83 CJ7 Build

[dizney4]

Brand new to list and 1st post and looking for some advice and help.

I have a 83 CJ7 with 258 and aftermarket FI (Howell chevy throttle body type) and
4 speed manual. Pretty much stock with a 4" lift and 33" tires. This is the way
I got it. After a recent trip to the dunes (pismo beach) I am in need of a new
motor (old motor seized up) and looking at my options. Not sure how bad the old
motor is, but it won't turn over. I was going to do the 350 swap but after a
little research am now against it. Now I am thinking about doing a stroker swap.
Any help to get me started, pitfalls to watch out for would be great. a couple
of questions to start off with (but feel free to chime in with any advice). This
will be combo of street, mountains, hills, dunes, so looking for best overall.

will a 4.o block mount right up in my jeep?

should I change the tranny?

Can I retain the FI I already have?

Should I just get a rebuilt 258 and put on the 4.0 head?

Also I have read about just following someone else recipe for their build. Anyone got one they want to offer up?

Thanks in advance to everyone.

Jeff

[Plechtan]

The 258 was rated around 125hp, the 4.0 is rated between 175 and 195 hp stock. So a 4.0 is the way to go. See if you can find a 93+ motor complete with the accessories and manifolds. You may be able to find a 2wd XJ with a bad motor cheap.

The 4.0 will bolt in, you could use the accessories from the 258, but it causes problems with the EFI because of the damper you would have to use.
You could stick with the howell stuff, but would need a new intake to go to the HO head.

Better move is to sell off the Howell stuff, Find a 4.0 core motor. Pull the crank and rods out of the 258, and build a stroker using the 4.0 block. you should be able to so this with some performance inprovments for less than 2k.

Then buy the EFI harness and the crank trigger kit from Hesco. Use a 93-94 CPU. The stock trans will bolt up. The trigger for the EFI will now pick up from the harmonic balancer instead of the flywheel like a stock XJ. A trans swap is a little hard because you have a dana 300 T case which has the driveshaft going up the passenger side, and the XJ's had the driveshaft going up the drivers side.

[dizney4]

Ok I have access to a 95 4.0 in Grand Cherokee 4x4 with approx 180K miles (it was in a roll over) & auto tranny. I do not want to go with an auto, I want to keep my tranny. Would this be a good donor? If so how much should it be worth?

Jeff

[yuppiexj]

Ok I have access to a 95 4.0 in Grand Cherokee 4x4 with approx 180K miles (it was in a roll over) & auto tranny<snip>. Would this be a good donor? If so how much should it be worth?

Jeff

Yes it would be a good donor.
If it runs, I would offer $500 for it, pull the trans and xfer case sell those for $400 and sell the rolling chassis for $100

[Plechtan]

I think a 95 is an ODB2 computer, I do not know if it is plug and play with the 93-94 odb1, You should call Hesco to see if their harness will work with the 95 CPU. Worst case would be that you would have to trade the 95 for a 93-94 cpu.

The Value of the should be judged against what it would cost you to aquire the parts seperately. You can usually get a core motor for $200 or so. It will not come with accessories or manifolds. You may opt for a 99+ intake and a header, so maybe the manifolds are not a big problem. The accessories could be costly. If you do not have power steering and AC, the only accessory you will need is an alternator.

You will need an ECU which will come with the Grand. If you purchase it seperately it could be costly. I do not know if it is the same ECU for a manual and auto trans. The transmission has it's own controller, so the ecu may be the same.

You could probably part out the Grand and more than make your money back. You just need a place to do it.

[eastin82]

i was thinking 91-95 were obd1 dont quote me but check it out and let me know

[RAPTORFAN85]

Yeah, I thought 96-on were OBD2...

[dizney4]

OK I have decide on the following (unless you can talk me out of it)
4.5L Low-buck simple stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Jeep 4.0L 3.875" standard bore pistons
9.7:1 CR
CompCams #68-231-4 206/214 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Stock 0.051" head gasket
0.081" quench height
Ford 24lb/hr injectors with adjustable FPR or MAP adjuster for '87-'95 engines, Ford 24lb/hr injectors with stock 49psi FPR for '96 and later engines
266hp @ 4950rpm, 322lbft @ 3500rpm

I will use the 95 Grand as my donor

What else will I need?
What is I can't get the comp cam?
What is I have to bore the block?
Is it better to use a standard crank if I can get one?
Any idea on which octane I will need to run?
Is Hesco the place to go for what I need (and still not sure what all I need to do this)?

Thanks to everyone for your help. This will be the 1st rebuild project for my son and I, so any help or advice you can give would be great.

Jeff

[eastin82]

you can use comp cam(im goin with 68-231-4) just not the springs and acc. they are dif. size and to stiff(made for the 258). ive got a 91 4.0 that im stroking to 4.6 that is going in a 81 cj5. you can also use 4.0 flywheel and send your bellhousing in to get it drilled for a cps sensor i think thats the way ill go should be cheaper. if you are going 4.5 no boring is needed but should check cylinders. hmm.. you will need inline fuel pump and fuel press. reg. or gas tank with fuel pump in it. may need el fan or dif water pump that centers the fan up. thats all i got for now

[dizney4]

I finally got a chance to see the donor motor yesterday. It's in a 95 grand 4X4 with a 7120 head and auto tranny. Is this a good canidate to put in my 83 cj7 with a 4 speed? Any special things I will need with this motor?


Jeff

[Plechtan]

You can either use you CJ flywheel, and put the crank trigger on the Harmonic damper, or find a flywheel for a standard trans out of a late 90's XJ and drill your bellhousing for the CPS. You will need an electric fuel pump capable of 49psi, A wiring harness that will plug into the Computer from the 95. You could purchase the manuals from the 95 and strip down the harness from that vehicle and put it into the CJ. I think the EFI harness is about $450.

[dizney4]

Peter, I am getting the entire Grand so I will have all the wiring and all. Do I need the harness due to I have a 4 speed and the grand is an Auto?

[Plechtan]

The trans should not be an issue, the automatic has it's own controller and just takes a few signals from the ECU. You can cut down the grand harness and make it work.