big66440 Posted June 22, 2016 Share Posted June 22, 2016 Hey guys I was daydreaming about building a stroker 4.0 today and came up with this combination. Edelbrock aluminum head, Comp 68-232-4 cam, port matched renix intake and exhaust ( I live in CA so EGR has to stay), 4.2 crank , 4.0 rods, and Icon IC944 .030 over pistons- according to Summits compression calculator the compression ratio would be 9.69:1 using Edelbrocks .042 thickness head gasket and pistons .020 in the hole. This would be a daily driven on 89 octane as well, what do you guys think? I've already gone through as much info as I could find for the head BTW and for those wondering I'd like the advantage of the modern combustion chamber. weight savings, thanks. Link to comment Share on other sites More sharing options...
A-man930 Posted June 22, 2016 Share Posted June 22, 2016 Not knowing the numbers off the top of my head I'd question how much of that "modern combustion chamber" benefit you'll actually realize with a Renix intake feeding it... But I do agree the weight savings and improved heat rejection of the alloy head is very attractive. Would it be possible to introduce an EGR passage into a better intake? What exactly are you restricted on in the People's Republic of Cali? Link to comment Share on other sites More sharing options...
big66440 Posted June 22, 2016 Author Share Posted June 22, 2016 I've thought about seeing if maybe I can have a shop weld/machine something to adapt the EGR tube, smog inspections in CA are both a visual and "sniff" test ( OBD cars must have readiness codes set and ready as well and they are checked with a scanner). There are ways of "making it pass" but I don't want to do that, I was hoping writing this on this forum would get me better results with the Renix stroker set up since most Comanches were Renix, I know to most it will seem as though the Edelbrock head will be overkill but I'm not trying to make this thing a 6000RPM screamer, on the contrary I'm looking for as much low end and mid-range as I can get. Link to comment Share on other sites More sharing options...
A-man930 Posted June 22, 2016 Share Posted June 22, 2016 So if the inspector knows his stuff a visual inspection would reveal a later intake. Sounds like a problem to me... Are you required to actually retain the Renix controls? If so you'd have to keep the Renix throttle body and adapt it to a late intake bolt pattern or adapt the Renix's TPS and IAC to a late intake's HO throttle body. Another hurdle. Not to knock on the Renix system (can't do that here without lots of flak :D ), it's served many of us well, but it's archaic. To drop the cash for Edelbrock's fancy new head only to be handcuffed by an engine management system that old and "un-tuneable" (is that a word?) is, um, less than ideal imho. I don't want to recommend anything illegal, but a different engine management system (*cough* MEGASQUIRT *cough*) with wideband support and the like running the show would make your investment much more sensible. Link to comment Share on other sites More sharing options...
outlaw star Posted June 23, 2016 Share Posted June 23, 2016 Built a 4.9L stroker in my old 86Xj. Everything was Renix with no issues. I did however have a bored throttle body and Ford 5.4L injectors in it. Nothing wrong with running a Renix system if you take care of it and do proper maintenance. Sent from my SM-J700P using Tapatalk Link to comment Share on other sites More sharing options...
1stDeuce Posted June 23, 2016 Share Posted June 23, 2016 Use one of the dynamic compression ratio calculators to see what your DCR ends up at. As I understand it, 8.7 is about the limit for "pump gas", and at sea level, it can be tough to get it that low w/o custom forged pistons, or a fairly big cam. The alum head will help prevent spark knock, and should buy you a few points. Most aftermarket cams will lower DCR as well, though I've found a lot of people had issues with the narrow cam lobes of the aftermarket cams wearing quickly, and ended up back with a stock cam, or one of the two remaining Mopar cams, which use wider lobes. Note that none of them are a huge gain over the factory cams, which are pretty hot already. Many now suggest going to 1.7:1 roller rockers for a little extra valve lift, but that really only helps at higher RPM, and with a ported head, which isn't useful to me anyway. The more I read, the more it sounds like the 4.0L was fairly "tuned" right out of the box. Particularly the HO's, which have pretty aggressive cam profiles, comparable to that of the later "magnum" engines, and decent cyl head flow too for a non-cross flow head. At least in the middle years... Keep researching... My build has changed several times over the last six months, and I'm about to pull the trigger on the rest of the parts I need... I'll clean up the cyl head, polish the chambers, and run the stock cam. With 14cc dish pistons that have the wrist pin .010" higher than the stock pistons and not decking the block, quench will be a tad fat, but DCR at 5k' will be ~7.8, which should be fine on mid-grade, or possibly even regular. At sea level, it was 8.7, which would be premium only. Lucky for me I live at altitude. :) Have fun with your build!! Link to comment Share on other sites More sharing options...
johnj92131 Posted June 23, 2016 Share Posted June 23, 2016 Check out the jeepstrokers site. Lots of good information there. Including some flow tests on the Edelbrock head. It is no better than the stock H.O. head with similar porting. As for the "modern combustion chamber", the problem is you need to make a special piston to match the head. Don't know that it has been done yet. You have the pistons .020 in the hole - that will up the octane requirement for the engine. Better to run flush with the block or +0.008 over the block. With the .043 gasket, that puts the the quench at .035 and reduces the engine octane requirement. Do spend some time on the jeepstrokers site. Lots of good information there about what works and what doesn't. Link to comment Share on other sites More sharing options...
cruiser54 Posted June 23, 2016 Share Posted June 23, 2016 Just do a poor man's stroker with a bored throttle body and the proper injectors. Link to comment Share on other sites More sharing options...
big66440 Posted June 23, 2016 Author Share Posted June 23, 2016 Just do a poor man's stroker with a bored throttle body and the proper injectors. I just may do this after all, I already have a 7120 head ready to go as well. Is there a piston you would recommend to use with 87 octane ? I know there are slight differences with 4.0 pistons, thanks. Link to comment Share on other sites More sharing options...
cruiser54 Posted June 23, 2016 Share Posted June 23, 2016 Just do a poor man's stroker with a bored throttle body and the proper injectors. I just may do this after all, I already have a 7120 head ready to go as well. Is there a piston you would recommend to use with 87 octane ? I know there are slight differences with 4.0 pistons, thanks. Match port the rEnix intake manifold and the cylinder intake ports to the rEnix gasket. I can't remember which pistons but I can find out. Link to comment Share on other sites More sharing options...
Eagle Posted June 23, 2016 Share Posted June 23, 2016 Bob Salemi's Pro Stock Comanche is a Renix ... http://comancheclub.com/topic/17726-drag-comanche/ Link to comment Share on other sites More sharing options...
big66440 Posted June 23, 2016 Author Share Posted June 23, 2016 Check out the jeepstrokers site. Lots of good information there. Including some flow tests on the Edelbrock head. It is no better than the stock H.O. head with similar porting. As for the "modern combustion chamber", the problem is you need to make a special piston to match the head. Don't know that it has been done yet. You have the pistons .020 in the hole - that will up the octane requirement for the engine. Better to run flush with the block or +0.008 over the block. With the .043 gasket, that puts the the quench at .035 and reduces the engine octane requirement. Do spend some time on the jeepstrokers site. Lots of good information there about what works and what doesn't. Thank you for the tip, I've actually tried to register to the forum twice but it hasn't worked. :???: Link to comment Share on other sites More sharing options...
jpdriver1 Posted June 24, 2016 Share Posted June 24, 2016 Bob Salemi, Forestdale, R.I., runs a '92 Jeep Comanche in a stock class in the IRHA He just set a new record with a , 12.95 ET , 100.19mph top speed in the quater mile. This is runnig a 4.0L I am trying to get more details and pictures. wouldn't this make it a high output rather than a renix ? Link to comment Share on other sites More sharing options...
cruiser54 Posted June 25, 2016 Share Posted June 25, 2016 Bob Salemi, Forestdale, R.I., runs a '92 Jeep Comanche in a stock class in the IRHA He just set a new record with a , 12.95 ET , 100.19mph top speed in the quater mile. This is runnig a 4.0L I am trying to get more details and pictures. wouldn't this make it a high output rather than a renix ? 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...
jpdriver1 Posted June 25, 2016 Share Posted June 25, 2016 thanks Cruiser, I consider myself schooled. when it comes from you, it is gratefully accepted. :bowdown: Link to comment Share on other sites More sharing options...
johnj92131 Posted June 25, 2016 Share Posted June 25, 2016 Cruiser, What is the difference between the Renix camshaft and the HO camshaft? Is it just timing for the open and close? The Renix era engine seems to have it's torque peak at a much lower (and truck friendly) rpm. Also, do you know what the different smog standards (if any) that were required when the H.O. came out in 1991 vs 87-90? Do understand the H.O. engine has fewer smog add on parts. Link to comment Share on other sites More sharing options...
cruiser54 Posted June 26, 2016 Share Posted June 26, 2016 Cam is same 87 to 95. Renix has EGR and HO may have retarded cam timing which would explain less low end and the EGR being no longer needed. Link to comment Share on other sites More sharing options...
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