sdsoon Posted November 12, 2009 Share Posted November 12, 2009 Who here has a V6 swap in a MJ? I want real opinions not the I heard it won't stay cool or its a PITA. I am talking about Chevy engines. My 2.5 is the most gutless POS I have ever driven. Also the AX5 won't take alot of abuse. I am going to put a TH350 behind it to a NP231 doubler. Just opinions needed. And no sugestions of swapping in a 4.0. Its the same amount of work for either swap. Link to comment Share on other sites More sharing options...
Pete M Posted November 12, 2009 Share Posted November 12, 2009 how big are your tires? Link to comment Share on other sites More sharing options...
sdsoon Posted November 12, 2009 Author Share Posted November 12, 2009 Currently 235/75/15s. I am wanting to run 35s-36s on Wagoneer D44s later on. Link to comment Share on other sites More sharing options...
Pete M Posted November 12, 2009 Share Posted November 12, 2009 But it is NOT the same amount of work. The big reason why the 4.0 swap is mentioned is because all the 4.0 stuff bolts in and an entire swap can be done for the price of a donor XJ (plus a rear shaft). Swapping in a 4.3 requires a bunch of expensive and/or custom built parts to adapt it to the truck. But the 4.3 swap has been done before. Get an donor rig and start measuring for the motor mounts and exhaust and cooling (or call up advanceadapters.com of novak-adapt.com and break out the credit card) Cooling is a problem with the v8s, but the 4.3 should not be a hassle as long as you get a decent size radiator. Link to comment Share on other sites More sharing options...
sdsoon Posted November 12, 2009 Author Share Posted November 12, 2009 Is the 4.0 a direct swap into a 86? If so I may lean that way. I like Chevy engines, I did a Chevy into a YJ years ago and it was an easy swap. I can do the entire swap for right about $1000 give or take a few bucks. Link to comment Share on other sites More sharing options...
freakjeep93 Posted November 12, 2009 Share Posted November 12, 2009 youll need abit of BFH on the firewall but itll work. youll need the 4.0 wiring harness too :thumbsup: have fun Link to comment Share on other sites More sharing options...
JeepcoMJ Posted November 12, 2009 Share Posted November 12, 2009 and you'll need a complete radiator support swap, front frame crossmember swap, and hood swap to put a 4.0 on. Link to comment Share on other sites More sharing options...
Pete M Posted November 12, 2009 Share Posted November 12, 2009 Yes, the 86 model year will need the front clip (rad mount supports, hood and hood latches mostly) off the 4.0 XJ so you can run the bigger 4.0 radiator. Early 86s will need a big dent added to the firewall, later 86s may not. Get the best condition drivetrain and wire harness you can find in a bad body with bad axles. :thumbsup: 97+ swaps are entirely possible too, they just require a tad more effort with the interior. See the couple we have in the projects forum. Link to comment Share on other sites More sharing options...
sdsoon Posted November 12, 2009 Author Share Posted November 12, 2009 Thanks for the info. I am going to look at both options, a 4.0 or a 4.3. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted November 13, 2009 Share Posted November 13, 2009 Thanks for the info. I am going to look at both options, a 4.0 or a 4.3. you'll still need the 4.0 front clip, radiator support, and hood (the hood latches are a PITA to refit to an 86 hood) in order to fit a 4.3 liter. Link to comment Share on other sites More sharing options...
sdsoon Posted November 13, 2009 Author Share Posted November 13, 2009 And why is that? the 4.3 is shorter than a 4.0. I have seen a few XJs with a 4.3 and no hood or front clips mods were necessary. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted November 13, 2009 Share Posted November 13, 2009 And why is that? the 4.3 is shorter than a 4.0. I have seen a few XJs with a 4.3 and no hood or front clips mods were necessary. to fit a bigger radiator, and retain hood latch. the radiator in your 86 is set back a few inches and it will interfere w/ the front of the motor and/or fans. plus the 86 radiator is NOT enough cooling for a 4.3 a 3.4 out of an early 90's camaro or firebird has the same bellhousing as your 2.5, and you can get one easily enough and then fuel inject it. you won't have quite as much power as a 4.0 or 4.3, but it's fairly straight forward and you can use exhaust and oil pan from any 84-86 jeep 2.8 liter. an ax5 should survive fairly well behind a 3.4 I did a buick 3800 swap on my 86 to replace the 2.8 that was in it...as much power (more) than a 4.3 or a 4.0, reliable motor, GREAT fuel economy. it's the same bellhousing pattern as your 2.5, BUT it has way too much power for an ax5 Link to comment Share on other sites More sharing options...
sdsoon Posted November 13, 2009 Author Share Posted November 13, 2009 I bet I could get a 4.3 radiator to fit. I plan to use as many parts as I can from the donor trucks. I am not a big fan of the 60 degree V6s. If I was to even mess with anything other than the 4.3 it would be a SC 3800. I also wouldnt keep a AX5 even if I was paid to. I have even thought of a Caddy Northstar V8 to a TF 904. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted November 13, 2009 Share Posted November 13, 2009 I bet I could get a 4.3 radiator to fit. I plan to use as many parts as I can from the donor trucks. I am not a big fan of the 60 degree V6s. If I was to even mess with anything other than the 4.3 it would be a SC 3800. I also wouldnt keep a AX5 even if I was paid to. I have even thought of a Caddy Northstar V8 to a TF 904. I suggest the SC 3800. the only issue you're gonna have with the SC 3800 is that the throttle body will be directly in the firewall. my series 2 3800 is sitting directly against the firewall (1" space between). there are around 9" in front of the engine though.... so, if you went with an SC 3800 and pushed it all the way as far forward as you could, you could then gain enough room for the supercharger and throttle body on back of the engine. but then the oil filter would be virtually inside the front crossmember and quite the PITA to do an oil change. and 4.3 swaps have been done before. you can't fit that 4.3 radiator into the engine bay because the steering box is in the way. Link to comment Share on other sites More sharing options...
Eagle Posted November 13, 2009 Share Posted November 13, 2009 And no sugestions of swapping in a 4.0. Its the same amount of work for either swap. No, it is NOT the same amount of work. All the parts needed for a 4.0L swap are readily available from junk XJs. You can get most of the parts needed to swap in a Chevy 3.4L V6 from 2.8L XJs, but not all. It sounds like you are thinking more along the lines of a 4.3L V6, which is an entirely different animal. You either need expensive adapters, or you need to do a lot of fabrication. One of the very early members of NAXJA lived a couple of miles from me and had done a 4.3L swap. A group of us used to meet at a local diner on Saturdays for breakfast. We asked him once if he would undertake the 4.3L swap again, now that he had done one. The answer: "No f***ing way!" So, since you asked for opinions, my opinion is ... forget it. But it sounds like your mind is made up, so stand by for opinions that reinforce your decision and proceed accordingly. Link to comment Share on other sites More sharing options...
sdsoon Posted November 13, 2009 Author Share Posted November 13, 2009 Yep I asked for opinions, they are like a**holes everyone has one. Just not a fan of the 4.0. For me the work to get a 4.3 in is the same to do a 4.0. Granted with a donor XJ all the parts are there. The only expensive part I would have to buy to put a 4.3 in is $140 bucks for bolt in engine mounts. Everything else comes with a donor rig. I will never understand what the big thing is about a 4.0. Link to comment Share on other sites More sharing options...
Eagle Posted November 13, 2009 Share Posted November 13, 2009 I will never understand what the big thing is about a 4.0. Torque. And 200,000 mile reliability. In fact, the 4.0L in my '88 Cherokee is currently at 287,000. Link to comment Share on other sites More sharing options...
sdsoon Posted November 13, 2009 Author Share Posted November 13, 2009 A 4.3 will go the same amount of miles, but with no piston slap or timing chain issues. But then thats my opinion and I like o go against the grain. Link to comment Share on other sites More sharing options...
mvusse Posted November 13, 2009 Share Posted November 13, 2009 Are you saying Jeep 4.0s have problems with piston slap or timing chains? I never heard that. A 4.3 is 3/4 of a 350/5.7. In 160,000 miles in my Suburban I went through 2 intake manifold gaskets, 2 sets of head gaskets and 3 timing chains. The 350 (and 4.3) is a reliable engine for GM standards. I would take a Jeep 4.0 over a 4.3 any day, though. Either way, do they make bolt in engine mounts for a Comanche (or Cherokee, same engine bay)? Would they actually be strong enough bolted to a unibody "frame" that is just a few layers of sheet metal stacked on top of each other? Since you seem to think you can fabricate everything else, you should have the skill and tools to fabricate something as simple as an engine mount for much less than $140, and make them exactly where and how high you want them. Link to comment Share on other sites More sharing options...
dasbulliwagen Posted November 13, 2009 Share Posted November 13, 2009 I just have to say this after reading through this. If you not such a fan of sooo many things Jeep, then why are you bothering to try to build one up???? Why not just build an S10? That seems to be what you want to build, why go through all the bother, just get an S10 and youll have everything you want already there in one handy already put together package! But thats just my opinion! Link to comment Share on other sites More sharing options...
sdsoon Posted November 13, 2009 Author Share Posted November 13, 2009 Well once you get rid of the stuff that ucks in a Jeep you get a good rig. And if a 4.0 is such a torque monster and supposedly it doesnt hurt the thin frame then a 4.3 with less torque won't hurt it and with unibody stiffners it won't make a difference. So get off your high horse and let other do what they want. I asked for opinions I got them and I respect them. But because I choose not to keep it Jeep I get told to buy a S10 and use it. Well when you can think outside the box go for it until then keep your Jeep thing to yourself and I will build what I want. Link to comment Share on other sites More sharing options...
Automan2164 Posted November 13, 2009 Share Posted November 13, 2009 Well once you get rid of the stuff that ucks in a Jeep you get a good rig. What are you after in building this jeep? What sucks/doesn't suck? Rob L. Link to comment Share on other sites More sharing options...
sdsoon Posted November 13, 2009 Author Share Posted November 13, 2009 Building it for rockcrawling and some light daily driving duties. I should say what doesnt suck, the body, thats about it. I am going to replace the axles, engine, tranny and tcase with different parts. I may keep the front and run a 8.8 rear for now but full width D60s is in its future. But even the unibody needs help. I bought it running for cheap and thats the reason I got it. And I found out after driving if alot lately that its gutless. Link to comment Share on other sites More sharing options...
Automan2164 Posted November 13, 2009 Share Posted November 13, 2009 That's to be expected. The 2.5L is a little peppier than most, but its no 4.0L. Don't take this the wrong way, because I saw someone else had said it, but why not build an S10/S10 Blazer? It sounds like you aren't saving much jeep stuff. You speak of getting a donor for the 4.3L stuff... If you are essentially getting rid of all the jeep stuff, why not just find a bow-tie that has your drivetrain and build that? It would be A LOT less work, and you could skip all the fabbing/legwork to get the 4.3L into an engine bay where it never was. Keep the MJ whole, and use it for a DD. Rob L. Link to comment Share on other sites More sharing options...
sdsoon Posted November 13, 2009 Author Share Posted November 13, 2009 Its alot of work to make a S10 a wheeling rig. Rather not have to swap in a solid axle. I also don't like the way S10s look like. The MJ has classic body lines. I plan to swap it when I can find a donor reguardless of what it is, if its a XJ then so be it. Link to comment Share on other sites More sharing options...
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