Dickinson County Comanche Posted June 22, 2021 Share Posted June 22, 2021 Hello all, so I was unable to get that Eliminator that I wanted for a donor, so with a quick search I found a nice 94’ XJ to swap the powertrain out of, only problem is the engine. Are they compatible? I know I’ll have to swap the distributor, intake and exhaust manifolds and sensors, but will I have to swap heads or do any major conversions? If not it would make my life much easier, but if so then I guess I’ll look some more. or if anyone has a cheap Renix 4x4 XJ with a Ax-15 they’d part with, I’d maybe be a taker… Link to comment Share on other sites More sharing options...
scaleless Posted June 22, 2021 Share Posted June 22, 2021 You'll need to drill out the temp sender hole at the back of the head. I don't think the HO block has the tapped hole for the knock sensor either (I may be wrong), but you could just drill and tap or relocate the sensor. If you'd like, you can also probably use the HO intake and exhaust, with significant modification. It flows better, for sure. Not sure if someone has already done a write-up, but it should be pretty straightforward. You just need to attach the Renix throttle body and sensors. But are you missing the engine, or do you just want the AX15? A rebuild would be easier, I think. Link to comment Share on other sites More sharing options...
Dickinson County Comanche Posted June 22, 2021 Author Share Posted June 22, 2021 3 hours ago, scaleless said: You'll need to drill out the temp sender hole at the back of the head. I don't think the HO block has the tapped hole for the knock sensor either (I may be wrong), but you could just drill and tap or relocate the sensor. If you'd like, you can also probably use the HO intake and exhaust, with significant modification. It flows better, for sure. Not sure if someone has already done a write-up, but it should be pretty straightforward. You just need to attach the Renix throttle body and sensors. But are you missing the engine, or do you just want the AX15? A rebuild would be easier, I think. It currently has a bad BA10/5, and I don’t want to rebuild that, so I’m looking for a complete donor. The engine has low oil pressure and I don’t want to rebuild/refresh it but if worst comes to worst I can. Link to comment Share on other sites More sharing options...
Pete M Posted June 22, 2021 Share Posted June 22, 2021 have you checked the oil pressure with a mechanical gauge? the dash gauge is notoriously for not being accurate. Link to comment Share on other sites More sharing options...
89 MJ Posted June 22, 2021 Share Posted June 22, 2021 Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 22, 2021 Share Posted June 22, 2021 Why. It just go with the obd1 ecu? It’s fairly straightforward to make it a stand alone engine management system Link to comment Share on other sites More sharing options...
Dickinson County Comanche Posted June 22, 2021 Author Share Posted June 22, 2021 1 hour ago, Pete M said: have you checked the oil pressure with a mechanical gauge? the dash gauge is notoriously for not being accurate. I haven’t, but it gets pretty noisy at operating temp, so I think the gauge is accurate. Link to comment Share on other sites More sharing options...
Dickinson County Comanche Posted June 22, 2021 Author Share Posted June 22, 2021 36 minutes ago, ghetdjc320 said: Why. It just go with the obd1 ecu? It’s fairly straightforward to make it a stand alone engine management system I don’t want to have to worry about any wiring stuff, and I have no problems with the renix so why fix an issue you don’t have, yk? I’ve complemented this but I just don’t feel like putting in all the work Link to comment Share on other sites More sharing options...
ghetdjc320 Posted June 22, 2021 Share Posted June 22, 2021 42 minutes ago, Dickinson County Comanche said: I don’t want to have to worry about any wiring stuff, and I have no problems with the renix so why fix an issue you don’t have, yk? I’ve complemented this but I just don’t feel like putting in all the work I can understand that. Just seems like it might be easier at this point. Link to comment Share on other sites More sharing options...
Pete M Posted June 23, 2021 Share Posted June 23, 2021 1 hour ago, Dickinson County Comanche said: I haven’t, but it gets pretty noisy at operating temp, so I think the gauge is accurate. noisy compared to modern engines? or compared to other 4.0s? does a thicker oil make any difference? Link to comment Share on other sites More sharing options...
Dickinson County Comanche Posted June 23, 2021 Author Share Posted June 23, 2021 6 minutes ago, Pete M said: noisy compared to modern engines? or compared to other 4.0s? does a thicker oil make any difference? Noisy as in really bad lifter clatter, I.e 0psi oil pressure at idle. Thicker oil does not help. Link to comment Share on other sites More sharing options...
Pete M Posted June 23, 2021 Share Posted June 23, 2021 checked the rockers for any loose bolts? I think that's all of the "cheaper" options I can think of. Link to comment Share on other sites More sharing options...
Dickinson County Comanche Posted June 23, 2021 Author Share Posted June 23, 2021 1 hour ago, Pete M said: checked the rockers for any loose bolts? I think that's all of the "cheaper" options I can think of. I haven’t, but given that it is quiet when cold (oil pressure is ok) and noisy when warm (no oil pressure) I’m gonna say unfortunately it’s probably not that, but I’ll have to check. I’m going to at least drop the pan and see if the pump is full of gunk Link to comment Share on other sites More sharing options...
cruiser54 Posted June 23, 2021 Share Posted June 23, 2021 You won't have to drill for the temp sender and the knock sensor hole is drilled and tapped already. Here's all you need to put an HO into a Renix. CRUISER'S MOSTLY RENIX TIPS HO INTO RENIX SWAP OCTOBER 31, 2015 SALAD 68 COMMENTS This swap is easier than some will lead you to believe. And generally Pooh-poohed by those who have never done it. Those of us who have done it, like myself, will share with you the things that need to be done for a successful swap. Just think of it as swapping in a long block. XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange. 2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange. YJ and 1997-1999 4.0L TJ blocks will interchange in XJ/ZJ XJ/ZJ blocks, and the 2000+ TJ/WJ blocks do not interchange without significant modifications. TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These blocks are not interchangeable with XJ/ZJ engine blocks. The reason is motor mount bolt holes and belt driven accessory mounting bolt holes are in different locations, or not present at all, TJ/WJ vs. XJ/ZJ. Now that we know which engines we can use, let’s get down to business. The HO and Renix have some differences but none that can’t be overcome very easily. One running change was that the rear of the head was no longer drilled and tapped for the temperature gauge sender beginning in the 96 model year. The sender can be relocated to the threaded hole in the thermostat housing taken from an HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head at the rear for the sender. You will be using the intake and exhaust manifolds from your Renix, along with all your sensors and wiring. Since the intake ports of the HO are slightly different, you use a new Renix gasket. Exhaust ports are identical. An alternative on exhaust manifolds: As far as exhaust, you can use the Renix exhaust manifold and be fine. If you want to use the HO exhaust manifold, you must go with an HO headpipe and screw your O2 sensor into that headpipe. Standard Renix harness is plenty long to do so. A bung can be welded into the HO manifold to accept the EGR tube. You will need to use your Renix distributor as it is different than the HO design. See Tips #12 – Setting Your 4.0 to #1 TDC and #13 – Distributor Indexing to be sure you get the distributor installed correctly. The flywheel or flexplate from the Renix must be used so your CPS gets the correct signals. The valve cover from the Renix allows you to keep your CCV system intact and requires no modifications. The HO block will have a plug in the coolant galley on the driver’s side of the block, closest to the front, which needs to be removed so your Coolant Temp Sensor can be installed in it’s place just as it is on the Renix. It requires a 5/16” square drive or a modified 3/8” drive that has been ground down to fit. Do this before installing the engine. As for the knock sensor, which is located just above the oil pan on the driver’s side of the engine about mid way, all the blocks I’ve seen are threaded for it. If not, I’ve heard they may be drilled but not tapped. Tap the hole if that’s the case. XJ: “Regular” (not Grand) Cherokees ’84-’01 ZJ: Grand Cherokee ’93-’98 (Gen1) WJ: Grand Cherokee ’99-’04 (Gen2) YJ: Wrangler ’87-’95 (Gen1) TJ: Wrangler ’97-’06 (Gen2) Link to comment Share on other sites More sharing options...
cruiser54 Posted June 23, 2021 Share Posted June 23, 2021 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 a 58 mm throttle body versus a 52 mm throttle body on a Renix. That’s 20% more air available through the HO throttle body. The HO also had a better design header. See where I'm going with this? It’s only a 4% horsepower increase….. 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 manifold using the Renix 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...
ghetdjc320 Posted June 23, 2021 Share Posted June 23, 2021 3 hours ago, cruiser54 said: 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 a 58 mm throttle body versus a 52 mm throttle body on a Renix. That’s 20% more air available through the HO throttle body. The HO also had a better design header. See where I'm going with this? It’s only a 4% horsepower increase….. 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 manifold using the Renix head, eliminate the "crush" in your headpipe with proper re-routing, and go for it. HO stands for Highly Overrated. __________________ Problem with Renix is there just isn’t as much parts availability. The HO head design was also better flowing but as you mentioned, depends on where you want your power at. Sbec can be fully tuned once socketed. So, if the renix fuel management system was on an HO engine, what are the power numbers? Link to comment Share on other sites More sharing options...
cruiser54 Posted June 24, 2021 Share Posted June 24, 2021 Parts availability. IAT, but there actually is a replacement. Knock sensor. There are alternatives. What else can't you get? We never did a dyno test, but I have run HOs on Renix as described above. HO exhaust manifold, crush removed, bored throttle body. I have done Renix with throttle bored throttle body and crush removed. Can't tell the difference. I will say this. I was Service Manager and Shop Foreman at a Jeep dealer from 1980 through 1992. I had 13 Comanches as demos. I ordered them myself. Myself, and the techs were disappointed in the performance of the HO compared to Renix. We were driving each version, side by side every day. Crank time to start was the only perceivable difference. And, I ran them HARD. Each and every one of them. Link to comment Share on other sites More sharing options...
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