from the same model, from the same year or newer? I think since the BII only ever came with a 2.9 that would mean anything is not legal... Luckily where I live if it goes and if it stops it's legal, lol

I was really into Datsun Z cars a while back and seem to remember a lot of people putting 350's into them, and I thought it was ok in the Democratic Peoples Republic of Kalifornia as long as the 350 came out of something newer. That was like 2002 though, so it's likely to have changed, and I could be misremembering.

In Oklahoma, I can put in whatever engine I want.

 

[holyford86]

What you can do to the 2.9 is this...

Get a MAF 3.0 computer and maf sensor from a taurus/ranger/aerostar, verify the pinout, but it should be the same, add a pigtail for the MAF sensor.

Send your cam to Delta camshaft and have them grind you up their RV grind and some new lifters.

Gasket match your lower intake to the head, and your upper intake to the lower intake, can easily be done with a dremel.

If I remember correctly, you can use the flat top pistons from a 2.8 in the 2.9 for a compression bump, however I could be wrong.

Dont waste your time porting the heads, chances are youll replace one in the future and you wont wanna go through the hassle of porting another head, plus the benefits are very little for the amount of work put into them. If you have the heads done, use 88tm castings or even better the world products castings. The 86tm heads have a VERY bad rep for cracking, the 88tm's crack too, but not as often.

You could have a machine shop turn you up some rocker arm spacers to get rid of the springs on the shafts, this will free up a couple of HP.

Get some headers on it, and make sure you have a nice free flowing cold air intake and thats just about all you can do short of boosting it.

If the BII is a california emissions model, the computer is already MAF if it is a '90. A cam will move your power band up a bit and make the 2.9 even more useless on the low end than it already is. The 4.0 is the best bang for your buck, hands down.

 

[Beanmachine7000]

I was really into Datsun Z cars a while back and seem to remember a lot of people putting 350's into them, and I thought it was ok in the Democratic Peoples Republic of Kalifornia as long as the 350 came out of something newer. That was like 2002 though, so it's likely to have changed, and I could be misremembering.

In Oklahoma, I can put in whatever engine I want.

I don't really know, or care that much... Here in Montgomery County, TN if it goes, and it stops it's pretty much legal, lol... Yes, I'm exaggerating a little... I say go for a 4.0... The power change is monumental compared to a 2.9....