I have a 1991 Wrangler 4 cylinder soft top with appx 122,000 miles. It still runs great but now that it is not a primary vehicle I can start 'tinkering' with it. I'm pretty sure that I will need to replace the engine with at least a 6 cylinder, maybe an 8 if possible, before I add larger tires - I am looking at 33's. Does anyone have any suggestions for what type of engine to drop in and a ballpark for how much it would cost? Do you think I'll have to do any transmission mods? Currently I can't really push the jeep over 65 mph in 5th gear b/c the revs get too high. I was hoping that the larger tires coupled with a more powerful engine would help me get up to interstate speeds. Would the larger motor put too much stress on the tranny?

I am going to do some light off roading but nothing too serious so I was considering a simple spring over suspension conversion for cheap to get more ground clearance instead of an expensive lift kit. I don't want a body lift. Any thoughts?

While I'm deciding on what to do about the engine I was going to replace the front seats, add 5 pt belts, take out the back seat and add a locking storage box, put a winch up front, replace both the bumpers, Rhino line the interior and add a CB. I thought from these mods I could get something that both looks nice and performs decently without breaking the bank.

I would love any suggestions.

If anything I would work with the 4 cylinder. I know it's a dog of an engine for the Wrangler, but a conversion could be cost prohibitive. The labor alone would be in the area of $700-$800 at my shop, add parts on top of that and it becomes cheaper to find a Jeep already set up with the good 4.0L motor. Hope this helps.

You're gonna need bigger axles.

http://www.we-todd-did-racing.com/wetoddimage.wtdr/wMTA2MDY4NTZzNDEzZGZkMzF5NTQx.jpg

1988 Wrangler

3 inch BDS suspension lift
1.5 inch extended shackles
Rubicon Express sway bar disconnects
front and rear differential rock sliders
Detroit Locker locking differential in the rear
Tom Wood's custom rear driveshaft
BDS Rock Lock front axle cable driven actuator
4.11 ring and pinion in both axles
33x12.5 inch Super Swamper Bogger tires
15x10 inch American Racing wheels
PIAA 520 lights mounted on the windshield
Hella 500 lights mounted on the front brush guard

Quite a few other goodies.  I used this thing off road all the time when I had it.  From mudding to rock crawling and everything in between, the thing never would break.  It would get up to right at 65 MPH before running out of pep in 5th gear (speedometer corrected by replacing the speedo gear).

You'll find that the worst part about your Jeep will be the rear axle's C-Clips.  They make the Dana 35 very easy to break.  A cheap solution would be to find a pre-1991 Dana 35 axle.  A lot of people will tell you that the D35 is a weak axle, but if you are only pushing the power of a 4 cylinder through it, you don't need that much, and many people get rid of thiers in order to go with something stronger for a stronger motor.  A Dana 35 will do you just fune.

Oh, and the Jeep had over 230,000 miles on it when I sold it in great running condition.

Spring over conversions are usually more expensive than you would expect.  Once you get everything you need, you'll realize that you need about twice as much to make it work right.  Oh, and the stock YJ springs usually aren't worth a damn after about 100,000 miles, especially if you are altering the geometry of the wheels / axle / drivetrain.  A true suspension lift will do you better, and provide you with all new hardware / bushings / shocks.  Decent shocks will be hard to find for a spring over, especially ones that will be properly valved for on-road use.  I agree with you, though.  Body lifts are a total waste.

Look into the BDS lifts.  They are great and some of the cheapest you will find on the market.

Thanks for the info:

OneShot: Do you think I could drop in a 6 for around $2500? I might consider that.

I'm afraid that the 4 cylinder won't be able to get up to even 55 with the larger tires...this engine runs well but its a tired old dog.

If this is going to be more of a toy and only going to see light off roading such as forest roads and no real rock crawling do I need to worry about switching out the axles and tranny?

Thanks again.

 Save your money, its not as much about the engine as it is about the gears, go with 33's and drop in a set of 4.88 ring and pinion. If you get into engine swaps your opening a whole new world, example........oh new engine.....need to beef up trans......opps need to beef axles.... and other part in the drive tran.

 Seriously though lower gearing with get you what you want. I think alot of the earlier unimogs where like 80 horse engines but geared very low.

My buddies 94 Wrangler tops out around 80mph.  He stayed with the 4cyl. motor, it works good for him.  The low-end torque is INSANE.

He went with a 4" suspension lift and 33's (maybe slightly smaller, they are narrower than 12.5in wide though, pretty sure), as well as having to beef up the differential.  

It's a beast though and never ceases to amaze me.  He thought maybe the extra weight of a V8 would bog him down in the mud easier.  So he turned down the idea.  

He also rhino-lined his interior...and mud stains wont come out of it, just to let ya know.  

ETA:  He has a Jasper 5-speed tranny in it, so his top-out speed may be different from stock.

The YJ 4 cylinder Wranglers came with the AX-5 tranny.  With 33 inch tires and 4.88 gears, you won't get over 50 MPH.  4.11's are perfect and they will be all you will ever need, especially when you toss it in 4-Low.  On a 4 cylinder that still sees the streets, 4.11's are where it's at.

Just be sure you have a new transmission mount (they're like $20 and easy as hell to put in) or else all your work might be in vain as your tranny binds the first time you get in the rough stuff and ends up screwing up somewhere along the drivetrain.

ummm 33's with 4.10 is not good on a 4cyl,  if you go by gearing charts you should have 4.56 but alot of people use 4.88 and you will be able to go as fast as you need to.  4.10 is what comes stock with a stick shift 4cyl. You will burn your clutch out alot quicker with 4.10

Here is a link to rpm and gearing chart jeephorizons.com/tech/rpmchart.html


You will see on the chart that the is only a 100 rpm differance between the stock tire size rpm at 55 with 4.10 and the 33s with 4.88

I agree that the easiest thing to do would be to buy a used Jeep with a larger engine but I'm stuck w/ this Jeep b/c my wife has had it since high school, there is no way she will let me get rid of it, and I don't want another car right now.

Hmm..decision time...

There is a guy over on turbododge.com who goes by the handle turbojeep. He has a turbo 4 cylinder wrangler that he is running alky on, and it seems to be rock solid. I have got to believe that the extra ft lbs. would really help out with your power situation. As others have stated, it might be a matter of gearing for the freeway.

I always wanted to get a wrangler and put a ford 2.3 turbo from the thunderbird into it


but that was just for transportation to work and occasional of roading

if you want to off road more then maybe you would want something with more low end

So...with my stock engine putting out 123 horses originall..probably a little less now...could it push 33 inch tires at 65 mph? My original worry was that the larger tires would be too much for the engine to push.

Quoted: ummm 33's with 4.10 is not good on a 4cyl,  if you go by gearing charts you should have 4.56 but alot of people use 4.88 and you will be able to go as fast as you need to.  4.10 is what comes stock with a stick shift 4cyl. You will burn your clutch out alot quicker with 4.10 Here is a link to rpm and gearing chart jeephorizons.com/tech/rpmchart.html You will see on the chart that the is only a 100 rpm differance between the stock tire size rpm at 55 with 4.10 and the 33s with 4.88

Well shit, it's been a while.  I thought for sure the YJ 4 cylinders came with 3.73's.  Maybe that was the 4 liter ones?  Now you have me wondering what gear I put in my Jeep.  Maybe I need to go digging for pictures and see if I can possibly count the threads on the ring gear when I was installing it or something.  I honestly can't rememebr, but I thought for sure it was 4.11's that I put in that thing.  I changed both front and rear, so I don't know why I would have only went up to 4.11 from 4.10 (this was done back in 2001).

Maybe I'm just getting too old to be doing this kind of thing anymore.  

Quoted: The YJ 4 cylinder Wranglers came with the AX-5 tranny.  With 33 inch tires and 4.88 gears, you won't get over 50 MPH.  4.11's are perfect and they will be all you will ever need, especially when you toss it in 4-Low.  On a 4 cylinder that still sees the streets, 4.11's are where it's at. Just be sure you have a new transmission mount (they're like $20 and easy as hell to put in) or else all your work might be in vain as your tranny binds the first time you get in the rough stuff and ends up screwing up somewhere along the drivetrain.

Believe it or not I ran 5.38's in my 86 CJ (which had a 5 speed and 35" tires) and was able to run highway speeds without much trouble.  However I did not consider the vehicle appropriate for speeds above 55.  In my opinion driving a lifted short-wheelbase rig with 35" tires at speeds over 55 is not prudent.

Good point on not going over 55 with a short wheel base with a lift. I really plan on driving this vehicle a little around town on weekends and to the mountains for weekend camping trips. The roads to the mountains are 55 mph and I would like to be able to do 55 w/o a problem but don't plan on pushing it over that. This won't be an intestate driver.

With that would the 4.11 gears w/ 33 inch tires be able to do this?

Quoted: I always wanted to get a wrangler and put a ford 2.3 turbo from the thunderbird into it but that was just for transportation to work and occasional of roading if you want to off road more then maybe you would want something with more low end

The 2.3 turbo out of an 87-88' would be great for this due to the little IHI turbo that they had on them. That would put out plenty of low end torque for you. Although there are so many kits out there for the jeeps these days that swap does not seem like it would be worth the time unless you are going for the look what I did factor.

One more thing that you'll need if you put 33 inch tires on her, especially if you want to drive it on the streets:

dual steering stabilizers....

Oh, and a steering gear box brace.

Quoted: Thanks for the info: OneShot: Do you think I could drop in a 6 for around $2500? I might consider that.

if you've got $2500 for a engine swap, just buy another YJ with a 4.2 or the 4.0 in it.

+ then you'll have two money pits, uh I mean Jeeps.

I really only want one wrangler and that means if I want to modify a wrangler its going to be the one I have since the wife is so attached to it. I had looked at a Scrambler about a year ago but passed.

My choices right now are either to work with what I've got (the 4 banger) and keep the weight down on the jeep, do an engine swap (too much of a pain in the ass), or I could buy a Land Cruiser FJ55 - I've always wanted one of these.