2.8L to 4.0 engine swap

J

justjeep94

NAXJA Forum User

Location

Elk Grove,CA

• May 27, 2010

• #1

I got a 86 comanche that has a 2.8L engine in it now. I want to swap in a stronger engine in so I will be able to run 37s. I was wondering if anyone on here has done this swap. If so do you know where I can find a right up and some pictures about it. Will the 4.0 fit or will I have to mod the mounts and fire wall. Let me know what you guys think, what engine would be easy (easier) to swap.

Justin

 

souske

NAXJA Forum User

Location

The land of competition

• May 27, 2010

• #2

You will have to mod the firewall for sure. If you look at a 4.0 firewall, there is a big dent for cyl 6 to sit in.

A LSX engine should be short enough that you could get away without having to clearance the firewall, but then you get into a host of other issues.

Is selling the current jeep and buying one with a 4.0 out of the question?

Or how about swapping in a 3.4 mpfi? Same family, better goodies

 

J

justjeep94

NAXJA Forum User

Location

Elk Grove,CA

• May 27, 2010

• #3

Yeah I just want to keep this jeep and swap an engine. With the 3.4 how much mods will I have to do?

 

souske

NAXJA Forum User

Location

The land of competition

• May 27, 2010

• #4

http://www.s10forum.com/forum/f106/2-8-to-a-3-4-swap-348470/

Yeah, I used to be into S-10's back in the day.

Cant imagine why I am not a mod over there anymore: You last visited: 01-06-2003 at 07:01 PM haha!

 

IslanderOffRoad

NAXJA Forum User

NAXJA Member

Location

Houston, Tx

• May 27, 2010

• #5

I'd say go for the Chevy 4.3L

 

souske

NAXJA Forum User

Location

The land of competition

• May 27, 2010

• #6

Completely different engine, would require new engine management. Would be roughly the same work as an LSX swap

 

4

4.3LXJ

NAXJA Forum User

Location

Chico, CA

• May 30, 2010

• #7

justjeep94 said:

Yeah I just want to keep this jeep and swap an engine. With the 3.4 how much mods will I have to do?

Click to expand...

It is a bolt in. You do need however to use the 3.4 flex plate or flywheel with it because the 3.4 in internally balanced and the 2.8 is externally balanced. Other than that there is no issues there. The only difficult thing will be with whatever fuel management system you choose. If you are going with a different carb and intake for simplicity those are available, even for the 2.8 from Edelbrock.