4.0L Head Swap or 4.0L engine switch? - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > YJ Wrangler Technical Forum > 4.0L Head Swap or 4.0L engine switch?

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed Line~Artec JK 1 TON SWAP~Advance Adapters SYE Kits

Reply
Unread 04-10-2010, 06:43 PM   #1
dimatrod
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2010
Location: Costa Rica
Posts: 182
4.0L Head Swap or 4.0L engine switch?

So I'm real close into buying a 4.0L head for my '90YJ 4.2L engine. People state it gives you a 30-40 HP increase in power to the meager 112HP the 258 I6 has, but I'm having pre-buyer's remorse right now. The 4.0L has ~190HP, and I feel to properly get around in my country, where there's loads of hills everywhere, I need something around 180HP for a car this size and with no aerodynamics to speak of. Really I don't like 2fast2furious **** at all, but it's also horrible to go up a hill at 25MPH at a 55MPH limit zone, going in 3rd gear ~1800RPM, where I can even go higher than the limit with my mom's Mitsubishi in 5th gear. I wouldn't mind going at 40MPH, just something not extremely slow.

So I guess the question is: will the 4.0L head swap suffice, or should I shell out the extra for a 4.0L engine altogether?

dimatrod is offline   Reply With Quote Quick reply to this message
Unread 04-10-2010, 06:46 PM   #2
kromberg
Registered User
1993 ZJ 
 
Join Date: Sep 2009
Location: Sidney, NE
Posts: 260
4 slow. lol jk. i would go for regearing it and adding some other parts. like a chip and cold air intake, or maybe just get a supercharger. if you want more power go with the hemi swap, a 4.0 will not give you that much more power without spending the cost of a new engine. so if u decide to put in a new engine, go with a bigger v8 or something
__________________
1993 ZJ 4.0L I6, White Jeep member #1993 Check out my build thread:http://www.jeepforum.com/forum/f22/krombergs-zj-build-thread-977508
kromberg is offline   Reply With Quote Quick reply to this message
Unread 04-10-2010, 06:57 PM   #3
dimatrod
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2010
Location: Costa Rica
Posts: 182
Haha I'd love to do a V8 swap but it's hard to come across engines in Costa Rica. The only place where I can get the 4.0L head and engine offers them for $140 and $500 respectively, both used from '94 XJ's. I'd have to send them in for cleaning, and the swap I would do with a friend. Also fuel economy comes into hand (I know the 4.2 I6 isn't a great example lol) and V8s offer none of that. Anyone with a head swap can comment where problems which I'm having have been resolved with this swap?
dimatrod is offline   Reply With Quote Quick reply to this message
Unread 04-10-2010, 07:27 PM   #4
kromberg
Registered User
1993 ZJ 
 
Join Date: Sep 2009
Location: Sidney, NE
Posts: 260
what is your gearing?
__________________
1993 ZJ 4.0L I6, White Jeep member #1993 Check out my build thread:http://www.jeepforum.com/forum/f22/krombergs-zj-build-thread-977508
kromberg is offline   Reply With Quote Quick reply to this message
Unread 04-10-2010, 07:28 PM   #5
dimatrod
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2010
Location: Costa Rica
Posts: 182
Stock? I believe 3.07's? Haven't checked really but AFAIK previous owners didn't change them from the stock 4.2L manual gears.
dimatrod is offline   Reply With Quote Quick reply to this message
Unread 04-10-2010, 10:02 PM   #6
RikRotorhead
Registered User
1988 YJ Wrangler 
 
Join Date: Aug 2008
Location: SloCal
Posts: 8,878
My son's '90 YJ has 3:07 gears, and the 4.0 head swap made a huge difference in performance on his Jeep. I have a hard time keeping up with him on the freeway and I've got 3:55's with my 4.2.
The head swap is on my list of to-do's for this summer. Easy install and big result.
__________________
Betcha' wish your girlfriend was as dirty as my Jeep!
Zombies hate fast food.
Hang on! This is gunna' be a thrill ride of geriatric proportion!
RJC#512
RikRotorhead is offline   Reply With Quote Quick reply to this message
Unread 04-10-2010, 10:51 PM   #7
kromberg
Registered User
1993 ZJ 
 
Join Date: Sep 2009
Location: Sidney, NE
Posts: 260
do gearing first. from what it sounds like, that would help you out with what you want.
__________________
1993 ZJ 4.0L I6, White Jeep member #1993 Check out my build thread:http://www.jeepforum.com/forum/f22/krombergs-zj-build-thread-977508
kromberg is offline   Reply With Quote Quick reply to this message
Unread 04-11-2010, 02:01 AM   #8
dimatrod
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2010
Location: Costa Rica
Posts: 182
Alright so I guess I'll change to 3.55's and do a head swap. Ultimately I want to do a 4.7L stroker but that looks to be more of a 3 year plan. I'm really not that unhappy with my performance, as it's doing fine off road and the car gets me everywhere and never has left me hanging (only once where I ran out of fuel), but this extra performance is just what I need for my DD needs. I've only done the nutter bypass for now, and from what I saw from a friend's Jeep, Team Rush helps a ton as well, so I'll see how much that'll help when I get the parts in two weeks.

Thanks people, you're the best!
dimatrod is offline   Reply With Quote Quick reply to this message
Unread 04-11-2010, 11:52 AM   #9
dadstoys2
Registered User
1987 YJ Wrangler 
 
Join Date: Feb 2005
Posts: 235
What size tires are you running or plan to run?
I personally would not spend the money to regear and on go to 3.54. 4.10 are good and can be found in a 4cyl wrangler.
dadstoys2 is offline   Reply With Quote Quick reply to this message
Unread 04-11-2010, 12:32 PM   #10
dimatrod
Registered User
1990 YJ Wrangler 
 
Join Date: Jan 2010
Location: Costa Rica
Posts: 182
Quote:
Originally Posted by dadstoys2 View Post
What size tires are you running or plan to run?
I personally would not spend the money to regear and on go to 3.54. 4.10 are good and can be found in a 4cyl wrangler.
I've got '31s, and don't plan on going higher than that. Isn't 4.10 too reduced? I fear going on the highway at 50mph will be a 2000+rpm run in fifth.
dimatrod is offline   Reply With Quote Quick reply to this message
Unread 04-11-2010, 03:19 PM   #11
kromberg
Registered User
1993 ZJ 
 
Join Date: Sep 2009
Location: Sidney, NE
Posts: 260
its not the rpm that drop your gas milage, i can run at 1200 rpm when my zj kicks into overdrive, but in order to get that low, the gas pedal has to be depressed a lot more. that is how it get worse. and there are plenty of charts on this forum and other websites, and just check to see what would maintain the best ratio

edit: here is the link: http://www.jeepforum.com/gallery/sho...&ppuser=212702
__________________
1993 ZJ 4.0L I6, White Jeep member #1993 Check out my build thread:http://www.jeepforum.com/forum/f22/krombergs-zj-build-thread-977508
kromberg is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.