streetjeep2.5 Posted November 2, 2009 Share Posted November 2, 2009 Lotsa chatter about heating problems and lack of space under the MJ/XJ hood for a GM 350. What about a GM 4.3? Seen some of them built to put out some serious HP. I know they are fairly equal to a 4.0, but for those who want a "V" engine under there ... Link to comment Share on other sites More sharing options...
JeepcoMJ Posted November 2, 2009 Share Posted November 2, 2009 the 4.3 is arguably the WORST V6 out there. well, the vortec is. that said, just about any vortec is just plain junk with too many electrical components to fail, and poorly designed vacuum/fuel line systems a 4.3 is a 305 with 2 less cylinders. if you're gonna put a 4.3 in, put a 350 in...it's just two more cylinders and the exact same mounts and radiator system. if you want a v6, I suggest the series two or newer buick 3800...you can draw mean hp from them, can get them already supercharged (and easy to modify for more hp), and the only real problem with them is the throttle body gaskets like to crap out...and they carry coolant to keep the TB from frosting up due to the extremely high air flow coming in. much more superior and much more reliable than any 4.3 will ever be. Link to comment Share on other sites More sharing options...
Eagle Posted November 2, 2009 Share Posted November 2, 2009 a 4.3 is a 305 with 2 less cylinders. if you're gonna put a 4.3 in, put a 350 in...it's just two more cylinders and the exact same mounts and radiator system. :agree: The 4.3 is, as noted, just a shortened small-block V8. It's a 90-degree engine that's really too wide to fit easily into an XJ or MJ engine compartment. You will need all the adapters and such you would need to do a V8 conversion, but you lose two cylinders. A MUCH better swap is the 3.4L V8 from rear wheel drive GM cars like the Camaro and Firebird. It's a 60-degree engine, so it's a lot narrower. Also, it happens to be physically the same block as the 2.8L that was used in the early XJs and MJs, so mounts, manifolds and brackets don't have to be custom fabricated. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted November 2, 2009 Share Posted November 2, 2009 a 4.3 is a 305 with 2 less cylinders. if you're gonna put a 4.3 in, put a 350 in...it's just two more cylinders and the exact same mounts and radiator system. :agree: The 4.3 is, as noted, just a shortened small-block V8. It's a 90-degree engine that's really too wide to fit easily into an XJ or MJ engine compartment. You will need all the adapters and such you would need to do a V8 conversion, but you lose two cylinders. A MUCH better swap is the 3.4L V8 from rear wheel drive GM cars like the Camaro and Firebird. It's a 60-degree engine, so it's a lot narrower. Also, it happens to be physically the same block as the 2.8L that was used in the early XJs and MJs, so mounts, manifolds and brackets don't have to be custom fabricated. that's only ideal in the case of a 2.8 or 2.5 upgrade to a 3.4...it's much, much less than ideal to go from a 4.0 to a 3.4.... a 4.0 and buick 3800 are in the same class hp-wise, with just as much aftermarket support for either. the 3800 actually has a higher hp and torque rating than a 4.0 too, plus a supercharger is extremely easy on a 3800, with the only real issue being where to put the darn throttle body since it would point directly into the firewall. but...if you're going to upgrade from a 4.0 then the only real consideration is a 350. going from a good, strong running 6 cylinder to a 6 cylinder that's known to have issues is just not the greatest idea on earth and offers little to no gain. Link to comment Share on other sites More sharing options...
veritas4156 Posted November 2, 2009 Share Posted November 2, 2009 I know quite a few people that have done a 4.3 and absolutely love it because of the aftermarket possibilities, although these swaps have been in YJs. A friend of mine has a supercharged 4.3L putting out a ridiculous amount of power, and as you said he has space to work under the hood and he doesn't have cooling issues. Link to comment Share on other sites More sharing options...
socal1200r Posted November 2, 2009 Share Posted November 2, 2009 I must've misunderstood the topic, because I though there was going to be talk of stuffing a Ford 5.0 into an MJ. If one already has the 4.0 straight 6 under the hood, I don't see the inherent advantage of going to another 6 cylinder engine, especially if it's only marginally bigger, and a "V" configuration. If the engine compartment will fit a straight 6, I would think a V8 would fit in there as well. 'Course I've heard the Ford V8's are popular, because the distributor is at the front, so you won't have firewall issues, and also the sump on the oil pan is at the front as well. I'm sure a V8 would fit easily, if one were to fabricate a one-piece tilt front-end, trim the inner fenders, etc... Link to comment Share on other sites More sharing options...
Pete M Posted November 2, 2009 Share Posted November 2, 2009 the inner fenders are sorta structural in an MJ. being unibody and all. Link to comment Share on other sites More sharing options...
Geonovast Posted November 2, 2009 Share Posted November 2, 2009 I must've misunderstood the topic, because I though there was going to be talk of stuffing a Ford 5.0 into an MJ. If one already has the 4.0 straight 6 under the hood, I don't see the inherent advantage of going to another 6 cylinder engine, especially if it's only marginally bigger, and a "V" configuration. If the engine compartment will fit a straight 6, I would think a V8 would fit in there as well. 'Course I've heard the Ford V8's are popular, because the distributor is at the front, so you won't have firewall issues, and also the sump on the oil pan is at the front as well. I'm sure a V8 would fit easily, if one were to fabricate a one-piece tilt front-end, trim the inner fenders, etc... A couple people on here have done V8s. Link to comment Share on other sites More sharing options...
BarracudaBlueXJ Posted November 4, 2009 Share Posted November 4, 2009 i was thinking about doing the 4.3 swap as well but i was planning on doing a carbed 4.3. it seems really practical for me seeing as i currently have the carbed 2.5. Link to comment Share on other sites More sharing options...
Geonovast Posted November 4, 2009 Share Posted November 4, 2009 i was thinking about doing the 4.3 swap as well but i was planning on doing a carbed 4.3. it seems really practical for me seeing as i currently have the carbed 2.5. What's a little wiring when you already gotta find a new transmission, possibly axles, and fab up motor mounts? Link to comment Share on other sites More sharing options...
FxRacing282 Posted November 4, 2009 Share Posted November 4, 2009 the chevy 4.3 is an incredible engine. its one of the most dependable 6 cyl. out there. and for performance you can easily put in flat top pistons, 1.94/1.60 valves port the heads and an edlebrock 1406 to top it off with a good cam you would be making way more power than just about every 4.0 out there. and vortec motors are awesome. i have lots of expierence with them and they are very reliable. when rubber turns 20 years old, it cracks and falls apart. when a ford turns 5 years old it needs frame work. compare. 4.3's are great and ive talked to people who have done it and love it. and you don't have to worry about overheating the engine either. just my 2 cents Link to comment Share on other sites More sharing options...
JeepcoMJ Posted November 4, 2009 Share Posted November 4, 2009 i was thinking about doing the 4.3 swap as well but i was planning on doing a carbed 4.3. it seems really practical for me seeing as i currently have the carbed 2.5. if it's a carb'd 2.5, it's not in a comanche. Link to comment Share on other sites More sharing options...
Geonovast Posted November 4, 2009 Share Posted November 4, 2009 i was thinking about doing the 4.3 swap as well but i was planning on doing a carbed 4.3. it seems really practical for me seeing as i currently have the carbed 2.5. if it's a carb'd 2.5, it's not in a comanche. Read his sig. He's got an 85 XJ. Link to comment Share on other sites More sharing options...
BarracudaBlueXJ Posted November 4, 2009 Share Posted November 4, 2009 yup mines in an xj...i just look here 4 tech cause no one seems 2 like the old cherokees and as far as wiring...it doesn't bother me I'm just a fan of oldschool carb setups Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted November 4, 2009 Author Share Posted November 4, 2009 i was thinking about doing the 4.3 swap as well but i was planning on doing a carbed 4.3. it seems really practical for me seeing as i currently have the carbed 2.5. What's a little wiring when you already gotta find a new transmission, possibly axles, and fab up motor mounts? http://advanceadapters.com Plug in your info and ... Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted November 4, 2009 Author Share Posted November 4, 2009 I started this post because my 87 4x2 nuttinbutstreet 'manche is pushing 320,000 with original 4 speed and D35. Syncro's are starting to not work as well, and I do believe I am detecting the beginnings of noise in the differential. My rebuilt 2.5 now has 50,000 on it. I figure in a couple of years I will need to do something about both, so I thought about taking the time to get everything together to do a 4.3 and a 44 for the back. I had a 4.3 in a 92 Sonoma extended cab with a 5 speed and stock it hauled a . ., and since I am now 61 I figure this would be my last "fling" at hot-rodding, something I haven't done since getting married, and to do so with staying jeep would mean swapping to a 4.0, doing a stroker, and needing to read diff, etc anyway. And, I like the look of a "v" engine under the hood, but a chevy v-8 in there appears to be problems waiting to happen. I would think a 4.0 radiator should be sufficient for the 4.3. When someone does a 4.0 stroker, do they keep the same radiator or need to upgrade? And, I would think with the 4.3 it could scoot forward in the engine bay a bit for distributor access. Thoughts? Link to comment Share on other sites More sharing options...
comanche09 Posted November 5, 2009 Share Posted November 5, 2009 a 4.3 is a 305 with 2 less cylinders. if you're gonna put a 4.3 in, put a 350 in... Actually, the 4.3L is a 5.7L with 2 less cylinders. But agree the 305 was largely a POS engine in stock form. Why not a FORD 4.0L V6? Although, back in the day, the Chevy 4.3L V6 and Ford 4.0L V6 couldn't hold a candle to the AMC 4.0L I6 FWIW. Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted November 5, 2009 Author Share Posted November 5, 2009 Found this on a budget build 4.3. http://www.hotrod.com/techarticles/engi ... index.html Link to comment Share on other sites More sharing options...
FxRacing282 Posted November 6, 2009 Share Posted November 6, 2009 sliding it foreward would be a good idea.. if i were you, i would only slide it forward enough to put the shifter where you want it. if you ended up running a SM-465 (4speed with granny as 1st) you can get a 70's shifter which has the bend to bring it toward the rear of the cabin and you could, i guess, slide the engine foreward some. assuming you would be running a carb, how about a small HEI v6? 74-8something i believe. i know you may be used to points seeing as thats what cars had for the first half of your life, but the HEI is awesome. not to make fun of your age or anything don't get me wrong, points are cool and i wish i knew how to properly adjust them. no need for an EGR system, catalyst, A.I.R. system or evaporative system. you can get headers off summit racing and with a little know how and some elbow grease you are well on your way to a dual 2'' exhaust. Link to comment Share on other sites More sharing options...
streetjeep2.5 Posted November 6, 2009 Author Share Posted November 6, 2009 It would definitely be injected, probably a balance shaft version if I did such a conversion. I would want to pump it up by at least 50hp, and that appears easy to do w/cam and pistons and other things. I was thinking shifting it forward just for being able to get to the back of the engine and create more air flow around the engine. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now