landlubber Posted July 12, 2012 Posted July 12, 2012 I am hopefully getting a 95 engine to replace my clapped out 88 renix 4.0l My question is: how similar are the blocks? I know the heads are different, but I plan on swapping in a renix head to the 95 block. any other opinions on this? what sorts of mods would be required to run a 95 head with a renix comanche?
cruiser54 Posted July 12, 2012 Posted July 12, 2012 You'll be fine. I've done a few of these. You don't have to swap the head either if you don't want to. Just use your intake and exhaust manifolds, dizzy, flywheel/flexplate and valve cover. Be sure to remove the coolant galley plug on the 95 engine so you have a place for your CTS.
mvusse Posted July 12, 2012 Posted July 12, 2012 Your Renix engine has a knock sensor, which the HO does not have, but the block *should* have a boss for it. You might have to drill and tap it, though.
cruiser54 Posted July 12, 2012 Posted July 12, 2012 Your Renix engine has a knock sensor, which the HO does not have, but the block *should* have a boss for it. You might have to drill and tap it, though. Haven't found an early HO yet that wasn't drilled and tapped for the knock sensor.
landlubber Posted July 12, 2012 Author Posted July 12, 2012 the knock sensor was on the list of concerns. So I can just pop the whole 95 setup in minus the intake/exhaust manifolds and flywheel and such. the distributor will work also? much thanks for the replies.
cruiser54 Posted July 12, 2012 Posted July 12, 2012 Just think of it as a longblock swap. Use the 95 head and block and use your flywheel, dizzy, sensors, manifolds, valve cover. Use an intake/exhaust gasket for the 88.
mvusse Posted July 13, 2012 Posted July 13, 2012 Do the ports in the HO head line up to the Renix manifolds?
Geonovast Posted July 13, 2012 Posted July 13, 2012 Do the ports in the HO head line up to the Renix manifolds? Exhaust, yes, intake.. not completely. I know it's been an issue for people swapping HO manifolds onto Renix heads. It will still work, though. May not even be noticeable. Yes, the dizzy must stay with the electrical system. Which generation transmission did you swap in? I don't know if there's a factory pilot bearing to use an older transmission behind a newer 4.0, like there is for a newer trans behind an older 4.0.
cruiser54 Posted July 13, 2012 Posted July 13, 2012 Do the ports in the HO head line up to the Renix manifolds? Off slightly at the bottom. No worse than some factory ports matching. Use the gasket for the manifold you're using and it's fine.
Stacks Posted July 13, 2012 Posted July 13, 2012 I put a '93 engine (out of a YJ) in my '89 MJ (BA10/NP231) and found that the pilot bearing from the older setup will fit in the newer one. The hole is stepped and will accept either bearing. Perhaps I got lucky. The engine had a complete rebuild done on it with a CompCams cam. I used a 7120 head and the '89 Renix intake and exhaust and sensors. (less the knock sensor) The only other issues I had was with the water pump and motor mounts. Had to use a water pump for the '89 engine and the motor mounts from the '89. It's been together and running fine for just about a year. Hope this info is of help. Later, Larry
mvusse Posted July 13, 2012 Posted July 13, 2012 Motor mounts were because your engine came out of a YJ. Water pump may have been also. Water pump should go with what year's serpentine belt routing is used as some years use reverse rotation and some do not. Other than that all MJ/XJ water pumps look identical.
landlubber Posted July 13, 2012 Author Posted July 13, 2012 Do the ports in the HO head line up to the Renix manifolds? Exhaust, yes, intake.. not completely. I know it's been an issue for people swapping HO manifolds onto Renix heads. It will still work, though. May not even be noticeable. Yes, the dizzy must stay with the electrical system. Which generation transmission did you swap in? I don't know if there's a factory pilot bearing to use an older transmission behind a newer 4.0, like there is for a newer trans behind an older 4.0. I have an AX15 from a 1990 XJ, It was the same pilot bearing that came out when i swapped over from the pukey. I have brown dog offroad motor mounts.
cruiser54 Posted July 13, 2012 Posted July 13, 2012 So, basically, no worries. Go for it. Any questions as you go, post them up.
Geonovast Posted July 13, 2012 Posted July 13, 2012 I have an AX15 from a 1990 XJ, It was the same pilot bearing that came out when i swapped over from the pukey. That's what I was afraid of. I've never heard of a bearing/bushing that will work for that application. Hopefully someone's got that info for you. Worst case, if you can't find one, you could swap the input shaft from your TJ trans in.
landlubber Posted July 17, 2012 Author Posted July 17, 2012 I don't want this to take forever as this is my daily driver. I would like to have all the kinks ironed out and ready to go together in a few days at the longest.
cruiser54 Posted July 17, 2012 Posted July 17, 2012 I don't see where the pilot bushing can possibly be an issue. The hole in the rear of the crank never changed to my knowledge.
Geonovast Posted July 17, 2012 Posted July 17, 2012 I don't see where the pilot bushing can possibly be an issue. The hole in the rear of the crank never changed to my knowledge. It did. 87-91 and 92+ are different. Changed the same time as the tip of the input shaft.
cruiser54 Posted July 17, 2012 Posted July 17, 2012 I don't see where the pilot bushing can possibly be an issue. The hole in the rear of the crank never changed to my knowledge. It did. 87-91 and 92+ are different. Changed the same time as the tip of the input shaft. Somebody's gotta have one that will work.
Geonovast Posted July 17, 2012 Posted July 17, 2012 I don't see where the pilot bushing can possibly be an issue. The hole in the rear of the crank never changed to my knowledge. It did. 87-91 and 92+ are different. Changed the same time as the tip of the input shaft. Somebody's gotta have one that will work. It's been quite common for people to put a newer trans with the bigger tip behind an older motor, when people do AX-15 swaps. This is easily fixed with the 74 CJ 304 bearing, which happens to have the correct OD and ID. I do not know of any that will work for the other way around.
landlubber Posted July 18, 2012 Author Posted July 18, 2012 ah, one think I overlooked mentioning is that the 95 engine happens to have a 4.2 crank. also it has a 1994 H.O head which I didn't notice before. how would that change things?
Geonovast Posted July 18, 2012 Posted July 18, 2012 I know nothing about the 4.2's pilot bearings. You may want to head over to the stroker forum for this.
cruiser54 Posted July 20, 2012 Posted July 20, 2012 Advance Adapters has the bushing you need. Just stumbled upon that doing additional research for my HO into Renix swap write-up.
landlubber Posted July 30, 2012 Author Posted July 30, 2012 Just picked it up today. We will see what is good and what isn't.. i'm sure i'll need some guidance, but that is what all you nice folks are good at. :cheers:
landlubber Posted August 19, 2012 Author Posted August 19, 2012 Everything seems pretty straightforward so far. have not actually started the swap yet, just getting parts, maybe tonight though. The biggest thing I can think of now is what sort of procedure to make sure than the new engine with the old dizzy has the proper timing and will run. Setting both engines at TDC is the best way to make this work?
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