dirtdemon Posted December 20, 2012 Share Posted December 20, 2012 What motor mounts would i need to put a inline 6 into my 2.8 powerd comanche? I'm planning on using the engine trans and transfercase out of the scrambler. The engine is the 4.2 and it has a TF 999 trans and the dana 300 transfercase. Thanks for the help. :cheers: -Jordon Link to comment Share on other sites More sharing options...
cruiser54 Posted December 20, 2012 Share Posted December 20, 2012 You do realize this is not a bolt in operation, correct? It would require great amounts of fabrication/welding skills. Not to mention the firewall would need to be modified. Link to comment Share on other sites More sharing options...
JeepcoMJ Posted December 20, 2012 Share Posted December 20, 2012 The same amount of work is required to install a 4.0. Why bother substituting one junk motor for another Link to comment Share on other sites More sharing options...
Pete M Posted December 20, 2012 Share Posted December 20, 2012 my guess is that you could use 4.0 mounts from an MJ/XJ. the MJ/XJ mounts bolt-on. what are you doing for axles? Link to comment Share on other sites More sharing options...
jpnjim Posted December 20, 2012 Share Posted December 20, 2012 They shortened the ft belt drive system when they designed the 4.0L Look at a 4.0L Cherokee/Comanche Even making the lower pulley part of the harmonic balancer, the ultra short serpentine setup barely squeals by. Link to comment Share on other sites More sharing options...
ejndssn Posted December 21, 2012 Share Posted December 21, 2012 may want to swap a firebird/camaro 3.4l engine which will swap kinda easy Link to comment Share on other sites More sharing options...
dirtdemon Posted December 21, 2012 Author Share Posted December 21, 2012 The drivetrain only had 40k miles when it was replaced with a 454 and it is free. That is why i want to put it in. Fab work aint a problem i know i will need to make a new trans mount and custom driveshafts. My truck is bone stock besides enough fender cutting to fit 32's. These are real rare arround here and if you do find one its so beat and rusted out that it aint worth scrap. Link to comment Share on other sites More sharing options...
dirtdemon Posted December 21, 2012 Author Share Posted December 21, 2012 it has a hp dana 30 in the front and a chrysler 8.25 in the rear. dana 35 died when i put 235's on it. it didnt like doing a burnout. thanks for the input! -Jordon :cheers: Link to comment Share on other sites More sharing options...
jpnjim Posted December 21, 2012 Share Posted December 21, 2012 40k mile 30 year old engine? I'd at the least want to change some seals in that engine anyway. Rear main seal at the very least. The ft pulley drive system HAS to be swapped for an XJ set up. Serpentine belt, XJ ps pump, reverse rotation waterpump, XJ fan, idler pulleys, etc etc. Your Alternator should fit the Renix mount, so long as the wires reach. Hopefully none of the brackets interfere with the fuel pump mounting (4.0L's don't have mechanical fuel pumps) The best harmonic balancer you could use for it would be from YJ with a serpentine belt drive. YJ's came both ways. A spacer will move the serpentine pulley where it needs to be on that long nose crankshaft. No way will that CJ ft drive setup fit. There just isn't room firewall to radiator for that long engine + the old school drive set up. If you use 87-90 4.0L Renix style belt drive parts, they will all work with your carburated engine. ^that is if the intake/carb & air cleaner clears the hood. It probably won't. They completely repackaged that engine to fit XJ/MJs. If it doesn't, a low profile air filter might squeak you by, if not, start cutting the hood for clearance, or swap to one of the two 4.0L fuel injecton setups that do fit (I would go HO, head and all in this case) Speaking of hoods, You'll need a 4.0L hood, radiator support, radiator, hood release setup, etc, and have to chop some sheet metal behind the hood to fit it all. 85 4cyl/V6 & 87 4.0L are completely different. The old hood latch & radiator had to be moved to fit the 4.0L too. Some say the firewall is different 86-87 for the change to 4.0L but others have said it didn't really change much. The swap has been done, It's just not an easy one. Link to comment Share on other sites More sharing options...
Pete M Posted December 21, 2012 Share Posted December 21, 2012 The dana 300 is a pass side drop. your Dana 30 is a drivers side diff. you'll need a flip kit. Link to comment Share on other sites More sharing options...
Walkenvol Posted December 21, 2012 Share Posted December 21, 2012 Advise is worth the price paid, but here's mine. Take the free drive train and part it out. Use the cash to pick up the suggested 3.4 liter which bolts right in. Folks have reported very good results with this. Good luck! Link to comment Share on other sites More sharing options...
Pete M Posted December 21, 2012 Share Posted December 21, 2012 that's what I would do. :thumbsup: just because it's a good deal, doesn't mean it's a good idea. Link to comment Share on other sites More sharing options...
dirtdemon Posted December 21, 2012 Author Share Posted December 21, 2012 The thing is that its almost impossible to find a 3.4 here in alaska. The reason that i got this drivetrain for free was so i could put my truck back on the road. If i aint gunna put the motor in then i can't have it a good friend of mine is giving it to me and helping me put it in. He also has the original axles from the scrambler and he just told me i could have them to. Link to comment Share on other sites More sharing options...
Pete M Posted December 21, 2012 Share Posted December 21, 2012 just trying to help. you're talking about a huge project here. harder than even a straight-up 4.0 swap. not exactly the "just get my truck on the road" kind of thing. :( are you anywhere near Wasilla? car-part.com shows a junkyard there that has a couple 3.4s. http://www.knikrecycling.com/ Link to comment Share on other sites More sharing options...
dirtdemon Posted December 21, 2012 Author Share Posted December 21, 2012 I'm 6-7 hours south of wasilla. I understand that it is a big project. I got 8 months to do this swap. I REALLY appreciate the input and all that. My income is low but i have ability and time to do this thats why i am going to use this drivetrain. Thank's :cheers: -Jordon Link to comment Share on other sites More sharing options...
jpnjim Posted December 22, 2012 Share Posted December 22, 2012 My last suggestion would be to have a 4.0L XJ parts car close by when you're ready for this swap. There's dozens of small parts needed to get even a 4.0L into an 84-86 XJ/MJ Nevermind a CJ 258. In this instance, a parts car would pay for itself in fuel costs back and forth to the junk yard alone. Edit, I just saw you mentioned the trans mount. 904/999's were used off and on through the years on XJ/MJ's, so the mount itself should be an off the shelf item. 84-86 4cyl auto's used them if you need an example for the parts store guy. Link to comment Share on other sites More sharing options...
misfitmechanic Posted December 22, 2012 Share Posted December 22, 2012 I am in the process of a 4.0l swap in a 86 mj and so far it has been big job. I had to cut the lower firewall out of the mj and section in a firewall out of a xj. I have a donor xj for my swap and I would be lost without it. I also ran into problems with the transmission cross member as it dose t have the same mounting points on the mj. I am also going to have to shorten the rear driveshaft and move the transfer case linkage as the inline 6 engine and trans assembly are way longer than the factory turbo diesel 4 cyl. Good luck with your swap! Link to comment Share on other sites More sharing options...
Tylerzap Posted December 24, 2012 Share Posted December 24, 2012 Its not worth it. Just wait for a 3.4 and be done with it. Link to comment Share on other sites More sharing options...
jimoshel Posted December 24, 2012 Share Posted December 24, 2012 Listen to these guys, They know what they're talking about. Sometimes you get your mind set on a project and you lose sight of reality. I recently received a 1999 7.3 diesel and I had big plans for dropping it into a '88 MJ, until I had them side by side and got a good look at it. Reality set in. No problem. Got a '77 J20 with a tired 360. Now that's a little more realistic. :thwak: :wrench: Link to comment Share on other sites More sharing options...
dirtdemon Posted January 5, 2013 Author Share Posted January 5, 2013 I will probably just get an ax-15 and put that behind it. I have no problem re working the trans tunnel and firewall. I have acsess to a 4.0 xj that was sunk in the ocean so the engine and trans are trash but i can get all the mounts the hood and the rad. support. I have no problem cutting a hole in the hood for the carb and airfilter. This truck will be a DD/weekend wheeler. Link to comment Share on other sites More sharing options...
cruiser54 Posted January 5, 2013 Share Posted January 5, 2013 Do a build thread. I wanna see this. Link to comment Share on other sites More sharing options...
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