2.9L Performance
 

Hey all,

I'm new to this specific engine forum(I frequently visit the 4.9L 300 section) but my brother is looking at a Bronco II that runs and drives for $150. Has a small soft spot on the frame that can be fixed with a small piece of new steel and it also has a big scratch and dent on one of the fenders. This Bronco II has a 2.9L and 5spd. What are possible performance upgrades for a 2.9L V6??? And also, if a V8 were swapped into a 2.9L V6 spot is the original 5spd still applicable to the V8 or is that only the bigger V6s? I know his 1988 Ranger has a 2.0(gas) with M5R1 and the M5R1 isnt applicable to a V6 or any motor other than the 2.0/2.3.

The 2.9 L V6 is what they call a cologne engine - the same family as the 2.8 and the 4.0. The transmission will bolt up to either of those engines. Do you know which 5 speed it has? Most likely, from what I understand, is the FM146 Mitsubishi transmission. Even though it bolts up to a 4.0, there is some debate out there as to how well it will hold up to the torque the 4.0 puts out.

From what I understand, there are some of the usual bolt on performance stuff (intake systems, exhaust systems, and the like), but nothing real dramatic. I've heard of the occasional person who gets real excited about building it up and gets the engine rebuilt for it (new cam, bore and stroke, and the like). Whether anything you can do to the 2.9 is better (or easier) than just dropping a 4.0 in, I don't know. If your brother wants to do some kind of engine swap, I would suggest trying to get the transmission with it.

Thanks shorty thats actually a bit helpful. I think if he decides to do an engine swap I'll have to point him towards a 5.0 and T-5 and buy a shift relocator kit from that one company that I can't remember the name to.

I suggest finding a wrecked Explorer. Pull the engine, transmission, computer and wiring. Rebuild the 4.0L. There are actually some decent performance options for the 4.0L. You can get different heads and / or pistons to get higher compression (some combinations too high for pump gas), and a couple Comp cams for it. With headers you'd have a really decent motor, that bolts up.

Of course there's nothing wrong with the 302 option. I've heard that you cant swap a 302 into a 4x4, but that may be wrong. I've also heard that with a 302, things get, um, cramped under the hood.

For the 2.9L, you could hop it up a little bit. World Products makes some heads that do flow better than the stock heads. A little porting and cleanup would help those too. The later non-EGR Rangers had a more agressive cam than the Bronco 2's, so a swap is possible there too. Find a throttle body from a 1986 or 1987 Bronco 2, as it is bigger than the one you have. Put a set of headers on and it should run good.

The T-5 is about the only transmission that can be swapped in behind a V8 that will stand up to the added torque and still be able to bolt up to the stock transfer case using an adapter. It's a somewhat pricey adapter as I recall and it's available from James Duff Enterprises (among others):

http://www.jamesduff.com/broncoII/v8conversion.html

1988 was sort of a changeover year, so you possibly have one of three transmissions: the M5R1 you mentioned above, which has an integral bellhousing that is specific to the engine and was available in both 4-cylinder (2.0/2.3) and V6 (2.9/4.0) versions. Also, both the Mitsubishi FM145 and FM146 were available that year, and have a seperate removable bellhousing for either application (as well as different input shaft).

I think there are adapters availble for the V8 to these trannies, but it's rather pointless because they won't hold up to the V8 for long unless you baby it, and what's the point of swapping in a V8 if you're going to have to baby it...?:D

For a shift relocater I believe you can use the tailshaft and housing from an S10 4X4 which moves the shifter back into pretty much the original forward position for the Ranger/Bronco II.However, I think the BII's all had bucket seats so keeping the relocated shifter in the more rearward position still works out ok, you just have to remove or modify the center console (if you have one). I switched to buckets in my Ranger so I could keep the shifter further back, I like it there.

Alternatively, you could swap in an M5R2 from an F150 with a 4.9 or 5.0 along with the F150's transfer case. That's probably the route I'd go. Cheapest and most likely easiest.

You can also stay with EFI, the rewiring isn't too bad. I just swapped a 5.0 HO into my '89 Ranger which originally had the 2.9. There are a lot of websites with info on doing the swap, and pretty good downloadable book available from one of them. Let me know if you want some links. Got lots of pics as well.

Well, really I never said the Bronco II was an 88...I said his Ranger is an 88 with a 2.0(gas) and M5R1.

Oops, that's what happens when I read too fast and miss a detail here and there. I just saw 1988 and that's what stuck in my mind. So what year is the BII?

I'm not exactly positive on the year...my brother doesn't even know but anyway, it must be newer than 86? I believe due to the fact it has a 2.9L.

Correct, since that was the first year of the 2.9. Do you know which front-end sheet metal it has? The earlier style would make it an '86, '87 or '88 and in '89 they changed to the smoother, more aero-look front so if it has that, it would be an '89 or '90.

https://images.google.com/images?q=t...hte/bronco.jpg
https://images.google.com/images?q=t...isilverred.jpg

nah no idea lol

there is actually quite a bit you can do to the 2.9l I just finished rebuilding mine from the ground up I put a set of pace setter headers on 5.0 fuel injectors (19lbs) ram air, ported and polished the intake upper and lower as well as the heads (did them my self) put the bigger throttle body on the TB from a 86-87 2.9 is larger then 88 and up about 1.5 ci bigger to be exact did a set of free flowing rockers turned it in to quite the peppy lil thing I noticed a huge diffrence I know I am forgetting a couple of other things I did but if ya wat anymore info I got it all here I can scan it in and e-mail it to you

the bronco II is an 89 model....he wont be able to get it until the dude finds another truck....thanks for all the help

mine is a 89 as well

cdncowboy,

I'd like to know more about what you did to the 2.9. I'm a little confused about which throttle bodies are which. Did you put a cam in and if so which one? What do you mean free flowing rockers?

to me the "free flowing rockers" sound like roller rockers?