Horsepower!!!!!

jeep1703 · 09-14-2004, 10:07 AM

Got a quick question for you everybody. I have got the I6 4.2L in my 90 YJ and I have read that it only makes about 115 horsepower is this correct. Everything is stock, but I am debating on doing the engine swap with the 4.0L or just upgrading my motor with the weber card and a MSD ignition. I am leaning towards staying with the 4.2 because I like the low RPM torque. Anyway I am just wondering how much horsepower I am looking at gaining with these two upgrades and if it would be anywhere comprable with the 4.0L. Any opinions would be greatly appreciated.

Thanks,

bigjeep310 · 09-14-2004, 11:11 AM

If you want to stay with the 4.2L you can always upgrade your head and stuff to the 4.0L fuel injected. Search around they make kits to do so. You should gain a noticeable difference.

Tshark299 · 09-14-2004, 11:28 AM

Actually it's 112hp stock but who's counting!

For performance upgrades I have a Weber carb, TFI ignition, high-flow catalytic converter, and electric fan so far. It definitely runs alot better than stock but still doesn't have the higher-rpm power that my friend's 4.0 does with the same gearing and tire size. So far I'm not complaining though because I can still keep up pretty well on the highway, only have to downshift to 4th for the steeper hills.

My future plans include a 4.0 head and an exhaust header and muffler to compliment my performance cat. I'm going to keep it carb'd because I really like the Weber alot... it's easy to tune and works great so I'm going to keep things simple.

I would say that you'd probably be happy with a Weber carb, TFI or HEI ignition, 4.0 head and a header. I'm sure it would cost less than a 4.0 swap and certainly would be a lot easier and take less time too.

acejeep · 09-14-2004, 05:02 PM

Quote:

Originally Posted by Tshark299

I'm going to keep it carb'd because I really like the Weber alot... it's easy to tune and works great so I'm going to keep things simple.

I would say that you'd probably be happy with a Weber carb, TFI or HEI ignition, 4.0 head and a header. I'm sure it would cost less than a 4.0 swap and certainly would be a lot easier and take less time too.

Thee and me.

Works great ! Without the installation hassles or $$$$$ of FI.

Might want to look at your gears, mine came with 3.07 and running 31's sucked.
4.11's put some life back into it.

Tshark299 · 09-14-2004, 06:50 PM

Quote:

Might want to look at your gears, mine came with 3.07 and running 31's sucked.
4.11's put some life back into it.

Oh yeah good call. Forgot all about gears. I've also got 3.07s right now and I'd call them barely tolerable with the 30s I have now. I'm really going to have to do something when it's time for me to upgrade to 33s, probably 4.11s also. Hey acejeep, how much did it cost you to go from 3.07s to 4.11s when it was all said and done?

acejeep · 09-15-2004, 06:07 AM

Quote:

Originally Posted by Tshark299

Hey acejeep, how much did it cost you to go from 3.07s to 4.11s when it was all said and done?

Bought used gears out of a 4 banger $75/each. Wanted to change out full diff's myself but couldn't find any near me. Master rebuild kits $65 & $85. Then paid a guy who works in a tranny shop $100/diff to moonlight the work. $500 all inclusive.

Tshark299 · 09-15-2004, 01:50 PM

Cool, that's not bad at all.