neohic Posted December 31, 2015 Share Posted December 31, 2015 Hey gang... I keep thinking about this and I don't see why some mixing and matching wouldn't work. Been doing a bunch of research to the point that I'm getting my numbers crossed and it's getting a little busy in my head. :thwak: Is there going to be tangents off of the main topic? You bet! Bear with me... Hypothetically, if one had a somewhat recently rebuilt Renix 4.0 (actually 4.6ish) and wanted to go HO or '97+, the original short block could be retained, correct? I'm really just thinking about the internal and external differences of the engine itself. This would start with an '88 4.0/AW4 combo and go from there. Everything external on the drivetrain is totally stock Renix minus Cruisers recommended upgrades, an EGR delete, an HO oil filter adapter, and a 4wd swap (also with Renix era components). Keep in mind that I don't have any actual donors mind nor any real time frame as to when something like this could happen. Here's two scenarios in my head... Scenario #1: Donor: '94 XJ with 4.0/AX15 Swap everything minus the Renix short block Retain aftermarket Renix intended tubular header I think this would be pretty well cut and dry. I'd use the engine, dash, and chassis wiring from the '94 donor. Obviously this would also be an auto to manual swap, but that really doesn't matter as everything else related to the trans would be moved over from the donor. I could retain the original look to the interior as '94 was the last year for the XJs to not have an airbag. Scenario #2: Donor: '01 XJ with 4.0/NV3550 Swap everything minus the Renix short block 7120 head swap Retain intake manifold from '01 donor Retain aftermarket Renix intended tubular header This is where I really start to confuse myself. If I'd go through the trouble of updating a vehicle, I'd think that I might as well go as new as I can without too much trouble. This would of course means swapping in the '01 dash and firewall differences, but that's not really what we're discussing here, is it? (On a side note, sometimes I like the idea of keeping as much of the interior original but other times it really doesn't concern me. 88Pghcomanche's interior has really swayed me into liking a mix of old and new.) There's the commonly disliked 0331 cylinder head that the internet continues to create horror stories about, and I'd just assume do away with it. Being that the exhaust ports are the same between the Renix and HOs (HA!... HOs. :shake: ) I could keep my ceramic coated header and not have to deal with figuring out any adapter plates to keep the '01 exhaust manifold. Would that snowball into throwing codes or not running correctly if I didn't keep the two cats directly off the manifold though? (I know... I know... nobody likes talking about getting rid of catalytic converters, but the truck is an '88 after all and would still be titled as such.) Then what about the four 02 sensors? I know that I'd need to figure out a bracket to hang the coil packs on, but that really doesn't concern me. I suppose another thought (scenarios #3? :dunno: ) would be to use a '97-'99 XJ as a donor and not worry about the coil packs, mass of 02 sensors, or the 0331 head. I like the idea of using a 7120 head though from all the good stuff you can find in interweb land about them as far as flow and casting quality. With how many miles that have been put on my engine (not all that much) I'd be stupid to just plop on a used head from the donor regardless of year. Truth be told, I'd probably try and find a wrecked vehicle that everything functions or one with tons of miles being that I'd still be using my rebuild long block (that is what I'm trying to get to the bottom of anyhow, right?). Either way, I'd be on the look out for a donor that preferably didn't even have so much as an aftermarket stereo. Mechanical components can be rebuild but original virgin wiring is really my main concern. Anyhow... I understand that this is now turning into a wall of text and that I'm starting to digress. This really sounds right up Don and Cruiser's alley over a Renix versus HO debate but, again, that's not what this is about. It's mostly about my want to swap to a manual transmission and to do away with aging and patched up wiring while upgrading at the same time. Here's a picture of my truck just because I know how people like pictures and any good topic needs pictures. :D Thoughts? Ready... go! Link to comment Share on other sites More sharing options...
johnj92131 Posted December 31, 2015 Share Posted December 31, 2015 Know you are just thinking out loud. But I do have to ask a question. What is it you are trying to accomplish? What's the goal/purpose? Sounds like you have a good running Renix stroker right now. Right? If so, Cruiser might say just keep it running. It is a great engine. Everything else is just a money pit. I do understand a money pit. That is why I have a Hesco head, a 4.095 stroker crank, a 3.895 stock 258 crank, 2 stock 4.0 cranks, a couple of spare blocks, 3 different sets of rods, (includes a set for the 4.095 stroker crank. And a bunch of other parts in the garage. All waiting to be put in some magic engine. Now, if you current engine is near the end of it's life, that is another story. I can understand planning for the future. But just to "update" a good running stroker Renix? Low return on your investment of both time and money. Now, if the answer is "Just Because", that is OK. Go with the 2001 conversion, buy an Edelbrock aluminum head, fresh pistons with the dish match to the Edelbrock combustion chamber, run compression of 10.5:1 with regular gas. Link to comment Share on other sites More sharing options...
neohic Posted December 31, 2015 Author Share Posted December 31, 2015 I suppose the goal would be... ... to swap to a manual transmission and to do away with aging and patched up wiring while upgrading at the same time... You're correct that the engine runs great. Couldn't be happier with it!... just the engine though. As far as everything else, it seems like it's every other year or so that I'm forced to fix one thing or another when it comes to the wiring in the truck. Between previous owner underhood "fixes" that have been long cleaned up and interior "custom stereo removal" by the previous owner having it broken into three times, the wiring in this truck has really gotten to be a mess. It was before my time, but it looks as though mice had made a home under the relays too. Spent a ton of time getting that all sorted out years ago. Inside is no different. I cringe at the thought of what still might be hiding behind the dash. Granted, I know that there isn't anything taking residence in my truck now, but I'm sure there something in there still waiting to fail. Link to comment Share on other sites More sharing options...
johnj92131 Posted December 31, 2015 Share Posted December 31, 2015 Confession: I did not read the very last paragraph (you could tell). Go with Option #3 if you get the late Cherokee to swap. More work, but in the end you would know everything was up to your good standards. Also likely the most expensive. The electrical issues you have will bite you at the most unfortunate times. Just bite the bullet and be done with it properly. Don't forget you will need the power steering pump bracket to go with the 2001 manifold and the 2001 ecu may not be happy if it doesn't see the 2001 exhaust system in place. But you can get the ecu retuned to eliminate that issue (just more $$). Link to comment Share on other sites More sharing options...
neohic Posted December 31, 2015 Author Share Posted December 31, 2015 What about the short block itself? Say, for example, I didn't have a built engine. If one had a low mileage Renix era engine and an HO Jeep that threw a rod but the head and everything else were fine, would it make sense to use the Renix block in place of the HO?... same for '97+? I know there are some differences, but would a stock Renix crank and camshafts get along with HO or '97+? ... now I'm just curious. :hmm: Link to comment Share on other sites More sharing options...
cruiser54 Posted January 2, 2016 Share Posted January 2, 2016 I've mixed and matched parts from 87 to 95. Actually made one engine out of 3 different ones for my son in law's XJ. Me, I'd address the wiring that's there. Carry on. Link to comment Share on other sites More sharing options...
neohic Posted January 2, 2016 Author Share Posted January 2, 2016 So... that's a vote for keeping the Renix? Not sure that was one of the hypothetical scenarios. :yes: Link to comment Share on other sites More sharing options...
Eagle Posted January 2, 2016 Share Posted January 2, 2016 The term "long block" means an engine with the head installed, but not the intake and exhaust manifolds, and not the external accessories. The basic 4.0L block will work with a Renix or Chrylser setup, but the intake ports in the head are different so using a Renix engine with a full Chrysler update will mean either settling for intake ports that don't mate -- or using a newer head, which means you're not really using the Renix long block, you're only using the short block. And then there are the differences in mounts for external accessories to be considered. Link to comment Share on other sites More sharing options...
Megadan Posted January 2, 2016 Share Posted January 2, 2016 Option 4. Keep the engine the way it is and replace factory computer and wiring with a Megasquirt?I'm considering doing this with my truck, and I have a slightly tired Renix with a rebuilt head. They have a decoder program for the factory CPS signal, and that is all you need for a basic batch fire setup on the injectors. The Megasquirt 3 even has a Target AFR that can be used in conjunction with a wideband O2 to auto-tune the engine. Add a second Map and you get barometric correction. I already have a Megasquirt 3 with the MS3X sitting in a box with all the sensors and wiring harnesses for another project. If I could find a way to get the right kind of cam signal I could do sequential injection and coil per plug too. The temptation is real... Link to comment Share on other sites More sharing options...
neohic Posted January 2, 2016 Author Share Posted January 2, 2016 The term "long block" means an engine with the head installed... Gah! You're right. Short block... I meant short block. Original post and thread title corrected. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3, 2016 Share Posted January 3, 2016 So... that's a vote for keeping the Renix? Not sure that was one of the hypothetical scenarios. :yes: Keep the Renix. Want more power? Link to comment Share on other sites More sharing options...
neohic Posted January 3, 2016 Author Share Posted January 3, 2016 I think what it really comes down to is my want to go through all of the wiring in the truck at some point to make sure that everything is sound and swap to a manual trans. Whenever that time comes and I need to find a donor, there are obviously more '91 and up Jeeps out there than '90 and down. I'd say that it would be easier to find a Renix era to swap to being that it my current head doesn't have all that many miles, but that does narrow things down for the transmission being I have a 21 spline transfer case. Granted, early AX15s do exist for a 21 spline NP231 (correct?), but then I'd still want to swap things around for an external slave setup. I think that if I were to find the right '94 XJ, it would have everything that I need to swap to everything I want all wrapped up in a convenient package without changing anything about the look of the interior. Anytime I've ever done a big enough parts swap on a Jeep, I've found that it's way cheaper and easier to just find a donor that has everything you want. I really don't think I want more power, but I wouldn't turn it down either. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3, 2016 Share Posted January 3, 2016 Why do you want a 5 speed? Did you ever see the "before" pics of my 87 when I got it? Link to comment Share on other sites More sharing options...
neohic Posted January 3, 2016 Author Share Posted January 3, 2016 Admittedly, really just because I want to. :D Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3, 2016 Share Posted January 3, 2016 Admittedly, really just because I want to. :D Been off roading since 1967. Why in the hell do you wanna try to control 3 pedals with only 2 feet? The AW4 is the best auto trans ever. Link to comment Share on other sites More sharing options...
neohic Posted January 3, 2016 Author Share Posted January 3, 2016 My '88 is no trail rig. :no: Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3, 2016 Share Posted January 3, 2016 I hate shifting anymore. Link to comment Share on other sites More sharing options...
neohic Posted January 3, 2016 Author Share Posted January 3, 2016 I love it in a "fun vehicle". My '98 XJ is an auto and I love it on the trail. My '88 sees streets only now and I catch myself sometimes reaching down as if to shift. Did you ever see the "before" pics of my 87 when I got it? I did see that thread. Lots of all too familiar pictures there. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3, 2016 Share Posted January 3, 2016 Wasn't that bad. Link to comment Share on other sites More sharing options...
neohic Posted January 3, 2016 Author Share Posted January 3, 2016 If I could find a good trans with an external slave, matching t-case, and pedals then I'd go that route. Pricing things locally though, I've found cheaper donor vehicles that I could later scrap to make up costs. Again, this is more of a thinking out loud type thread... and I'm enjoying this! :banana: Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3, 2016 Share Posted January 3, 2016 Take it from a guy who parts out Jeeps. Get a donor...... Link to comment Share on other sites More sharing options...
neohic Posted January 3, 2016 Author Share Posted January 3, 2016 ... but if I were to do that and it happened to be HO, should I take the time to swap it all over (if it's got an uncut harness), and would a stock Renix short block (or just a stock Renix cam in my case) get along with the HO components and computer? Still hypothetical. :laughin: Link to comment Share on other sites More sharing options...
cruiser54 Posted January 3, 2016 Share Posted January 3, 2016 You're describing exactly what I've done twice now. HO motor into a Renix. Computer could give 2 $#!&s what the engine is. Did I ever post this for you? HO myth buster Renix in 90 made 182 HP. HO in 91 made 190 HP. That's 8 HP difference. HO only made more HP than Renix at higher RPMs and not a bit more torque. HO had 58 mm throttle body versus a 52 mm throttle body on a Renix and also had a better design header. See where I'm going with this? The whole 8HP was not mostly from the head, but from the bigger TB and better exhaust manifold. Put a 60mm TB from www.strokedjeep.com on your present head, eliminate the "crush" in your headpipe with proper re-routing, and go for it. HO stands for Highly Overrated. __________________ Link to comment Share on other sites More sharing options...
neohic Posted January 3, 2016 Author Share Posted January 3, 2016 Here I thought there was a difference in cams... should've looked into that more. :dunno: Looks like it was the same cam from '87 to '95. Really the only easy or budget minded thing I haven't done to my engine is the bigger throttle body. I'm still running the original '88 ECU also. Think I remember you posting something about '89-'90 ECUs giving a slight boost also. I slightly lean towards HO, but as far as the long standing HO to Renix debate, I could really go either way. Sorry, Cruiser... I'd consider me a draw. Fortunately, that also means that Don didn't win either. :rotf: Link to comment Share on other sites More sharing options...
HOrnbrod Posted January 3, 2016 Share Posted January 3, 2016 You're describing exactly what I've done twice now. HO motor into a Renix. Computer could give 2 $#!&s what the engine is. Did I ever post this for you? HO myth buster Renix in 90 made 182 HP. HO in 91 made 190 HP. That's 8 HP difference. HO only made more HP than Renix at higher RPMs and not a bit more torque. HO had 58 mm throttle body versus a 52 mm throttle body on a Renix and also had a better design header. See where I'm going with this? The whole 8HP was not mostly from the head, but from the bigger TB and better exhaust manifold. Put a 60mm TB from www.strokedjeep.com on your present head, eliminate the "crush" in your headpipe with proper re-routing, and go for it. HO stands for Highly Overrated. __________________ The same tired old litany again. And again. And again. :shake: You need to come up with some fresh material. Litany: A tedious recital or repetitivly boring series of meaningless gibberish. Link to comment Share on other sites More sharing options...
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