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WhiteJeep93 08-20-2010 12:19 AM

4 Cyl. to 8 Cyl. Engine Swap
Hey, i am 16 and bought a jeep 93 yj, and the 4 cyl. is good for driving around town but on the highway and speeds above 60mph its terrible. I dont wanna do new gearing, and from what i hear small mods like cold air intakes and throttle bodys spacers dont make much of a difference, that you can feel.
I need to know what parts i would need to do the swap, (grocery List status)
And an estimated price. Idk what 8 cylinder engine we would go with.... Another question would be what engine would be the cheapest to go with in terms of the least modifications it would need to set it up. My dad is recommending that i just switch in a new 4 Cyl. but why spend the money on that and get a little more power from the engine (higher compression) and the 6 cyl. i would need to swap the same amount of parts as i would to do an 8.
Please list any benefits to doing the swap. How hard it was. Pictures. Anything.

bobjenkins 08-20-2010 12:24 AM

Its gunna cost alot, from my newb knowledge youre gunna need basically a entirely new driveline

engine of course
axles etc.

lot of tweaking and fab work involved too

WhiteJeep93 08-20-2010 12:29 AM

From what i have heard the rear axel would be the only axel that would need to be replaced and it would hold up for a little if you were just driving street

uplifted 08-20-2010 12:46 AM

Start here.... Chevrolet & GM Engine Conversions in the Jeep YJ Wrangler

It's not hard at all if your mechanically inclined and can handle light fab work.... I love my V8..

pakman55 08-20-2010 12:56 AM

Have we not already gone over this with you?

WhiteJeep93 08-20-2010 12:57 AM

pakman55 i wanted more opinions.... its a big decision.... i need to know what i would need and i might be able to do it.

WhiteJeep93 08-20-2010 01:00 AM

uplifted how long did it take you to do the swap and how much did it cost you to do it all the stuff you HAD to do?

pakman55 08-20-2010 01:02 AM

To do it the right way this is a list of the stuff you will need for the drivetrain:
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

Plus axels and gearing. Not including the time it will take. By the time you are done, you could have bought yourself a 6 cyl TJ/YJ

Fweaky 08-20-2010 01:02 AM

If you don't dog it at all the axle will make it for a little while.
If you don't have to worry about emissions testing you will need at least a...
motor mounts
an upgraded cooling system, radiator fan that will fit in the space you have, (possibly a electric fan if space is an issue some V8s are longer than others).
HEI ignition works well for Chevy and AMC
access to a welder
fabrication of shift brakets and linkages
a complete exhaust system

...and that will get you started.

WhiteJeep93 08-20-2010 01:06 AM

Fweaky- how far into the project is that.... sorry i am a newbie. And without the cost of the engine what would the other parts run?

pakman55 08-20-2010 01:08 AM

Not to sound like a prick, but if you don't know ahead of time how to do it/don't know somebody who has done it before, how can you expect this to go smoothly?

WhiteJeep93 08-20-2010 01:12 AM

Well my best friends dad has rebuilt engines and my other close friends dad, customizes cars for drag racing and i would probably pay someone to put it in. idk if i am gonna do any of it though, i am just trying to see how much it would cost....

stangfreak 08-20-2010 01:14 AM

if you are unhappy with your 4cyl you would probably be better off to clean it up real good and sell it for as much as you can and buy a 4.0

the project you are talking about is going to cost quite a bit of money to do right and once you get the main components there is always unexpected nickel and dime stuff that add up quick

pakman55 08-20-2010 01:15 AM

It would cost a lot. Unless you are building a competition style offroader, a V8 is basically pointless. Jeeps aren't dragster and were never meant to go fast.

uplifted 08-20-2010 01:27 AM

I didn't keep track of costs but the whole thing only took me 2 days but this is also what i do for a living so it's second nature to me... Best advice i can give you is to take your time and collect all your parts..Total cost is going to greatly depend on where your getting your engine, how complete it is, carb or injection, auto or stick, etc.. way to many variables to even ballpark a cost for you..

Fweaky 08-20-2010 01:33 AM

I would say I have between $3500 and $4000 in my swap.

markstibbyspot 08-20-2010 08:31 AM

Rear mount turbo FTW!!

UABYJ94 08-20-2010 01:06 PM

1st- swapping in a 4.0l is very cheap and a great mate with the stock 4.10 gears that are already in your jeep.
2nd- There are only 3 things to address in swapping in the 4.0 to your jeep:
Get the ax-15 tranny and t-case with the 4.0l. The ax-5 doesn't mate to the 4.0l
Make sure its external slave, saves alot of headaches.
3rd- You can keep your wiring harness and just add 2 more fuel injector connections to the ECM and thats it!
4th- move the motor mounts and most times the xfer skid bolts line rite up..

pakman55 08-20-2010 01:31 PM

I hope you are saying "Very Cheap" relitive to doing a V8 swap.

yjkid95 08-20-2010 01:34 PM

Theres a few stages of the project. First stage plan it out.....figure out what you want to do with the jeep how big of a lift and tires youll be running yada yada (yada yada stands for a lot of others things to plan out and research by the way). Second stage (this is where i am at with my swap right now) get the motor and transmission you want and build up all the parts you need to swap it into your jeep (this is not cheap and there is no way to do this cheap to get it done right). I got a deal on a chevy 350 carbuerated and a 700r4 (4speed auto with overdrive) for 400 bucks. But then theres the adapting plate to hook my np231j to the 700r4...510 bucks not including shipping. Then theres the radiator...since i plan on getting more horsepower out of it down the road i want a radiator that can handle 400-600 horsepower and the one i want has an inegrated tranny cooler....624 bucks not including shipping....already bought the mounts and rear mount from novak...214 shipped. Im going to try to keep the stock manifolds (in my opinion headers just rot out to quickly) if i can keep em thats another 400 bucks saved on headers. then theres the driveshaft to worry about and the exhaust and fuel pressure regulater (going from fuel injection to carb fuel injection fuel pressure is around 44 psi carbs need 4 psi of pressure). Then theres wiring to worry about thankfully i have a neighbor whos swapped a 350 fuel injection into his s10 built a 72 camaro ground up to help me with that (and a few tips from uplifted). Youll also need to route tranny lines powersteering lines if you have powersteering cooling lines heater hoses and figure out ac if your going to have that (i am not). Stage three is work time good luck

pakman55 08-20-2010 01:44 PM

Just like the first time you asked this question WhiteYJ, it is a very expensive task that requires DAYS of labor and fabrication.

yjkid95 08-20-2010 01:52 PM

And also to add this if your in the same boat as me with your jeep being your daily driver youll want to get a beater like a 500 dollar civic just to get you around while the jeep is in pieces and even for when you get it back together because chances are theres going to be some issues that will need to be ironed out.

pakman55 08-20-2010 01:55 PM

That too. Good point YJkid. Add to that insurance, and registration.

Bondgreg 08-20-2010 02:00 PM

Swapping out for an 8cyl is overkill, try gving your 4cyl a tune up and if still want more power take stangfreak's suggestion and sell it and buy what you want. Unless of course everyting in prestine then go with a 6. Forget the 8!

yjkid95 08-20-2010 02:01 PM

My guess is if I really work my a$$ off i can start doing the swap in spring and maybe have it done before summer. (I did just graduate highschool last year so give me a bit of a break)

pakman55 08-20-2010 02:06 PM


Originally Posted by Bondgreg (Post 733706)
Swapping out for an 8cyl is overkill, try gving your 4cyl a tune up and if still want more power take stangfreak's suggestion and sell it and buy what you want. Unless of course everyting in prestine then go with a 6. Forget the 8!

The problem is he has a 4 cyl with 33's. And he didn't take our advice to regear. Instead of a $1200 regear he wants to do a $5000+ engine swap.

Ibuildembig 08-20-2010 02:44 PM

I'd rather have a V8 and 4.10s versus a 2.5 and 4.88's wouldn't you all?

pakman55 08-20-2010 02:51 PM

Thats not a question, V8 FTW!!!! but would you rather put in $7000 or $1200 into a rig probably worth $2-3 k?

Ibuildembig 08-20-2010 02:55 PM

Well I'm not one to ask that question of honestly. I take pieces of crap all the time and make stuff out of um, so if it was mine and that's what I wanted...then yes. But, there's no way it would cost 7K...I'm budgeting 3800 for mine

pakman55 08-20-2010 02:58 PM

Origionally, he said he was going to buy a crated engine. I'm sure the prices may vary. I can see the point of what you do (your post in the "toys" tread were beautiful) but for a 16 y.o. to drop a V8 into his daily driver just seems like a bad idea. I am 16 and if I had 7 grand, it wouldnt be going into a V8.

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