Swaping Out The Powertrain Soon I Hope

[Spectormj]

What would be a good power to weight ratio motor and entire drive system swap to do for an 86?

I want to be able to go anywhere that i can think of

i like the craptastic 2.8 v6 but its lackin in get up and go 

ideas?

 

[gogmorgo]

If you pick up a 3.4 from a V6 Camaro or Firebird, you can bolt it right in where your 2.8 was because it's externally the same engine. 160hp/200lb-ft over your 115hp/150lb-ft. Weight shouldn't be noticeably different. You'd be looking for engine code S (eighth digit of vin) on a 93-95 Camaro/Firebird.

 

That's probably the best/easiest swap you could do as it shouldn't involve any fabrication.

[onlyinajeep726]

Simplest route to rid yourself of the 2.8L is to get a '91+ 2.5L (because it's MPFI and boasts 130 hp / 139 ft-lbs) and would not need fabrication to the hood latches or firewall to fit.  Also, you could retain your current tranny or find a Dakota bellhousing and swap in an AX15 while you're there.  You'd have to run the engine/PCM and dash harnesses, get a electric fuel pump and appropriate sending unit for your tank.  I'm sure there something I'm missing but others will chime in.

 

My 4.0L/AX15 swap was tedious but not impossible.  Did have to swap the hood and its latches and bash in the firewall.  Also had to relocate the tranny crossmember.  If I ever get my hands on another '86 (assuming it's not running right), I will be going with a '91+ 2.5L.

 

V8 swap is another option, but then you get into some trouble with keeping the engine properly cooled since the nose of the MJ/XJ is so narrow.

 

The other option is the 3.4L as suggested.  Not sure all the in's and out's on that one (not sure if it's carb'd or fuel injected).  Fuel injected option would require the same work as 2.5L.  Same suggestion on tranny upgrade there too.

[mvusse]

Another option, but according to jeepcoMJ not really all that simple is a Buick 3800. Bolts up to the same transmissions as the 2.8, but will eat AX4 and AX5 transmissions for breakfast, so for this engine an automatic transmission or an AX15 with a 2.5l Dakota bellhousing is a must. Horsepower started at 165 for the 89 LN3. The series 2 (1995+) produced 205 hp (L36), the supercharged L67 made 240 but needs 91 octane fuel. Both of these were available in some RWD cars including the Firebird. These engines should also produce better than 4.0 (and possibly better than 2.5) fuel economy.

 

Although relatively new the Series 3 is a "super ultra low emission vehicle" engine for the natural aspirated version, with better yet fuel economy and a bit more hp, up to 260 for the supercharged version. The supercharged one still does need 91 octane.

[Spectormj]

whats yalls take on a 4 bt swap?

[mvusse]

Time consuming, expensive, and the engines aren't as readily available anymore as they once were. If you want to go twin turbo you'll have to cut up the hood to make room for the second one.

 

And those suckers are HEAVY.

[onlyinajeep726]

4BT swaps have been done, but like mvusse mentioned, they're heavy as hell, extensive fabrication to get it to work and parts are getting harder and harder to come by.  I'd love to do something like that myself, but there are a lot of other options if you want to go diesel.  Krustyballer is working on a B3.3 swap, there's a guy floating around on some Jeep forum doing an OM617 swap and another doing a Kubota swap.  Just depends on what you're willing to do and how deep your pockets are. 

[mvusse]

There are kits to put a Mercedes diesel in a Toyota. Since the AX15 and Toyota transmission are pretty much the same, it might not be too difficult to adapt this kit to put one in an MJ.