2.5L 4cyl to Chevy V8 swap in a TJ - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > General Jeep Discussions > Builders Corner

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 07-06-2010, 09:20 PM   #1
Newb
 
Join Date: Jun 2010
Location: Hillsboro
Posts: 4
2.5L 4cyl to Chevy V8 swap in a TJ

About to start a V8 conversion for my '97 TJ. I would like to know if anyone has done this conversion to a 2.5L 4cyl TJ? Aparently Novak, Advance Adapters and other manufacturers make conversion kits for the small block Chevy V8 conversion. I'll retain the stock NP231 Transfer Case since it should be adequate for the 2003 Chevy 5.3L 300HP Silverado motor I'm planning to use, but the AX5 will be swapped for the more beefy AX15 tranny. A few questions:
Will the stock front suspension take the extra weight of the 5.3L V8?
Will the stock rear axles need to be upgraded to stronger Dana units?
Will the 5.3L V8 Throttle body have clearance under the TJ hood?
Is there a wiring harness conversion diagram somewhere out there?
Sensors and the like, what should be retained from the 2.5L TJ motor or should anything, since I plan on using the wiring harness and engine management computer from the Chevy?

Thanks in advance for your time and help.

Dan

1BadGetOff is offline   Quote Quick Reply
Old 07-06-2010, 09:28 PM   #2
Jeeper
 
Ageless Stranger's Avatar
 
Join Date: Apr 2010
Posts: 26,792
Quote:
Originally Posted by 1BadGetOff View Post
About to start a V8 conversion for my '97 TJ. A few questions:
Will the stock front suspension take the extra weight of the 5.3L V8?
Probably not. You are talking about going from a 4cyl to a V8.


Quote:
Originally Posted by 1BadGetOff View Post
Will the stock rear axles need to be upgraded to stronger Dana units?
My answer is yes. If it's a D35. The D35 won't hold up to that kind of punishment. If you are willing to install a motor that was never meant for it and a new trans. then it only makes sense to do the axle upgrade then too.

Quote:
Originally Posted by 1BadGetOff View Post
Thanks in advance for your time and help.

Dan
You are welcome for what little help I may have been. Jeepers much wiser than I ever will be will likely be able to answer these and other questions far better than I have. But I like to help out the forum. Good luck with your engine swap. Start a thread to update us on your progress when you get started!

Ageless Stranger is offline   Quote Quick Reply
Old 07-06-2010, 09:32 PM   #3
Jeeper
 
pakman55's Avatar
 
Join Date: Nov 2009
Location: The 363
Posts: 4,803
Send a message via Yahoo to pakman55
may I ask the motivation behind putting a V8 into a stocker? Do you plan on lifting it afterwards? If you do this don't skimp...the money will be worth it in the end.
__________________
Life, Liberty and the Pursuit of Happiness
pakman55 is offline   Quote Quick Reply
Old 07-06-2010, 09:35 PM   #4
IITYWTMWYBMAB

WF Supporting Member
::WF Administrator::
 
4Jeepn's Avatar
 
Join Date: Apr 2005
Location: Florence, KY
Posts: 10,106
Images: 5
Not sure ax-15 is upto 300hp v8.
Also plan to upgrade the dana 35 at some point.
__________________
79.96.85.00.01.97.00.97.93.97.95.94
CJ.XJ.CJ. TJ. TJ.ZJ. TJ.TJ. ZJ.ZJ.YJ. XJ
4Jeepn is online now   Quote Quick Reply
Old 07-07-2010, 12:45 AM   #5
Supporting Member

WF Supporting Member
 
schnutzy's Avatar
 
Join Date: Sep 2009
Location: ring side seats to the the country's largest circus
Posts: 28,185
Send a message via AIM to schnutzy
Quote:
Originally Posted by 1BadGetOff View Post
Will the stock front suspension take the extra weight of the 5.3L V8?




Dan
Quote:
Originally Posted by Ageless Stranger View Post
Probably not. You are talking about going from a 4cyl to a V8.
actually, it should be fine, maybe some beefed up springs, but it wont be to bad. the 5.3 is a pretty light motor and the 2.5 is a bit on the heavy side for what it is. check out novak conversions, they have the weight of the motors listed on their website.
__________________
clinging on to sanity, one motorcycle at a time.
schnutzy is offline   Quote Quick Reply
Old 07-07-2010, 11:40 AM   #6
Newb
 
Join Date: Jun 2010
Location: Hillsboro
Posts: 4
Thanks guys!

Yes, the axles will need attention and further upgrading. You're right about the 2.5L 4cyl. It's a porker and the GM 5.3L SBC is relatively "light" with aluminum heads, plastic intake and aluminum sump.

I'm going to chance the AX15 tranny and stock NP321 transfer case. From what I've read from Novak they should hold up as long as I don't do any other serious HP mods to the SBC mill.

Axle selection will be stronger Dana units front and rear.

And why would I put a motor in something not designed for it? It's the American way. Not to mention, boat loads more power, reliability, economy and driveability... Anyway, it'll be fun just doing it... and I'm excited about it.

I'll take plenty of pics and keep everyone posted... The highs and the lows!
1BadGetOff is offline   Quote Quick Reply
Old 07-07-2010, 02:07 PM   #7
Supporting Member

WF Supporting Member
 
schnutzy's Avatar
 
Join Date: Sep 2009
Location: ring side seats to the the country's largest circus
Posts: 28,185
Send a message via AIM to schnutzy
the front axle should hold up just fine, the d30 is not a bad axle at all.
good luck with your swap and did i mention we love pictures on this forum
__________________
clinging on to sanity, one motorcycle at a time.
schnutzy is offline   Quote Quick Reply
Old 07-07-2010, 04:49 PM   #8
Newb
 
Join Date: Jun 2010
Location: Hillsboro
Posts: 4
Yes, that's what I've heard. D30's are adequated but rears need attention. here's my shopping list so far;
1997 Jeep TJ 2.5L 4Cyl to GM 5.3L Gen III+ Engine Swap
Part Supplier P/N Price Ea
Performance Electric Fan & Shroud Kit Novak FX2800 219.65
RadLock Radiator Novak R-TJ10S 451.05
Engine Mount Kit (GM SBC to 2.5L 4Cyl) Novak MMTJ-G4 174.00
Headers, Block Huggers, Coated Novak CCLS1C 435.00
AX15 Transmission or Overhaul Kit Novak or Salvage Yard 600.00
NP231 Rebuild Kit Novak 212.00
23 Spline input gear for NP231 Transfer Case Novak 160.00
Slip Yoke Eliminator Kit Novak 383.00
AX15 Transmission Adapter to GM Bellhousing Novak 295.00
Chevy Truck Bellhousing (Manual Shift, '73-'80) Salvage Yard 100.00
Billet Flywheel for GM III+ Motor to Manual Shift McLeod 400.00
Reflash Chevrolet Engine Computer Novak 175.00
Modify Chevrolet Wiring Harness Novak 400.00
Modify Jeep Gauge Cluster Novak 200.00
Chevrolet 5.3L Gen III+ Motor w/ intake & fuel sys Salvage Yard 250.00

OMG!-------------- 4,454.70
1BadGetOff is offline   Quote Quick Reply
Old 07-07-2010, 07:28 PM   #9
Jeeper
 
pakman55's Avatar
 
Join Date: Nov 2009
Location: The 363
Posts: 4,803
Send a message via Yahoo to pakman55
thats not a terrible price....any plans other than the engine swap?
__________________
Life, Liberty and the Pursuit of Happiness
pakman55 is offline   Quote Quick Reply
Old 07-09-2010, 12:58 AM   #10
Newb
 
Join Date: Jun 2010
Location: Hillsboro
Posts: 4
Other plans beside the SBC? Yeah, but I'm dreaming right now. I just want reliable V8 power with a 5spd. The shopping list is expensive, but I think I can beat some of those prices by shopping around. The flywheel, radiator/fan assy, headers, and other stuff can be gotten much cheaper, but the correct wiring harness may cost me additional bucks. Anyway, first pics forthcoming...
1BadGetOff is offline   Quote Quick Reply
Old 07-16-2010, 06:32 PM   #11
Newb
 
Join Date: Jul 2010
Posts: 2
I recently bought a almost finished project similar to yours. Mine is a '97 TJ w/ a '98 vortec 350 & auto trans from a suburban donor car. As I am finishing this project, some of my issues may be of help to you.
1. w/ winch & bumper required 2" lift springs in front & no lift in rear. Had a major sag in the front when I got it. Plan on 33" tires, may need another 3/4" spacer for moderate trail use.

2. Just a 2" lift created terrible driveline vibration. A SYE & cv driveshaft w/ adjustable upper control arms corrected this problem. I used a stock front driveshaft from salvage yard(cherokee or tj maybe) , 2" diameter, shortened it and used it for the rear. Works great, much cheaper.

3.Gauges. Will you use stock or aftermarket? The stock run off the ecm, which means you have to keep jeep ecm for gauges & chevy ecm for motor.Probably still the easiest & cheapest way but tach won't work. Also open up instrument cluster and fabricate a way to connect check engine light to chevy ecm. Aftermarket gauges create other issues, ie fuel sender compatibility.

4. If you keep a/c, more fabrication of custom hoses and wiring issues, but it can be done & cools well.

5. Your 5.3 will most likely need a Camaro oil pan for axle clearance. Hood clearance will also be tight, aftermarket hood w/ cowl induction scoop may help.

6. Axle strength. Depends on tire size and driving style. If your easy on it, no lockers, and keep small tires it may live, but where's the fun?

7. Wiring harness. Maybe Painless for an aftermarket or get cozy w/ a FACTORY service manual for both vehicles and spend a lot of time studying.
Wiring problems kill more projects than anything else.

Hope this helps get you started. PM me if you want.

gus
gus33 is offline   Quote Quick Reply
Old 07-18-2010, 03:55 PM   #12
Jeeper
 
legman68's Avatar
 
Join Date: Apr 2010
Location: NoCal
Posts: 369
I've been thinking same thing, as far as more power and fun "project" for myself. I'm a weekend mechanic at best, any best guess on how much "shop time" will add? Like welding, not possible. Love to see pics on how this goes.
__________________
"Are you a pothead Focker?"
legman68 is offline   Quote Quick Reply
Old 07-18-2010, 04:00 PM   #13
IITYWTMWYBMAB

WF Supporting Member
::WF Administrator::
 
4Jeepn's Avatar
 
Join Date: Apr 2005
Location: Florence, KY
Posts: 10,106
Images: 5
If your willing/planning to spend 600 for an ax15.. look for an nv3550.. that will take the v8 power. 2000 -04 tj's
__________________
79.96.85.00.01.97.00.97.93.97.95.94
CJ.XJ.CJ. TJ. TJ.ZJ. TJ.TJ. ZJ.ZJ.YJ. XJ
4Jeepn is online now   Quote Quick Reply
Old 08-11-2010, 09:28 PM   #14
Jeeper
 
Join Date: Aug 2010
Posts: 26
2nd that on the trans, if your going that far get a better tranny
XJSean is offline   Quote Quick Reply
Old 08-11-2010, 09:46 PM   #15
Jeeper
 
EdJonesJeeper's Avatar
 
Join Date: Jan 2010
Location: Western NC
Posts: 1,005
dana 300 transfer case (eliminates sye and stronger) $150
1 tons front and rear (1k-2k)
Champion cooling radiator 3 row $220

Why not go this route?
__________________
99' TJ Sahara d44 on 35's
EdJonesJeeper is offline   Quote Quick Reply
Old 08-11-2010, 09:51 PM   #16
I HAVE A BELLYBUTTON!

WF Supporting Member
 
cavediverjc's Avatar
 
Join Date: Mar 2007
Location: On the grassy knoll...
Posts: 7,058
PM a gentleman on the forum named MrClifford. He's had a number of big Jeeps and at least one that he did a SBC conversion on. He can probably give you any hints/tips that will prove invaluable.
__________________
Americans sleep safely in their beds because rough men stand ready in the night to visit violence on those who would do them harm...

Happiness is a Barrett M82A1 .50 caliber and a target at least a click out........

I come in peace. I didn't bring artillery. But I'm pleading with you with tears in my eyes, if you f**k with me, I'll kill you all.....
cavediverjc is offline   Quote Quick Reply
Old 09-03-2010, 11:53 PM   #17
Jeeper
 
Shadeemry's Avatar
 
Join Date: Aug 2010
Posts: 101
So if I did a swap, I'll need the axles,transfer case, custom fitted bracket engine mount,engine, ecu, throttle body,and intake/ exaust? Do I need to adjust the diff?

Shadeemry is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
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

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
The Jeep Wave Saint101 General Jeep Discussion 115 05-06-2011 06:45 PM
Chevy vs jeep Mclaughlin_1234 TJ General Discussion Forum 19 03-06-2009 11:39 AM
fuel pump problem in jeep wrangler to chevy engine conversion guardian YJ Tech Forum 8 11-11-2008 02:44 PM
2.5L 4cyl wanted MrD Classifieds Archive 0 03-10-2006 09:17 PM



» Featured Product

All times are GMT -5. The time now is 11:44 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC