Kano808 Posted August 11, 2014 Share Posted August 11, 2014 Hey everyone, I am new to the comanche club, definitely love all the Comanche trucks and projects being posted up. I currently own a 86 2.8l Comanche, but I am not a big fan of the 2.8l and was wondering if anyone could tell me whether the 4.0l Inline or the 2.1l diesel would be compatible with my firewall and generally an easy swap in and out? Up until now I have heard both yes and no from random online sites all over the internet and am hoping to clear that up before I proceed. Any and all input is welcome, thanks everyone in advance! Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted August 11, 2014 Share Posted August 11, 2014 This should help some. http://comancheclub.com/topic/39539-links-for-25l-to-40l-swap/ Here's my build thread starting from when I decided to figure out how to stuff a 4.0 into my '86: http://www.cherokeeforum.com/f46/86-comanche-dd-159524/index4/#post2542580 Link to comment Share on other sites More sharing options...
Kano808 Posted August 11, 2014 Author Share Posted August 11, 2014 Thanks! Wow so you had to chop a lot off to make room? Is the swap from the 2.5 basically the same as the 2.8? Link to comment Share on other sites More sharing options...
Eagle Posted August 11, 2014 Share Posted August 11, 2014 Why don't you swap in a GM 3.4L V6 from a mid-90s Camaro or Trans Am? Same basic block as the 2.8L so it'll drop right in, but a much better engine. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted August 11, 2014 Share Posted August 11, 2014 Thanks! Wow so you had to chop a lot off to make room? Is the swap from the 2.5 basically the same as the 2.8? Yea, I did a lot of work to make it work. Before I tackled this project, I had never done something this involved in fab work. I learned a lot. As far as swapping out the 2.8 being similar to swapping out a 2.5... yes, swapping the actual engine and doing all the fab work would be the same. You'll have some added steps like swapping in a electric fuel pump and some harness stuff. I don't know what else, but I'm sure another member will chime in who has experience removing that 2.8 junk. Why don't you swap in a GM 3.4L V6 from a mid-90s Camaro or Trans Am? Same basic block as the 2.8L so it'll drop right in, but a much better engine. This is another good, viable option. Coupled with some sort of EFI, it would be a really good option. Link to comment Share on other sites More sharing options...
Kano808 Posted August 11, 2014 Author Share Posted August 11, 2014 Yeah that was the other option I had considered, definitely a great Idea and worth looking into. Any idea if the renault diesel 2.1 would fit in smoothly? Or require a lot of fab/work to make it work? Also what type of trans should I drop in if I go with the 3.4? Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted August 11, 2014 Share Posted August 11, 2014 The 2.1L TD will fit without firewall/radiator support modification (as they were an engine choice for these trucks in '86).If you go with the GM 3.4L, you can continue to use your current AX4/5 transmission (or whatever trans you currently have), but my advice would be to find the elusive Dakota bell housing (used to mate the 2.5L to an AX15, same will work on the GM 3.4L) and find an external slaved AX15. Or, you could find the Isuzu AW4 bell housing and mate an AW4 behind it. You would just have to find a stand alone TCM to shift the transmission correctly. Link to comment Share on other sites More sharing options...
dasbulliwagen Posted August 12, 2014 Share Posted August 12, 2014 For an auto trans you could also stick with the auto used behind a 2.8 the A904. Its a lighter duty version of the Chrysler TF727 and was used behind the slant 6 and small V8's and requires no computer. Its a good trans and is easily upgradeable with a shift kit. The 86 XJ waggy parts truck I have has the 2.8 A904 NP228 combo in it. I might use some combo of this in my 86 MJ if I ever get to build it. Link to comment Share on other sites More sharing options...
onlyinajeep726 Posted August 12, 2014 Share Posted August 12, 2014 That's an option, also. The only thing though is that it lacks over-drive. Link to comment Share on other sites More sharing options...
86FUBAR Posted August 12, 2014 Share Posted August 12, 2014 I did the 3.4 swap and love it ! Had to keep the carb for emissions reasons but some say keeping the fuel injection is easy . It was a super easy swap and the power gain is ten times better. !! Link to comment Share on other sites More sharing options...
Kano808 Posted August 12, 2014 Author Share Posted August 12, 2014 When you did the 3.4 swap, was the knock sensor or A/C compressor in the way of the passenger motor mount? Link to comment Share on other sites More sharing options...
mpace6a Posted August 12, 2014 Share Posted August 12, 2014 In the process of putting a simple carb on my 2.8 to get it back on the road while i keep looking for a donor xj. Just milled out an adapter plate from a piece of 5/8" aluminum plate. Milling the plate down to 15/32". Just enough room for the studs. Sitting on the intake. Just gotta figure out the throttle linkage, and what emissions and vacuum crap i can rip outta the engine bay. Link to comment Share on other sites More sharing options...
86FUBAR Posted August 12, 2014 Share Posted August 12, 2014 When you did the 3.4 swap, was the knock sensor or A/C compressor in the way of the passenger motor mount?I didn't need the knock sensor so it was ditched and I don't have AC but both engines use the same motor mounting locations so I would guess it wouldn't be in the way and the stock AC compressor is mounted on top of the engine next to the alt . Link to comment Share on other sites More sharing options...
outlaw star Posted August 14, 2014 Share Posted August 14, 2014 In the process of putting a simple carb on my 2.8 to get it back on the road while i keep looking for a donor xj. Just milled out an adapter plate from a piece of 5/8" aluminum plate. Milling the plate down to 15/32". Just enough room for the studs. Sitting on the intake. Just gotta figure out the throttle linkage, and what emissions and vacuum crap i can rip outta the engine bay. Have you thought about the Weber 32/36 DGEV Carb instead of the Rochester junk carb? Link to comment Share on other sites More sharing options...
Mr.Oz Posted August 20, 2014 Share Posted August 20, 2014 Son and I are looking into this also. Right now we have the weber 32/36 carb installed, way better then the crappy stock one. Now that stupid mech fuel pump is giving us issues. I think we are gonna go electric and since we will be swapping in a 3.4, you got to do that anyway, no place for the mech. fuel pump. Link to comment Share on other sites More sharing options...
mpace6a Posted August 21, 2014 Share Posted August 21, 2014 In the process of putting a simple carb on my 2.8 to get it back on the road while i keep looking for a donor xj. Just milled out an adapter plate from a piece of 5/8" aluminum plate. Milling the plate down to 15/32". Just enough room for the studs. Sitting on the intake. Just gotta figure out the throttle linkage, and what emissions and vacuum crap i can rip outta the engine bay. Have you thought about the Weber 32/36 DGEV Carb instead of the Rochester junk carb?My oe carb had a float support(?) break on the inside, can't buy a new one according to all my google searches of the number on the top of it. The adapter plate I made is for a marine carb off a mercury my uncle gave me for free. I looked into the weber, but I refuse to spend that much money on the 2.8. The long and short of it is, the motor isn't worth it. It's not even worth the time I spent making the adapter plate, but I miss driving it so that's what I'm doing. I'll take my $300 for a weber and save it for a parts xj to do a 4.0 swap. Link to comment Share on other sites More sharing options...
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