Jtrux Posted March 31, 2017 Share Posted March 31, 2017 I should have been a little proactive and searched for myself but I'm in a rush to get out the door so I thought I'd just throw this in here. Which one is preferred? I'm strictly referring to mechanical components since I have a Megasquirt 2.0 that I will be using to control everything and it will be getting a new wiring harness. Thanks Link to comment Share on other sites More sharing options...
johnj92131 Posted March 31, 2017 Share Posted March 31, 2017 Do you want a used engine or are you going to rebuild one or buy a long block. Also it would sure help to know what you are starting with and if this is your toy/project or a must have daily driver. Does your Megasquirt system utilize the factory Renix knock sensor? If so then stick with the Renix era block . Link to comment Share on other sites More sharing options...
75sv1 Posted March 31, 2017 Share Posted March 31, 2017 Are you going to mix parts or complete engine? Complete engine I'd say 96-99. For the block, Mexican block RENIX era or the latter blocks. '91-95 head. I'd add the crank support cradle from the latter engines if using a RENIX block. Might look into a budget stroker or even the long rod one. Link to comment Share on other sites More sharing options...
Jtrux Posted March 31, 2017 Author Share Posted March 31, 2017 I was in a rush last night so I wasn't able to give many specifics. I will be buying a whole Cherokee to do the swap and I've found several running ones for less than 1k. 91, 93 and a few others that I can't recall at the moment. So for that reason, I'd like to have a specific year or range. Link to comment Share on other sites More sharing options...
omega_rugal Posted March 31, 2017 Share Posted March 31, 2017 mixed parts = renix block (89 or earlier) with HO head (90 and later) and the crankshaft girdle from a 96+ whole engine = 96-99 OH of course Link to comment Share on other sites More sharing options...
Jtrux Posted March 31, 2017 Author Share Posted March 31, 2017 So the 96+ had a crankshaft girdle? Was itintegrated into the block or something that can be added A buddy of mine go back and forth doimg favors for each other and now it's his turn. I bought some stuff for him a while back when he needed help and now it's time yo pay back. Rather than pay back with cash, I was gonna use the money for the Comanche and do a 4.0 swap. I could buy a whole engine from a junyard or one of those online places but it would be very nice to have the whole vehicle sitting right besides the Comanche while I swap so I'm looking at just getting a whole complete running vehicle. Link to comment Share on other sites More sharing options...
DirtyComanche Posted March 31, 2017 Share Posted March 31, 2017 What's the goals of the engine? Boost? Big power? Link to comment Share on other sites More sharing options...
Jtrux Posted March 31, 2017 Author Share Posted March 31, 2017 Cam, head improvements, higher compression. The goal is 300hp. I have access to an engine dyno amd chassis dyno so I'll be able to play around with it prior to dropping it in. Link to comment Share on other sites More sharing options...
mnkyboy Posted March 31, 2017 Share Posted March 31, 2017 91-95 are in my opinion the best years and have the good 7120 head. 96+ is when the pistons changed and are known to drop skirts,96-99 have an 0630 head that is more crack prone than the 7120. 00-01 have the 0331 head that is even worse for cracking. Link to comment Share on other sites More sharing options...
omega_rugal Posted March 31, 2017 Share Posted March 31, 2017 So the 96+ had a crankshaft girdle? Was itintegrated into the block or something that can be added it a bolt on piece but AFAIK you need to drill holes in older blocks to put it... Link to comment Share on other sites More sharing options...
johnj92131 Posted March 31, 2017 Share Posted March 31, 2017 Cam, head improvements, higher compression. The goal is 300hp. I have access to an engine dyno amd chassis dyno so I'll be able to play around with it prior to dropping it in. Your 300 hp goal is TOTALLY unreasonable for the 4.0 Jeep engine on the street or the trail. You will spend $10-15K just on the engine to get close. Link to comment Share on other sites More sharing options...
DirtyComanche Posted March 31, 2017 Share Posted March 31, 2017 IMHO, you'll want the Edlebrock head. I'd get a later block for convenience. I'd run the coil pack ignition. No idea how achievable 300HP is N/A, probably not easy short of building a big stroker and I'm not sure what reliability is going to be like... Link to comment Share on other sites More sharing options...
johnj92131 Posted March 31, 2017 Share Posted March 31, 2017 IMHO, you'll want the Edlebrock head. I'd get a later block for convenience. I'd run the coil pack ignition. No idea how achievable 300HP is N/A, probably not easy short of building a big stroker and I'm not sure what reliability is going to be like... The Edlebrock head doesn't flow any better than a ported stock H.O.head according to posts on the Jeepstrokers site. Or even as well as the old HESCO aluminum head.(I have one in my stash of old parts). Link to comment Share on other sites More sharing options...
omega_rugal Posted March 31, 2017 Share Posted March 31, 2017 Your 300 hp goal is TOTALLY unreasonable for the 4.0 Jeep engine on the street or the trail. You will spend $10-15K just on the engine to get close. stroke it and turbocharge it? otherwise you can have 100+ HPs out of nowhere... Link to comment Share on other sites More sharing options...
DirtyComanche Posted March 31, 2017 Share Posted March 31, 2017 IMHO, you'll want the Edlebrock head. I'd get a later block for convenience. I'd run the coil pack ignition. No idea how achievable 300HP is N/A, probably not easy short of building a big stroker and I'm not sure what reliability is going to be like... The Edlebrock head doesn't flow any better than a ported stock H.O.head according to posts on the Jeepstrokers site. Or even as well as the old HESCO aluminum head.(I have one in my stash of old parts). I would have said the Hesco head, but they're not exactly available. IMHO the head is worth it for the heat dissipation and detonation avoidance. But once the 300HP number is thrown out there, there isn't a cheap way to do it. Save that he could just file the ring gap right out, buy a progressive nitrous kit, and spray n' pray... Link to comment Share on other sites More sharing options...
Jtrux Posted April 1, 2017 Author Share Posted April 1, 2017 I do have a stash of 4.2 parts lying around, so stroking it isn't out of the question, nor was I dead set on not doing that. My main goal was to start off with the best candidate for swapping and go from there. Perhaps I should not have thrown any HP number out there since I've attracted at least one I-have-nothing-to-contribute-so-I'll-just-say-something-negative response. I truly am not fixated on a number. Once I start buying parts and assembling things, I'll see how it goes. I'll run it on the dyno and be happy with whatever I get. Link to comment Share on other sites More sharing options...
johnj92131 Posted April 1, 2017 Share Posted April 1, 2017 Here is a good site for getting good ideas on what to get in the way of a stroker. http://www.jeep4.0performance.4mg.com/stroker.html Many of the tips apply to a standard 4.0 rebuild The 96(?) was the first year to have the crank support and other noise, vibration, harshness improvements. So a bit better to start off with than the older blocks. Also have less core shifts because the blocks were cast with newer tooling. As DirtyComanche mentioned the 99+blocks are built with the coil pack ingnition. And they are supposed to be even lighter, with more precise casting still. The Renix era blocks were made with long on tooth AMC tooling and supposedly had more core shifts, compared to later blocks. The 2 spare blocks I have are both in the 97-2003 range. 1 is stock bore, the other .020 oversize. Both should be good for up to .080 oversize bores. The H.O head flows better than most jeep heads out of the box, but it needs supporting modifications like a larger throttle body to make more power. When you build your engine you want to pay close attention the "squish/quench" between the head and the top of the piston. Aim for .035 to .045 and you will get a much less knock sensitive engine. Spend a bunch of time reading on the jeepstrokes site. There are a number of experienced and sharp Jeep engine builders over there. You will also find there a couple of suppliers to avoid. Link to comment Share on other sites More sharing options...
Jtrux Posted April 1, 2017 Author Share Posted April 1, 2017 Excellent post. Much appreciated. I haven't put much thought into quench yet. .035 seems awfully tight but I suppose since these are not turning too high you can get away with it. A buddy of mine played around with different thickness head gaskets in his 350 and ended up somewhere in the .030 range, maybe slightly more; I don't recall anymore. It would hit a certain RPM range and then just stop. Turns out that it was just tight enough that the pistons were contacting the valves and restricting it from turning up higher. No damage done but could have, I suppose. I also realized that I completely pulled the 300hp number far out of my a$$ when I started looking up actual dyno results on 4.0 and stroker builds. My experience up to this point is strictly V8's and it is relatively easy to hit those numbers with affordable, aftermarket parts. In my HS days, I worked a machine shop where we focused primarily on large displacement big block chevys. Our shop car ran 8.80's while being propelled down the track by a 496. Anyways, you can kinda see why I casually through out 300hp. All the same, I'm looking forward to this build. I really like the way my 4.0 runs in my '06 LJ and I bet this little MANche will be a blast if it has even a little more power than that. Link to comment Share on other sites More sharing options...
johnj92131 Posted April 1, 2017 Share Posted April 1, 2017 Here is a link to a really good article by David Vizard: http://www.hotrod.com/articles/0311em-power-squeeze/ About half way into the article he discusses quench. You will see he even ran a super tight .025 (?) quench on one of his test engines at 7K RPM, pistons just kissed the valves. In the late 1960's this was the hot ticket on air cooled Corvair heads to boost compression and power. It also killed detonation and allowed more timing advance at exactly the same time. A real life case of have your cake and eat it at the same time. For a real, high power Jeep 6 cylinder engine - Look WAY back to about 1963. Barney Navarro built a couple of 700 hp, turbo charged 199 cubic inch AMC 6s for the Indy 500. Did not qualify. But it gives you an idea of how strong the bottom end of the Jeep 6 engine is. Unfortunately the Jeep 6 cylinder head is not designed to be a high power head. But for low end torque/power, it is just FINE. Link to comment Share on other sites More sharing options...
Jtrux Posted April 2, 2017 Author Share Posted April 2, 2017 Last night I spent a little time reading about Mr. Navarro. Talk about being ahead of his time. Makes me feel like a real dummy reading about his accomplishments. Is there any difference at all between XJ and ZJ 4.0's, bracket-wise? I've been finding a ton of ZJ's for cheap with blown rear ends, and various other ailments, but with sound engines. Link to comment Share on other sites More sharing options...
Jtrux Posted April 2, 2017 Author Share Posted April 2, 2017 Oh, and I did read about his Rambler engines. What really upsets me is that it wasn't the engines that disqualified him, it was car or driver issues. What a shame. Link to comment Share on other sites More sharing options...
cruiser54 Posted April 2, 2017 Share Posted April 2, 2017 So the 96+ had a crankshaft girdle? Was itintegrated into the block or something that can be added it a bolt on piece but AFAIK you need to drill holes in older blocks to put it... Nope. Just need the main bearing cap bolts/studs. Link to comment Share on other sites More sharing options...
cruiser54 Posted April 2, 2017 Share Posted April 2, 2017 Do you want a used engine or are you going to rebuild one or buy a long block. Also it would sure help to know what you are starting with and if this is your toy/project or a must have daily driver. Does your Megasquirt system utilize the factory Renix knock sensor? If so then stick with the Renix era block . All the blocks have the threaded hole for the knock sensor. Link to comment Share on other sites More sharing options...
75sv1 Posted April 3, 2017 Share Posted April 3, 2017 I would add the 99.5+ intake manifold. I think some advertise 300 hp with the stroker. 260-270 is commonly advertised with strokers. Link to comment Share on other sites More sharing options...
johnj92131 Posted April 3, 2017 Share Posted April 3, 2017 I would add the 99.5+ intake manifold. I think some advertise 300 hp with the stroker. 260-270 is commonly advertised with strokers. Sorry to say it, BUT the key word above is "advertise". I think Don may have a before/after dyno with the addition of the 99.5+ intake to share. The factory claimed 195 horsepower, including a number of other minor tweeks made. Surely if it made a bigger horsepower difference, the factory would have reported it? Link to comment Share on other sites More sharing options...
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