Topic: Opinions Wanted

[Jeffy]

This is where I'm a little lost I have always been happy w/ my 4 squirrels off road it keeps me light and well balanced it has good power in low range and works well, I've been thinking of rebuilding a spare 2.5l I have to make more power for on road, as I run a lot of highways when I do drive it and when I'm on the hills I really have to push the 4 to keep up with traffic.

With that said I also can see a real benefit to going to a bigger motor as a little more power should let me idle through stuff on the trail that I had to be on the gas for before to have enough power.  I also am a redneck and power is a good thing, so the 5.2l seems the way to go, then I look at how small a HP30 is and wonder will it live w/ 34's, V-8 power and weight, 4.88 gears, and the locker when I'm in the rocks.  I don't want to end up with a Jeep the blows an axle shaft every time I go wheeling.

After thinking of this I started to think about the 3.9l as a nice middle ground place to be, but is middle ground really a good option, especially when if I use it I will end up scrapping a v-8, and that just seems wrong to the redneck inside me.

Well, the choice I see is either live with teh 2.5L then maybe turbo or SC it or go with the 5.2L and baby it.  I don't think you'll ever say, boy, I wish I went with the 3.9L after swapping to the 5.2L.   The 5.2L will also handle your existing gearing nicely.  You can get by with the D30 as long as you're not jumping the Jeep.  Otherwise it should be OK.

Although, if you sold the 3.9L and the 5.2L you could probably get a 5.7L which would be easier to install since everyone swaps 5.7l's.  Gas mileage might also be a bit better as well.  I'd go for a pre-1996 OBDI TBI for simplicity but that's just me.  Parts are also cheap and plentiful.

[BigCountry]

I second Jeffy's thoughts. you could sell off the 3.9 and the 5.2 and go with the 5.7l. i'm in the process of planning out a 5.7l swap, along with axles, trans and t-case.

As far as would your front hp30 handle the 5.2l, yeah it would. the dana 30, tho on the smaller side and not thought of as a strong axle, is actually pretty tough and can live with some abuse. i'd be more concerned with bending an axle tube than i would be with snapping a shaft.

if i had a 5.2l engine laying around i wouldn't even consider keeping the 2.5l. it would be a matter of swap in the 5.2 or do an upgrade for the 5.7 simply as a matter of aftermarket support. another big + for swapping in the 5.2 is you have a manual trans all hooked up to it already.

the 5.2 puts out some decent numbers, but you can manage with the d30 for a while as long as you aren't trying things worthy of the Ultimate Adventure or TTC. If you are really concerned about the d30 standing up to it, get a junkyard d44 and swap that in, shouldn't cost too much to do.

to play devil's advocate against myself however, jeep magazine had the 5.2 as one of the stupid swaps, along with the chevy 2.8, the dodge 5.9, the viper v10 and weird engines like cadillac's northstar v8 and things like that.

do a pros and cons sheet of what you'll need to do for both the 5.2 swap and a chevy 5.7, and see which one you would rather invest time and a little money into, and what you are most comfortable living with.

[DaCarmack]

For me when my 2.5L dies, I hope it not for some time, I going to put a 4.3L/4L60 combo in it from Novak. There's a guy out here in the Phoenix area that does nothing but 4.3L/ s-10 trucks and does built 4.3. That's my plan but not for some time though.

DaCarmackl

[BigCountry]

For me when my 2.5L dies, I hope it not for some time, I going to put a 4.3L/4L60 combo in it from Novak. There's a guy out here in the Phoenix area that does nothing but 4.3L/ s-10 trucks and does built 4.3. That's my plan but not for some time though.

DaCarmackl

that sounds like a pretty good package. i'm not fond of auto transmissions tho, but yet again, your build not mine right? 

never really thought much about doing a 4.3L swap, how's the power/torque/fuel economy/aftermarket/and ease of swap on those?

[DaCarmack]

Hello BigCountry the 4.3L is rated at 190-200hp to 245-260tq. I for one do not like off roading with a stick I don't like the feel of riding the clutch, but any manual that was behind a 350ci will fit a 4.3L. I had one is a GMC Sonoma back in 98 with a 3.42 axle and it would tow anything I wanted to, lots of low end TQ. The guy I met in Chandler AZ that does built 4.3 has tried everything to them to get the most power out of them. I cant remember everything he does to them but intake, throtle body spacer, flat top pistons, and some flow/ valve work, there may be more but I'm not sure. Here is his web site

http://www.s10blazer.com/index.html

He told me that with those mod a TBI 4.3L would out run a SFI one. that's pretty good I think sence the old TBI's had like 150hp.
On the truck and blazer with his mods and an electric fan they would get 23-25mpg, so I hope with a jeep it will get me 17ish.

As for the swap Ive read that its easier the a 4.0L six and or any of the Mopar v6/v8.

[chardrc]

for reference my stoker s10 4.3l tbi gets about 18-20mpg mixed and got 19 mpg highway with a 4wheeler in the back even with the lower 150 hp tbi version the torque is great (even after 174,000 miles). the 4.3l (at-least mine) has the 231c transfer-case so similar to the 231 t-case in the jeeps (may be-able to mix match parts to get an easy conversion)

[BigCountry]

might have to throw that into the mix for consideration on my project. i'm thinking the 5.7l might still be worth it for the jeep tho. looking to turn my yj into mainly an offroad and bad weather. get an XJ or a ZJ or some other reliable 4x4 that the fiancee can drive in the snow/ice, while i drive the YJ. so far i'm feeling dana 44 fr and dana 60 or ford 9 inch rear. looking at a dana 300 or atlas t-case, sm420/sm465 to plant behind the 5.7. might also look at the 6.0L chevy v8 as well.

[DodgeMudder]

I finally got the cheep running again.  Didn't really like my option and I'm still thinking a motor swap might be fun, but for now I have an AX-15 in it, to get it back up and running.  This otion came when a buddy of mine offered me his for $50.  So I went with it.

Maden voyage with it I was just playing in the ditch out front to make sure nothing sounded off, and I popped a cap on a wheel joint, it was tacked in too.  Maybe bigger axles should come before  thoughts of bigger more power.

[Jeffy]

Honestly, if you're OK with the engine then bigger axles will net you lower gears.  If you're crawling then that would mean more then a bigger motor.

[DodgeMudder]

Honestly, if you're OK with the engine then bigger axles will net you lower gears.  If you're crawling then that would mean more then a bigger motor.

I crawl when I can find rocks, but that isn't very often and they are usually covered in mud or moss, the rest of the time I wheel trails that are mud, and I need to keep the ability to have wheel speed for the mud, so lower gears don't really interest me that much.  A dubler or something, to get more gears is worth more to me than lower gears.

And I always tried to figure out what to put in the front, to go w/ the 8.8 rear so that I don't need new wheels, since I run 4 different sets of tires including spares, I don't want to change bolt patterns.

[neale_rs]

If you don't need much additional strength, then a TJ Rubicon front D44 would be the way to go to keep the bolt pattern.  But if you want a real increase in strength then you will pretty much have to change bolt patterns.  I think you can get 8.8 shafts with different bolt patterns, someone here I think mentioned it recently.