Torque Gains

I have purchased an engine from a 90 model. It will be swapped into my 89. I want to know what upgrades i can do to gain some torque. I already have Bocsh(spelling) Platinum 4 plugs, Jacobs Off Road ignition,FIPK, 2.5in exhaust piping to a 3in hi flow cat and flowmaster. what else can i do to gain some torque(without porting) and better gas mileage?

Your best bet would be an RV-type cam. And I think the mods you've done so far would really compliment the cam. Plus, the cam would probably give you more gain than any one of your other mods. Do a search, there's a ton of discussion on that subject, Good Luck!

ya ive been reading other threads and they all talk about doin porting. what is an RV-type cam?

ReBeL XJ said:

I have purchased an engine from a 90 model. It will be swapped into my 89. I want to know what upgrades i can do to gain some torque. I already have Bocsh(spelling) Platinum 4 plugs, Jacobs Off Road ignition,FIPK, 2.5in exhaust piping to a 3in hi flow cat and flowmaster. what else can i do to gain some torque(without porting) and better gas mileage?

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You can copy a lot of the mods that I've done to my 4.0. Take a look around my website for ideas. The only differences in your case will be:

1. Mopar Performance computer (if you can still find one and that ain't cheap).
2. You can get a bored HO TB and fit it to your intake manifold using Joe Attardo's adapter plate. There's more info. about that on the "intakes" page of my website.
3. Your non-HO head doesn't flow as well as the HO head out of the box, but porting it will bring it close to the flow of a ported HO head so it's worth doing. You should gain at least 10hp and possibly as much as 15hp.
4. An "RV cam" has a short duration to produce more torque at low rpm. The best cam for low/medium rpm on a 4.0 is the Crane 248/260 degree cam #750501. Cost, together with lifters and springs, is about $350. Installation by a repair shop will cost over $500 because it's a minimum 8 hour job. If you do it yourself with a friend to help you, installation will only cost you a few beers and a pizza.
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Modified 1992 4.0 XJ Laredo UpCountry, 170k miles, AX15, NP231, D35c rear, D30 front
Estimated 240hp@5250rpm/280lbft@3500-4000rpm
1/[email protected], race weight 3490lb
Future mods: 4.6L stroker
Website: Jeep 4.0 performance
Webpages: Electric fan, IAT sensor relocation, Intake manifold heatshield, Oil temp. gauge install, Jeep 4.0 cam specs, Jeep engine dyno graphs, Automotive formulae, CTS resistor trick, MAP adjuster

Try reducing your tail pipe down to 2.25" or even 2.0" because the 3" exhaust will over scavenge and lose your lowend torque. Checkout www.go.jeep-xj.info/ he's worked out the torque related to diameter issue pretty well.
Good luck.